Integrate from google internal.

Java files are moved to un-do the hack in the prevous commit, which
moved the java files to the original position for integration.

52 files changed, 25277 insertions, 0 deletions

diff --git a/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
new file mode 100644
index 00000000..d964ef59
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
@@ -0,0 +1,527 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import protobuf_unittest.UnittestOptimizeFor.TestOptimizedForSize;
+import protobuf_unittest.UnittestProto;
+import protobuf_unittest.UnittestProto.ForeignMessage;
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestPackedTypes;
+import protobuf_unittest.UnittestProto.TestRequired;
+import protobuf_unittest.UnittestProto.TestRequiredForeign;
+import protobuf_unittest.UnittestProto.TestUnpackedTypes;
+
+import junit.framework.TestCase;
+
+import java.util.Map;
+
+/**
+ * Unit test for {@link AbstractMessage}.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class AbstractMessageTest extends TestCase {
+  /**
+   * Extends AbstractMessage and wraps some other message object.  The methods
+   * of the Message interface which aren't explicitly implemented by
+   * AbstractMessage are forwarded to the wrapped object.  This allows us to
+   * test that AbstractMessage's implementations work even if the wrapped
+   * object does not use them.
+   */
+  private static class AbstractMessageWrapper extends AbstractMessage {
+    private final Message wrappedMessage;
+
+    public AbstractMessageWrapper(Message wrappedMessage) {
+      this.wrappedMessage = wrappedMessage;
+    }
+
+    public Descriptors.Descriptor getDescriptorForType() {
+      return wrappedMessage.getDescriptorForType();
+    }
+    public AbstractMessageWrapper getDefaultInstanceForType() {
+      return new AbstractMessageWrapper(
+        wrappedMessage.getDefaultInstanceForType());
+    }
+    public Map<Descriptors.FieldDescriptor, Object> getAllFields() {
+      return wrappedMessage.getAllFields();
+    }
+    public boolean hasField(Descriptors.FieldDescriptor field) {
+      return wrappedMessage.hasField(field);
+    }
+    public Object getField(Descriptors.FieldDescriptor field) {
+      return wrappedMessage.getField(field);
+    }
+    public int getRepeatedFieldCount(Descriptors.FieldDescriptor field) {
+      return wrappedMessage.getRepeatedFieldCount(field);
+    }
+    public Object getRepeatedField(
+        Descriptors.FieldDescriptor field, int index) {
+      return wrappedMessage.getRepeatedField(field, index);
+    }
+    public UnknownFieldSet getUnknownFields() {
+      return wrappedMessage.getUnknownFields();
+    }
+    public Builder newBuilderForType() {
+      return new Builder(wrappedMessage.newBuilderForType());
+    }
+    public Builder toBuilder() {
+      return new Builder(wrappedMessage.toBuilder());
+    }
+
+    static class Builder extends AbstractMessage.Builder<Builder> {
+      private final Message.Builder wrappedBuilder;
+
+      public Builder(Message.Builder wrappedBuilder) {
+        this.wrappedBuilder = wrappedBuilder;
+      }
+
+      public AbstractMessageWrapper build() {
+        return new AbstractMessageWrapper(wrappedBuilder.build());
+      }
+      public AbstractMessageWrapper buildPartial() {
+        return new AbstractMessageWrapper(wrappedBuilder.buildPartial());
+      }
+      public Builder clone() {
+        return new Builder(wrappedBuilder.clone());
+      }
+      public boolean isInitialized() {
+        return clone().buildPartial().isInitialized();
+      }
+      public Descriptors.Descriptor getDescriptorForType() {
+        return wrappedBuilder.getDescriptorForType();
+      }
+      public AbstractMessageWrapper getDefaultInstanceForType() {
+        return new AbstractMessageWrapper(
+          wrappedBuilder.getDefaultInstanceForType());
+      }
+      public Map<Descriptors.FieldDescriptor, Object> getAllFields() {
+        return wrappedBuilder.getAllFields();
+      }
+      public Builder newBuilderForField(Descriptors.FieldDescriptor field) {
+        return new Builder(wrappedBuilder.newBuilderForField(field));
+      }
+      public boolean hasField(Descriptors.FieldDescriptor field) {
+        return wrappedBuilder.hasField(field);
+      }
+      public Object getField(Descriptors.FieldDescriptor field) {
+        return wrappedBuilder.getField(field);
+      }
+      public Builder setField(Descriptors.FieldDescriptor field, Object value) {
+        wrappedBuilder.setField(field, value);
+        return this;
+      }
+      public Builder clearField(Descriptors.FieldDescriptor field) {
+        wrappedBuilder.clearField(field);
+        return this;
+      }
+      public int getRepeatedFieldCount(Descriptors.FieldDescriptor field) {
+        return wrappedBuilder.getRepeatedFieldCount(field);
+      }
+      public Object getRepeatedField(
+          Descriptors.FieldDescriptor field, int index) {
+        return wrappedBuilder.getRepeatedField(field, index);
+      }
+      public Builder setRepeatedField(Descriptors.FieldDescriptor field,
+                                      int index, Object value) {
+        wrappedBuilder.setRepeatedField(field, index, value);
+        return this;
+      }
+      public Builder addRepeatedField(
+          Descriptors.FieldDescriptor field, Object value) {
+        wrappedBuilder.addRepeatedField(field, value);
+        return this;
+      }
+      public UnknownFieldSet getUnknownFields() {
+        return wrappedBuilder.getUnknownFields();
+      }
+      public Builder setUnknownFields(UnknownFieldSet unknownFields) {
+        wrappedBuilder.setUnknownFields(unknownFields);
+        return this;
+      }
+      @Override
+      public Message.Builder getFieldBuilder(FieldDescriptor field) {
+        return wrappedBuilder.getFieldBuilder(field);
+      }
+    }
+    public Parser<? extends Message> getParserForType() {
+      return wrappedMessage.getParserForType();
+    }
+  }
+
+  // =================================================================
+
+  TestUtil.ReflectionTester reflectionTester =
+    new TestUtil.ReflectionTester(TestAllTypes.getDescriptor(), null);
+
+  TestUtil.ReflectionTester extensionsReflectionTester =
+    new TestUtil.ReflectionTester(TestAllExtensions.getDescriptor(),
+                                  TestUtil.getExtensionRegistry());
+
+  public void testClear() throws Exception {
+    AbstractMessageWrapper message =
+      new AbstractMessageWrapper.Builder(
+          TestAllTypes.newBuilder(TestUtil.getAllSet()))
+        .clear().build();
+    TestUtil.assertClear((TestAllTypes) message.wrappedMessage);
+  }
+
+  public void testCopy() throws Exception {
+    AbstractMessageWrapper message =
+      new AbstractMessageWrapper.Builder(TestAllTypes.newBuilder())
+        .mergeFrom(TestUtil.getAllSet()).build();
+    TestUtil.assertAllFieldsSet((TestAllTypes) message.wrappedMessage);
+  }
+
+  public void testSerializedSize() throws Exception {
+    TestAllTypes message = TestUtil.getAllSet();
+    Message abstractMessage = new AbstractMessageWrapper(TestUtil.getAllSet());
+
+    assertEquals(message.getSerializedSize(),
+                 abstractMessage.getSerializedSize());
+  }
+
+  public void testSerialization() throws Exception {
+    Message abstractMessage = new AbstractMessageWrapper(TestUtil.getAllSet());
+
+    TestUtil.assertAllFieldsSet(
+      TestAllTypes.parseFrom(abstractMessage.toByteString()));
+
+    assertEquals(TestUtil.getAllSet().toByteString(),
+                 abstractMessage.toByteString());
+  }
+
+  public void testParsing() throws Exception {
+    AbstractMessageWrapper.Builder builder =
+      new AbstractMessageWrapper.Builder(TestAllTypes.newBuilder());
+    AbstractMessageWrapper message =
+      builder.mergeFrom(TestUtil.getAllSet().toByteString()).build();
+    TestUtil.assertAllFieldsSet((TestAllTypes) message.wrappedMessage);
+  }
+
+  public void testParsingUninitialized() throws Exception {
+    TestRequiredForeign.Builder builder = TestRequiredForeign.newBuilder();
+    builder.getOptionalMessageBuilder().setDummy2(10);
+    ByteString bytes = builder.buildPartial().toByteString();
+    Message.Builder abstractMessageBuilder =
+        new AbstractMessageWrapper.Builder(TestRequiredForeign.newBuilder());
+    // mergeFrom() should not throw initialization error.
+    abstractMessageBuilder.mergeFrom(bytes).buildPartial();
+    try {
+      abstractMessageBuilder.mergeFrom(bytes).build();
+      fail();
+    } catch (UninitializedMessageException ex) {
+      // pass
+    }
+
+    // test DynamicMessage directly.
+    Message.Builder dynamicMessageBuilder = DynamicMessage.newBuilder(
+        TestRequiredForeign.getDescriptor());
+    // mergeFrom() should not throw initialization error.
+    dynamicMessageBuilder.mergeFrom(bytes).buildPartial();
+    try {
+      dynamicMessageBuilder.mergeFrom(bytes).build();
+      fail();
+    } catch (UninitializedMessageException ex) {
+      // pass
+    }
+  }
+
+  public void testPackedSerialization() throws Exception {
+    Message abstractMessage =
+        new AbstractMessageWrapper(TestUtil.getPackedSet());
+
+    TestUtil.assertPackedFieldsSet(
+      TestPackedTypes.parseFrom(abstractMessage.toByteString()));
+
+    assertEquals(TestUtil.getPackedSet().toByteString(),
+                 abstractMessage.toByteString());
+  }
+
+  public void testPackedParsing() throws Exception {
+    AbstractMessageWrapper.Builder builder =
+      new AbstractMessageWrapper.Builder(TestPackedTypes.newBuilder());
+    AbstractMessageWrapper message =
+      builder.mergeFrom(TestUtil.getPackedSet().toByteString()).build();
+    TestUtil.assertPackedFieldsSet((TestPackedTypes) message.wrappedMessage);
+  }
+
+  public void testUnpackedSerialization() throws Exception {
+    Message abstractMessage =
+      new AbstractMessageWrapper(TestUtil.getUnpackedSet());
+
+    TestUtil.assertUnpackedFieldsSet(
+      TestUnpackedTypes.parseFrom(abstractMessage.toByteString()));
+
+    assertEquals(TestUtil.getUnpackedSet().toByteString(),
+                 abstractMessage.toByteString());
+  }
+
+  public void testParsePackedToUnpacked() throws Exception {
+    AbstractMessageWrapper.Builder builder =
+      new AbstractMessageWrapper.Builder(TestUnpackedTypes.newBuilder());
+    AbstractMessageWrapper message =
+      builder.mergeFrom(TestUtil.getPackedSet().toByteString()).build();
+    TestUtil.assertUnpackedFieldsSet(
+      (TestUnpackedTypes) message.wrappedMessage);
+  }
+
+  public void testParseUnpackedToPacked() throws Exception {
+    AbstractMessageWrapper.Builder builder =
+      new AbstractMessageWrapper.Builder(TestPackedTypes.newBuilder());
+    AbstractMessageWrapper message =
+      builder.mergeFrom(TestUtil.getUnpackedSet().toByteString()).build();
+    TestUtil.assertPackedFieldsSet((TestPackedTypes) message.wrappedMessage);
+  }
+
+  public void testUnpackedParsing() throws Exception {
+    AbstractMessageWrapper.Builder builder =
+      new AbstractMessageWrapper.Builder(TestUnpackedTypes.newBuilder());
+    AbstractMessageWrapper message =
+      builder.mergeFrom(TestUtil.getUnpackedSet().toByteString()).build();
+    TestUtil.assertUnpackedFieldsSet(
+      (TestUnpackedTypes) message.wrappedMessage);
+  }
+
+  public void testOptimizedForSize() throws Exception {
+    // We're mostly only checking that this class was compiled successfully.
+    TestOptimizedForSize message =
+      TestOptimizedForSize.newBuilder().setI(1).build();
+    message = TestOptimizedForSize.parseFrom(message.toByteString());
+    assertEquals(2, message.getSerializedSize());
+  }
+
+  // -----------------------------------------------------------------
+  // Tests for isInitialized().
+
+  private static final TestRequired TEST_REQUIRED_UNINITIALIZED =
+    TestRequired.getDefaultInstance();
+  private static final TestRequired TEST_REQUIRED_INITIALIZED =
+    TestRequired.newBuilder().setA(1).setB(2).setC(3).build();
+
+  public void testIsInitialized() throws Exception {
+    TestRequired.Builder builder = TestRequired.newBuilder();
+    AbstractMessageWrapper.Builder abstractBuilder =
+      new AbstractMessageWrapper.Builder(builder);
+
+    assertFalse(abstractBuilder.isInitialized());
+    assertEquals("a, b, c", abstractBuilder.getInitializationErrorString());
+    builder.setA(1);
+    assertFalse(abstractBuilder.isInitialized());
+    assertEquals("b, c", abstractBuilder.getInitializationErrorString());
+    builder.setB(1);
+    assertFalse(abstractBuilder.isInitialized());
+    assertEquals("c", abstractBuilder.getInitializationErrorString());
+    builder.setC(1);
+    assertTrue(abstractBuilder.isInitialized());
+    assertEquals("", abstractBuilder.getInitializationErrorString());
+  }
+
+  public void testForeignIsInitialized() throws Exception {
+    TestRequiredForeign.Builder builder = TestRequiredForeign.newBuilder();
+    AbstractMessageWrapper.Builder abstractBuilder =
+      new AbstractMessageWrapper.Builder(builder);
+
+    assertTrue(abstractBuilder.isInitialized());
+    assertEquals("", abstractBuilder.getInitializationErrorString());
+
+    builder.setOptionalMessage(TEST_REQUIRED_UNINITIALIZED);
+    assertFalse(abstractBuilder.isInitialized());
+    assertEquals(
+        "optional_message.a, optional_message.b, optional_message.c",
+        abstractBuilder.getInitializationErrorString());
+
+    builder.setOptionalMessage(TEST_REQUIRED_INITIALIZED);
+    assertTrue(abstractBuilder.isInitialized());
+    assertEquals("", abstractBuilder.getInitializationErrorString());
+
+    builder.addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED);
+    assertFalse(abstractBuilder.isInitialized());
+    assertEquals(
+        "repeated_message[0].a, repeated_message[0].b, repeated_message[0].c",
+        abstractBuilder.getInitializationErrorString());
+
+    builder.setRepeatedMessage(0, TEST_REQUIRED_INITIALIZED);
+    assertTrue(abstractBuilder.isInitialized());
+    assertEquals("", abstractBuilder.getInitializationErrorString());
+  }
+
+  // -----------------------------------------------------------------
+  // Tests for mergeFrom
+
+  static final TestAllTypes MERGE_SOURCE =
+    TestAllTypes.newBuilder()
+      .setOptionalInt32(1)
+      .setOptionalString("foo")
+      .setOptionalForeignMessage(ForeignMessage.getDefaultInstance())
+      .addRepeatedString("bar")
+      .build();
+
+  static final TestAllTypes MERGE_DEST =
+    TestAllTypes.newBuilder()
+      .setOptionalInt64(2)
+      .setOptionalString("baz")
+      .setOptionalForeignMessage(ForeignMessage.newBuilder().setC(3).build())
+      .addRepeatedString("qux")
+      .build();
+
+  static final String MERGE_RESULT_TEXT =
+      "optional_int32: 1\n" +
+      "optional_int64: 2\n" +
+      "optional_string: \"foo\"\n" +
+      "optional_foreign_message {\n" +
+      "  c: 3\n" +
+      "}\n" +
+      "repeated_string: \"qux\"\n" +
+      "repeated_string: \"bar\"\n";
+
+  public void testMergeFrom() throws Exception {
+    AbstractMessageWrapper result =
+      new AbstractMessageWrapper.Builder(
+        TestAllTypes.newBuilder(MERGE_DEST))
+      .mergeFrom(MERGE_SOURCE).build();
+
+    assertEquals(MERGE_RESULT_TEXT, result.toString());
+  }
+
+  // -----------------------------------------------------------------
+  // Tests for equals and hashCode
+
+  public void testEqualsAndHashCode() throws Exception {
+    TestAllTypes a = TestUtil.getAllSet();
+    TestAllTypes b = TestAllTypes.newBuilder().build();
+    TestAllTypes c = TestAllTypes.newBuilder(b).addRepeatedString("x").build();
+    TestAllTypes d = TestAllTypes.newBuilder(c).addRepeatedString("y").build();
+    TestAllExtensions e = TestUtil.getAllExtensionsSet();
+    TestAllExtensions f = TestAllExtensions.newBuilder(e)
+        .addExtension(UnittestProto.repeatedInt32Extension, 999).build();
+
+    checkEqualsIsConsistent(a);
+    checkEqualsIsConsistent(b);
+    checkEqualsIsConsistent(c);
+    checkEqualsIsConsistent(d);
+    checkEqualsIsConsistent(e);
+    checkEqualsIsConsistent(f);
+
+    checkNotEqual(a, b);
+    checkNotEqual(a, c);
+    checkNotEqual(a, d);
+    checkNotEqual(a, e);
+    checkNotEqual(a, f);
+
+    checkNotEqual(b, c);
+    checkNotEqual(b, d);
+    checkNotEqual(b, e);
+    checkNotEqual(b, f);
+
+    checkNotEqual(c, d);
+    checkNotEqual(c, e);
+    checkNotEqual(c, f);
+
+    checkNotEqual(d, e);
+    checkNotEqual(d, f);
+
+    checkNotEqual(e, f);
+
+    // Deserializing into the TestEmptyMessage such that every field
+    // is an {@link UnknownFieldSet.Field}.
+    UnittestProto.TestEmptyMessage eUnknownFields =
+        UnittestProto.TestEmptyMessage.parseFrom(e.toByteArray());
+    UnittestProto.TestEmptyMessage fUnknownFields =
+        UnittestProto.TestEmptyMessage.parseFrom(f.toByteArray());
+    checkNotEqual(eUnknownFields, fUnknownFields);
+    checkEqualsIsConsistent(eUnknownFields);
+    checkEqualsIsConsistent(fUnknownFields);
+
+    // Subsequent reconstitutions should be identical
+    UnittestProto.TestEmptyMessage eUnknownFields2 =
+        UnittestProto.TestEmptyMessage.parseFrom(e.toByteArray());
+    checkEqualsIsConsistent(eUnknownFields, eUnknownFields2);
+  }
+
+
+  /**
+   * Asserts that the given proto has symmetric equals and hashCode methods.
+   */
+  private void checkEqualsIsConsistent(Message message) {
+    // Object should be equal to itself.
+    assertEquals(message, message);
+
+    // Object should be equal to a dynamic copy of itself.
+    DynamicMessage dynamic = DynamicMessage.newBuilder(message).build();
+    checkEqualsIsConsistent(message, dynamic);
+  }
+
+  /**
+   * Asserts that the given protos are equal and have the same hash code.
+   */
+  private void checkEqualsIsConsistent(Message message1, Message message2) {
+    assertEquals(message1, message2);
+    assertEquals(message2, message1);
+    assertEquals(message2.hashCode(), message1.hashCode());
+  }
+
+  /**
+   * Asserts that the given protos are not equal and have different hash codes.
+   *
+   * @warning It's valid for non-equal objects to have the same hash code, so
+   *   this test is stricter than it needs to be. However, this should happen
+   *   relatively rarely.
+   */
+  private void checkNotEqual(Message m1, Message m2) {
+    String equalsError = String.format("%s should not be equal to %s", m1, m2);
+    assertFalse(equalsError, m1.equals(m2));
+    assertFalse(equalsError, m2.equals(m1));
+
+    assertFalse(
+        String.format("%s should have a different hash code from %s", m1, m2),
+        m1.hashCode() == m2.hashCode());
+  }
+
+  public void testCheckByteStringIsUtf8OnUtf8() {
+    ByteString byteString = ByteString.copyFromUtf8("some text");
+    AbstractMessageLite.checkByteStringIsUtf8(byteString);
+    // No exception thrown.
+  }
+
+  public void testCheckByteStringIsUtf8OnNonUtf8() {
+    ByteString byteString =
+        ByteString.copyFrom(new byte[]{(byte) 0x80}); // A lone continuation byte.
+    try {
+      AbstractMessageLite.checkByteStringIsUtf8(byteString);
+      fail("Expected AbstractMessageLite.checkByteStringIsUtf8 to throw IllegalArgumentException");
+    } catch (IllegalArgumentException exception) {
+      assertEquals("Byte string is not UTF-8.", exception.getMessage());
+    }
+  }
+
+}
diff --git a/java/core/src/test/java/com/google/protobuf/AnyTest.java b/java/core/src/test/java/com/google/protobuf/AnyTest.java
new file mode 100644
index 00000000..e169f69d
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/AnyTest.java
@@ -0,0 +1,92 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import any_test.AnyTestProto.TestAny;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+
+import junit.framework.TestCase;
+
+/**
+ * Unit tests for Any message.
+ */
+public class AnyTest extends TestCase {
+  public void testAnyGeneratedApi() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestAllTypes message = builder.build();
+
+    TestAny container = TestAny.newBuilder()
+        .setValue(Any.pack(message)).build();
+
+    assertTrue(container.getValue().is(TestAllTypes.class));
+    assertFalse(container.getValue().is(TestAny.class));
+
+    TestAllTypes result = container.getValue().unpack(TestAllTypes.class);
+    TestUtil.assertAllFieldsSet(result);
+
+
+    // Unpacking to a wrong type will throw an exception.
+    try {
+      TestAny wrongMessage = container.getValue().unpack(TestAny.class);
+      fail("Exception is expected.");
+    } catch (InvalidProtocolBufferException e) {
+      // expected.
+    }
+
+    // Test that unpacking throws an exception if parsing fails.
+    TestAny.Builder containerBuilder = container.toBuilder();
+    containerBuilder.getValueBuilder().setValue(
+        ByteString.copyFrom(new byte[]{0x11}));
+    container = containerBuilder.build();
+    try {
+      TestAllTypes parsingFailed = container.getValue().unpack(TestAllTypes.class);
+      fail("Exception is expected.");
+    } catch (InvalidProtocolBufferException e) {
+      // expected.
+    }
+  }
+
+  public void testCachedUnpackResult() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestAllTypes message = builder.build();
+
+    TestAny container = TestAny.newBuilder()
+        .setValue(Any.pack(message)).build();
+
+    assertTrue(container.getValue().is(TestAllTypes.class));
+
+    TestAllTypes result1 = container.getValue().unpack(TestAllTypes.class);
+    TestAllTypes result2 = container.getValue().unpack(TestAllTypes.class);
+    assertTrue(result1 == result2);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java b/java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java
new file mode 100644
index 00000000..b8ad1fe4
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java
@@ -0,0 +1,469 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.util.Arrays.asList;
+
+import junit.framework.TestCase;
+
+import java.util.Collections;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+
+/**
+ * Tests for {@link BooleanArrayList}.
+ * 
+ * @author dweis@google.com (Daniel Weis)
+ */
+public class BooleanArrayListTest extends TestCase {
+  
+  private static final BooleanArrayList UNARY_LIST = newImmutableBooleanArrayList(true);
+  private static final BooleanArrayList TERTIARY_LIST =
+      newImmutableBooleanArrayList(true, true, false);
+  
+  private BooleanArrayList list;
+  
+  @Override
+  protected void setUp() throws Exception {
+    list = new BooleanArrayList();
+  }
+  
+  public void testEmptyListReturnsSameInstance() {
+    assertSame(BooleanArrayList.emptyList(), BooleanArrayList.emptyList());
+  }
+  
+  public void testEmptyListIsImmutable() {
+    assertImmutable(BooleanArrayList.emptyList());
+  }
+  
+  public void testMakeImmutable() {
+    list.addBoolean(true);
+    list.addBoolean(false);
+    list.addBoolean(true);
+    list.addBoolean(true);
+    list.makeImmutable();
+    assertImmutable(list);
+  }
+  
+  public void testCopyConstructor() {
+    BooleanArrayList copy = new BooleanArrayList(TERTIARY_LIST);
+    assertEquals(TERTIARY_LIST, copy);
+
+    copy = new BooleanArrayList(BooleanArrayList.emptyList());
+    assertEquals(BooleanArrayList.emptyList(), copy);
+    
+    copy = new BooleanArrayList(asList(false, false, true));
+    assertEquals(asList(false, false, true), copy);
+
+    copy = new BooleanArrayList(Collections.<Boolean>emptyList());
+    assertEquals(BooleanArrayList.emptyList(), copy);
+  }
+  
+  public void testModificationWithIteration() {
+    list.addAll(asList(true, false, false, true));
+    Iterator<Boolean> iterator = list.iterator();
+    assertEquals(4, list.size());
+    assertEquals(true, (boolean) list.get(0));
+    assertEquals(true, (boolean) iterator.next());
+    list.set(0, true);
+    assertEquals(false, (boolean) iterator.next());
+    
+    list.remove(0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+    
+    iterator = list.iterator();
+    list.add(0, false);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+  }
+  
+  public void testGet() {
+    assertEquals(true, (boolean) TERTIARY_LIST.get(0));
+    assertEquals(true, (boolean) TERTIARY_LIST.get(1));
+    assertEquals(false, (boolean) TERTIARY_LIST.get(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testGetInt() {
+    assertEquals(true, TERTIARY_LIST.getBoolean(0));
+    assertEquals(true, TERTIARY_LIST.getBoolean(1));
+    assertEquals(false, TERTIARY_LIST.getBoolean(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSize() {
+    assertEquals(0, BooleanArrayList.emptyList().size());
+    assertEquals(1, UNARY_LIST.size());
+    assertEquals(3, TERTIARY_LIST.size());
+
+    list.addBoolean(true);
+    list.addBoolean(false);
+    list.addBoolean(false);
+    list.addBoolean(false);
+    assertEquals(4, list.size());
+    
+    list.remove(0);
+    assertEquals(3, list.size());
+    
+    list.add(true);
+    assertEquals(4, list.size());
+  }
+  
+  public void testSet() {
+    list.addBoolean(false);
+    list.addBoolean(false);
+    
+    assertEquals(false, (boolean) list.set(0, true));
+    assertEquals(true, list.getBoolean(0));
+
+    assertEquals(false, (boolean) list.set(1, false));
+    assertEquals(false, list.getBoolean(1));
+    
+    try {
+      list.set(-1, true);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.set(2, false);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSetInt() {
+    list.addBoolean(true);
+    list.addBoolean(true);
+    
+    assertEquals(true, list.setBoolean(0, false));
+    assertEquals(false, list.getBoolean(0));
+
+    assertEquals(true, list.setBoolean(1, false));
+    assertEquals(false, list.getBoolean(1));
+    
+    try {
+      list.setBoolean(-1, false);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.setBoolean(2, true);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAdd() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.add(true));
+    assertEquals(asList(true), list);
+
+    assertTrue(list.add(false));
+    list.add(0, false);
+    assertEquals(asList(false, true, false), list);
+    
+    list.add(0, false);
+    list.add(0, true);
+    // Force a resize by getting up to 11 elements.
+    for (int i = 0; i < 6; i++) {
+      list.add(true);
+    }
+    assertEquals(asList(true, false, false, true, false, true, true, true, true, true, true), list);
+    
+    try {
+      list.add(-1, false);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.add(4, true);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAddInt() {
+    assertEquals(0, list.size());
+
+    list.addBoolean(true);
+    assertEquals(asList(true), list);
+
+    list.addBoolean(false);
+    assertEquals(asList(true, false), list);
+  }
+  
+  public void testAddAll() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.addAll(Collections.singleton(false)));
+    assertEquals(1, list.size());
+    assertEquals(false, (boolean) list.get(0));
+    assertEquals(false, list.getBoolean(0));
+    
+    assertTrue(list.addAll(asList(true, false, false, false, true)));
+    assertEquals(asList(false, true, false, false, false, true), list);
+    
+    assertTrue(list.addAll(TERTIARY_LIST));
+    assertEquals(asList(false, true, false, false, false, true, true, true, false), list);
+
+    assertFalse(list.addAll(Collections.<Boolean>emptyList()));
+    assertFalse(list.addAll(BooleanArrayList.emptyList()));
+  }
+  
+  public void testRemove() {
+    list.addAll(TERTIARY_LIST);
+    assertEquals(true, (boolean) list.remove(0));
+    assertEquals(asList(true, false), list);
+
+    assertTrue(list.remove(Boolean.TRUE));
+    assertEquals(asList(false), list);
+
+    assertFalse(list.remove(Boolean.TRUE));
+    assertEquals(asList(false), list);
+
+    assertEquals(false, (boolean) list.remove(0));
+    assertEquals(asList(), list);
+    
+    try {
+      list.remove(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(0);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  private void assertImmutable(BooleanArrayList list) {
+    try {
+      list.add(false);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.add(0, true);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.<Boolean>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.singletonList(false));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(new BooleanArrayList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.singleton(true));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.<Boolean>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addBoolean(true);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.clear();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+
+    try {
+      list.remove(1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.<Boolean>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.singleton(Boolean.TRUE));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.<Boolean>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.singleton(Boolean.TRUE));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, true);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.setBoolean(0, false);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+  }
+  
+  private static BooleanArrayList newImmutableBooleanArrayList(boolean... elements) {
+    BooleanArrayList list = new BooleanArrayList();
+    for (boolean element : elements) {
+      list.addBoolean(element);
+    }
+    list.makeImmutable();
+    return list;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java b/java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java
new file mode 100644
index 00000000..7a8a0a5e
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java
@@ -0,0 +1,101 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.UnsupportedEncodingException;
+
+
+/**
+ * This class tests {@link BoundedByteString}, which extends {@link LiteralByteString},
+ * by inheriting the tests from {@link LiteralByteStringTest}.  The only method which
+ * is strange enough that it needs to be overridden here is {@link #testToString()}.
+ *
+ * @author carlanton@google.com (Carl Haverl)
+ */
+public class BoundedByteStringTest extends LiteralByteStringTest {
+
+  @Override
+  protected void setUp() throws Exception {
+    classUnderTest = "BoundedByteString";
+    byte[] sourceBytes = ByteStringTest.getTestBytes(2341, 11337766L);
+    int from = 100;
+    int to = sourceBytes.length - 100;
+    stringUnderTest = ByteString.copyFrom(sourceBytes).substring(from, to);
+    referenceBytes = new byte[to - from];
+    System.arraycopy(sourceBytes, from, referenceBytes, 0, to - from);
+    expectedHashCode = 727575887;
+  }
+
+  @Override
+  public void testToString() throws UnsupportedEncodingException {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString unicode = ByteString.wrap(testString.getBytes(Internal.UTF_8));
+    ByteString chopped = unicode.substring(2, unicode.size() - 6);
+    assertEquals(classUnderTest + ".substring() must have the expected type",
+        classUnderTest, getActualClassName(chopped));
+
+    String roundTripString = chopped.toString(UTF_8);
+    assertEquals(classUnderTest + " unicode bytes must match",
+        testString.substring(2, testString.length() - 6), roundTripString);
+  }
+
+  @Override
+  public void testCharsetToString() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString unicode = ByteString.wrap(testString.getBytes(Internal.UTF_8));
+    ByteString chopped = unicode.substring(2, unicode.size() - 6);
+    assertEquals(classUnderTest + ".substring() must have the expected type",
+        classUnderTest, getActualClassName(chopped));
+
+    String roundTripString = chopped.toString(Internal.UTF_8);
+    assertEquals(classUnderTest + " unicode bytes must match",
+        testString.substring(2, testString.length() - 6), roundTripString);
+  }
+
+  @Override
+  public void testJavaSerialization() throws Exception {
+    ByteArrayOutputStream out = new ByteArrayOutputStream();
+    ObjectOutputStream oos = new ObjectOutputStream(out);
+    oos.writeObject(stringUnderTest);
+    oos.close();
+    byte[] pickled = out.toByteArray();
+    InputStream in = new ByteArrayInputStream(pickled);
+    ObjectInputStream ois = new ObjectInputStream(in);
+    Object o = ois.readObject();
+    assertTrue("Didn't get a ByteString back", o instanceof ByteString);
+    assertEquals("Should get an equal ByteString back", stringUnderTest, o);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/ByteStringTest.java b/java/core/src/test/java/com/google/protobuf/ByteStringTest.java
new file mode 100644
index 00000000..5267c160
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ByteStringTest.java
@@ -0,0 +1,760 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.ByteString.Output;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.Random;
+
+/**
+ * Test methods with implementations in {@link ByteString}, plus do some top-level "integration"
+ * tests.
+ *
+ * @author carlanton@google.com (Carl Haverl)
+ */
+public class ByteStringTest extends TestCase {
+
+  private static final Charset UTF_16 = Charset.forName("UTF-16");
+
+  static byte[] getTestBytes(int size, long seed) {
+    Random random = new Random(seed);
+    byte[] result = new byte[size];
+    random.nextBytes(result);
+    return result;
+  }
+
+  private byte[] getTestBytes(int size) {
+    return getTestBytes(size, 445566L);
+  }
+
+  private byte[] getTestBytes() {
+    return getTestBytes(1000);
+  }
+
+  // Compare the entire left array with a subset of the right array.
+  private boolean isArrayRange(byte[] left, byte[] right, int rightOffset, int length) {
+    boolean stillEqual = (left.length == length);
+    for (int i = 0; (stillEqual && i < length); ++i) {
+      stillEqual = (left[i] == right[rightOffset + i]);
+    }
+    return stillEqual;
+  }
+
+  // Returns true only if the given two arrays have identical contents.
+  private boolean isArray(byte[] left, byte[] right) {
+    return left.length == right.length && isArrayRange(left, right, 0, left.length);
+  }
+
+  public void testSubstring_BeginIndex() {
+    byte[] bytes = getTestBytes();
+    ByteString substring = ByteString.copyFrom(bytes).substring(500);
+    assertTrue("substring must contain the tail of the string",
+        isArrayRange(substring.toByteArray(), bytes, 500, bytes.length - 500));
+  }
+
+  public void testCopyFrom_BytesOffsetSize() {
+    byte[] bytes = getTestBytes();
+    ByteString byteString = ByteString.copyFrom(bytes, 500, 200);
+    assertTrue("copyFrom sub-range must contain the expected bytes",
+        isArrayRange(byteString.toByteArray(), bytes, 500, 200));
+  }
+
+  public void testCopyFrom_Bytes() {
+    byte[] bytes = getTestBytes();
+    ByteString byteString = ByteString.copyFrom(bytes);
+    assertTrue("copyFrom must contain the expected bytes",
+        isArray(byteString.toByteArray(), bytes));
+  }
+
+  public void testCopyFrom_ByteBufferSize() {
+    byte[] bytes = getTestBytes();
+    ByteBuffer byteBuffer = ByteBuffer.allocate(bytes.length);
+    byteBuffer.put(bytes);
+    byteBuffer.position(500);
+    ByteString byteString = ByteString.copyFrom(byteBuffer, 200);
+    assertTrue("copyFrom byteBuffer sub-range must contain the expected bytes",
+        isArrayRange(byteString.toByteArray(), bytes, 500, 200));
+  }
+
+  public void testCopyFrom_ByteBuffer() {
+    byte[] bytes = getTestBytes();
+    ByteBuffer byteBuffer = ByteBuffer.allocate(bytes.length);
+    byteBuffer.put(bytes);
+    byteBuffer.position(500);
+    ByteString byteString = ByteString.copyFrom(byteBuffer);
+    assertTrue("copyFrom byteBuffer sub-range must contain the expected bytes",
+        isArrayRange(byteString.toByteArray(), bytes, 500, bytes.length - 500));
+  }
+
+  public void testCopyFrom_StringEncoding() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString byteString = ByteString.copyFrom(testString, UTF_16);
+    byte[] testBytes = testString.getBytes(UTF_16);
+    assertTrue("copyFrom string must respect the charset",
+        isArrayRange(byteString.toByteArray(), testBytes, 0, testBytes.length));
+  }
+
+  public void testCopyFrom_Utf8() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString byteString = ByteString.copyFromUtf8(testString);
+    byte[] testBytes = testString.getBytes(Internal.UTF_8);
+    assertTrue("copyFromUtf8 string must respect the charset",
+        isArrayRange(byteString.toByteArray(), testBytes, 0, testBytes.length));
+  }
+
+  public void testCopyFrom_Iterable() {
+    byte[] testBytes = getTestBytes(77777, 113344L);
+    final List<ByteString> pieces = makeConcretePieces(testBytes);
+    // Call copyFrom() on a Collection
+    ByteString byteString = ByteString.copyFrom(pieces);
+    assertTrue("copyFrom a List must contain the expected bytes",
+        isArrayRange(byteString.toByteArray(), testBytes, 0, testBytes.length));
+    // Call copyFrom on an iteration that's not a collection
+    ByteString byteStringAlt = ByteString.copyFrom(new Iterable<ByteString>() {
+      @Override
+      public Iterator<ByteString> iterator() {
+        return pieces.iterator();
+      }
+    });
+    assertEquals("copyFrom from an Iteration must contain the expected bytes",
+        byteString, byteStringAlt);
+  }
+
+  public void testCopyTo_TargetOffset() {
+    byte[] bytes = getTestBytes();
+    ByteString byteString = ByteString.copyFrom(bytes);
+    byte[] target = new byte[bytes.length + 1000];
+    byteString.copyTo(target, 400);
+    assertTrue("copyFrom byteBuffer sub-range must contain the expected bytes",
+        isArrayRange(bytes, target, 400, bytes.length));
+  }
+
+  public void testReadFrom_emptyStream() throws IOException {
+    ByteString byteString =
+        ByteString.readFrom(new ByteArrayInputStream(new byte[0]));
+    assertSame("reading an empty stream must result in the EMPTY constant "
+        + "byte string", ByteString.EMPTY, byteString);
+  }
+
+  public void testReadFrom_smallStream() throws IOException {
+    assertReadFrom(getTestBytes(10));
+  }
+
+  public void testReadFrom_mutating() throws IOException {
+    byte[] capturedArray = null;
+    EvilInputStream eis = new EvilInputStream();
+    ByteString byteString = ByteString.readFrom(eis);
+
+    capturedArray = eis.capturedArray;
+    byte[] originalValue = byteString.toByteArray();
+    for (int x = 0; x < capturedArray.length; ++x) {
+      capturedArray[x] = (byte) 0;
+    }
+
+    byte[] newValue = byteString.toByteArray();
+    assertTrue("copyFrom byteBuffer must not grant access to underlying array",
+        Arrays.equals(originalValue, newValue));
+  }
+
+  // Tests sizes that are near the rope copy-out threshold.
+  public void testReadFrom_mediumStream() throws IOException {
+    assertReadFrom(getTestBytes(ByteString.CONCATENATE_BY_COPY_SIZE - 1));
+    assertReadFrom(getTestBytes(ByteString.CONCATENATE_BY_COPY_SIZE));
+    assertReadFrom(getTestBytes(ByteString.CONCATENATE_BY_COPY_SIZE + 1));
+    assertReadFrom(getTestBytes(200));
+  }
+
+  // Tests sizes that are over multi-segment rope threshold.
+  public void testReadFrom_largeStream() throws IOException {
+    assertReadFrom(getTestBytes(0x100));
+    assertReadFrom(getTestBytes(0x101));
+    assertReadFrom(getTestBytes(0x110));
+    assertReadFrom(getTestBytes(0x1000));
+    assertReadFrom(getTestBytes(0x1001));
+    assertReadFrom(getTestBytes(0x1010));
+    assertReadFrom(getTestBytes(0x10000));
+    assertReadFrom(getTestBytes(0x10001));
+    assertReadFrom(getTestBytes(0x10010));
+  }
+
+  // Tests sizes that are near the read buffer size.
+  public void testReadFrom_byteBoundaries() throws IOException {
+    final int min = ByteString.MIN_READ_FROM_CHUNK_SIZE;
+    final int max = ByteString.MAX_READ_FROM_CHUNK_SIZE;
+
+    assertReadFrom(getTestBytes(min - 1));
+    assertReadFrom(getTestBytes(min));
+    assertReadFrom(getTestBytes(min + 1));
+
+    assertReadFrom(getTestBytes(min * 2 - 1));
+    assertReadFrom(getTestBytes(min * 2));
+    assertReadFrom(getTestBytes(min * 2 + 1));
+
+    assertReadFrom(getTestBytes(min * 4 - 1));
+    assertReadFrom(getTestBytes(min * 4));
+    assertReadFrom(getTestBytes(min * 4 + 1));
+
+    assertReadFrom(getTestBytes(min * 8 - 1));
+    assertReadFrom(getTestBytes(min * 8));
+    assertReadFrom(getTestBytes(min * 8 + 1));
+
+    assertReadFrom(getTestBytes(max - 1));
+    assertReadFrom(getTestBytes(max));
+    assertReadFrom(getTestBytes(max + 1));
+
+    assertReadFrom(getTestBytes(max * 2 - 1));
+    assertReadFrom(getTestBytes(max * 2));
+    assertReadFrom(getTestBytes(max * 2 + 1));
+  }
+
+  // Tests that IOExceptions propagate through ByteString.readFrom().
+  public void testReadFrom_IOExceptions() {
+    try {
+      ByteString.readFrom(new FailStream());
+      fail("readFrom must throw the underlying IOException");
+
+    } catch (IOException e) {
+      assertEquals("readFrom must throw the expected exception",
+                   "synthetic failure", e.getMessage());
+    }
+  }
+
+  // Tests that ByteString.readFrom works with streams that don't
+  // always fill their buffers.
+  public void testReadFrom_reluctantStream() throws IOException {
+    final byte[] data = getTestBytes(0x1000);
+
+    ByteString byteString = ByteString.readFrom(new ReluctantStream(data));
+    assertTrue("readFrom byte stream must contain the expected bytes",
+        isArray(byteString.toByteArray(), data));
+
+    // Same test as above, but with some specific chunk sizes.
+    assertReadFromReluctantStream(data, 100);
+    assertReadFromReluctantStream(data, 248);
+    assertReadFromReluctantStream(data, 249);
+    assertReadFromReluctantStream(data, 250);
+    assertReadFromReluctantStream(data, 251);
+    assertReadFromReluctantStream(data, 0x1000);
+    assertReadFromReluctantStream(data, 0x1001);
+  }
+
+  // Fails unless ByteString.readFrom reads the bytes correctly from a
+  // reluctant stream with the given chunkSize parameter.
+  private void assertReadFromReluctantStream(byte[] bytes, int chunkSize)
+      throws IOException {
+    ByteString b = ByteString.readFrom(new ReluctantStream(bytes), chunkSize);
+    assertTrue("readFrom byte stream must contain the expected bytes",
+        isArray(b.toByteArray(), bytes));
+  }
+
+  // Tests that ByteString.readFrom works with streams that implement
+  // available().
+  public void testReadFrom_available() throws IOException {
+    final byte[] data = getTestBytes(0x1001);
+
+    ByteString byteString = ByteString.readFrom(new AvailableStream(data));
+    assertTrue("readFrom byte stream must contain the expected bytes",
+        isArray(byteString.toByteArray(), data));
+  }
+
+  // Fails unless ByteString.readFrom reads the bytes correctly.
+  private void assertReadFrom(byte[] bytes) throws IOException {
+    ByteString byteString =
+        ByteString.readFrom(new ByteArrayInputStream(bytes));
+    assertTrue("readFrom byte stream must contain the expected bytes",
+        isArray(byteString.toByteArray(), bytes));
+  }
+
+  // A stream that fails when read.
+  private static final class FailStream extends InputStream {
+    @Override public int read() throws IOException {
+      throw new IOException("synthetic failure");
+    }
+  }
+
+  // A stream that simulates blocking by only producing 250 characters
+  // per call to read(byte[]).
+  private static class ReluctantStream extends InputStream {
+    protected final byte[] data;
+    protected int pos = 0;
+
+    public ReluctantStream(byte[] data) {
+      this.data = data;
+    }
+
+    @Override public int read() {
+      if (pos == data.length) {
+        return -1;
+      } else {
+        return data[pos++];
+      }
+    }
+
+    @Override public int read(byte[] buf) {
+      return read(buf, 0, buf.length);
+    }
+
+    @Override public int read(byte[] buf, int offset, int size) {
+      if (pos == data.length) {
+        return -1;
+      }
+      int count = Math.min(Math.min(size, data.length - pos), 250);
+      System.arraycopy(data, pos, buf, offset, count);
+      pos += count;
+      return count;
+    }
+  }
+
+  // Same as above, but also implements available().
+  private static final class AvailableStream extends ReluctantStream {
+    public AvailableStream(byte[] data) {
+      super(data);
+    }
+
+    @Override public int available() {
+      return Math.min(250, data.length - pos);
+    }
+  }
+
+  // A stream which exposes the byte array passed into read(byte[], int, int).
+  private static class EvilInputStream extends InputStream {
+    public byte[] capturedArray = null;
+
+    @Override
+    public int read(byte[] buf, int off, int len) {
+      if (capturedArray != null) {
+        return -1;
+      } else {
+        capturedArray = buf;
+        for (int x = 0; x < len; ++x) {
+          buf[x] = (byte) x;
+        }
+        return len;
+      }
+    }
+
+    @Override
+    public int read() {
+      // Purposefully do nothing.
+      return -1;
+    }
+  }
+
+  // A stream which exposes the byte array passed into write(byte[], int, int).
+  private static class EvilOutputStream extends OutputStream {
+    public byte[] capturedArray = null;
+
+    @Override
+    public void write(byte[] buf, int off, int len) {
+      if (capturedArray == null) {
+        capturedArray = buf;
+      }
+    }
+
+    @Override
+    public void write(int ignored) {
+      // Purposefully do nothing.
+    }
+  }
+
+  public void testToStringUtf8() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    byte[] testBytes = testString.getBytes(Internal.UTF_8);
+    ByteString byteString = ByteString.copyFrom(testBytes);
+    assertEquals("copyToStringUtf8 must respect the charset",
+        testString, byteString.toStringUtf8());
+  }
+
+  public void testNewOutput_InitialCapacity() throws IOException {
+    byte[] bytes = getTestBytes();
+    ByteString.Output output = ByteString.newOutput(bytes.length + 100);
+    output.write(bytes);
+    ByteString byteString = output.toByteString();
+    assertTrue(
+        "String built from newOutput(int) must contain the expected bytes",
+        isArrayRange(bytes, byteString.toByteArray(), 0, bytes.length));
+  }
+
+  // Test newOutput() using a variety of buffer sizes and a variety of (fixed)
+  // write sizes
+  public void testNewOutput_ArrayWrite() {
+    byte[] bytes = getTestBytes();
+    int length = bytes.length;
+    int[] bufferSizes = {128, 256, length / 2, length - 1, length, length + 1,
+                         2 * length, 3 * length};
+    int[] writeSizes = {1, 4, 5, 7, 23, bytes.length};
+
+    for (int bufferSize : bufferSizes) {
+      for (int writeSize : writeSizes) {
+        // Test writing the entire output writeSize bytes at a time.
+        ByteString.Output output = ByteString.newOutput(bufferSize);
+        for (int i = 0; i < length; i += writeSize) {
+          output.write(bytes, i, Math.min(writeSize, length - i));
+        }
+        ByteString byteString = output.toByteString();
+        assertTrue("String built from newOutput() must contain the expected bytes",
+            isArrayRange(bytes, byteString.toByteArray(), 0, bytes.length));
+      }
+    }
+  }
+
+  // Test newOutput() using a variety of buffer sizes, but writing all the
+  // characters using write(byte);
+  public void testNewOutput_WriteChar() {
+    byte[] bytes = getTestBytes();
+    int length = bytes.length;
+    int[] bufferSizes = {0, 1, 128, 256, length / 2,
+                         length - 1, length, length + 1,
+                         2 * length, 3 * length};
+    for (int bufferSize : bufferSizes) {
+      ByteString.Output output = ByteString.newOutput(bufferSize);
+      for (byte byteValue : bytes) {
+        output.write(byteValue);
+      }
+      ByteString byteString = output.toByteString();
+      assertTrue("String built from newOutput() must contain the expected bytes",
+          isArrayRange(bytes, byteString.toByteArray(), 0, bytes.length));
+    }
+  }
+
+  // Test newOutput() in which we write the bytes using a variety of methods
+  // and sizes, and in which we repeatedly call toByteString() in the middle.
+  public void testNewOutput_Mixed() {
+    Random rng = new Random(1);
+    byte[] bytes = getTestBytes();
+    int length = bytes.length;
+    int[] bufferSizes = {0, 1, 128, 256, length / 2,
+                         length - 1, length, length + 1,
+                         2 * length, 3 * length};
+
+    for (int bufferSize : bufferSizes) {
+      // Test writing the entire output using a mixture of write sizes and
+      // methods;
+      ByteString.Output output = ByteString.newOutput(bufferSize);
+      int position = 0;
+      while (position < bytes.length) {
+        if (rng.nextBoolean()) {
+          int count = 1 + rng.nextInt(bytes.length - position);
+          output.write(bytes, position, count);
+          position += count;
+        } else {
+          output.write(bytes[position]);
+          position++;
+        }
+        assertEquals("size() returns the right value", position, output.size());
+        assertTrue("newOutput() substring must have correct bytes",
+            isArrayRange(output.toByteString().toByteArray(),
+                bytes, 0, position));
+      }
+      ByteString byteString = output.toByteString();
+      assertTrue("String built from newOutput() must contain the expected bytes",
+          isArrayRange(bytes, byteString.toByteArray(), 0, bytes.length));
+    }
+  }
+
+  public void testNewOutputEmpty() {
+    // Make sure newOutput() correctly builds empty byte strings
+    ByteString byteString = ByteString.newOutput().toByteString();
+    assertEquals(ByteString.EMPTY, byteString);
+  }
+
+  public void testNewOutput_Mutating() throws IOException {
+    Output os = ByteString.newOutput(5);
+    os.write(new byte[] {1, 2, 3, 4, 5});
+    EvilOutputStream eos = new EvilOutputStream();
+    os.writeTo(eos);
+    byte[] capturedArray = eos.capturedArray;
+    ByteString byteString = os.toByteString();
+    byte[] oldValue = byteString.toByteArray();
+    Arrays.fill(capturedArray, (byte) 0);
+    byte[] newValue = byteString.toByteArray();
+    assertTrue("Output must not provide access to the underlying byte array",
+        Arrays.equals(oldValue, newValue));
+  }
+
+  public void testNewCodedBuilder() throws IOException {
+    byte[] bytes = getTestBytes();
+    ByteString.CodedBuilder builder = ByteString.newCodedBuilder(bytes.length);
+    builder.getCodedOutput().writeRawBytes(bytes);
+    ByteString byteString = builder.build();
+    assertTrue("String built from newCodedBuilder() must contain the expected bytes",
+        isArrayRange(bytes, byteString.toByteArray(), 0, bytes.length));
+  }
+
+  public void testSubstringParity() {
+    byte[] bigBytes = getTestBytes(2048 * 1024, 113344L);
+    int start = 512 * 1024 - 3333;
+    int end   = 512 * 1024 + 7777;
+    ByteString concreteSubstring = ByteString.copyFrom(bigBytes).substring(start, end);
+    boolean ok = true;
+    for (int i = start; ok && i < end; ++i) {
+      ok = (bigBytes[i] == concreteSubstring.byteAt(i - start));
+    }
+    assertTrue("Concrete substring didn't capture the right bytes", ok);
+
+    ByteString literalString = ByteString.copyFrom(bigBytes, start, end - start);
+    assertTrue("Substring must be equal to literal string",
+        concreteSubstring.equals(literalString));
+    assertEquals("Substring must have same hashcode as literal string",
+        literalString.hashCode(), concreteSubstring.hashCode());
+  }
+
+  public void testCompositeSubstring() {
+    byte[] referenceBytes = getTestBytes(77748, 113344L);
+
+    List<ByteString> pieces = makeConcretePieces(referenceBytes);
+    ByteString listString = ByteString.copyFrom(pieces);
+
+    int from = 1000;
+    int to = 40000;
+    ByteString compositeSubstring = listString.substring(from, to);
+    byte[] substringBytes = compositeSubstring.toByteArray();
+    boolean stillEqual = true;
+    for (int i = 0; stillEqual && i < to - from; ++i) {
+      stillEqual = referenceBytes[from + i] == substringBytes[i];
+    }
+    assertTrue("Substring must return correct bytes", stillEqual);
+
+    stillEqual = true;
+    for (int i = 0; stillEqual && i < to - from; ++i) {
+      stillEqual = referenceBytes[from + i] == compositeSubstring.byteAt(i);
+    }
+    assertTrue("Substring must support byteAt() correctly", stillEqual);
+
+    ByteString literalSubstring = ByteString.copyFrom(referenceBytes, from, to - from);
+    assertTrue("Composite substring must equal a literal substring over the same bytes",
+        compositeSubstring.equals(literalSubstring));
+    assertTrue("Literal substring must equal a composite substring over the same bytes",
+        literalSubstring.equals(compositeSubstring));
+
+    assertEquals("We must get the same hashcodes for composite and literal substrings",
+        literalSubstring.hashCode(), compositeSubstring.hashCode());
+
+    assertFalse("We can't be equal to a proper substring",
+        compositeSubstring.equals(literalSubstring.substring(0, literalSubstring.size() - 1)));
+  }
+
+  public void testCopyFromList() {
+    byte[] referenceBytes = getTestBytes(77748, 113344L);
+    ByteString literalString = ByteString.copyFrom(referenceBytes);
+
+    List<ByteString> pieces = makeConcretePieces(referenceBytes);
+    ByteString listString = ByteString.copyFrom(pieces);
+
+    assertTrue("Composite string must be equal to literal string",
+        listString.equals(literalString));
+    assertEquals("Composite string must have same hashcode as literal string",
+        literalString.hashCode(), listString.hashCode());
+  }
+
+  public void testConcat() {
+    byte[] referenceBytes = getTestBytes(77748, 113344L);
+    ByteString literalString = ByteString.copyFrom(referenceBytes);
+
+    List<ByteString> pieces = makeConcretePieces(referenceBytes);
+
+    Iterator<ByteString> iter = pieces.iterator();
+    ByteString concatenatedString = iter.next();
+    while (iter.hasNext()) {
+      concatenatedString = concatenatedString.concat(iter.next());
+    }
+
+    assertTrue("Concatenated string must be equal to literal string",
+        concatenatedString.equals(literalString));
+    assertEquals("Concatenated string must have same hashcode as literal string",
+        literalString.hashCode(), concatenatedString.hashCode());
+  }
+
+  /**
+   * Test the Rope implementation can deal with Empty nodes, even though we
+   * guard against them. See also {@link LiteralByteStringTest#testConcat_empty()}.
+   */
+  public void testConcat_empty() {
+    byte[] referenceBytes = getTestBytes(7748, 113344L);
+    ByteString literalString = ByteString.copyFrom(referenceBytes);
+
+    ByteString duo = RopeByteString.newInstanceForTest(literalString, literalString);
+    ByteString temp = RopeByteString.newInstanceForTest(
+        RopeByteString.newInstanceForTest(literalString, ByteString.EMPTY),
+        RopeByteString.newInstanceForTest(ByteString.EMPTY, literalString));
+    ByteString quintet = RopeByteString.newInstanceForTest(temp, ByteString.EMPTY);
+
+    assertTrue("String with concatenated nulls must equal simple concatenate",
+        duo.equals(quintet));
+    assertEquals("String with concatenated nulls have same hashcode as simple concatenate",
+        duo.hashCode(), quintet.hashCode());
+
+    ByteString.ByteIterator duoIter = duo.iterator();
+    ByteString.ByteIterator quintetIter = quintet.iterator();
+    boolean stillEqual = true;
+    while (stillEqual && quintetIter.hasNext()) {
+      stillEqual = (duoIter.nextByte() == quintetIter.nextByte());
+    }
+    assertTrue("We must get the same characters by iterating", stillEqual);
+    assertFalse("Iterator must be exhausted", duoIter.hasNext());
+    try {
+      duoIter.nextByte();
+      fail("Should have thrown an exception.");
+    } catch (NoSuchElementException e) {
+      // This is success
+    }
+    try {
+      quintetIter.nextByte();
+      fail("Should have thrown an exception.");
+    } catch (NoSuchElementException e) {
+      // This is success
+    }
+
+    // Test that even if we force empty strings in as rope leaves in this
+    // configuration, we always get a (possibly Bounded) LiteralByteString
+    // for a length 1 substring.
+    //
+    // It is possible, using the testing factory method to create deeply nested
+    // trees of empty leaves, to make a string that will fail this test.
+    for (int i = 1; i < duo.size(); ++i) {
+      assertTrue("Substrings of size() < 2 must not be RopeByteStrings",
+          duo.substring(i - 1, i) instanceof ByteString.LeafByteString);
+    }
+    for (int i = 1; i < quintet.size(); ++i) {
+      assertTrue("Substrings of size() < 2 must not be RopeByteStrings",
+          quintet.substring(i - 1, i) instanceof ByteString.LeafByteString);
+    }
+  }
+
+  public void testStartsWith() {
+    byte[] bytes = getTestBytes(1000, 1234L);
+    ByteString string = ByteString.copyFrom(bytes);
+    ByteString prefix = ByteString.copyFrom(bytes, 0, 500);
+    ByteString suffix = ByteString.copyFrom(bytes, 400, 600);
+    assertTrue(string.startsWith(ByteString.EMPTY));
+    assertTrue(string.startsWith(string));
+    assertTrue(string.startsWith(prefix));
+    assertFalse(string.startsWith(suffix));
+    assertFalse(prefix.startsWith(suffix));
+    assertFalse(suffix.startsWith(prefix));
+    assertFalse(ByteString.EMPTY.startsWith(prefix));
+    assertTrue(ByteString.EMPTY.startsWith(ByteString.EMPTY));
+  }
+
+  public void testEndsWith() {
+    byte[] bytes = getTestBytes(1000, 1234L);
+    ByteString string = ByteString.copyFrom(bytes);
+    ByteString prefix = ByteString.copyFrom(bytes, 0, 500);
+    ByteString suffix = ByteString.copyFrom(bytes, 400, 600);
+    assertTrue(string.endsWith(ByteString.EMPTY));
+    assertTrue(string.endsWith(string));
+    assertTrue(string.endsWith(suffix));
+    assertFalse(string.endsWith(prefix));
+    assertFalse(suffix.endsWith(prefix));
+    assertFalse(prefix.endsWith(suffix));
+    assertFalse(ByteString.EMPTY.endsWith(suffix));
+    assertTrue(ByteString.EMPTY.endsWith(ByteString.EMPTY));
+  }
+
+  static List<ByteString> makeConcretePieces(byte[] referenceBytes) {
+    List<ByteString> pieces = new ArrayList<ByteString>();
+    // Starting length should be small enough that we'll do some concatenating by
+    // copying if we just concatenate all these pieces together.
+    for (int start = 0, length = 16; start < referenceBytes.length; start += length) {
+      length = (length << 1) - 1;
+      if (start + length > referenceBytes.length) {
+        length = referenceBytes.length - start;
+      }
+      pieces.add(ByteString.copyFrom(referenceBytes, start, length));
+    }
+    return pieces;
+  }
+
+  private byte[] substringUsingWriteTo(
+      ByteString data, int offset, int length) throws IOException {
+    ByteArrayOutputStream output = new ByteArrayOutputStream();
+    data.writeTo(output, offset, length);
+    return output.toByteArray();
+  }
+
+  public void testWriteToOutputStream() throws Exception {
+    // Choose a size large enough so when two ByteStrings are concatenated they
+    // won't be merged into one byte array due to some optimizations.
+    final int dataSize = ByteString.CONCATENATE_BY_COPY_SIZE + 1;
+    byte[] data1 = new byte[dataSize];
+    for (int i = 0; i < data1.length; i++) {
+      data1[i] = (byte) 1;
+    }
+    data1[1] = (byte) 11;
+    // Test LiteralByteString.writeTo(OutputStream,int,int)
+    ByteString left = ByteString.wrap(data1);
+    byte[] result = substringUsingWriteTo(left, 1, 1);
+    assertEquals(1, result.length);
+    assertEquals((byte) 11, result[0]);
+
+    byte[] data2 = new byte[dataSize];
+    for (int i = 0; i < data1.length; i++) {
+      data2[i] = (byte) 2;
+    }
+    ByteString right = ByteString.wrap(data2);
+    // Concatenate two ByteStrings to create a RopeByteString.
+    ByteString root = left.concat(right);
+    // Make sure we are actually testing a RopeByteString with a simple tree
+    // structure.
+    assertEquals(1, root.getTreeDepth());
+    // Write parts of the left node.
+    result = substringUsingWriteTo(root, 0, dataSize);
+    assertEquals(dataSize, result.length);
+    assertEquals((byte) 1, result[0]);
+    assertEquals((byte) 1, result[dataSize - 1]);
+    // Write parts of the right node.
+    result = substringUsingWriteTo(root, dataSize, dataSize);
+    assertEquals(dataSize, result.length);
+    assertEquals((byte) 2, result[0]);
+    assertEquals((byte) 2, result[dataSize - 1]);
+    // Write a segment of bytes that runs across both nodes.
+    result = substringUsingWriteTo(root, dataSize / 2, dataSize);
+    assertEquals(dataSize, result.length);
+    assertEquals((byte) 1, result[0]);
+    assertEquals((byte) 1, result[dataSize - dataSize / 2 - 1]);
+    assertEquals((byte) 2, result[dataSize - dataSize / 2]);
+    assertEquals((byte) 2, result[dataSize - 1]);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java b/java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java
new file mode 100644
index 00000000..3d6381c9
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java
@@ -0,0 +1,140 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import proto2_test_check_utf8.TestCheckUtf8.BytesWrapper;
+import proto2_test_check_utf8.TestCheckUtf8.StringWrapper;
+import proto2_test_check_utf8_size.TestCheckUtf8Size.BytesWrapperSize;
+import proto2_test_check_utf8_size.TestCheckUtf8Size.StringWrapperSize;
+import junit.framework.TestCase;
+
+/**
+ * Test that protos generated with file option java_string_check_utf8 do in
+ * fact perform appropriate UTF-8 checks.
+ *
+ * @author jbaum@google.com (Jacob Butcher)
+ */
+public class CheckUtf8Test extends TestCase {
+
+  private static final String UTF8_BYTE_STRING_TEXT = "some text";
+  private static final ByteString UTF8_BYTE_STRING =
+      ByteString.copyFromUtf8(UTF8_BYTE_STRING_TEXT);
+  private static final ByteString NON_UTF8_BYTE_STRING =
+      ByteString.copyFrom(new byte[]{(byte) 0x80}); // A lone continuation byte.
+
+  public void testBuildRequiredStringWithGoodUtf8() throws Exception {
+    assertEquals(UTF8_BYTE_STRING_TEXT,
+                 StringWrapper.newBuilder().setReqBytes(UTF8_BYTE_STRING).getReq());
+  }
+
+  public void testParseRequiredStringWithGoodUtf8() throws Exception {
+    ByteString serialized =
+        BytesWrapper.newBuilder().setReq(UTF8_BYTE_STRING).build().toByteString();
+    assertEquals(UTF8_BYTE_STRING_TEXT, StringWrapper.parser().parseFrom(serialized).getReq());
+  }
+
+  public void testBuildRequiredStringWithBadUtf8() throws Exception {
+    try {
+      StringWrapper.newBuilder().setReqBytes(NON_UTF8_BYTE_STRING);
+      fail("Expected IllegalArgumentException for non UTF-8 byte string.");
+    } catch (IllegalArgumentException exception) {
+      assertEquals("Byte string is not UTF-8.", exception.getMessage());
+    }
+  }
+
+  public void testBuildOptionalStringWithBadUtf8() throws Exception {
+    try {
+      StringWrapper.newBuilder().setOptBytes(NON_UTF8_BYTE_STRING);
+      fail("Expected IllegalArgumentException for non UTF-8 byte string.");
+    } catch (IllegalArgumentException exception) {
+      assertEquals("Byte string is not UTF-8.", exception.getMessage());
+    }
+  }
+
+  public void testBuildRepeatedStringWithBadUtf8() throws Exception {
+    try {
+      StringWrapper.newBuilder().addRepBytes(NON_UTF8_BYTE_STRING);
+      fail("Expected IllegalArgumentException for non UTF-8 byte string.");
+    } catch (IllegalArgumentException exception) {
+      assertEquals("Byte string is not UTF-8.", exception.getMessage());
+    }
+  }
+
+  public void testParseRequiredStringWithBadUtf8() throws Exception {
+    ByteString serialized =
+        BytesWrapper.newBuilder().setReq(NON_UTF8_BYTE_STRING).build().toByteString();
+    try {
+      StringWrapper.parser().parseFrom(serialized);
+      fail("Expected InvalidProtocolBufferException for non UTF-8 byte string.");
+    } catch (InvalidProtocolBufferException exception) {
+      assertEquals("Protocol message had invalid UTF-8.", exception.getMessage());
+    }
+  }
+
+  public void testBuildRequiredStringWithBadUtf8Size() throws Exception {
+    try {
+      StringWrapperSize.newBuilder().setReqBytes(NON_UTF8_BYTE_STRING);
+      fail("Expected IllegalArgumentException for non UTF-8 byte string.");
+    } catch (IllegalArgumentException exception) {
+      assertEquals("Byte string is not UTF-8.", exception.getMessage());
+    }
+  }
+
+  public void testBuildOptionalStringWithBadUtf8Size() throws Exception {
+    try {
+      StringWrapperSize.newBuilder().setOptBytes(NON_UTF8_BYTE_STRING);
+      fail("Expected IllegalArgumentException for non UTF-8 byte string.");
+    } catch (IllegalArgumentException exception) {
+      assertEquals("Byte string is not UTF-8.", exception.getMessage());
+    }
+  }
+
+  public void testBuildRepeatedStringWithBadUtf8Size() throws Exception {
+    try {
+      StringWrapperSize.newBuilder().addRepBytes(NON_UTF8_BYTE_STRING);
+      fail("Expected IllegalArgumentException for non UTF-8 byte string.");
+    } catch (IllegalArgumentException exception) {
+      assertEquals("Byte string is not UTF-8.", exception.getMessage());
+    }
+  }
+
+  public void testParseRequiredStringWithBadUtf8Size() throws Exception {
+    ByteString serialized =
+        BytesWrapperSize.newBuilder().setReq(NON_UTF8_BYTE_STRING).build().toByteString();
+    try {
+      StringWrapperSize.parser().parseFrom(serialized);
+      fail("Expected InvalidProtocolBufferException for non UTF-8 byte string.");
+    } catch (InvalidProtocolBufferException exception) {
+      assertEquals("Protocol message had invalid UTF-8.", exception.getMessage());
+    }
+  }
+
+}
diff --git a/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java b/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
new file mode 100644
index 00000000..18d8142c
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
@@ -0,0 +1,769 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto.BoolMessage;
+import protobuf_unittest.UnittestProto.Int32Message;
+import protobuf_unittest.UnittestProto.Int64Message;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestRecursiveMessage;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+
+/**
+ * Unit test for {@link CodedInputStream}.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class CodedInputStreamTest extends TestCase {
+  /**
+   * Helper to construct a byte array from a bunch of bytes.  The inputs are
+   * actually ints so that I can use hex notation and not get stupid errors
+   * about precision.
+   */
+  private byte[] bytes(int... bytesAsInts) {
+    byte[] bytes = new byte[bytesAsInts.length];
+    for (int i = 0; i < bytesAsInts.length; i++) {
+      bytes[i] = (byte) bytesAsInts[i];
+    }
+    return bytes;
+  }
+
+  /**
+   * An InputStream which limits the number of bytes it reads at a time.
+   * We use this to make sure that CodedInputStream doesn't screw up when
+   * reading in small blocks.
+   */
+  private static final class SmallBlockInputStream extends FilterInputStream {
+    private final int blockSize;
+
+    public SmallBlockInputStream(byte[] data, int blockSize) {
+      this(new ByteArrayInputStream(data), blockSize);
+    }
+
+    public SmallBlockInputStream(InputStream in, int blockSize) {
+      super(in);
+      this.blockSize = blockSize;
+    }
+
+    public int read(byte[] b) throws IOException {
+      return super.read(b, 0, Math.min(b.length, blockSize));
+    }
+
+    public int read(byte[] b, int off, int len) throws IOException {
+      return super.read(b, off, Math.min(len, blockSize));
+    }
+  }
+
+  private void assertDataConsumed(byte[] data, CodedInputStream input)
+      throws IOException {
+    assertEquals(data.length, input.getTotalBytesRead());
+    assertTrue(input.isAtEnd());
+  }
+
+  /**
+   * Parses the given bytes using readRawVarint32() and readRawVarint64() and
+   * checks that the result matches the given value.
+   */
+  private void assertReadVarint(byte[] data, long value) throws Exception {
+    CodedInputStream input = CodedInputStream.newInstance(data);
+    assertEquals((int) value, input.readRawVarint32());
+    assertDataConsumed(data, input);
+
+    input = CodedInputStream.newInstance(data);
+    assertEquals(value, input.readRawVarint64());
+    assertDataConsumed(data, input);
+
+    input = CodedInputStream.newInstance(data);
+    assertEquals(value, input.readRawVarint64SlowPath());
+    assertDataConsumed(data, input);
+
+    input = CodedInputStream.newInstance(data);
+    assertTrue(input.skipField(WireFormat.WIRETYPE_VARINT));
+    assertDataConsumed(data, input);
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(data, blockSize));
+      assertEquals((int) value, input.readRawVarint32());
+      assertDataConsumed(data, input);
+
+      input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(data, blockSize));
+      assertEquals(value, input.readRawVarint64());
+      assertDataConsumed(data, input);
+
+      input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(data, blockSize));
+      assertEquals(value, input.readRawVarint64SlowPath());
+      assertDataConsumed(data, input);
+
+      input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(data, blockSize));
+      assertTrue(input.skipField(WireFormat.WIRETYPE_VARINT));
+      assertDataConsumed(data, input);
+    }
+
+    // Try reading direct from an InputStream.  We want to verify that it
+    // doesn't read past the end of the input, so we copy to a new, bigger
+    // array first.
+    byte[] longerData = new byte[data.length + 1];
+    System.arraycopy(data, 0, longerData, 0, data.length);
+    InputStream rawInput = new ByteArrayInputStream(longerData);
+    assertEquals((int) value, CodedInputStream.readRawVarint32(rawInput));
+    assertEquals(1, rawInput.available());
+  }
+
+  /**
+   * Parses the given bytes using readRawVarint32() and readRawVarint64() and
+   * expects them to fail with an InvalidProtocolBufferException whose
+   * description matches the given one.
+   */
+  private void assertReadVarintFailure(
+      InvalidProtocolBufferException expected, byte[] data)
+      throws Exception {
+    CodedInputStream input = CodedInputStream.newInstance(data);
+    try {
+      input.readRawVarint32();
+      fail("Should have thrown an exception.");
+    } catch (InvalidProtocolBufferException e) {
+      assertEquals(expected.getMessage(), e.getMessage());
+    }
+
+    input = CodedInputStream.newInstance(data);
+    try {
+      input.readRawVarint64();
+      fail("Should have thrown an exception.");
+    } catch (InvalidProtocolBufferException e) {
+      assertEquals(expected.getMessage(), e.getMessage());
+    }
+
+    input = CodedInputStream.newInstance(data);
+    try {
+      input.readRawVarint64SlowPath();
+      fail("Should have thrown an exception.");
+    } catch (InvalidProtocolBufferException e) {
+      assertEquals(expected.getMessage(), e.getMessage());
+    }
+
+    // Make sure we get the same error when reading direct from an InputStream.
+    try {
+      CodedInputStream.readRawVarint32(new ByteArrayInputStream(data));
+      fail("Should have thrown an exception.");
+    } catch (InvalidProtocolBufferException e) {
+      assertEquals(expected.getMessage(), e.getMessage());
+    }
+  }
+
+  /** Tests readRawVarint32() and readRawVarint64(). */
+  public void testReadVarint() throws Exception {
+    assertReadVarint(bytes(0x00), 0);
+    assertReadVarint(bytes(0x01), 1);
+    assertReadVarint(bytes(0x7f), 127);
+    // 14882
+    assertReadVarint(bytes(0xa2, 0x74), (0x22 << 0) | (0x74 << 7));
+    // 2961488830
+    assertReadVarint(bytes(0xbe, 0xf7, 0x92, 0x84, 0x0b),
+      (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) |
+      (0x0bL << 28));
+
+    // 64-bit
+    // 7256456126
+    assertReadVarint(bytes(0xbe, 0xf7, 0x92, 0x84, 0x1b),
+      (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) |
+      (0x1bL << 28));
+    // 41256202580718336
+    assertReadVarint(
+      bytes(0x80, 0xe6, 0xeb, 0x9c, 0xc3, 0xc9, 0xa4, 0x49),
+      (0x00 << 0) | (0x66 << 7) | (0x6b << 14) | (0x1c << 21) |
+      (0x43L << 28) | (0x49L << 35) | (0x24L << 42) | (0x49L << 49));
+    // 11964378330978735131
+    assertReadVarint(
+      bytes(0x9b, 0xa8, 0xf9, 0xc2, 0xbb, 0xd6, 0x80, 0x85, 0xa6, 0x01),
+      (0x1b << 0) | (0x28 << 7) | (0x79 << 14) | (0x42 << 21) |
+      (0x3bL << 28) | (0x56L << 35) | (0x00L << 42) |
+      (0x05L << 49) | (0x26L << 56) | (0x01L << 63));
+
+    // Failures
+    assertReadVarintFailure(
+      InvalidProtocolBufferException.malformedVarint(),
+      bytes(0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+            0x00));
+    assertReadVarintFailure(
+      InvalidProtocolBufferException.truncatedMessage(),
+      bytes(0x80));
+  }
+
+  /**
+   * Parses the given bytes using readRawLittleEndian32() and checks
+   * that the result matches the given value.
+   */
+  private void assertReadLittleEndian32(byte[] data, int value)
+                                        throws Exception {
+    CodedInputStream input = CodedInputStream.newInstance(data);
+    assertEquals(value, input.readRawLittleEndian32());
+    assertTrue(input.isAtEnd());
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(data, blockSize));
+      assertEquals(value, input.readRawLittleEndian32());
+      assertTrue(input.isAtEnd());
+    }
+  }
+
+  /**
+   * Parses the given bytes using readRawLittleEndian64() and checks
+   * that the result matches the given value.
+   */
+  private void assertReadLittleEndian64(byte[] data, long value)
+                                        throws Exception {
+    CodedInputStream input = CodedInputStream.newInstance(data);
+    assertEquals(value, input.readRawLittleEndian64());
+    assertTrue(input.isAtEnd());
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(data, blockSize));
+      assertEquals(value, input.readRawLittleEndian64());
+      assertTrue(input.isAtEnd());
+    }
+  }
+
+  /** Tests readRawLittleEndian32() and readRawLittleEndian64(). */
+  public void testReadLittleEndian() throws Exception {
+    assertReadLittleEndian32(bytes(0x78, 0x56, 0x34, 0x12), 0x12345678);
+    assertReadLittleEndian32(bytes(0xf0, 0xde, 0xbc, 0x9a), 0x9abcdef0);
+
+    assertReadLittleEndian64(
+      bytes(0xf0, 0xde, 0xbc, 0x9a, 0x78, 0x56, 0x34, 0x12),
+      0x123456789abcdef0L);
+    assertReadLittleEndian64(
+      bytes(0x78, 0x56, 0x34, 0x12, 0xf0, 0xde, 0xbc, 0x9a),
+      0x9abcdef012345678L);
+  }
+
+  /** Test decodeZigZag32() and decodeZigZag64(). */
+  public void testDecodeZigZag() throws Exception {
+    assertEquals( 0, CodedInputStream.decodeZigZag32(0));
+    assertEquals(-1, CodedInputStream.decodeZigZag32(1));
+    assertEquals( 1, CodedInputStream.decodeZigZag32(2));
+    assertEquals(-2, CodedInputStream.decodeZigZag32(3));
+    assertEquals(0x3FFFFFFF, CodedInputStream.decodeZigZag32(0x7FFFFFFE));
+    assertEquals(0xC0000000, CodedInputStream.decodeZigZag32(0x7FFFFFFF));
+    assertEquals(0x7FFFFFFF, CodedInputStream.decodeZigZag32(0xFFFFFFFE));
+    assertEquals(0x80000000, CodedInputStream.decodeZigZag32(0xFFFFFFFF));
+
+    assertEquals( 0, CodedInputStream.decodeZigZag64(0));
+    assertEquals(-1, CodedInputStream.decodeZigZag64(1));
+    assertEquals( 1, CodedInputStream.decodeZigZag64(2));
+    assertEquals(-2, CodedInputStream.decodeZigZag64(3));
+    assertEquals(0x000000003FFFFFFFL,
+                 CodedInputStream.decodeZigZag64(0x000000007FFFFFFEL));
+    assertEquals(0xFFFFFFFFC0000000L,
+                 CodedInputStream.decodeZigZag64(0x000000007FFFFFFFL));
+    assertEquals(0x000000007FFFFFFFL,
+                 CodedInputStream.decodeZigZag64(0x00000000FFFFFFFEL));
+    assertEquals(0xFFFFFFFF80000000L,
+                 CodedInputStream.decodeZigZag64(0x00000000FFFFFFFFL));
+    assertEquals(0x7FFFFFFFFFFFFFFFL,
+                 CodedInputStream.decodeZigZag64(0xFFFFFFFFFFFFFFFEL));
+    assertEquals(0x8000000000000000L,
+                 CodedInputStream.decodeZigZag64(0xFFFFFFFFFFFFFFFFL));
+  }
+
+  /** Tests reading and parsing a whole message with every field type. */
+  public void testReadWholeMessage() throws Exception {
+    TestAllTypes message = TestUtil.getAllSet();
+
+    byte[] rawBytes = message.toByteArray();
+    assertEquals(rawBytes.length, message.getSerializedSize());
+
+    TestAllTypes message2 = TestAllTypes.parseFrom(rawBytes);
+    TestUtil.assertAllFieldsSet(message2);
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize < 256; blockSize *= 2) {
+      message2 = TestAllTypes.parseFrom(
+        new SmallBlockInputStream(rawBytes, blockSize));
+      TestUtil.assertAllFieldsSet(message2);
+    }
+  }
+
+  /** Tests skipField(). */
+  public void testSkipWholeMessage() throws Exception {
+    TestAllTypes message = TestUtil.getAllSet();
+    byte[] rawBytes = message.toByteArray();
+
+    // Create two parallel inputs.  Parse one as unknown fields while using
+    // skipField() to skip each field on the other.  Expect the same tags.
+    CodedInputStream input1 = CodedInputStream.newInstance(rawBytes);
+    CodedInputStream input2 = CodedInputStream.newInstance(rawBytes);
+    UnknownFieldSet.Builder unknownFields = UnknownFieldSet.newBuilder();
+
+    while (true) {
+      int tag = input1.readTag();
+      assertEquals(tag, input2.readTag());
+      if (tag == 0) {
+        break;
+      }
+      unknownFields.mergeFieldFrom(tag, input1);
+      input2.skipField(tag);
+    }
+  }
+
+
+  /**
+   * Test that a bug in skipRawBytes() has been fixed:  if the skip skips
+   * exactly up to a limit, this should not break things.
+   */
+  public void testSkipRawBytesBug() throws Exception {
+    byte[] rawBytes = new byte[] { 1, 2 };
+    CodedInputStream input = CodedInputStream.newInstance(rawBytes);
+
+    int limit = input.pushLimit(1);
+    input.skipRawBytes(1);
+    input.popLimit(limit);
+    assertEquals(2, input.readRawByte());
+  }
+
+  /**
+   * Test that a bug in skipRawBytes() has been fixed:  if the skip skips
+   * past the end of a buffer with a limit that has been set past the end of
+   * that buffer, this should not break things.
+   */
+  public void testSkipRawBytesPastEndOfBufferWithLimit() throws Exception {
+    byte[] rawBytes = new byte[] { 1, 2, 3, 4, 5 };
+    CodedInputStream input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(rawBytes, 3));
+
+    int limit = input.pushLimit(4);
+    // In order to expose the bug we need to read at least one byte to prime the
+    // buffer inside the CodedInputStream.
+    assertEquals(1, input.readRawByte());
+    // Skip to the end of the limit.
+    input.skipRawBytes(3);
+    assertTrue(input.isAtEnd());
+    input.popLimit(limit);
+    assertEquals(5, input.readRawByte());
+  }
+
+  public void testReadHugeBlob() throws Exception {
+    // Allocate and initialize a 1MB blob.
+    byte[] blob = new byte[1 << 20];
+    for (int i = 0; i < blob.length; i++) {
+      blob[i] = (byte) i;
+    }
+
+    // Make a message containing it.
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    builder.setOptionalBytes(ByteString.copyFrom(blob));
+    TestAllTypes message = builder.build();
+
+    // Serialize and parse it.  Make sure to parse from an InputStream, not
+    // directly from a ByteString, so that CodedInputStream uses buffered
+    // reading.
+    TestAllTypes message2 =
+      TestAllTypes.parseFrom(message.toByteString().newInput());
+
+    assertEquals(message.getOptionalBytes(), message2.getOptionalBytes());
+
+    // Make sure all the other fields were parsed correctly.
+    TestAllTypes message3 = TestAllTypes.newBuilder(message2)
+      .setOptionalBytes(TestUtil.getAllSet().getOptionalBytes())
+      .build();
+    TestUtil.assertAllFieldsSet(message3);
+  }
+
+  public void testReadMaliciouslyLargeBlob() throws Exception {
+    ByteString.Output rawOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+
+    int tag = WireFormat.makeTag(1, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+    output.writeRawVarint32(tag);
+    output.writeRawVarint32(0x7FFFFFFF);
+    output.writeRawBytes(new byte[32]);  // Pad with a few random bytes.
+    output.flush();
+
+    CodedInputStream input = rawOutput.toByteString().newCodedInput();
+    assertEquals(tag, input.readTag());
+
+    try {
+      input.readBytes();
+      fail("Should have thrown an exception!");
+    } catch (InvalidProtocolBufferException e) {
+      // success.
+    }
+  }
+
+  private TestRecursiveMessage makeRecursiveMessage(int depth) {
+    if (depth == 0) {
+      return TestRecursiveMessage.newBuilder().setI(5).build();
+    } else {
+      return TestRecursiveMessage.newBuilder()
+        .setA(makeRecursiveMessage(depth - 1)).build();
+    }
+  }
+
+  private void assertMessageDepth(TestRecursiveMessage message, int depth) {
+    if (depth == 0) {
+      assertFalse(message.hasA());
+      assertEquals(5, message.getI());
+    } else {
+      assertTrue(message.hasA());
+      assertMessageDepth(message.getA(), depth - 1);
+    }
+  }
+
+  public void testMaliciousRecursion() throws Exception {
+    ByteString data100 = makeRecursiveMessage(100).toByteString();
+    ByteString data101 = makeRecursiveMessage(101).toByteString();
+
+    assertMessageDepth(TestRecursiveMessage.parseFrom(data100), 100);
+
+    try {
+      TestRecursiveMessage.parseFrom(data101);
+      fail("Should have thrown an exception!");
+    } catch (InvalidProtocolBufferException e) {
+      // success.
+    }
+
+    CodedInputStream input = data100.newCodedInput();
+    input.setRecursionLimit(8);
+    try {
+      TestRecursiveMessage.parseFrom(input);
+      fail("Should have thrown an exception!");
+    } catch (InvalidProtocolBufferException e) {
+      // success.
+    }
+  }
+
+  private void checkSizeLimitExceeded(InvalidProtocolBufferException e) {
+      assertEquals(
+          InvalidProtocolBufferException.sizeLimitExceeded().getMessage(),
+          e.getMessage());
+  }
+
+  public void testSizeLimit() throws Exception {
+    CodedInputStream input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(
+            TestUtil.getAllSet().toByteString().newInput(), 16));
+    input.setSizeLimit(16);
+
+    try {
+      TestAllTypes.parseFrom(input);
+      fail("Should have thrown an exception!");
+    } catch (InvalidProtocolBufferException expected) {
+      checkSizeLimitExceeded(expected);
+    }
+  }
+
+  public void testResetSizeCounter() throws Exception {
+    CodedInputStream input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(new byte[256], 8));
+    input.setSizeLimit(16);
+    input.readRawBytes(16);
+    assertEquals(16, input.getTotalBytesRead());
+
+    try {
+      input.readRawByte();
+      fail("Should have thrown an exception!");
+    } catch (InvalidProtocolBufferException expected) {
+      checkSizeLimitExceeded(expected);
+    }
+
+    input.resetSizeCounter();
+    assertEquals(0, input.getTotalBytesRead());
+    input.readRawByte();  // No exception thrown.
+    input.resetSizeCounter();
+    assertEquals(0, input.getTotalBytesRead());
+    input.readRawBytes(16);
+    assertEquals(16, input.getTotalBytesRead());
+    input.resetSizeCounter();
+
+    try {
+      input.readRawBytes(17);  // Hits limit again.
+      fail("Should have thrown an exception!");
+    } catch (InvalidProtocolBufferException expected) {
+      checkSizeLimitExceeded(expected);
+    }
+  }
+
+  public void testSizeLimitMultipleMessages() throws Exception {
+    byte[] bytes = new byte[256];
+    for (int i = 0; i < bytes.length; i++) {
+      bytes[i] = (byte) i;
+    }
+    CodedInputStream input = CodedInputStream.newInstance(
+        new SmallBlockInputStream(bytes, 7));
+    input.setSizeLimit(16);
+    for (int i = 0; i < 256 / 16; i++) {
+      byte[] message = input.readRawBytes(16);
+      for (int j = 0; j < message.length; j++) {
+        assertEquals(i * 16 + j, message[j] & 0xff);
+      }
+      assertEquals(16, input.getTotalBytesRead());
+      input.resetSizeCounter();
+      assertEquals(0, input.getTotalBytesRead());
+    }
+  }
+
+  /**
+   * Tests that if we readString invalid UTF-8 bytes, no exception
+   * is thrown.  Instead, the invalid bytes are replaced with the Unicode
+   * "replacement character" U+FFFD.
+   */
+  public void testReadStringInvalidUtf8() throws Exception {
+    ByteString.Output rawOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+
+    int tag = WireFormat.makeTag(1, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+    output.writeRawVarint32(tag);
+    output.writeRawVarint32(1);
+    output.writeRawBytes(new byte[] { (byte) 0x80 });
+    output.flush();
+
+    CodedInputStream input = rawOutput.toByteString().newCodedInput();
+    assertEquals(tag, input.readTag());
+    String text = input.readString();
+    assertEquals(0xfffd, text.charAt(0));
+  }
+
+  /**
+   * Tests that if we readStringRequireUtf8 invalid UTF-8 bytes, an
+   * InvalidProtocolBufferException is thrown.
+   */
+  public void testReadStringRequireUtf8InvalidUtf8() throws Exception {
+    ByteString.Output rawOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+
+    int tag = WireFormat.makeTag(1, WireFormat.WIRETYPE_LENGTH_DELIMITED);
+    output.writeRawVarint32(tag);
+    output.writeRawVarint32(1);
+    output.writeRawBytes(new byte[] { (byte) 0x80 });
+    output.flush();
+
+    CodedInputStream input = rawOutput.toByteString().newCodedInput();
+    assertEquals(tag, input.readTag());
+    try {
+      input.readStringRequireUtf8();
+      fail("Expected invalid UTF-8 exception.");
+    } catch (InvalidProtocolBufferException exception) {
+      assertEquals("Protocol message had invalid UTF-8.", exception.getMessage());
+    }
+  }
+
+  public void testReadFromSlice() throws Exception {
+    byte[] bytes = bytes(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);
+    CodedInputStream in = CodedInputStream.newInstance(bytes, 3, 5);
+    assertEquals(0, in.getTotalBytesRead());
+    for (int i = 3; i < 8; i++) {
+      assertEquals(i, in.readRawByte());
+      assertEquals(i - 2, in.getTotalBytesRead());
+    }
+    // eof
+    assertEquals(0, in.readTag());
+    assertEquals(5, in.getTotalBytesRead());
+  }
+
+  public void testInvalidTag() throws Exception {
+    // Any tag number which corresponds to field number zero is invalid and
+    // should throw InvalidProtocolBufferException.
+    for (int i = 0; i < 8; i++) {
+      try {
+        CodedInputStream.newInstance(bytes(i)).readTag();
+        fail("Should have thrown an exception.");
+      } catch (InvalidProtocolBufferException e) {
+        assertEquals(InvalidProtocolBufferException.invalidTag().getMessage(),
+                     e.getMessage());
+      }
+    }
+  }
+
+  public void testReadByteArray() throws Exception {
+    ByteString.Output rawOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+    // Zero-sized bytes field.
+    output.writeRawVarint32(0);
+    // One one-byte bytes field
+    output.writeRawVarint32(1);
+    output.writeRawBytes(new byte[] { (byte) 23 });
+    // Another one-byte bytes field
+    output.writeRawVarint32(1);
+    output.writeRawBytes(new byte[] { (byte) 45 });
+    // A bytes field large enough that won't fit into the 4K buffer.
+    final int bytesLength = 16 * 1024;
+    byte[] bytes = new byte[bytesLength];
+    bytes[0] = (byte) 67;
+    bytes[bytesLength - 1] = (byte) 89;
+    output.writeRawVarint32(bytesLength);
+    output.writeRawBytes(bytes);
+
+    output.flush();
+    CodedInputStream inputStream = rawOutput.toByteString().newCodedInput();
+
+    byte[] result = inputStream.readByteArray();
+    assertEquals(0, result.length);
+    result = inputStream.readByteArray();
+    assertEquals(1, result.length);
+    assertEquals((byte) 23, result[0]);
+    result = inputStream.readByteArray();
+    assertEquals(1, result.length);
+    assertEquals((byte) 45, result[0]);
+    result = inputStream.readByteArray();
+    assertEquals(bytesLength, result.length);
+    assertEquals((byte) 67, result[0]);
+    assertEquals((byte) 89, result[bytesLength - 1]);
+  }
+
+  public void testReadByteBuffer() throws Exception {
+    ByteString.Output rawOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+    // Zero-sized bytes field.
+    output.writeRawVarint32(0);
+    // One one-byte bytes field
+    output.writeRawVarint32(1);
+    output.writeRawBytes(new byte[]{(byte) 23});
+    // Another one-byte bytes field
+    output.writeRawVarint32(1);
+    output.writeRawBytes(new byte[]{(byte) 45});
+    // A bytes field large enough that won't fit into the 4K buffer.
+    final int bytesLength = 16 * 1024;
+    byte[] bytes = new byte[bytesLength];
+    bytes[0] = (byte) 67;
+    bytes[bytesLength - 1] = (byte) 89;
+    output.writeRawVarint32(bytesLength);
+    output.writeRawBytes(bytes);
+
+    output.flush();
+    CodedInputStream inputStream = rawOutput.toByteString().newCodedInput();
+
+    ByteBuffer result = inputStream.readByteBuffer();
+    assertEquals(0, result.capacity());
+    result = inputStream.readByteBuffer();
+    assertEquals(1, result.capacity());
+    assertEquals((byte) 23, result.get());
+    result = inputStream.readByteBuffer();
+    assertEquals(1, result.capacity());
+    assertEquals((byte) 45, result.get());
+    result = inputStream.readByteBuffer();
+    assertEquals(bytesLength, result.capacity());
+    assertEquals((byte) 67, result.get());
+    result.position(bytesLength - 1);
+    assertEquals((byte) 89, result.get());
+  }
+
+  public void testReadByteBufferAliasing() throws Exception {
+    ByteArrayOutputStream byteArrayStream = new ByteArrayOutputStream();
+    CodedOutputStream output = CodedOutputStream.newInstance(byteArrayStream);
+    // Zero-sized bytes field.
+    output.writeRawVarint32(0);
+    // One one-byte bytes field
+    output.writeRawVarint32(1);
+    output.writeRawBytes(new byte[]{(byte) 23});
+    // Another one-byte bytes field
+    output.writeRawVarint32(1);
+    output.writeRawBytes(new byte[]{(byte) 45});
+    // A bytes field large enough that won't fit into the 4K buffer.
+    final int bytesLength = 16 * 1024;
+    byte[] bytes = new byte[bytesLength];
+    bytes[0] = (byte) 67;
+    bytes[bytesLength - 1] = (byte) 89;
+    output.writeRawVarint32(bytesLength);
+    output.writeRawBytes(bytes);
+    output.flush();
+    byte[] data = byteArrayStream.toByteArray();
+
+    // Without aliasing
+    CodedInputStream inputStream = CodedInputStream.newInstance(data);
+    ByteBuffer result = inputStream.readByteBuffer();
+    assertEquals(0, result.capacity());
+    result = inputStream.readByteBuffer();
+    assertTrue(result.array() != data);
+    assertEquals(1, result.capacity());
+    assertEquals((byte) 23, result.get());
+    result = inputStream.readByteBuffer();
+    assertTrue(result.array() != data);
+    assertEquals(1, result.capacity());
+    assertEquals((byte) 45, result.get());
+    result = inputStream.readByteBuffer();
+    assertTrue(result.array() != data);
+    assertEquals(bytesLength, result.capacity());
+    assertEquals((byte) 67, result.get());
+    result.position(bytesLength - 1);
+    assertEquals((byte) 89, result.get());
+
+    // Enable aliasing
+    inputStream = CodedInputStream.newInstance(data);
+    inputStream.enableAliasing(true);
+    result = inputStream.readByteBuffer();
+    assertEquals(0, result.capacity());
+    result = inputStream.readByteBuffer();
+    assertTrue(result.array() == data);
+    assertEquals(1, result.capacity());
+    assertEquals((byte) 23, result.get());
+    result = inputStream.readByteBuffer();
+    assertTrue(result.array() == data);
+    assertEquals(1, result.capacity());
+    assertEquals((byte) 45, result.get());
+    result = inputStream.readByteBuffer();
+    assertTrue(result.array() == data);
+    assertEquals(bytesLength, result.capacity());
+    assertEquals((byte) 67, result.get());
+    result.position(bytesLength - 1);
+    assertEquals((byte) 89, result.get());
+  }
+
+  public void testCompatibleTypes() throws Exception {
+    long data = 0x100000000L;
+    Int64Message message = Int64Message.newBuilder().setData(data).build();
+    ByteString serialized = message.toByteString();
+
+    // Test int64(long) is compatible with bool(boolean)
+    BoolMessage msg2 = BoolMessage.parseFrom(serialized);
+    assertTrue(msg2.getData());
+
+    // Test int64(long) is compatible with int32(int)
+    Int32Message msg3 = Int32Message.parseFrom(serialized);
+    assertEquals((int) data, msg3.getData());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java b/java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
new file mode 100644
index 00000000..6018ea55
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
@@ -0,0 +1,546 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto.SparseEnumMessage;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestPackedTypes;
+import protobuf_unittest.UnittestProto.TestSparseEnum;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Unit test for {@link CodedOutputStream}.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class CodedOutputStreamTest extends TestCase {
+  /**
+   * Helper to construct a byte array from a bunch of bytes.  The inputs are
+   * actually ints so that I can use hex notation and not get stupid errors
+   * about precision.
+   */
+  private byte[] bytes(int... bytesAsInts) {
+    byte[] bytes = new byte[bytesAsInts.length];
+    for (int i = 0; i < bytesAsInts.length; i++) {
+      bytes[i] = (byte) bytesAsInts[i];
+    }
+    return bytes;
+  }
+
+  /** Arrays.asList() does not work with arrays of primitives.  :( */
+  private List<Byte> toList(byte[] bytes) {
+    List<Byte> result = new ArrayList<Byte>();
+    for (byte b : bytes) {
+      result.add(b);
+    }
+    return result;
+  }
+
+  private void assertEqualBytes(byte[] a, byte[] b) {
+    assertEquals(toList(a), toList(b));
+  }
+
+  /**
+   * Writes the given value using writeRawVarint32() and writeRawVarint64() and
+   * checks that the result matches the given bytes.
+   */
+  private void assertWriteVarint(byte[] data, long value) throws Exception {
+    // Only test 32-bit write if the value fits into an int.
+    if (value == (int) value) {
+      ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+      CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+      output.writeRawVarint32((int) value);
+      output.flush();
+      assertEqualBytes(data, rawOutput.toByteArray());
+
+      // Also try computing size.
+      assertEquals(data.length,
+                   CodedOutputStream.computeRawVarint32Size((int) value));
+    }
+
+    {
+      ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+      CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+      output.writeRawVarint64(value);
+      output.flush();
+      assertEqualBytes(data, rawOutput.toByteArray());
+
+      // Also try computing size.
+      assertEquals(data.length,
+                   CodedOutputStream.computeRawVarint64Size(value));
+    }
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      // Only test 32-bit write if the value fits into an int.
+      if (value == (int) value) {
+        ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+        CodedOutputStream output =
+          CodedOutputStream.newInstance(rawOutput, blockSize);
+        output.writeRawVarint32((int) value);
+        output.flush();
+        assertEqualBytes(data, rawOutput.toByteArray());
+      }
+
+      {
+        ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+        CodedOutputStream output =
+          CodedOutputStream.newInstance(rawOutput, blockSize);
+        output.writeRawVarint64(value);
+        output.flush();
+        assertEqualBytes(data, rawOutput.toByteArray());
+      }
+    }
+  }
+
+  private void assertVarintRoundTrip(long value) throws Exception {
+    {
+      ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+      CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+      output.writeRawVarint64(value);
+      output.flush();
+      byte[] bytes = rawOutput.toByteArray();
+      assertEquals(bytes.length, CodedOutputStream.computeRawVarint64Size(value));
+      CodedInputStream input = CodedInputStream.newInstance(new ByteArrayInputStream(bytes));
+      assertEquals(value, input.readRawVarint64());
+    }
+
+    if (value == (int) value) {
+      ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+      CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+      output.writeRawVarint32((int) value);
+      output.flush();
+      byte[] bytes = rawOutput.toByteArray();
+      assertEquals(bytes.length, CodedOutputStream.computeRawVarint32Size((int) value));
+      CodedInputStream input = CodedInputStream.newInstance(new ByteArrayInputStream(bytes));
+      assertEquals(value, input.readRawVarint32());
+    }
+  }
+
+  /** Checks that invariants are maintained for varint round trip input and output. */
+  public void testVarintRoundTrips() throws Exception {
+    assertVarintRoundTrip(0L);
+    for (int bits = 0; bits < 64; bits++) {
+      long value = 1L << bits;
+      assertVarintRoundTrip(value);
+      assertVarintRoundTrip(value + 1);
+      assertVarintRoundTrip(value - 1);
+      assertVarintRoundTrip(-value);
+    }
+  }
+
+  /** Tests writeRawVarint32() and writeRawVarint64(). */
+  public void testWriteVarint() throws Exception {
+    assertWriteVarint(bytes(0x00), 0);
+    assertWriteVarint(bytes(0x01), 1);
+    assertWriteVarint(bytes(0x7f), 127);
+    // 14882
+    assertWriteVarint(bytes(0xa2, 0x74), (0x22 << 0) | (0x74 << 7));
+    // 2961488830
+    assertWriteVarint(bytes(0xbe, 0xf7, 0x92, 0x84, 0x0b),
+      (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) |
+      (0x0bL << 28));
+
+    // 64-bit
+    // 7256456126
+    assertWriteVarint(bytes(0xbe, 0xf7, 0x92, 0x84, 0x1b),
+      (0x3e << 0) | (0x77 << 7) | (0x12 << 14) | (0x04 << 21) |
+      (0x1bL << 28));
+    // 41256202580718336
+    assertWriteVarint(
+      bytes(0x80, 0xe6, 0xeb, 0x9c, 0xc3, 0xc9, 0xa4, 0x49),
+      (0x00 << 0) | (0x66 << 7) | (0x6b << 14) | (0x1c << 21) |
+      (0x43L << 28) | (0x49L << 35) | (0x24L << 42) | (0x49L << 49));
+    // 11964378330978735131
+    assertWriteVarint(
+      bytes(0x9b, 0xa8, 0xf9, 0xc2, 0xbb, 0xd6, 0x80, 0x85, 0xa6, 0x01),
+      (0x1b << 0) | (0x28 << 7) | (0x79 << 14) | (0x42 << 21) |
+      (0x3bL << 28) | (0x56L << 35) | (0x00L << 42) |
+      (0x05L << 49) | (0x26L << 56) | (0x01L << 63));
+  }
+
+  /**
+   * Parses the given bytes using writeRawLittleEndian32() and checks
+   * that the result matches the given value.
+   */
+  private void assertWriteLittleEndian32(byte[] data, int value)
+                                         throws Exception {
+    ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+    output.writeRawLittleEndian32(value);
+    output.flush();
+    assertEqualBytes(data, rawOutput.toByteArray());
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      rawOutput = new ByteArrayOutputStream();
+      output = CodedOutputStream.newInstance(rawOutput, blockSize);
+      output.writeRawLittleEndian32(value);
+      output.flush();
+      assertEqualBytes(data, rawOutput.toByteArray());
+    }
+  }
+
+  /**
+   * Parses the given bytes using writeRawLittleEndian64() and checks
+   * that the result matches the given value.
+   */
+  private void assertWriteLittleEndian64(byte[] data, long value)
+                                         throws Exception {
+    ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+    CodedOutputStream output = CodedOutputStream.newInstance(rawOutput);
+    output.writeRawLittleEndian64(value);
+    output.flush();
+    assertEqualBytes(data, rawOutput.toByteArray());
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize <= 16; blockSize *= 2) {
+      rawOutput = new ByteArrayOutputStream();
+      output = CodedOutputStream.newInstance(rawOutput, blockSize);
+      output.writeRawLittleEndian64(value);
+      output.flush();
+      assertEqualBytes(data, rawOutput.toByteArray());
+    }
+  }
+
+  /** Tests writeRawLittleEndian32() and writeRawLittleEndian64(). */
+  public void testWriteLittleEndian() throws Exception {
+    assertWriteLittleEndian32(bytes(0x78, 0x56, 0x34, 0x12), 0x12345678);
+    assertWriteLittleEndian32(bytes(0xf0, 0xde, 0xbc, 0x9a), 0x9abcdef0);
+
+    assertWriteLittleEndian64(
+      bytes(0xf0, 0xde, 0xbc, 0x9a, 0x78, 0x56, 0x34, 0x12),
+      0x123456789abcdef0L);
+    assertWriteLittleEndian64(
+      bytes(0x78, 0x56, 0x34, 0x12, 0xf0, 0xde, 0xbc, 0x9a),
+      0x9abcdef012345678L);
+  }
+
+  /** Test encodeZigZag32() and encodeZigZag64(). */
+  public void testEncodeZigZag() throws Exception {
+    assertEquals(0, CodedOutputStream.encodeZigZag32( 0));
+    assertEquals(1, CodedOutputStream.encodeZigZag32(-1));
+    assertEquals(2, CodedOutputStream.encodeZigZag32( 1));
+    assertEquals(3, CodedOutputStream.encodeZigZag32(-2));
+    assertEquals(0x7FFFFFFE, CodedOutputStream.encodeZigZag32(0x3FFFFFFF));
+    assertEquals(0x7FFFFFFF, CodedOutputStream.encodeZigZag32(0xC0000000));
+    assertEquals(0xFFFFFFFE, CodedOutputStream.encodeZigZag32(0x7FFFFFFF));
+    assertEquals(0xFFFFFFFF, CodedOutputStream.encodeZigZag32(0x80000000));
+
+    assertEquals(0, CodedOutputStream.encodeZigZag64( 0));
+    assertEquals(1, CodedOutputStream.encodeZigZag64(-1));
+    assertEquals(2, CodedOutputStream.encodeZigZag64( 1));
+    assertEquals(3, CodedOutputStream.encodeZigZag64(-2));
+    assertEquals(0x000000007FFFFFFEL,
+                 CodedOutputStream.encodeZigZag64(0x000000003FFFFFFFL));
+    assertEquals(0x000000007FFFFFFFL,
+                 CodedOutputStream.encodeZigZag64(0xFFFFFFFFC0000000L));
+    assertEquals(0x00000000FFFFFFFEL,
+                 CodedOutputStream.encodeZigZag64(0x000000007FFFFFFFL));
+    assertEquals(0x00000000FFFFFFFFL,
+                 CodedOutputStream.encodeZigZag64(0xFFFFFFFF80000000L));
+    assertEquals(0xFFFFFFFFFFFFFFFEL,
+                 CodedOutputStream.encodeZigZag64(0x7FFFFFFFFFFFFFFFL));
+    assertEquals(0xFFFFFFFFFFFFFFFFL,
+                 CodedOutputStream.encodeZigZag64(0x8000000000000000L));
+
+    // Some easier-to-verify round-trip tests.  The inputs (other than 0, 1, -1)
+    // were chosen semi-randomly via keyboard bashing.
+    assertEquals(0,
+      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(0)));
+    assertEquals(1,
+      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(1)));
+    assertEquals(-1,
+      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(-1)));
+    assertEquals(14927,
+      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(14927)));
+    assertEquals(-3612,
+      CodedOutputStream.encodeZigZag32(CodedInputStream.decodeZigZag32(-3612)));
+
+    assertEquals(0,
+      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(0)));
+    assertEquals(1,
+      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(1)));
+    assertEquals(-1,
+      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(-1)));
+    assertEquals(14927,
+      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(14927)));
+    assertEquals(-3612,
+      CodedOutputStream.encodeZigZag64(CodedInputStream.decodeZigZag64(-3612)));
+
+    assertEquals(856912304801416L,
+      CodedOutputStream.encodeZigZag64(
+        CodedInputStream.decodeZigZag64(
+          856912304801416L)));
+    assertEquals(-75123905439571256L,
+      CodedOutputStream.encodeZigZag64(
+        CodedInputStream.decodeZigZag64(
+          -75123905439571256L)));
+  }
+
+  /** Tests writing a whole message with every field type. */
+  public void testWriteWholeMessage() throws Exception {
+    TestAllTypes message = TestUtil.getAllSet();
+
+    byte[] rawBytes = message.toByteArray();
+    assertEqualBytes(TestUtil.getGoldenMessage().toByteArray(), rawBytes);
+
+    // Try different block sizes.
+    for (int blockSize = 1; blockSize < 256; blockSize *= 2) {
+      ByteArrayOutputStream rawOutput = new ByteArrayOutputStream();
+      CodedOutputStream output =
+        CodedOutputStream.newInstance(rawOutput, blockSize);
+      message.writeTo(output);
+      output.flush();
+      assertEqualBytes(rawBytes, rawOutput.toByteArray());
+    }
+  }
+
+  /** Tests writing a whole message with every packed field type. Ensures the
+   * wire format of packed fields is compatible with C++. */
+  public void testWriteWholePackedFieldsMessage() throws Exception {
+    TestPackedTypes message = TestUtil.getPackedSet();
+
+    byte[] rawBytes = message.toByteArray();
+    assertEqualBytes(TestUtil.getGoldenPackedFieldsMessage().toByteArray(),
+                     rawBytes);
+  }
+
+  /** Test writing a message containing a negative enum value. This used to
+   * fail because the size was not properly computed as a sign-extended varint.
+   */
+  public void testWriteMessageWithNegativeEnumValue() throws Exception {
+    SparseEnumMessage message = SparseEnumMessage.newBuilder()
+        .setSparseEnum(TestSparseEnum.SPARSE_E) .build();
+    assertTrue(message.getSparseEnum().getNumber() < 0);
+    byte[] rawBytes = message.toByteArray();
+    SparseEnumMessage message2 = SparseEnumMessage.parseFrom(rawBytes);
+    assertEquals(TestSparseEnum.SPARSE_E, message2.getSparseEnum());
+  }
+
+  /** Test getTotalBytesWritten() */
+  public void testGetTotalBytesWritten() throws Exception {
+    final int BUFFER_SIZE = 4 * 1024;
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream(BUFFER_SIZE);
+    CodedOutputStream codedStream = CodedOutputStream.newInstance(outputStream);
+    byte[] value = "abcde".getBytes(Internal.UTF_8);
+    for (int i = 0; i < 1024; ++i) {
+      codedStream.writeRawBytes(value, 0, value.length);
+    }
+    String string =
+        "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz";
+    // Ensure we take the slower fast path.
+    assertTrue(CodedOutputStream.computeRawVarint32Size(string.length())
+        != CodedOutputStream.computeRawVarint32Size(string.length() * Utf8.MAX_BYTES_PER_CHAR));
+    
+    codedStream.writeStringNoTag(string);
+    int stringSize = CodedOutputStream.computeStringSizeNoTag(string);
+    
+    // Make sure we have written more bytes than the buffer could hold. This is
+    // to make the test complete.
+    assertTrue(codedStream.getTotalBytesWritten() > BUFFER_SIZE);
+    
+    // Verify that the total bytes written is correct
+    assertEquals((value.length * 1024) + stringSize, codedStream.getTotalBytesWritten());
+  }
+  
+  // TODO(dweis): Write a comprehensive test suite for CodedOutputStream that covers more than just
+  //    this case.
+  public void testWriteStringNoTag_fastpath() throws Exception {
+    int bufferSize = 153;
+    String threeBytesPer = "\u0981";
+    String string = threeBytesPer;
+    for (int i = 0; i < 50; i++) {
+      string += threeBytesPer;
+    }
+    // These checks ensure we will tickle the slower fast path.
+    assertEquals(1, CodedOutputStream.computeRawVarint32Size(string.length()));
+    assertEquals(
+        2, CodedOutputStream.computeRawVarint32Size(string.length() * Utf8.MAX_BYTES_PER_CHAR));
+    assertEquals(bufferSize, string.length() * Utf8.MAX_BYTES_PER_CHAR);
+    
+    CodedOutputStream output =
+        CodedOutputStream.newInstance(ByteBuffer.allocate(bufferSize), bufferSize);
+    output.writeStringNoTag(string);
+  }
+
+  public void testWriteToByteBuffer() throws Exception {
+    final int bufferSize = 16 * 1024;
+    ByteBuffer buffer = ByteBuffer.allocate(bufferSize);
+    CodedOutputStream codedStream = CodedOutputStream.newInstance(buffer);
+    // Write raw bytes into the ByteBuffer.
+    final int length1 = 5000;
+    for (int i = 0; i < length1; i++) {
+      codedStream.writeRawByte((byte) 1);
+    }
+    final int length2 = 8 * 1024;
+    byte[] data = new byte[length2];
+    for (int i = 0; i < length2; i++) {
+      data[i] = (byte) 2;
+    }
+    codedStream.writeRawBytes(data);
+    final int length3 = bufferSize - length1 - length2;
+    for (int i = 0; i < length3; i++) {
+      codedStream.writeRawByte((byte) 3);
+    }
+    codedStream.flush();
+
+    // Check that data is correctly written to the ByteBuffer.
+    assertEquals(0, buffer.remaining());
+    buffer.flip();
+    for (int i = 0; i < length1; i++) {
+      assertEquals((byte) 1, buffer.get());
+    }
+    for (int i = 0; i < length2; i++) {
+      assertEquals((byte) 2, buffer.get());
+    }
+    for (int i = 0; i < length3; i++) {
+      assertEquals((byte) 3, buffer.get());
+    }
+  }
+
+  public void testWriteByteBuffer() throws Exception {
+    byte[] value = "abcde".getBytes(Internal.UTF_8);
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    CodedOutputStream codedStream = CodedOutputStream.newInstance(outputStream);
+    ByteBuffer byteBuffer = ByteBuffer.wrap(value, 0, 1);
+    // This will actually write 5 bytes into the CodedOutputStream as the
+    // ByteBuffer's capacity() is 5.
+    codedStream.writeRawBytes(byteBuffer);
+    // The above call shouldn't affect the ByteBuffer's state.
+    assertEquals(0, byteBuffer.position());
+    assertEquals(1, byteBuffer.limit());
+
+    // The correct way to write part of an array using ByteBuffer.
+    codedStream.writeRawBytes(ByteBuffer.wrap(value, 2, 1).slice());
+
+    codedStream.flush();
+    byte[] result = outputStream.toByteArray();
+    assertEquals(6, result.length);
+    for (int i = 0; i < 5; i++) {
+      assertEquals(value[i], result[i]);
+    }
+    assertEquals(value[2], result[5]);
+  }
+
+  public void testWriteByteArrayWithOffsets() throws Exception {
+    byte[] fullArray = bytes(0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88);
+    byte[] destination = new byte[4];
+    CodedOutputStream codedStream = CodedOutputStream.newInstance(destination);
+    codedStream.writeByteArrayNoTag(fullArray, 2, 2);
+    assertEqualBytes(bytes(0x02, 0x33, 0x44, 0x00), destination);
+    assertEquals(3, codedStream.getTotalBytesWritten());
+  }
+  
+  public void testSerializeInvalidUtf8() throws Exception {
+    String[] invalidStrings = new String[] {
+        newString(Character.MIN_HIGH_SURROGATE),
+        "foobar" + newString(Character.MIN_HIGH_SURROGATE),
+        newString(Character.MIN_LOW_SURROGATE),
+        "foobar" + newString(Character.MIN_LOW_SURROGATE),
+        newString(Character.MIN_HIGH_SURROGATE, Character.MIN_HIGH_SURROGATE)
+    };
+    
+    CodedOutputStream outputWithStream = CodedOutputStream.newInstance(new ByteArrayOutputStream());
+    CodedOutputStream outputWithArray = CodedOutputStream.newInstance(new byte[10000]);
+    for (String s : invalidStrings) {
+      // TODO(dweis): These should all fail; instead they are corrupting data.
+      CodedOutputStream.computeStringSizeNoTag(s);
+      outputWithStream.writeStringNoTag(s);
+      outputWithArray.writeStringNoTag(s);
+    }
+  }
+  
+  private static String newString(char... chars) {
+    return new String(chars);
+  }
+
+  /** Regression test for https://github.com/google/protobuf/issues/292 */
+  public void testCorrectExceptionThrowWhenEncodingStringsWithoutEnoughSpace() throws Exception {
+    String testCase = "Foooooooo";
+    assertEquals(CodedOutputStream.computeRawVarint32Size(testCase.length()),
+        CodedOutputStream.computeRawVarint32Size(testCase.length() * 3));
+    assertEquals(11, CodedOutputStream.computeStringSize(1, testCase));
+    // Tag is one byte, varint describing string length is 1 byte, string length is 9 bytes.
+    // An array of size 1 will cause a failure when trying to write the varint.
+    for (int i = 0; i < 11; i++) {
+      CodedOutputStream output = CodedOutputStream.newInstance(new byte[i]);
+      try {
+        output.writeString(1, testCase);
+        fail("Should have thrown an out of space exception");
+      } catch (CodedOutputStream.OutOfSpaceException expected) {}
+    }
+  }
+  
+  public void testDifferentStringLengths() throws Exception {
+    // Test string serialization roundtrip using strings of the following lengths,
+    // with ASCII and Unicode characters requiring different UTF-8 byte counts per
+    // char, hence causing the length delimiter varint to sometimes require more
+    // bytes for the Unicode strings than the ASCII string of the same length.
+    int[] lengths = new int[] {
+            0,
+            1,
+            (1 << 4) - 1,  // 1 byte for ASCII and Unicode
+            (1 << 7) - 1,  // 1 byte for ASCII, 2 bytes for Unicode
+            (1 << 11) - 1, // 2 bytes for ASCII and Unicode
+            (1 << 14) - 1, // 2 bytes for ASCII, 3 bytes for Unicode
+            (1 << 17) - 1, // 3 bytes for ASCII and Unicode
+    };
+    for (int i : lengths) {
+      testEncodingOfString('q', i);      // 1 byte per char
+      testEncodingOfString('\u07FF', i); // 2 bytes per char
+      testEncodingOfString('\u0981', i); // 3 bytes per char
+    }
+  }
+
+  private void testEncodingOfString(char c, int length) throws Exception {
+    String fullString = fullString(c, length);
+    TestAllTypes testAllTypes = TestAllTypes.newBuilder()
+        .setOptionalString(fullString)
+        .build();
+    assertEquals(
+        fullString, TestAllTypes.parseFrom(testAllTypes.toByteArray()).getOptionalString());
+  }
+
+  private String fullString(char c, int length) {
+    char[] result = new char[length];
+    Arrays.fill(result, c);
+    return new String(result);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/DeprecatedFieldTest.java b/java/core/src/test/java/com/google/protobuf/DeprecatedFieldTest.java
new file mode 100644
index 00000000..e7905f79
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/DeprecatedFieldTest.java
@@ -0,0 +1,80 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto.TestDeprecatedFields;
+
+import junit.framework.TestCase;
+
+import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Method;
+/**
+ * Test field deprecation
+ * 
+ * @author birdo@google.com (Roberto Scaramuzzi)
+ */
+public class DeprecatedFieldTest extends TestCase {
+  private String[] deprecatedGetterNames = {
+      "hasDeprecatedInt32",
+      "getDeprecatedInt32"};
+  
+  private String[] deprecatedBuilderGetterNames = {
+      "hasDeprecatedInt32",
+      "getDeprecatedInt32",
+      "clearDeprecatedInt32"};
+  
+  private String[] deprecatedBuilderSetterNames = {
+      "setDeprecatedInt32"}; 
+  
+  public void testDeprecatedField() throws Exception {
+    Class<?> deprecatedFields = TestDeprecatedFields.class;
+    Class<?> deprecatedFieldsBuilder = TestDeprecatedFields.Builder.class;
+    for (String name : deprecatedGetterNames) {
+      Method method = deprecatedFields.getMethod(name);
+      assertTrue("Method " + name + " should be deprecated",
+          isDeprecated(method));
+    }
+    for (String name : deprecatedBuilderGetterNames) {
+      Method method = deprecatedFieldsBuilder.getMethod(name);
+      assertTrue("Method " + name + " should be deprecated",
+          isDeprecated(method));
+    }
+    for (String name : deprecatedBuilderSetterNames) {
+      Method method = deprecatedFieldsBuilder.getMethod(name, int.class);
+      assertTrue("Method " + name + " should be deprecated",
+          isDeprecated(method));
+    }
+  }
+  
+  private boolean isDeprecated(AnnotatedElement annotated) {
+    return annotated.isAnnotationPresent(Deprecated.class);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/DescriptorsTest.java b/java/core/src/test/java/com/google/protobuf/DescriptorsTest.java
new file mode 100644
index 00000000..82ff34af
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/DescriptorsTest.java
@@ -0,0 +1,765 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.DescriptorProtos.DescriptorProto;
+import com.google.protobuf.DescriptorProtos.EnumDescriptorProto;
+import com.google.protobuf.DescriptorProtos.EnumValueDescriptorProto;
+import com.google.protobuf.DescriptorProtos.FieldDescriptorProto;
+import com.google.protobuf.DescriptorProtos.FileDescriptorProto;
+import com.google.protobuf.Descriptors.Descriptor;
+import com.google.protobuf.Descriptors.DescriptorValidationException;
+import com.google.protobuf.Descriptors.EnumDescriptor;
+import com.google.protobuf.Descriptors.EnumValueDescriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.Descriptors.MethodDescriptor;
+import com.google.protobuf.Descriptors.OneofDescriptor;
+import com.google.protobuf.Descriptors.ServiceDescriptor;
+import com.google.protobuf.test.UnittestImport;
+import com.google.protobuf.test.UnittestImport.ImportEnum;
+import com.google.protobuf.test.UnittestImport.ImportEnumForMap;
+import protobuf_unittest.TestCustomOptions;
+import protobuf_unittest.UnittestCustomOptions;
+import protobuf_unittest.UnittestProto;
+import protobuf_unittest.UnittestProto.ForeignEnum;
+import protobuf_unittest.UnittestProto.ForeignMessage;
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestExtremeDefaultValues;
+import protobuf_unittest.UnittestProto.TestMultipleExtensionRanges;
+import protobuf_unittest.UnittestProto.TestRequired;
+import protobuf_unittest.UnittestProto.TestReservedFields;
+import protobuf_unittest.UnittestProto.TestService;
+
+import junit.framework.TestCase;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Unit test for {@link Descriptors}.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class DescriptorsTest extends TestCase {
+
+  // Regression test for bug where referencing a FieldDescriptor.Type value
+  // before a FieldDescriptorProto.Type value would yield a
+  // ExceptionInInitializerError.
+  @SuppressWarnings("unused")
+  private static final Object STATIC_INIT_TEST = FieldDescriptor.Type.BOOL;
+
+  public void testFieldTypeEnumMapping() throws Exception {
+    assertEquals(FieldDescriptor.Type.values().length,
+        FieldDescriptorProto.Type.values().length);
+    for (FieldDescriptor.Type type : FieldDescriptor.Type.values()) {
+      FieldDescriptorProto.Type protoType = type.toProto();
+      assertEquals("TYPE_" + type.name(), protoType.name());
+      assertEquals(type, FieldDescriptor.Type.valueOf(protoType));
+    }
+  }
+
+  public void testFileDescriptor() throws Exception {
+    FileDescriptor file = UnittestProto.getDescriptor();
+
+    assertEquals("google/protobuf/unittest.proto", file.getName());
+    assertEquals("protobuf_unittest", file.getPackage());
+
+    assertEquals("UnittestProto", file.getOptions().getJavaOuterClassname());
+    assertEquals("google/protobuf/unittest.proto",
+                 file.toProto().getName());
+
+    assertEquals(Arrays.asList(UnittestImport.getDescriptor()),
+                 file.getDependencies());
+
+    Descriptor messageType = TestAllTypes.getDescriptor();
+    assertEquals(messageType, file.getMessageTypes().get(0));
+    assertEquals(messageType, file.findMessageTypeByName("TestAllTypes"));
+    assertNull(file.findMessageTypeByName("NoSuchType"));
+    assertNull(file.findMessageTypeByName("protobuf_unittest.TestAllTypes"));
+    for (int i = 0; i < file.getMessageTypes().size(); i++) {
+      assertEquals(i, file.getMessageTypes().get(i).getIndex());
+    }
+
+    EnumDescriptor enumType = ForeignEnum.getDescriptor();
+    assertEquals(enumType, file.getEnumTypes().get(0));
+    assertEquals(enumType, file.findEnumTypeByName("ForeignEnum"));
+    assertNull(file.findEnumTypeByName("NoSuchType"));
+    assertNull(file.findEnumTypeByName("protobuf_unittest.ForeignEnum"));
+    assertEquals(Arrays.asList(ImportEnum.getDescriptor(),
+                               ImportEnumForMap.getDescriptor()),
+                 UnittestImport.getDescriptor().getEnumTypes());
+    for (int i = 0; i < file.getEnumTypes().size(); i++) {
+      assertEquals(i, file.getEnumTypes().get(i).getIndex());
+    }
+
+    ServiceDescriptor service = TestService.getDescriptor();
+    assertEquals(service, file.getServices().get(0));
+    assertEquals(service, file.findServiceByName("TestService"));
+    assertNull(file.findServiceByName("NoSuchType"));
+    assertNull(file.findServiceByName("protobuf_unittest.TestService"));
+    assertEquals(Collections.emptyList(),
+                 UnittestImport.getDescriptor().getServices());
+    for (int i = 0; i < file.getServices().size(); i++) {
+      assertEquals(i, file.getServices().get(i).getIndex());
+    }
+
+    FieldDescriptor extension =
+      UnittestProto.optionalInt32Extension.getDescriptor();
+    assertEquals(extension, file.getExtensions().get(0));
+    assertEquals(extension,
+                 file.findExtensionByName("optional_int32_extension"));
+    assertNull(file.findExtensionByName("no_such_ext"));
+    assertNull(file.findExtensionByName(
+      "protobuf_unittest.optional_int32_extension"));
+    assertEquals(Collections.emptyList(),
+                 UnittestImport.getDescriptor().getExtensions());
+    for (int i = 0; i < file.getExtensions().size(); i++) {
+      assertEquals(i, file.getExtensions().get(i).getIndex());
+    }
+  }
+
+  public void testDescriptor() throws Exception {
+    Descriptor messageType = TestAllTypes.getDescriptor();
+    Descriptor nestedType = TestAllTypes.NestedMessage.getDescriptor();
+
+    assertEquals("TestAllTypes", messageType.getName());
+    assertEquals("protobuf_unittest.TestAllTypes", messageType.getFullName());
+    assertEquals(UnittestProto.getDescriptor(), messageType.getFile());
+    assertNull(messageType.getContainingType());
+    assertEquals(DescriptorProtos.MessageOptions.getDefaultInstance(),
+                 messageType.getOptions());
+    assertEquals("TestAllTypes", messageType.toProto().getName());
+
+    assertEquals("NestedMessage", nestedType.getName());
+    assertEquals("protobuf_unittest.TestAllTypes.NestedMessage",
+                 nestedType.getFullName());
+    assertEquals(UnittestProto.getDescriptor(), nestedType.getFile());
+    assertEquals(messageType, nestedType.getContainingType());
+
+    FieldDescriptor field = messageType.getFields().get(0);
+    assertEquals("optional_int32", field.getName());
+    assertEquals(field, messageType.findFieldByName("optional_int32"));
+    assertNull(messageType.findFieldByName("no_such_field"));
+    assertEquals(field, messageType.findFieldByNumber(1));
+    assertNull(messageType.findFieldByNumber(571283));
+    for (int i = 0; i < messageType.getFields().size(); i++) {
+      assertEquals(i, messageType.getFields().get(i).getIndex());
+    }
+
+    assertEquals(nestedType, messageType.getNestedTypes().get(0));
+    assertEquals(nestedType, messageType.findNestedTypeByName("NestedMessage"));
+    assertNull(messageType.findNestedTypeByName("NoSuchType"));
+    for (int i = 0; i < messageType.getNestedTypes().size(); i++) {
+      assertEquals(i, messageType.getNestedTypes().get(i).getIndex());
+    }
+
+    EnumDescriptor enumType = TestAllTypes.NestedEnum.getDescriptor();
+    assertEquals(enumType, messageType.getEnumTypes().get(0));
+    assertEquals(enumType, messageType.findEnumTypeByName("NestedEnum"));
+    assertNull(messageType.findEnumTypeByName("NoSuchType"));
+    for (int i = 0; i < messageType.getEnumTypes().size(); i++) {
+      assertEquals(i, messageType.getEnumTypes().get(i).getIndex());
+    }
+  }
+
+  public void testFieldDescriptor() throws Exception {
+    Descriptor messageType = TestAllTypes.getDescriptor();
+    FieldDescriptor primitiveField =
+      messageType.findFieldByName("optional_int32");
+    FieldDescriptor enumField =
+      messageType.findFieldByName("optional_nested_enum");
+    FieldDescriptor messageField =
+      messageType.findFieldByName("optional_foreign_message");
+    FieldDescriptor cordField =
+      messageType.findFieldByName("optional_cord");
+    FieldDescriptor extension =
+      UnittestProto.optionalInt32Extension.getDescriptor();
+    FieldDescriptor nestedExtension = TestRequired.single.getDescriptor();
+
+    assertEquals("optional_int32", primitiveField.getName());
+    assertEquals("protobuf_unittest.TestAllTypes.optional_int32",
+                 primitiveField.getFullName());
+    assertEquals(1, primitiveField.getNumber());
+    assertEquals(messageType, primitiveField.getContainingType());
+    assertEquals(UnittestProto.getDescriptor(), primitiveField.getFile());
+    assertEquals(FieldDescriptor.Type.INT32, primitiveField.getType());
+    assertEquals(FieldDescriptor.JavaType.INT, primitiveField.getJavaType());
+    assertEquals(DescriptorProtos.FieldOptions.getDefaultInstance(),
+                 primitiveField.getOptions());
+    assertFalse(primitiveField.isExtension());
+    assertEquals("optional_int32", primitiveField.toProto().getName());
+
+    assertEquals("optional_nested_enum", enumField.getName());
+    assertEquals(FieldDescriptor.Type.ENUM, enumField.getType());
+    assertEquals(FieldDescriptor.JavaType.ENUM, enumField.getJavaType());
+    assertEquals(TestAllTypes.NestedEnum.getDescriptor(),
+                 enumField.getEnumType());
+
+    assertEquals("optional_foreign_message", messageField.getName());
+    assertEquals(FieldDescriptor.Type.MESSAGE, messageField.getType());
+    assertEquals(FieldDescriptor.JavaType.MESSAGE, messageField.getJavaType());
+    assertEquals(ForeignMessage.getDescriptor(), messageField.getMessageType());
+
+    assertEquals("optional_cord", cordField.getName());
+    assertEquals(FieldDescriptor.Type.STRING, cordField.getType());
+    assertEquals(FieldDescriptor.JavaType.STRING, cordField.getJavaType());
+    assertEquals(DescriptorProtos.FieldOptions.CType.CORD,
+                 cordField.getOptions().getCtype());
+
+    assertEquals("optional_int32_extension", extension.getName());
+    assertEquals("protobuf_unittest.optional_int32_extension",
+                 extension.getFullName());
+    assertEquals(1, extension.getNumber());
+    assertEquals(TestAllExtensions.getDescriptor(),
+                 extension.getContainingType());
+    assertEquals(UnittestProto.getDescriptor(), extension.getFile());
+    assertEquals(FieldDescriptor.Type.INT32, extension.getType());
+    assertEquals(FieldDescriptor.JavaType.INT, extension.getJavaType());
+    assertEquals(DescriptorProtos.FieldOptions.getDefaultInstance(),
+                 extension.getOptions());
+    assertTrue(extension.isExtension());
+    assertEquals(null, extension.getExtensionScope());
+    assertEquals("optional_int32_extension", extension.toProto().getName());
+
+    assertEquals("single", nestedExtension.getName());
+    assertEquals("protobuf_unittest.TestRequired.single",
+                 nestedExtension.getFullName());
+    assertEquals(TestRequired.getDescriptor(),
+                 nestedExtension.getExtensionScope());
+  }
+
+  public void testFieldDescriptorLabel() throws Exception {
+    FieldDescriptor requiredField =
+      TestRequired.getDescriptor().findFieldByName("a");
+    FieldDescriptor optionalField =
+      TestAllTypes.getDescriptor().findFieldByName("optional_int32");
+    FieldDescriptor repeatedField =
+      TestAllTypes.getDescriptor().findFieldByName("repeated_int32");
+
+    assertTrue(requiredField.isRequired());
+    assertFalse(requiredField.isRepeated());
+    assertFalse(optionalField.isRequired());
+    assertFalse(optionalField.isRepeated());
+    assertFalse(repeatedField.isRequired());
+    assertTrue(repeatedField.isRepeated());
+  }
+  
+  public void testFieldDescriptorJsonName() throws Exception {
+    FieldDescriptor requiredField = TestRequired.getDescriptor().findFieldByName("a");
+    FieldDescriptor optionalField = TestAllTypes.getDescriptor().findFieldByName("optional_int32");
+    FieldDescriptor repeatedField = TestAllTypes.getDescriptor().findFieldByName("repeated_int32");
+    assertEquals("a", requiredField.getJsonName());
+    assertEquals("optionalInt32", optionalField.getJsonName());
+    assertEquals("repeatedInt32", repeatedField.getJsonName());
+  }
+
+  public void testFieldDescriptorDefault() throws Exception {
+    Descriptor d = TestAllTypes.getDescriptor();
+    assertFalse(d.findFieldByName("optional_int32").hasDefaultValue());
+    assertEquals(0, d.findFieldByName("optional_int32").getDefaultValue());
+    assertTrue(d.findFieldByName("default_int32").hasDefaultValue());
+    assertEquals(41, d.findFieldByName("default_int32").getDefaultValue());
+
+    d = TestExtremeDefaultValues.getDescriptor();
+    assertEquals(
+      ByteString.copyFrom(
+        "\0\001\007\b\f\n\r\t\013\\\'\"\u00fe".getBytes(Internal.ISO_8859_1)),
+      d.findFieldByName("escaped_bytes").getDefaultValue());
+    assertEquals(-1, d.findFieldByName("large_uint32").getDefaultValue());
+    assertEquals(-1L, d.findFieldByName("large_uint64").getDefaultValue());
+  }
+
+  public void testEnumDescriptor() throws Exception {
+    EnumDescriptor enumType = ForeignEnum.getDescriptor();
+    EnumDescriptor nestedType = TestAllTypes.NestedEnum.getDescriptor();
+
+    assertEquals("ForeignEnum", enumType.getName());
+    assertEquals("protobuf_unittest.ForeignEnum", enumType.getFullName());
+    assertEquals(UnittestProto.getDescriptor(), enumType.getFile());
+    assertNull(enumType.getContainingType());
+    assertEquals(DescriptorProtos.EnumOptions.getDefaultInstance(),
+                 enumType.getOptions());
+
+    assertEquals("NestedEnum", nestedType.getName());
+    assertEquals("protobuf_unittest.TestAllTypes.NestedEnum",
+                 nestedType.getFullName());
+    assertEquals(UnittestProto.getDescriptor(), nestedType.getFile());
+    assertEquals(TestAllTypes.getDescriptor(), nestedType.getContainingType());
+
+    EnumValueDescriptor value = ForeignEnum.FOREIGN_FOO.getValueDescriptor();
+    assertEquals(value, enumType.getValues().get(0));
+    assertEquals("FOREIGN_FOO", value.getName());
+    assertEquals("FOREIGN_FOO", value.toString());
+    assertEquals(4, value.getNumber());
+    assertEquals(value, enumType.findValueByName("FOREIGN_FOO"));
+    assertEquals(value, enumType.findValueByNumber(4));
+    assertNull(enumType.findValueByName("NO_SUCH_VALUE"));
+    for (int i = 0; i < enumType.getValues().size(); i++) {
+      assertEquals(i, enumType.getValues().get(i).getIndex());
+    }
+  }
+
+  public void testServiceDescriptor() throws Exception {
+    ServiceDescriptor service = TestService.getDescriptor();
+
+    assertEquals("TestService", service.getName());
+    assertEquals("protobuf_unittest.TestService", service.getFullName());
+    assertEquals(UnittestProto.getDescriptor(), service.getFile());
+
+
+    MethodDescriptor fooMethod = service.getMethods().get(0);
+    assertEquals("Foo", fooMethod.getName());
+    assertEquals(UnittestProto.FooRequest.getDescriptor(),
+                 fooMethod.getInputType());
+    assertEquals(UnittestProto.FooResponse.getDescriptor(),
+                 fooMethod.getOutputType());
+    assertEquals(fooMethod, service.findMethodByName("Foo"));
+
+    MethodDescriptor barMethod = service.getMethods().get(1);
+    assertEquals("Bar", barMethod.getName());
+    assertEquals(UnittestProto.BarRequest.getDescriptor(),
+                 barMethod.getInputType());
+    assertEquals(UnittestProto.BarResponse.getDescriptor(),
+                 barMethod.getOutputType());
+    assertEquals(barMethod, service.findMethodByName("Bar"));
+
+    assertNull(service.findMethodByName("NoSuchMethod"));
+
+    for (int i = 0; i < service.getMethods().size(); i++) {
+      assertEquals(i, service.getMethods().get(i).getIndex());
+    }
+  }
+
+
+  public void testCustomOptions() throws Exception {
+    // Get the descriptor indirectly from a dependent proto class. This is to
+    // ensure that when a proto class is loaded, custom options defined in its
+    // dependencies are also properly initialized.
+    Descriptor descriptor =
+        TestCustomOptions.TestMessageWithCustomOptionsContainer.getDescriptor()
+        .findFieldByName("field").getMessageType();
+
+    assertTrue(
+      descriptor.getOptions().hasExtension(UnittestCustomOptions.messageOpt1));
+    assertEquals(Integer.valueOf(-56),
+      descriptor.getOptions().getExtension(UnittestCustomOptions.messageOpt1));
+
+    FieldDescriptor field = descriptor.findFieldByName("field1");
+    assertNotNull(field);
+
+    assertTrue(
+      field.getOptions().hasExtension(UnittestCustomOptions.fieldOpt1));
+    assertEquals(Long.valueOf(8765432109L),
+      field.getOptions().getExtension(UnittestCustomOptions.fieldOpt1));
+
+    EnumDescriptor enumType =
+      UnittestCustomOptions.TestMessageWithCustomOptions.AnEnum.getDescriptor();
+
+    assertTrue(
+      enumType.getOptions().hasExtension(UnittestCustomOptions.enumOpt1));
+    assertEquals(Integer.valueOf(-789),
+      enumType.getOptions().getExtension(UnittestCustomOptions.enumOpt1));
+
+    ServiceDescriptor service =
+      UnittestCustomOptions.TestServiceWithCustomOptions.getDescriptor();
+
+    assertTrue(
+      service.getOptions().hasExtension(UnittestCustomOptions.serviceOpt1));
+    assertEquals(Long.valueOf(-9876543210L),
+      service.getOptions().getExtension(UnittestCustomOptions.serviceOpt1));
+
+    MethodDescriptor method = service.findMethodByName("Foo");
+    assertNotNull(method);
+
+    assertTrue(
+      method.getOptions().hasExtension(UnittestCustomOptions.methodOpt1));
+    assertEquals(UnittestCustomOptions.MethodOpt1.METHODOPT1_VAL2,
+      method.getOptions().getExtension(UnittestCustomOptions.methodOpt1));
+  }
+
+  /**
+   * Test that the FieldDescriptor.Type enum is the same as the
+   * WireFormat.FieldType enum.
+   */
+  public void testFieldTypeTablesMatch() throws Exception {
+    FieldDescriptor.Type[] values1 = FieldDescriptor.Type.values();
+    WireFormat.FieldType[] values2 = WireFormat.FieldType.values();
+
+    assertEquals(values1.length, values2.length);
+
+    for (int i = 0; i < values1.length; i++) {
+      assertEquals(values1[i].toString(), values2[i].toString());
+    }
+  }
+
+  /**
+   * Test that the FieldDescriptor.JavaType enum is the same as the
+   * WireFormat.JavaType enum.
+   */
+  public void testJavaTypeTablesMatch() throws Exception {
+    FieldDescriptor.JavaType[] values1 = FieldDescriptor.JavaType.values();
+    WireFormat.JavaType[] values2 = WireFormat.JavaType.values();
+
+    assertEquals(values1.length, values2.length);
+
+    for (int i = 0; i < values1.length; i++) {
+      assertEquals(values1[i].toString(), values2[i].toString());
+    }
+  }
+
+  public void testEnormousDescriptor() throws Exception {
+    // The descriptor for this file is larger than 64k, yet it did not cause
+    // a compiler error due to an over-long string literal.
+    assertTrue(
+        UnittestEnormousDescriptor.getDescriptor()
+          .toProto().getSerializedSize() > 65536);
+  }
+
+  /**
+   * Tests that the DescriptorValidationException works as intended.
+   */
+  public void testDescriptorValidatorException() throws Exception {
+    FileDescriptorProto fileDescriptorProto = FileDescriptorProto.newBuilder()
+      .setName("foo.proto")
+      .addMessageType(DescriptorProto.newBuilder()
+      .setName("Foo")
+        .addField(FieldDescriptorProto.newBuilder()
+          .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+          .setType(FieldDescriptorProto.Type.TYPE_INT32)
+          .setName("foo")
+          .setNumber(1)
+          .setDefaultValue("invalid")
+          .build())
+        .build())
+      .build();
+    try {
+      Descriptors.FileDescriptor.buildFrom(fileDescriptorProto,
+          new FileDescriptor[0]);
+      fail("DescriptorValidationException expected");
+    } catch (DescriptorValidationException e) {
+      // Expected; check that the error message contains some useful hints
+      assertTrue(e.getMessage().indexOf("foo") != -1);
+      assertTrue(e.getMessage().indexOf("Foo") != -1);
+      assertTrue(e.getMessage().indexOf("invalid") != -1);
+      assertTrue(e.getCause() instanceof NumberFormatException);
+      assertTrue(e.getCause().getMessage().indexOf("invalid") != -1);
+    }
+  }
+
+  /**
+   * Tests the translate/crosslink for an example where a message field's name
+   * and type name are the same.
+   */
+  public void testDescriptorComplexCrosslink() throws Exception {
+    FileDescriptorProto fileDescriptorProto = FileDescriptorProto.newBuilder()
+      .setName("foo.proto")
+      .addMessageType(DescriptorProto.newBuilder()
+        .setName("Foo")
+        .addField(FieldDescriptorProto.newBuilder()
+          .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+          .setType(FieldDescriptorProto.Type.TYPE_INT32)
+          .setName("foo")
+          .setNumber(1)
+          .build())
+        .build())
+      .addMessageType(DescriptorProto.newBuilder()
+        .setName("Bar")
+        .addField(FieldDescriptorProto.newBuilder()
+          .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+          .setTypeName("Foo")
+          .setName("Foo")
+          .setNumber(1)
+          .build())
+        .build())
+      .build();
+    // translate and crosslink
+    FileDescriptor file =
+      Descriptors.FileDescriptor.buildFrom(fileDescriptorProto,
+          new FileDescriptor[0]);
+    // verify resulting descriptors
+    assertNotNull(file);
+    List<Descriptor> msglist = file.getMessageTypes();
+    assertNotNull(msglist);
+    assertTrue(msglist.size() == 2);
+    boolean barFound = false;
+    for (Descriptor desc : msglist) {
+      if (desc.getName().equals("Bar")) {
+        barFound = true;
+        assertNotNull(desc.getFields());
+        List<FieldDescriptor> fieldlist = desc.getFields();
+        assertNotNull(fieldlist);
+        assertTrue(fieldlist.size() == 1);
+        assertTrue(fieldlist.get(0).getType() == FieldDescriptor.Type.MESSAGE);
+        assertTrue(fieldlist.get(0).getMessageType().getName().equals("Foo"));
+      }
+    }
+    assertTrue(barFound);
+  }
+
+  public void testDependencyOrder() throws Exception {
+    FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
+        .setName("foo.proto").build();
+    FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
+        .setName("bar.proto")
+        .addDependency("foo.proto")
+        .build();
+    FileDescriptorProto bazProto = FileDescriptorProto.newBuilder()
+        .setName("baz.proto")
+        .addDependency("foo.proto")
+        .addDependency("bar.proto")
+        .addPublicDependency(0)
+        .addPublicDependency(1)
+        .build();
+    FileDescriptor fooFile = Descriptors.FileDescriptor.buildFrom(fooProto,
+        new FileDescriptor[0]);
+    FileDescriptor barFile = Descriptors.FileDescriptor.buildFrom(barProto,
+        new FileDescriptor[] {fooFile});
+
+    // Items in the FileDescriptor array can be in any order.
+    Descriptors.FileDescriptor.buildFrom(bazProto,
+        new FileDescriptor[] {fooFile, barFile});
+    Descriptors.FileDescriptor.buildFrom(bazProto,
+        new FileDescriptor[] {barFile, fooFile});
+  }
+
+  public void testInvalidPublicDependency() throws Exception {
+    FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
+        .setName("foo.proto").build();
+    FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
+        .setName("boo.proto")
+        .addDependency("foo.proto")
+        .addPublicDependency(1)  // Error, should be 0.
+        .build();
+    FileDescriptor fooFile = Descriptors.FileDescriptor.buildFrom(fooProto,
+        new FileDescriptor[0]);
+    try {
+      Descriptors.FileDescriptor.buildFrom(barProto,
+          new FileDescriptor[] {fooFile});
+      fail("DescriptorValidationException expected");
+    } catch (DescriptorValidationException e) {
+      assertTrue(
+          e.getMessage().indexOf("Invalid public dependency index.") != -1);
+    }
+  }
+
+  public void testHiddenDependency() throws Exception {
+    FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
+        .setName("bar.proto")
+        .addMessageType(DescriptorProto.newBuilder().setName("Bar"))
+        .build();
+    FileDescriptorProto forwardProto = FileDescriptorProto.newBuilder()
+        .setName("forward.proto")
+        .addDependency("bar.proto")
+        .build();
+    FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
+        .setName("foo.proto")
+        .addDependency("forward.proto")
+        .addMessageType(DescriptorProto.newBuilder()
+            .setName("Foo")
+            .addField(FieldDescriptorProto.newBuilder()
+                .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+                .setTypeName("Bar")
+                .setName("bar")
+                .setNumber(1)))
+        .build();
+    FileDescriptor barFile = Descriptors.FileDescriptor.buildFrom(
+        barProto, new FileDescriptor[0]);
+    FileDescriptor forwardFile = Descriptors.FileDescriptor.buildFrom(
+        forwardProto, new FileDescriptor[] {barFile});
+
+    try {
+      Descriptors.FileDescriptor.buildFrom(
+          fooProto, new FileDescriptor[] {forwardFile});
+      fail("DescriptorValidationException expected");
+    } catch (DescriptorValidationException e) {
+      assertTrue(e.getMessage().indexOf("Bar") != -1);
+      assertTrue(e.getMessage().indexOf("is not defined") != -1);
+    }
+  }
+
+  public void testPublicDependency() throws Exception {
+    FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
+        .setName("bar.proto")
+        .addMessageType(DescriptorProto.newBuilder().setName("Bar"))
+        .build();
+    FileDescriptorProto forwardProto = FileDescriptorProto.newBuilder()
+        .setName("forward.proto")
+        .addDependency("bar.proto")
+        .addPublicDependency(0)
+        .build();
+    FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
+        .setName("foo.proto")
+        .addDependency("forward.proto")
+        .addMessageType(DescriptorProto.newBuilder()
+            .setName("Foo")
+            .addField(FieldDescriptorProto.newBuilder()
+                .setLabel(FieldDescriptorProto.Label.LABEL_OPTIONAL)
+                .setTypeName("Bar")
+                .setName("bar")
+                .setNumber(1)))
+        .build();
+    FileDescriptor barFile = Descriptors.FileDescriptor.buildFrom(
+        barProto, new FileDescriptor[0]);
+    FileDescriptor forwardFile = Descriptors.FileDescriptor.buildFrom(
+        forwardProto, new FileDescriptor[]{barFile});
+    Descriptors.FileDescriptor.buildFrom(
+        fooProto, new FileDescriptor[] {forwardFile});
+  }
+
+  /**
+   * Tests the translate/crosslink for an example with a more complex namespace
+   * referencing.
+   */
+  public void testComplexNamespacePublicDependency() throws Exception {
+    FileDescriptorProto fooProto = FileDescriptorProto.newBuilder()
+        .setName("bar.proto")
+        .setPackage("a.b.c.d.bar.shared")
+        .addEnumType(EnumDescriptorProto.newBuilder()
+            .setName("MyEnum")
+            .addValue(EnumValueDescriptorProto.newBuilder()
+                .setName("BLAH")
+                .setNumber(1)))
+        .build();
+    FileDescriptorProto barProto = FileDescriptorProto.newBuilder()
+        .setName("foo.proto")
+        .addDependency("bar.proto")
+        .setPackage("a.b.c.d.foo.shared")
+        .addMessageType(DescriptorProto.newBuilder()
+            .setName("MyMessage")
+            .addField(FieldDescriptorProto.newBuilder()
+                .setLabel(FieldDescriptorProto.Label.LABEL_REPEATED)
+                .setTypeName("bar.shared.MyEnum")
+                .setName("MyField")
+                .setNumber(1)))
+        .build();
+    // translate and crosslink
+    FileDescriptor fooFile = Descriptors.FileDescriptor.buildFrom(
+        fooProto, new FileDescriptor[0]);
+    FileDescriptor barFile = Descriptors.FileDescriptor.buildFrom(
+        barProto, new FileDescriptor[]{fooFile});
+    // verify resulting descriptors
+    assertNotNull(barFile);
+    List<Descriptor> msglist = barFile.getMessageTypes();
+    assertNotNull(msglist);
+    assertTrue(msglist.size() == 1);
+    Descriptor desc = msglist.get(0);
+    if (desc.getName().equals("MyMessage")) {
+      assertNotNull(desc.getFields());
+      List<FieldDescriptor> fieldlist = desc.getFields();
+      assertNotNull(fieldlist);
+      assertTrue(fieldlist.size() == 1);
+      FieldDescriptor field = fieldlist.get(0);
+      assertTrue(field.getType() == FieldDescriptor.Type.ENUM);
+      assertTrue(field.getEnumType().getName().equals("MyEnum"));
+      assertTrue(field.getEnumType().getFile().getName().equals("bar.proto"));
+      assertTrue(field.getEnumType().getFile().getPackage().equals(
+          "a.b.c.d.bar.shared"));
+    }
+  }
+
+  public void testOneofDescriptor() throws Exception {
+    Descriptor messageType = TestAllTypes.getDescriptor();
+    FieldDescriptor field =
+        messageType.findFieldByName("oneof_nested_message");
+    OneofDescriptor oneofDescriptor = field.getContainingOneof();
+    assertNotNull(oneofDescriptor);
+    assertSame(oneofDescriptor, messageType.getOneofs().get(0));
+    assertEquals("oneof_field", oneofDescriptor.getName());
+
+    assertEquals(4, oneofDescriptor.getFieldCount());
+    assertSame(oneofDescriptor.getField(1), field);
+
+    assertEquals(4, oneofDescriptor.getFields().size());
+    assertEquals(oneofDescriptor.getFields().get(1), field);
+  }
+
+  public void testMessageDescriptorExtensions() throws Exception {
+    assertFalse(TestAllTypes.getDescriptor().isExtendable());
+    assertTrue(TestAllExtensions.getDescriptor().isExtendable());
+    assertTrue(TestMultipleExtensionRanges.getDescriptor().isExtendable());
+
+    assertFalse(TestAllTypes.getDescriptor().isExtensionNumber(3));
+    assertTrue(TestAllExtensions.getDescriptor().isExtensionNumber(3));
+    assertTrue(TestMultipleExtensionRanges.getDescriptor().isExtensionNumber(42));
+    assertFalse(TestMultipleExtensionRanges.getDescriptor().isExtensionNumber(43));
+    assertFalse(TestMultipleExtensionRanges.getDescriptor().isExtensionNumber(4142));
+    assertTrue(TestMultipleExtensionRanges.getDescriptor().isExtensionNumber(4143));
+  }
+
+  public void testReservedFields() {
+    Descriptor d = TestReservedFields.getDescriptor();
+    assertTrue(d.isReservedNumber(2));
+    assertFalse(d.isReservedNumber(8));
+    assertTrue(d.isReservedNumber(9));
+    assertTrue(d.isReservedNumber(10));
+    assertTrue(d.isReservedNumber(11));
+    assertFalse(d.isReservedNumber(12));
+    assertFalse(d.isReservedName("foo"));
+    assertTrue(d.isReservedName("bar"));
+    assertTrue(d.isReservedName("baz"));
+  }
+
+  public void testToString() {
+    assertEquals("protobuf_unittest.TestAllTypes.optional_uint64",
+        UnittestProto.TestAllTypes.getDescriptor().findFieldByNumber(
+            UnittestProto.TestAllTypes.OPTIONAL_UINT64_FIELD_NUMBER).toString());
+  }
+
+  public void testPackedEnumField() throws Exception {
+    FileDescriptorProto fileDescriptorProto = FileDescriptorProto.newBuilder()
+        .setName("foo.proto")
+        .addEnumType(EnumDescriptorProto.newBuilder()
+          .setName("Enum")
+          .addValue(EnumValueDescriptorProto.newBuilder()
+            .setName("FOO")
+            .setNumber(1)
+            .build())
+          .build())
+        .addMessageType(DescriptorProto.newBuilder()
+          .setName("Message")
+          .addField(FieldDescriptorProto.newBuilder()
+            .setName("foo")
+            .setTypeName("Enum")
+            .setNumber(1)
+            .setLabel(FieldDescriptorProto.Label.LABEL_REPEATED)
+            .setOptions(DescriptorProtos.FieldOptions.newBuilder()
+              .setPacked(true)
+              .build())
+            .build())
+          .build())
+        .build();
+    Descriptors.FileDescriptor.buildFrom(
+        fileDescriptorProto, new FileDescriptor[0]);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java b/java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java
new file mode 100644
index 00000000..d3deaa07
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java
@@ -0,0 +1,473 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.util.Arrays.asList;
+
+import junit.framework.TestCase;
+
+import java.util.Collections;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+
+/**
+ * Tests for {@link DoubleArrayList}.
+ * 
+ * @author dweis@google.com (Daniel Weis)
+ */
+public class DoubleArrayListTest extends TestCase {
+  
+  private static final DoubleArrayList UNARY_LIST = newImmutableDoubleArrayList(1);
+  private static final DoubleArrayList TERTIARY_LIST =
+      newImmutableDoubleArrayList(1, 2, 3);
+  
+  private DoubleArrayList list;
+  
+  @Override
+  protected void setUp() throws Exception {
+    list = new DoubleArrayList();
+  }
+  
+  public void testEmptyListReturnsSameInstance() {
+    assertSame(DoubleArrayList.emptyList(), DoubleArrayList.emptyList());
+  }
+  
+  public void testEmptyListIsImmutable() {
+    assertImmutable(DoubleArrayList.emptyList());
+  }
+  
+  public void testMakeImmutable() {
+    list.addDouble(2);
+    list.addDouble(4);
+    list.addDouble(6);
+    list.addDouble(8);
+    list.makeImmutable();
+    assertImmutable(list);
+  }
+  
+  public void testCopyConstructor() {
+    DoubleArrayList copy = new DoubleArrayList(TERTIARY_LIST);
+    assertEquals(TERTIARY_LIST, copy);
+
+    copy = new DoubleArrayList(DoubleArrayList.emptyList());
+    assertEquals(DoubleArrayList.emptyList(), copy);
+    
+    copy = new DoubleArrayList(asList(1D, 2D, 3D));
+    assertEquals(asList(1D, 2D, 3D), copy);
+
+    copy = new DoubleArrayList(Collections.<Double>emptyList());
+    assertEquals(DoubleArrayList.emptyList(), copy);
+  }
+  
+  public void testModificationWithIteration() {
+    list.addAll(asList(1D, 2D, 3D, 4D));
+    Iterator<Double> iterator = list.iterator();
+    assertEquals(4, list.size());
+    assertEquals(1D, (double) list.get(0));
+    assertEquals(1D, (double) iterator.next());
+    list.set(0, 1D);
+    assertEquals(2D, (double) iterator.next());
+    
+    list.remove(0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+    
+    iterator = list.iterator();
+    list.add(0, 0D);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+  }
+  
+  public void testGet() {
+    assertEquals(1D, (double) TERTIARY_LIST.get(0));
+    assertEquals(2D, (double) TERTIARY_LIST.get(1));
+    assertEquals(3D, (double) TERTIARY_LIST.get(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testGetInt() {
+    assertEquals(1D, TERTIARY_LIST.getDouble(0));
+    assertEquals(2D, TERTIARY_LIST.getDouble(1));
+    assertEquals(3D, TERTIARY_LIST.getDouble(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSize() {
+    assertEquals(0, DoubleArrayList.emptyList().size());
+    assertEquals(1, UNARY_LIST.size());
+    assertEquals(3, TERTIARY_LIST.size());
+
+    list.addDouble(2);
+    list.addDouble(4);
+    list.addDouble(6);
+    list.addDouble(8);
+    assertEquals(4, list.size());
+    
+    list.remove(0);
+    assertEquals(3, list.size());
+    
+    list.add(16D);
+    assertEquals(4, list.size());
+  }
+  
+  public void testSet() {
+    list.addDouble(2);
+    list.addDouble(4);
+    
+    assertEquals(2D, (double) list.set(0, 0D));
+    assertEquals(0D, list.getDouble(0));
+
+    assertEquals(4D, (double) list.set(1, 0D));
+    assertEquals(0D, list.getDouble(1));
+    
+    try {
+      list.set(-1, 0D);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.set(2, 0D);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSetInt() {
+    list.addDouble(2);
+    list.addDouble(4);
+    
+    assertEquals(2D, list.setDouble(0, 0));
+    assertEquals(0D, list.getDouble(0));
+
+    assertEquals(4D, list.setDouble(1, 0));
+    assertEquals(0D, list.getDouble(1));
+    
+    try {
+      list.setDouble(-1, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.setDouble(2, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAdd() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.add(2D));
+    assertEquals(asList(2D), list);
+
+    assertTrue(list.add(3D));
+    list.add(0, 4D);
+    assertEquals(asList(4D, 2D, 3D), list);
+    
+    list.add(0, 1D);
+    list.add(0, 0D);
+    // Force a resize by getting up to 11 elements.
+    for (int i = 0; i < 6; i++) {
+      list.add(Double.valueOf(5 + i));
+    }
+    assertEquals(asList(0D, 1D, 4D, 2D, 3D, 5D, 6D, 7D, 8D, 9D, 10D), list);
+    
+    try {
+      list.add(-1, 5D);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.add(4, 5D);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAddInt() {
+    assertEquals(0, list.size());
+
+    list.addDouble(2);
+    assertEquals(asList(2D), list);
+
+    list.addDouble(3);
+    assertEquals(asList(2D, 3D), list);
+  }
+  
+  public void testAddAll() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.addAll(Collections.singleton(1D)));
+    assertEquals(1, list.size());
+    assertEquals(1D, (double) list.get(0));
+    assertEquals(1D, list.getDouble(0));
+    
+    assertTrue(list.addAll(asList(2D, 3D, 4D, 5D, 6D)));
+    assertEquals(asList(1D, 2D, 3D, 4D, 5D, 6D), list);
+    
+    assertTrue(list.addAll(TERTIARY_LIST));
+    assertEquals(asList(1D, 2D, 3D, 4D, 5D, 6D, 1D, 2D, 3D), list);
+
+    assertFalse(list.addAll(Collections.<Double>emptyList()));
+    assertFalse(list.addAll(DoubleArrayList.emptyList()));
+  }
+  
+  public void testRemove() {
+    list.addAll(TERTIARY_LIST);
+    assertEquals(1D, (double) list.remove(0));
+    assertEquals(asList(2D, 3D), list);
+
+    assertTrue(list.remove(Double.valueOf(3)));
+    assertEquals(asList(2D), list);
+
+    assertFalse(list.remove(Double.valueOf(3)));
+    assertEquals(asList(2D), list);
+
+    assertEquals(2D, (double) list.remove(0));
+    assertEquals(asList(), list);
+    
+    try {
+      list.remove(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(0);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  private void assertImmutable(DoubleArrayList list) {
+    if (list.contains(1D)) {
+      throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
+    }
+    
+    try {
+      list.add(1D);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.add(0, 1D);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.<Double>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.singletonList(1D));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(new DoubleArrayList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.singleton(1D));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.<Double>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addDouble(0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.clear();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+
+    try {
+      list.remove(1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.<Double>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.singleton(1D));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+
+    try {
+      list.retainAll(Collections.<Double>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.singleton(1D));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, 0D);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.setDouble(0, 0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+  }
+  
+  private static DoubleArrayList newImmutableDoubleArrayList(double... elements) {
+    DoubleArrayList list = new DoubleArrayList();
+    for (double element : elements) {
+      list.addDouble(element);
+    }
+    list.makeImmutable();
+    return list;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java b/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java
new file mode 100644
index 00000000..55144e7c
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java
@@ -0,0 +1,326 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.EnumDescriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.Descriptors.OneofDescriptor;
+
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestEmptyMessage;
+import protobuf_unittest.UnittestProto.TestPackedTypes;
+
+import junit.framework.TestCase;
+import java.util.Arrays;
+
+/**
+ * Unit test for {@link DynamicMessage}.  See also {@link MessageTest}, which
+ * tests some {@link DynamicMessage} functionality.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class DynamicMessageTest extends TestCase {
+  TestUtil.ReflectionTester reflectionTester =
+    new TestUtil.ReflectionTester(TestAllTypes.getDescriptor(), null);
+
+  TestUtil.ReflectionTester extensionsReflectionTester =
+    new TestUtil.ReflectionTester(TestAllExtensions.getDescriptor(),
+                                  TestUtil.getExtensionRegistry());
+  TestUtil.ReflectionTester packedReflectionTester =
+    new TestUtil.ReflectionTester(TestPackedTypes.getDescriptor(), null);
+
+  public void testDynamicMessageAccessors() throws Exception {
+    Message.Builder builder =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    reflectionTester.setAllFieldsViaReflection(builder);
+    Message message = builder.build();
+    reflectionTester.assertAllFieldsSetViaReflection(message);
+  }
+
+  public void testSettersAfterBuild() throws Exception {
+    Message.Builder builder =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    Message firstMessage = builder.build();
+    // double build()
+    builder.build();
+    // clear() after build()
+    builder.clear();
+    // setters after build()
+    reflectionTester.setAllFieldsViaReflection(builder);
+    Message message = builder.build();
+    reflectionTester.assertAllFieldsSetViaReflection(message);
+    // repeated setters after build()
+    reflectionTester.modifyRepeatedFieldsViaReflection(builder);
+    message = builder.build();
+    reflectionTester.assertRepeatedFieldsModifiedViaReflection(message);
+    // firstMessage shouldn't have been modified.
+    reflectionTester.assertClearViaReflection(firstMessage);
+  }
+
+  public void testUnknownFields() throws Exception {
+    Message.Builder builder =
+        DynamicMessage.newBuilder(TestEmptyMessage.getDescriptor());
+    builder.setUnknownFields(UnknownFieldSet.newBuilder()
+        .addField(1, UnknownFieldSet.Field.newBuilder().addVarint(1).build())
+        .addField(2, UnknownFieldSet.Field.newBuilder().addFixed32(1).build())
+        .build());
+    Message message = builder.build();
+    assertEquals(2, message.getUnknownFields().asMap().size());
+    // clone() with unknown fields
+    Message.Builder newBuilder = builder.clone();
+    assertEquals(2, newBuilder.getUnknownFields().asMap().size());
+    // clear() with unknown fields
+    newBuilder.clear();
+    assertTrue(newBuilder.getUnknownFields().asMap().isEmpty());
+    // serialize/parse with unknown fields
+    newBuilder.mergeFrom(message.toByteString());
+    assertEquals(2, newBuilder.getUnknownFields().asMap().size());
+  }
+
+  public void testDynamicMessageSettersRejectNull() throws Exception {
+    Message.Builder builder =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    reflectionTester.assertReflectionSettersRejectNull(builder);
+  }
+
+  public void testDynamicMessageExtensionAccessors() throws Exception {
+    // We don't need to extensively test DynamicMessage's handling of
+    // extensions because, frankly, it doesn't do anything special with them.
+    // It treats them just like any other fields.
+    Message.Builder builder =
+      DynamicMessage.newBuilder(TestAllExtensions.getDescriptor());
+    extensionsReflectionTester.setAllFieldsViaReflection(builder);
+    Message message = builder.build();
+    extensionsReflectionTester.assertAllFieldsSetViaReflection(message);
+  }
+
+  public void testDynamicMessageExtensionSettersRejectNull() throws Exception {
+    Message.Builder builder =
+      DynamicMessage.newBuilder(TestAllExtensions.getDescriptor());
+    extensionsReflectionTester.assertReflectionSettersRejectNull(builder);
+  }
+
+  public void testDynamicMessageRepeatedSetters() throws Exception {
+    Message.Builder builder =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    reflectionTester.setAllFieldsViaReflection(builder);
+    reflectionTester.modifyRepeatedFieldsViaReflection(builder);
+    Message message = builder.build();
+    reflectionTester.assertRepeatedFieldsModifiedViaReflection(message);
+  }
+
+  public void testDynamicMessageRepeatedSettersRejectNull() throws Exception {
+    Message.Builder builder =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    reflectionTester.assertReflectionRepeatedSettersRejectNull(builder);
+  }
+
+  public void testDynamicMessageDefaults() throws Exception {
+    reflectionTester.assertClearViaReflection(
+      DynamicMessage.getDefaultInstance(TestAllTypes.getDescriptor()));
+    reflectionTester.assertClearViaReflection(
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor()).build());
+  }
+
+  public void testDynamicMessageSerializedSize() throws Exception {
+    TestAllTypes message = TestUtil.getAllSet();
+
+    Message.Builder dynamicBuilder =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    reflectionTester.setAllFieldsViaReflection(dynamicBuilder);
+    Message dynamicMessage = dynamicBuilder.build();
+
+    assertEquals(message.getSerializedSize(),
+                 dynamicMessage.getSerializedSize());
+  }
+
+  public void testDynamicMessageSerialization() throws Exception {
+    Message.Builder builder =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    reflectionTester.setAllFieldsViaReflection(builder);
+    Message message = builder.build();
+
+    ByteString rawBytes = message.toByteString();
+    TestAllTypes message2 = TestAllTypes.parseFrom(rawBytes);
+
+    TestUtil.assertAllFieldsSet(message2);
+
+    // In fact, the serialized forms should be exactly the same, byte-for-byte.
+    assertEquals(TestUtil.getAllSet().toByteString(), rawBytes);
+  }
+
+  public void testDynamicMessageParsing() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestAllTypes message = builder.build();
+
+    ByteString rawBytes = message.toByteString();
+
+    Message message2 =
+      DynamicMessage.parseFrom(TestAllTypes.getDescriptor(), rawBytes);
+    reflectionTester.assertAllFieldsSetViaReflection(message2);
+
+    // Test Parser interface.
+    Message message3 = message2.getParserForType().parseFrom(rawBytes);
+    reflectionTester.assertAllFieldsSetViaReflection(message3);
+  }
+
+  public void testDynamicMessageExtensionParsing() throws Exception {
+    ByteString rawBytes = TestUtil.getAllExtensionsSet().toByteString();
+    Message message = DynamicMessage.parseFrom(
+        TestAllExtensions.getDescriptor(), rawBytes,
+        TestUtil.getExtensionRegistry());
+    extensionsReflectionTester.assertAllFieldsSetViaReflection(message);
+
+    // Test Parser interface.
+    Message message2 = message.getParserForType().parseFrom(
+        rawBytes, TestUtil.getExtensionRegistry());
+    extensionsReflectionTester.assertAllFieldsSetViaReflection(message2);
+  }
+
+  public void testDynamicMessagePackedSerialization() throws Exception {
+    Message.Builder builder =
+        DynamicMessage.newBuilder(TestPackedTypes.getDescriptor());
+    packedReflectionTester.setPackedFieldsViaReflection(builder);
+    Message message = builder.build();
+
+    ByteString rawBytes = message.toByteString();
+    TestPackedTypes message2 = TestPackedTypes.parseFrom(rawBytes);
+
+    TestUtil.assertPackedFieldsSet(message2);
+
+    // In fact, the serialized forms should be exactly the same, byte-for-byte.
+    assertEquals(TestUtil.getPackedSet().toByteString(), rawBytes);
+  }
+
+  public void testDynamicMessagePackedParsing() throws Exception {
+    TestPackedTypes.Builder builder = TestPackedTypes.newBuilder();
+    TestUtil.setPackedFields(builder);
+    TestPackedTypes message = builder.build();
+
+    ByteString rawBytes = message.toByteString();
+
+    Message message2 =
+      DynamicMessage.parseFrom(TestPackedTypes.getDescriptor(), rawBytes);
+    packedReflectionTester.assertPackedFieldsSetViaReflection(message2);
+
+    // Test Parser interface.
+    Message message3 = message2.getParserForType().parseFrom(rawBytes);
+    packedReflectionTester.assertPackedFieldsSetViaReflection(message3);
+  }
+
+  public void testDynamicMessageCopy() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestAllTypes message = builder.build();
+
+    DynamicMessage copy = DynamicMessage.newBuilder(message).build();
+    reflectionTester.assertAllFieldsSetViaReflection(copy);
+
+    // Test oneof behavior
+    FieldDescriptor bytesField =
+        TestAllTypes.getDescriptor().findFieldByName("oneof_bytes");
+    FieldDescriptor uint32Field =
+        TestAllTypes.getDescriptor().findFieldByName("oneof_uint32");
+    assertTrue(copy.hasField(bytesField));
+    assertFalse(copy.hasField(uint32Field));
+    DynamicMessage copy2 =
+        DynamicMessage.newBuilder(message).setField(uint32Field, 123).build();
+    assertFalse(copy2.hasField(bytesField));
+    assertTrue(copy2.hasField(uint32Field));
+    assertEquals(123, copy2.getField(uint32Field));
+  }
+
+  public void testToBuilder() throws Exception {
+    DynamicMessage.Builder builder =
+        DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    reflectionTester.setAllFieldsViaReflection(builder);
+    int unknownFieldNum = 9;
+    long unknownFieldVal = 90;
+    builder.setUnknownFields(UnknownFieldSet.newBuilder()
+        .addField(unknownFieldNum,
+            UnknownFieldSet.Field.newBuilder()
+                .addVarint(unknownFieldVal).build())
+        .build());
+    DynamicMessage message = builder.build();
+
+    DynamicMessage derived = message.toBuilder().build();
+    reflectionTester.assertAllFieldsSetViaReflection(derived);
+    assertEquals(Arrays.asList(unknownFieldVal),
+        derived.getUnknownFields().getField(unknownFieldNum).getVarintList());
+  }
+
+  public void testDynamicOneofMessage() throws Exception {
+    DynamicMessage.Builder builder =
+        DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    OneofDescriptor oneof = TestAllTypes.getDescriptor().getOneofs().get(0);
+    assertFalse(builder.hasOneof(oneof));
+    assertSame(null, builder.getOneofFieldDescriptor(oneof));
+
+    reflectionTester.setAllFieldsViaReflection(builder);
+    assertTrue(builder.hasOneof(oneof));
+    FieldDescriptor field = oneof.getField(3);
+    assertSame(field, builder.getOneofFieldDescriptor(oneof));
+
+    DynamicMessage message = builder.buildPartial();
+    assertTrue(message.hasOneof(oneof));
+
+    DynamicMessage.Builder mergedBuilder =
+        DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    FieldDescriptor mergedField = oneof.getField(0);
+    mergedBuilder.setField(mergedField, 123);
+    assertTrue(mergedBuilder.hasField(mergedField));
+    mergedBuilder.mergeFrom(message);
+    assertTrue(mergedBuilder.hasField(field));
+    assertFalse(mergedBuilder.hasField(mergedField));
+
+    builder.clearOneof(oneof);
+    assertSame(null, builder.getOneofFieldDescriptor(oneof));
+    message = builder.build();
+    assertSame(null, message.getOneofFieldDescriptor(oneof));
+  }
+
+  // Regression test for a bug that makes setField() not work for repeated
+  // enum fields.
+  public void testSettersForRepeatedEnumField() throws Exception {
+    DynamicMessage.Builder builder =
+        DynamicMessage.newBuilder(TestAllTypes.getDescriptor());
+    FieldDescriptor repeatedEnumField =
+        TestAllTypes.getDescriptor().findFieldByName(
+            "repeated_nested_enum");
+    EnumDescriptor enumDescriptor = TestAllTypes.NestedEnum.getDescriptor();
+    builder.setField(repeatedEnumField, enumDescriptor.getValues());
+    DynamicMessage message = builder.build();
+    assertEquals(
+        enumDescriptor.getValues(), message.getField(repeatedEnumField));
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
new file mode 100644
index 00000000..eaeec0b8
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
@@ -0,0 +1,373 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.Descriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.FieldPresenceTestProto.TestAllTypes;
+import com.google.protobuf.FieldPresenceTestProto.TestOptionalFieldsOnly;
+import com.google.protobuf.FieldPresenceTestProto.TestRepeatedFieldsOnly;
+import protobuf_unittest.UnittestProto;
+
+import junit.framework.TestCase;
+
+/**
+ * Unit tests for protos that doesn't support field presence test for optional
+ * non-message fields.
+ */
+public class FieldPresenceTest extends TestCase {
+  private static boolean hasMethod(Class clazz, String name) {
+    try {
+      if (clazz.getMethod(name, new Class[]{}) != null) {
+        return true;
+      } else {
+        return false;
+      }
+    } catch (NoSuchMethodException e) {
+      return false;
+    }
+  }
+
+  private static boolean isHasMethodRemoved(
+      Class classWithFieldPresence,
+      Class classWithoutFieldPresence,
+      String camelName) {
+    return hasMethod(classWithFieldPresence, "get" + camelName)
+        && hasMethod(classWithFieldPresence, "has" + camelName)
+        && hasMethod(classWithoutFieldPresence, "get" + camelName)
+        && !hasMethod(classWithoutFieldPresence, "has" + camelName);
+  }
+
+  public void testHasMethod() {
+    // Optional non-message fields don't have a hasFoo() method generated.
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.class,
+        TestAllTypes.class,
+        "OptionalInt32"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.class,
+        TestAllTypes.class,
+        "OptionalString"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.class,
+        TestAllTypes.class,
+        "OptionalBytes"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.class,
+        TestAllTypes.class,
+        "OptionalNestedEnum"));
+
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.Builder.class,
+        TestAllTypes.Builder.class,
+        "OptionalInt32"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.Builder.class,
+        TestAllTypes.Builder.class,
+        "OptionalString"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.Builder.class,
+        TestAllTypes.Builder.class,
+        "OptionalBytes"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.Builder.class,
+        TestAllTypes.Builder.class,
+        "OptionalNestedEnum"));
+
+    // message fields still have the hasFoo() method generated.
+    assertFalse(TestAllTypes.newBuilder().build().hasOptionalNestedMessage());
+    assertFalse(TestAllTypes.newBuilder().hasOptionalNestedMessage());
+
+    // oneof fields don't have hasFoo() methods (even for message types).
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.class,
+        TestAllTypes.class,
+        "OneofUint32"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.class,
+        TestAllTypes.class,
+        "OneofString"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.class,
+        TestAllTypes.class,
+        "OneofBytes"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.class,
+        TestAllTypes.class,
+        "OneofNestedMessage"));
+
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.Builder.class,
+        TestAllTypes.Builder.class,
+        "OneofUint32"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.Builder.class,
+        TestAllTypes.Builder.class,
+        "OneofString"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.Builder.class,
+        TestAllTypes.Builder.class,
+        "OneofBytes"));
+    assertTrue(isHasMethodRemoved(
+        UnittestProto.TestAllTypes.Builder.class,
+        TestAllTypes.Builder.class,
+        "OneofNestedMessage"));
+  }
+
+  public void testOneofEquals() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestAllTypes message1 = builder.build();
+    // Set message2's oneof_uint32 field to defalut value. The two
+    // messages should be different when check with oneof case.
+    builder.setOneofUint32(0);
+    TestAllTypes message2 = builder.build();
+    assertFalse(message1.equals(message2));
+  }
+
+  public void testFieldPresence() {
+    // Optional non-message fields set to their default value are treated the
+    // same way as not set.
+
+    // Serialization will ignore such fields.
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.setOptionalInt32(0);
+    builder.setOptionalString("");
+    builder.setOptionalBytes(ByteString.EMPTY);
+    builder.setOptionalNestedEnum(TestAllTypes.NestedEnum.FOO);
+    TestAllTypes message = builder.build();
+    assertEquals(0, message.getSerializedSize());
+
+    // mergeFrom() will ignore such fields.
+    TestAllTypes.Builder a = TestAllTypes.newBuilder();
+    a.setOptionalInt32(1);
+    a.setOptionalString("x");
+    a.setOptionalBytes(ByteString.copyFromUtf8("y"));
+    a.setOptionalNestedEnum(TestAllTypes.NestedEnum.BAR);
+    TestAllTypes.Builder b = TestAllTypes.newBuilder();
+    b.setOptionalInt32(0);
+    b.setOptionalString("");
+    b.setOptionalBytes(ByteString.EMPTY);
+    b.setOptionalNestedEnum(TestAllTypes.NestedEnum.FOO);
+    a.mergeFrom(b.build());
+    message = a.build();
+    assertEquals(1, message.getOptionalInt32());
+    assertEquals("x", message.getOptionalString());
+    assertEquals(ByteString.copyFromUtf8("y"), message.getOptionalBytes());
+    assertEquals(TestAllTypes.NestedEnum.BAR, message.getOptionalNestedEnum());
+
+    // equals()/hashCode() should produce the same results.
+    TestAllTypes empty = TestAllTypes.newBuilder().build();
+    message = builder.build();
+    assertTrue(empty.equals(message));
+    assertTrue(message.equals(empty));
+    assertEquals(empty.hashCode(), message.hashCode());
+  }
+
+  public void testFieldPresenceByReflection() {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+    FieldDescriptor optionalInt32Field = descriptor.findFieldByName("optional_int32");
+    FieldDescriptor optionalStringField = descriptor.findFieldByName("optional_string");
+    FieldDescriptor optionalBytesField = descriptor.findFieldByName("optional_bytes");
+    FieldDescriptor optionalNestedEnumField = descriptor.findFieldByName("optional_nested_enum");
+
+    // Field not present.
+    TestAllTypes message = TestAllTypes.newBuilder().build();
+    assertFalse(message.hasField(optionalInt32Field));
+    assertFalse(message.hasField(optionalStringField));
+    assertFalse(message.hasField(optionalBytesField));
+    assertFalse(message.hasField(optionalNestedEnumField));
+    assertEquals(0, message.getAllFields().size());
+
+    // Field set to default value is seen as not present.
+    message = TestAllTypes.newBuilder()
+        .setOptionalInt32(0)
+        .setOptionalString("")
+        .setOptionalBytes(ByteString.EMPTY)
+        .setOptionalNestedEnum(TestAllTypes.NestedEnum.FOO)
+        .build();
+    assertFalse(message.hasField(optionalInt32Field));
+    assertFalse(message.hasField(optionalStringField));
+    assertFalse(message.hasField(optionalBytesField));
+    assertFalse(message.hasField(optionalNestedEnumField));
+    assertEquals(0, message.getAllFields().size());
+
+    // Field set to non-default value is seen as present.
+    message = TestAllTypes.newBuilder()
+        .setOptionalInt32(1)
+        .setOptionalString("x")
+        .setOptionalBytes(ByteString.copyFromUtf8("y"))
+        .setOptionalNestedEnum(TestAllTypes.NestedEnum.BAR)
+        .build();
+    assertTrue(message.hasField(optionalInt32Field));
+    assertTrue(message.hasField(optionalStringField));
+    assertTrue(message.hasField(optionalBytesField));
+    assertTrue(message.hasField(optionalNestedEnumField));
+    assertEquals(4, message.getAllFields().size());
+  }
+  
+  public void testMessageField() {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    assertFalse(builder.hasOptionalNestedMessage());
+    assertFalse(builder.build().hasOptionalNestedMessage());
+    
+    TestAllTypes.NestedMessage.Builder nestedBuilder =
+        builder.getOptionalNestedMessageBuilder();
+    assertTrue(builder.hasOptionalNestedMessage());
+    assertTrue(builder.build().hasOptionalNestedMessage());
+    
+    nestedBuilder.setValue(1);
+    assertEquals(1, builder.build().getOptionalNestedMessage().getValue());
+    
+    builder.clearOptionalNestedMessage();
+    assertFalse(builder.hasOptionalNestedMessage());
+    assertFalse(builder.build().hasOptionalNestedMessage());
+    
+    // Unlike non-message fields, if we set a message field to its default value (i.e.,
+    // default instance), the field should be seen as present.
+    builder.setOptionalNestedMessage(TestAllTypes.NestedMessage.getDefaultInstance());
+    assertTrue(builder.hasOptionalNestedMessage());
+    assertTrue(builder.build().hasOptionalNestedMessage());
+  }
+
+  public void testSerializeAndParse() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.setOptionalInt32(1234);
+    builder.setOptionalString("hello");
+    builder.setOptionalNestedMessage(TestAllTypes.NestedMessage.getDefaultInstance());
+    // Set an oneof field to its default value and expect it to be serialized (i.e.,
+    // an oneof field set to the default value should be treated as present).
+    builder.setOneofInt32(0);
+    ByteString data = builder.build().toByteString();
+
+    TestAllTypes message = TestAllTypes.parseFrom(data);
+    assertEquals(1234, message.getOptionalInt32());
+    assertEquals("hello", message.getOptionalString());
+    // Fields not set will have the default value.
+    assertEquals(ByteString.EMPTY, message.getOptionalBytes());
+    assertEquals(TestAllTypes.NestedEnum.FOO, message.getOptionalNestedEnum());
+    // The message field is set despite that it's set with a default instance.
+    assertTrue(message.hasOptionalNestedMessage());
+    assertEquals(0, message.getOptionalNestedMessage().getValue());
+    // The oneof field set to its default value is also present.
+    assertEquals(
+        TestAllTypes.OneofFieldCase.ONEOF_INT32, message.getOneofFieldCase());
+  }
+
+  // Regression test for b/16173397
+  // Make sure we haven't screwed up the code generation for repeated fields.
+  public void testRepeatedFields() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.setOptionalInt32(1234);
+    builder.setOptionalString("hello");
+    builder.setOptionalNestedMessage(TestAllTypes.NestedMessage.getDefaultInstance());
+    builder.addRepeatedInt32(4321);
+    builder.addRepeatedString("world");
+    builder.addRepeatedNestedMessage(TestAllTypes.NestedMessage.getDefaultInstance());
+    ByteString data = builder.build().toByteString();
+
+    TestOptionalFieldsOnly optionalOnlyMessage = TestOptionalFieldsOnly.parseFrom(data);
+    assertEquals(1234, optionalOnlyMessage.getOptionalInt32());
+    assertEquals("hello", optionalOnlyMessage.getOptionalString());
+    assertTrue(optionalOnlyMessage.hasOptionalNestedMessage());
+    assertEquals(0, optionalOnlyMessage.getOptionalNestedMessage().getValue());
+
+    TestRepeatedFieldsOnly repeatedOnlyMessage = TestRepeatedFieldsOnly.parseFrom(data);
+    assertEquals(1, repeatedOnlyMessage.getRepeatedInt32Count());
+    assertEquals(4321, repeatedOnlyMessage.getRepeatedInt32(0));
+    assertEquals(1, repeatedOnlyMessage.getRepeatedStringCount());
+    assertEquals("world", repeatedOnlyMessage.getRepeatedString(0));
+    assertEquals(1, repeatedOnlyMessage.getRepeatedNestedMessageCount());
+    assertEquals(0, repeatedOnlyMessage.getRepeatedNestedMessage(0).getValue());
+  }
+
+  public void testIsInitialized() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+
+    // Test optional proto2 message fields.
+    UnittestProto.TestRequired.Builder proto2Builder =
+        builder.getOptionalProto2MessageBuilder();
+    assertFalse(builder.isInitialized());
+    assertFalse(builder.buildPartial().isInitialized());
+
+    proto2Builder.setA(1).setB(2).setC(3);
+    assertTrue(builder.isInitialized());
+    assertTrue(builder.buildPartial().isInitialized());
+
+    // Test oneof proto2 message fields.
+    proto2Builder = builder.getOneofProto2MessageBuilder();
+    assertFalse(builder.isInitialized());
+    assertFalse(builder.buildPartial().isInitialized());
+
+    proto2Builder.setA(1).setB(2).setC(3);
+    assertTrue(builder.isInitialized());
+    assertTrue(builder.buildPartial().isInitialized());
+
+    // Test repeated proto2 message fields.
+    proto2Builder = builder.addRepeatedProto2MessageBuilder();
+    assertFalse(builder.isInitialized());
+    assertFalse(builder.buildPartial().isInitialized());
+
+    proto2Builder.setA(1).setB(2).setC(3);
+    assertTrue(builder.isInitialized());
+    assertTrue(builder.buildPartial().isInitialized());
+  }
+
+  
+  // Test that unknown fields are dropped.
+  public void testUnknownFields() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.setOptionalInt32(1234);
+    builder.addRepeatedInt32(5678);
+    TestAllTypes message = builder.build();
+    ByteString data = message.toByteString();
+    
+    TestOptionalFieldsOnly optionalOnlyMessage =
+        TestOptionalFieldsOnly.parseFrom(data);
+    // UnknownFieldSet should be empty.
+    assertEquals(
+        0, optionalOnlyMessage.getUnknownFields().toByteString().size());
+    assertEquals(1234, optionalOnlyMessage.getOptionalInt32());
+    message = TestAllTypes.parseFrom(optionalOnlyMessage.toByteString());
+    assertEquals(1234, message.getOptionalInt32());
+    // The repeated field is discarded because it's unknown to the optional-only
+    // message.
+    assertEquals(0, message.getRepeatedInt32Count());
+    
+    DynamicMessage dynamicOptionalOnlyMessage =
+        DynamicMessage.getDefaultInstance(
+            TestOptionalFieldsOnly.getDescriptor())
+        .getParserForType().parseFrom(data);
+    assertEquals(
+        0, dynamicOptionalOnlyMessage.getUnknownFields().toByteString().size());
+    assertEquals(optionalOnlyMessage.toByteString(),
+        dynamicOptionalOnlyMessage.toByteString());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java b/java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java
new file mode 100644
index 00000000..a5e65424
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java
@@ -0,0 +1,473 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.util.Arrays.asList;
+
+import junit.framework.TestCase;
+
+import java.util.Collections;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+
+/**
+ * Tests for {@link FloatArrayList}.
+ * 
+ * @author dweis@google.com (Daniel Weis)
+ */
+public class FloatArrayListTest extends TestCase {
+  
+  private static final FloatArrayList UNARY_LIST = newImmutableFloatArrayList(1);
+  private static final FloatArrayList TERTIARY_LIST =
+      newImmutableFloatArrayList(1, 2, 3);
+  
+  private FloatArrayList list;
+  
+  @Override
+  protected void setUp() throws Exception {
+    list = new FloatArrayList();
+  }
+  
+  public void testEmptyListReturnsSameInstance() {
+    assertSame(FloatArrayList.emptyList(), FloatArrayList.emptyList());
+  }
+  
+  public void testEmptyListIsImmutable() {
+    assertImmutable(FloatArrayList.emptyList());
+  }
+  
+  public void testMakeImmutable() {
+    list.addFloat(2);
+    list.addFloat(4);
+    list.addFloat(6);
+    list.addFloat(8);
+    list.makeImmutable();
+    assertImmutable(list);
+  }
+  
+  public void testCopyConstructor() {
+    FloatArrayList copy = new FloatArrayList(TERTIARY_LIST);
+    assertEquals(TERTIARY_LIST, copy);
+
+    copy = new FloatArrayList(FloatArrayList.emptyList());
+    assertEquals(FloatArrayList.emptyList(), copy);
+    
+    copy = new FloatArrayList(asList(1F, 2F, 3F));
+    assertEquals(asList(1F, 2F, 3F), copy);
+
+    copy = new FloatArrayList(Collections.<Float>emptyList());
+    assertEquals(FloatArrayList.emptyList(), copy);
+  }
+  
+  public void testModificationWithIteration() {
+    list.addAll(asList(1F, 2F, 3F, 4F));
+    Iterator<Float> iterator = list.iterator();
+    assertEquals(4, list.size());
+    assertEquals(1F, (float) list.get(0));
+    assertEquals(1F, (float) iterator.next());
+    list.set(0, 1F);
+    assertEquals(2F, (float) iterator.next());
+    
+    list.remove(0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+    
+    iterator = list.iterator();
+    list.add(0, 0F);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+  }
+  
+  public void testGet() {
+    assertEquals(1F, (float) TERTIARY_LIST.get(0));
+    assertEquals(2F, (float) TERTIARY_LIST.get(1));
+    assertEquals(3F, (float) TERTIARY_LIST.get(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testGetFloat() {
+    assertEquals(1F, TERTIARY_LIST.getFloat(0));
+    assertEquals(2F, TERTIARY_LIST.getFloat(1));
+    assertEquals(3F, TERTIARY_LIST.getFloat(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSize() {
+    assertEquals(0, FloatArrayList.emptyList().size());
+    assertEquals(1, UNARY_LIST.size());
+    assertEquals(3, TERTIARY_LIST.size());
+
+    list.addFloat(2);
+    list.addFloat(4);
+    list.addFloat(6);
+    list.addFloat(8);
+    assertEquals(4, list.size());
+    
+    list.remove(0);
+    assertEquals(3, list.size());
+    
+    list.add(16F);
+    assertEquals(4, list.size());
+  }
+  
+  public void testSet() {
+    list.addFloat(2);
+    list.addFloat(4);
+    
+    assertEquals(2F, (float) list.set(0, 0F));
+    assertEquals(0F, list.getFloat(0));
+
+    assertEquals(4F, (float) list.set(1, 0F));
+    assertEquals(0F, list.getFloat(1));
+    
+    try {
+      list.set(-1, 0F);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.set(2, 0F);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSetFloat() {
+    list.addFloat(2);
+    list.addFloat(4);
+    
+    assertEquals(2F, list.setFloat(0, 0));
+    assertEquals(0F, list.getFloat(0));
+
+    assertEquals(4F, list.setFloat(1, 0));
+    assertEquals(0F, list.getFloat(1));
+    
+    try {
+      list.setFloat(-1, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.setFloat(2, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAdd() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.add(2F));
+    assertEquals(asList(2F), list);
+
+    assertTrue(list.add(3F));
+    list.add(0, 4F);
+    assertEquals(asList(4F, 2F, 3F), list);
+    
+    list.add(0, 1F);
+    list.add(0, 0F);
+    // Force a resize by getting up to 11 elements.
+    for (int i = 0; i < 6; i++) {
+      list.add(Float.valueOf(5 + i));
+    }
+    assertEquals(asList(0F, 1F, 4F, 2F, 3F, 5F, 6F, 7F, 8F, 9F, 10F), list);
+    
+    try {
+      list.add(-1, 5F);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.add(4, 5F);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAddFloat() {
+    assertEquals(0, list.size());
+
+    list.addFloat(2);
+    assertEquals(asList(2F), list);
+
+    list.addFloat(3);
+    assertEquals(asList(2F, 3F), list);
+  }
+  
+  public void testAddAll() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.addAll(Collections.singleton(1F)));
+    assertEquals(1, list.size());
+    assertEquals(1F, (float) list.get(0));
+    assertEquals(1F, list.getFloat(0));
+    
+    assertTrue(list.addAll(asList(2F, 3F, 4F, 5F, 6F)));
+    assertEquals(asList(1F, 2F, 3F, 4F, 5F, 6F), list);
+    
+    assertTrue(list.addAll(TERTIARY_LIST));
+    assertEquals(asList(1F, 2F, 3F, 4F, 5F, 6F, 1F, 2F, 3F), list);
+
+    assertFalse(list.addAll(Collections.<Float>emptyList()));
+    assertFalse(list.addAll(FloatArrayList.emptyList()));
+  }
+  
+  public void testRemove() {
+    list.addAll(TERTIARY_LIST);
+    assertEquals(1F, (float) list.remove(0));
+    assertEquals(asList(2F, 3F), list);
+
+    assertTrue(list.remove(Float.valueOf(3)));
+    assertEquals(asList(2F), list);
+
+    assertFalse(list.remove(Float.valueOf(3)));
+    assertEquals(asList(2F), list);
+
+    assertEquals(2F, (float) list.remove(0));
+    assertEquals(asList(), list);
+    
+    try {
+      list.remove(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(0);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  private void assertImmutable(FloatArrayList list) {
+    if (list.contains(1F)) {
+      throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
+    }
+    
+    try {
+      list.add(1F);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.add(0, 1F);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.<Float>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.singletonList(1F));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(new FloatArrayList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.singleton(1F));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.<Float>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addFloat(0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.clear();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+
+    try {
+      list.remove(1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.<Float>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.singleton(1F));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.<Float>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.singleton(1F));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, 0F);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.setFloat(0, 0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+  }
+  
+  private static FloatArrayList newImmutableFloatArrayList(int... elements) {
+    FloatArrayList list = new FloatArrayList();
+    for (int element : elements) {
+      list.addFloat(element);
+    }
+    list.makeImmutable();
+    return list;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java b/java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java
new file mode 100644
index 00000000..a92ba374
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java
@@ -0,0 +1,48 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+/**
+ * A prerun for a test suite that allows running the full protocol buffer
+ * tests in a mode that disables the optimization for not using
+ * {@link RepeatedFieldBuilder} and {@link SingleFieldBuilder} until they are
+ * requested. This allows us to run all the tests through both code paths
+ * and ensures that both code paths produce identical results.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ */
+public class ForceFieldBuildersPreRun implements Runnable {
+
+  //@Override (Java 1.6 override semantics, but we must support 1.5)
+  public void run() {
+    GeneratedMessage.enableAlwaysUseFieldBuildersForTesting();
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java b/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java
new file mode 100644
index 00000000..70812b95
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java
@@ -0,0 +1,1661 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.Descriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
+import com.google.protobuf.test.UnittestImport;
+import protobuf_unittest.EnumWithNoOuter;
+import protobuf_unittest.MessageWithNoOuter;
+import protobuf_unittest.MultipleFilesTestProto;
+import protobuf_unittest.NestedExtension.MyNestedExtension;
+import protobuf_unittest.NestedExtensionLite.MyNestedExtensionLite;
+import protobuf_unittest.NonNestedExtension;
+import protobuf_unittest.NonNestedExtension.MessageToBeExtended;
+import protobuf_unittest.NonNestedExtension.MyNonNestedExtension;
+import protobuf_unittest.NonNestedExtensionLite;
+import protobuf_unittest.NonNestedExtensionLite.MessageLiteToBeExtended;
+import protobuf_unittest.NonNestedExtensionLite.MyNonNestedExtensionLite;
+import protobuf_unittest.OuterClassNameTest2OuterClass;
+import protobuf_unittest.OuterClassNameTest3OuterClass;
+import protobuf_unittest.OuterClassNameTestOuterClass;
+import protobuf_unittest.ServiceWithNoOuter;
+import protobuf_unittest.UnittestOptimizeFor.TestOptimizedForSize;
+import protobuf_unittest.UnittestOptimizeFor.TestOptionalOptimizedForSize;
+import protobuf_unittest.UnittestOptimizeFor.TestRequiredOptimizedForSize;
+import protobuf_unittest.UnittestProto;
+import protobuf_unittest.UnittestProto.ForeignEnum;
+import protobuf_unittest.UnittestProto.ForeignMessage;
+import protobuf_unittest.UnittestProto.ForeignMessageOrBuilder;
+import protobuf_unittest.UnittestProto.NestedTestAllTypes;
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestAllTypes.NestedMessage;
+import protobuf_unittest.UnittestProto.TestAllTypesOrBuilder;
+import protobuf_unittest.UnittestProto.TestExtremeDefaultValues;
+import protobuf_unittest.UnittestProto.TestOneof2;
+import protobuf_unittest.UnittestProto.TestPackedTypes;
+import protobuf_unittest.UnittestProto.TestUnpackedTypes;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Unit test for generated messages and generated code.  See also
+ * {@link MessageTest}, which tests some generated message functionality.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class GeneratedMessageTest extends TestCase {
+  TestUtil.ReflectionTester reflectionTester =
+    new TestUtil.ReflectionTester(TestAllTypes.getDescriptor(), null);
+
+  public void testDefaultInstance() throws Exception {
+    assertSame(TestAllTypes.getDefaultInstance(),
+               TestAllTypes.getDefaultInstance().getDefaultInstanceForType());
+    assertSame(TestAllTypes.getDefaultInstance(),
+               TestAllTypes.newBuilder().getDefaultInstanceForType());
+  }
+
+  public void testMessageOrBuilder() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestAllTypes message = builder.build();
+    TestUtil.assertAllFieldsSet(message);
+  }
+
+  public void testUsingBuilderMultipleTimes() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    // primitive field scalar and repeated
+    builder.setOptionalSfixed64(100);
+    builder.addRepeatedInt32(100);
+    // enum field scalar and repeated
+    builder.setOptionalImportEnum(UnittestImport.ImportEnum.IMPORT_BAR);
+    builder.addRepeatedImportEnum(UnittestImport.ImportEnum.IMPORT_BAR);
+    // proto field scalar and repeated
+    builder.setOptionalForeignMessage(ForeignMessage.newBuilder().setC(1));
+    builder.addRepeatedForeignMessage(ForeignMessage.newBuilder().setC(1));
+
+    TestAllTypes value1 = builder.build();
+
+    assertEquals(100, value1.getOptionalSfixed64());
+    assertEquals(100, value1.getRepeatedInt32(0));
+    assertEquals(UnittestImport.ImportEnum.IMPORT_BAR,
+        value1.getOptionalImportEnum());
+    assertEquals(UnittestImport.ImportEnum.IMPORT_BAR,
+        value1.getRepeatedImportEnum(0));
+    assertEquals(1, value1.getOptionalForeignMessage().getC());
+    assertEquals(1, value1.getRepeatedForeignMessage(0).getC());
+
+    // Make sure that builder didn't update previously created values
+    builder.setOptionalSfixed64(200);
+    builder.setRepeatedInt32(0, 200);
+    builder.setOptionalImportEnum(UnittestImport.ImportEnum.IMPORT_FOO);
+    builder.setRepeatedImportEnum(0, UnittestImport.ImportEnum.IMPORT_FOO);
+    builder.setOptionalForeignMessage(ForeignMessage.newBuilder().setC(2));
+    builder.setRepeatedForeignMessage(0, ForeignMessage.newBuilder().setC(2));
+
+    TestAllTypes value2 = builder.build();
+
+    // Make sure value1 didn't change.
+    assertEquals(100, value1.getOptionalSfixed64());
+    assertEquals(100, value1.getRepeatedInt32(0));
+    assertEquals(UnittestImport.ImportEnum.IMPORT_BAR,
+        value1.getOptionalImportEnum());
+    assertEquals(UnittestImport.ImportEnum.IMPORT_BAR,
+        value1.getRepeatedImportEnum(0));
+    assertEquals(1, value1.getOptionalForeignMessage().getC());
+    assertEquals(1, value1.getRepeatedForeignMessage(0).getC());
+
+    // Make sure value2 is correct
+    assertEquals(200, value2.getOptionalSfixed64());
+    assertEquals(200, value2.getRepeatedInt32(0));
+    assertEquals(UnittestImport.ImportEnum.IMPORT_FOO,
+        value2.getOptionalImportEnum());
+    assertEquals(UnittestImport.ImportEnum.IMPORT_FOO,
+        value2.getRepeatedImportEnum(0));
+    assertEquals(2, value2.getOptionalForeignMessage().getC());
+    assertEquals(2, value2.getRepeatedForeignMessage(0).getC());
+  }
+
+  public void testProtosShareRepeatedArraysIfDidntChange() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.addRepeatedInt32(100);
+    builder.addRepeatedForeignMessage(ForeignMessage.getDefaultInstance());
+
+    TestAllTypes value1 = builder.build();
+    TestAllTypes value2 = value1.toBuilder().build();
+
+    assertSame(value1.getRepeatedInt32List(), value2.getRepeatedInt32List());
+    assertSame(value1.getRepeatedForeignMessageList(),
+        value2.getRepeatedForeignMessageList());
+  }
+
+  public void testRepeatedArraysAreImmutable() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.addRepeatedInt32(100);
+    builder.addRepeatedImportEnum(UnittestImport.ImportEnum.IMPORT_BAR);
+    builder.addRepeatedForeignMessage(ForeignMessage.getDefaultInstance());
+    assertIsUnmodifiable(builder.getRepeatedInt32List());
+    assertIsUnmodifiable(builder.getRepeatedImportEnumList());
+    assertIsUnmodifiable(builder.getRepeatedForeignMessageList());
+    assertIsUnmodifiable(builder.getRepeatedFloatList());
+
+
+    TestAllTypes value = builder.build();
+    assertIsUnmodifiable(value.getRepeatedInt32List());
+    assertIsUnmodifiable(value.getRepeatedImportEnumList());
+    assertIsUnmodifiable(value.getRepeatedForeignMessageList());
+    assertIsUnmodifiable(value.getRepeatedFloatList());
+  }
+
+  public void testParsedMessagesAreImmutable() throws Exception {
+    TestAllTypes value = TestAllTypes.parser().parseFrom(TestUtil.getAllSet().toByteString());
+    assertIsUnmodifiable(value.getRepeatedInt32List());
+    assertIsUnmodifiable(value.getRepeatedInt64List());
+    assertIsUnmodifiable(value.getRepeatedUint32List());
+    assertIsUnmodifiable(value.getRepeatedUint64List());
+    assertIsUnmodifiable(value.getRepeatedSint32List());
+    assertIsUnmodifiable(value.getRepeatedSint64List());
+    assertIsUnmodifiable(value.getRepeatedFixed32List());
+    assertIsUnmodifiable(value.getRepeatedFixed64List());
+    assertIsUnmodifiable(value.getRepeatedSfixed32List());
+    assertIsUnmodifiable(value.getRepeatedSfixed64List());
+    assertIsUnmodifiable(value.getRepeatedFloatList());
+    assertIsUnmodifiable(value.getRepeatedDoubleList());
+    assertIsUnmodifiable(value.getRepeatedBoolList());
+    assertIsUnmodifiable(value.getRepeatedStringList());
+    assertIsUnmodifiable(value.getRepeatedBytesList());
+    assertIsUnmodifiable(value.getRepeatedGroupList());
+    assertIsUnmodifiable(value.getRepeatedNestedMessageList());
+    assertIsUnmodifiable(value.getRepeatedForeignMessageList());
+    assertIsUnmodifiable(value.getRepeatedImportMessageList());
+    assertIsUnmodifiable(value.getRepeatedNestedEnumList());
+    assertIsUnmodifiable(value.getRepeatedForeignEnumList());
+    assertIsUnmodifiable(value.getRepeatedImportEnumList());
+  }
+
+  private void assertIsUnmodifiable(List<?> list) {
+    if (list == Collections.emptyList()) {
+      // OKAY -- Need to check this b/c EmptyList allows you to call clear.
+    } else {
+      try {
+        list.clear();
+        fail("List wasn't immutable");
+      } catch (UnsupportedOperationException e) {
+        // good
+      }
+    }
+  }
+
+  public void testSettersRejectNull() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    try {
+      builder.setOptionalString(null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.setOptionalBytes(null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.setOptionalNestedMessage((TestAllTypes.NestedMessage) null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.setOptionalNestedMessage(
+          (TestAllTypes.NestedMessage.Builder) null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.setOptionalNestedEnum(null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.addRepeatedString(null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.addRepeatedBytes(null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.addRepeatedNestedMessage((TestAllTypes.NestedMessage) null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.addRepeatedNestedMessage(
+          (TestAllTypes.NestedMessage.Builder) null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.addRepeatedNestedEnum(null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+  }
+
+  public void testRepeatedSetters() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestUtil.modifyRepeatedFields(builder);
+    TestAllTypes message = builder.build();
+    TestUtil.assertRepeatedFieldsModified(message);
+  }
+
+  public void testRepeatedSettersRejectNull() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+
+    builder.addRepeatedString("one");
+    builder.addRepeatedString("two");
+    try {
+      builder.setRepeatedString(1, null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+
+    builder.addRepeatedBytes(TestUtil.toBytes("one"));
+    builder.addRepeatedBytes(TestUtil.toBytes("two"));
+    try {
+      builder.setRepeatedBytes(1, null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+
+    builder.addRepeatedNestedMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(218).build());
+    builder.addRepeatedNestedMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(456).build());
+    try {
+      builder.setRepeatedNestedMessage(1, (TestAllTypes.NestedMessage) null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.setRepeatedNestedMessage(
+          1, (TestAllTypes.NestedMessage.Builder) null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+
+    builder.addRepeatedNestedEnum(TestAllTypes.NestedEnum.FOO);
+    builder.addRepeatedNestedEnum(TestAllTypes.NestedEnum.BAR);
+    try {
+      builder.setRepeatedNestedEnum(1, null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+  }
+
+  public void testRepeatedAppend() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+
+    builder.addAllRepeatedInt32(Arrays.asList(1, 2, 3, 4));
+    builder.addAllRepeatedForeignEnum(Arrays.asList(ForeignEnum.FOREIGN_BAZ));
+
+    ForeignMessage foreignMessage =
+        ForeignMessage.newBuilder().setC(12).build();
+    builder.addAllRepeatedForeignMessage(Arrays.asList(foreignMessage));
+
+    TestAllTypes message = builder.build();
+    assertEquals(message.getRepeatedInt32List(), Arrays.asList(1, 2, 3, 4));
+    assertEquals(message.getRepeatedForeignEnumList(),
+        Arrays.asList(ForeignEnum.FOREIGN_BAZ));
+    assertEquals(1, message.getRepeatedForeignMessageCount());
+    assertEquals(12, message.getRepeatedForeignMessage(0).getC());
+  }
+
+  public void testRepeatedAppendRejectsNull() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+
+    ForeignMessage foreignMessage =
+        ForeignMessage.newBuilder().setC(12).build();
+    try {
+      builder.addAllRepeatedForeignMessage(
+          Arrays.asList(foreignMessage, (ForeignMessage) null));
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+
+    try {
+      builder.addAllRepeatedForeignEnum(
+          Arrays.asList(ForeignEnum.FOREIGN_BAZ, null));
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+
+    try {
+      builder.addAllRepeatedString(Arrays.asList("one", null));
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+
+    try {
+      builder.addAllRepeatedBytes(Arrays.asList(TestUtil.toBytes("one"), null));
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+  }
+  
+  public void testRepeatedAppendIterateOnlyOnce() throws Exception {
+    // Create a Iterable that can only be iterated once.
+    Iterable<String> stringIterable = new Iterable<String>() {
+      private boolean called = false;
+      @Override
+      public Iterator<String> iterator() {
+        if (called) {
+          throw new IllegalStateException();
+        }
+        called = true;
+        return Arrays.asList("one", "two", "three").iterator();
+      }
+    };
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.addAllRepeatedString(stringIterable);
+    assertEquals(3, builder.getRepeatedStringCount());
+    assertEquals("one", builder.getRepeatedString(0));
+    assertEquals("two", builder.getRepeatedString(1));
+    assertEquals("three", builder.getRepeatedString(2));
+
+    try {
+      builder.addAllRepeatedString(stringIterable);
+      fail("Exception was not thrown");
+    } catch (IllegalStateException e) {
+      // We expect this exception.
+    }
+  }
+
+  public void testMergeFromOtherRejectsNull() throws Exception {
+    try {
+      TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+      builder.mergeFrom((TestAllTypes) null);
+      fail("Exception was not thrown");
+    } catch (NullPointerException e) {
+      // We expect this exception.
+    }
+  }
+
+  public void testSettingForeignMessageUsingBuilder() throws Exception {
+    TestAllTypes message = TestAllTypes.newBuilder()
+        // Pass builder for foreign message instance.
+        .setOptionalForeignMessage(ForeignMessage.newBuilder().setC(123))
+        .build();
+    TestAllTypes expectedMessage = TestAllTypes.newBuilder()
+        // Create expected version passing foreign message instance explicitly.
+        .setOptionalForeignMessage(
+            ForeignMessage.newBuilder().setC(123).build())
+        .build();
+    // TODO(ngd): Upgrade to using real #equals method once implemented
+    assertEquals(expectedMessage.toString(), message.toString());
+  }
+
+  public void testSettingRepeatedForeignMessageUsingBuilder() throws Exception {
+    TestAllTypes message = TestAllTypes.newBuilder()
+        // Pass builder for foreign message instance.
+        .addRepeatedForeignMessage(ForeignMessage.newBuilder().setC(456))
+        .build();
+    TestAllTypes expectedMessage = TestAllTypes.newBuilder()
+        // Create expected version passing foreign message instance explicitly.
+        .addRepeatedForeignMessage(
+            ForeignMessage.newBuilder().setC(456).build())
+        .build();
+    assertEquals(expectedMessage.toString(), message.toString());
+  }
+
+  public void testDefaults() throws Exception {
+    TestUtil.assertClear(TestAllTypes.getDefaultInstance());
+    TestUtil.assertClear(TestAllTypes.newBuilder().build());
+
+    TestExtremeDefaultValues message =
+        TestExtremeDefaultValues.getDefaultInstance();
+    assertEquals("\u1234", message.getUtf8String());
+    assertEquals(Double.POSITIVE_INFINITY, message.getInfDouble());
+    assertEquals(Double.NEGATIVE_INFINITY, message.getNegInfDouble());
+    assertTrue(Double.isNaN(message.getNanDouble()));
+    assertEquals(Float.POSITIVE_INFINITY, message.getInfFloat());
+    assertEquals(Float.NEGATIVE_INFINITY, message.getNegInfFloat());
+    assertTrue(Float.isNaN(message.getNanFloat()));
+    assertEquals("? ? ?? ?? ??? ??/ ??-", message.getCppTrigraph());
+  }
+
+  public void testClear() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.assertClear(builder);
+    TestUtil.setAllFields(builder);
+    builder.clear();
+    TestUtil.assertClear(builder);
+  }
+
+  public void testReflectionGetters() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    reflectionTester.assertAllFieldsSetViaReflection(builder);
+
+    TestAllTypes message = builder.build();
+    reflectionTester.assertAllFieldsSetViaReflection(message);
+  }
+
+  public void testReflectionSetters() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    reflectionTester.setAllFieldsViaReflection(builder);
+    TestUtil.assertAllFieldsSet(builder);
+
+    TestAllTypes message = builder.build();
+    TestUtil.assertAllFieldsSet(message);
+  }
+
+  public void testReflectionSettersRejectNull() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    reflectionTester.assertReflectionSettersRejectNull(builder);
+  }
+
+  public void testReflectionRepeatedSetters() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    reflectionTester.setAllFieldsViaReflection(builder);
+    reflectionTester.modifyRepeatedFieldsViaReflection(builder);
+    TestUtil.assertRepeatedFieldsModified(builder);
+
+    TestAllTypes message = builder.build();
+    TestUtil.assertRepeatedFieldsModified(message);
+  }
+
+  public void testReflectionRepeatedSettersRejectNull() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    reflectionTester.assertReflectionRepeatedSettersRejectNull(builder);
+  }
+
+  public void testReflectionDefaults() throws Exception {
+    reflectionTester.assertClearViaReflection(
+      TestAllTypes.getDefaultInstance());
+    reflectionTester.assertClearViaReflection(
+      TestAllTypes.newBuilder().build());
+  }
+
+  public void testReflectionGetOneof() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    reflectionTester.setAllFieldsViaReflection(builder);
+    Descriptors.OneofDescriptor oneof =
+        TestAllTypes.getDescriptor().getOneofs().get(0);
+    Descriptors.FieldDescriptor field =
+        TestAllTypes.getDescriptor().findFieldByName("oneof_bytes");
+    assertSame(field, builder.getOneofFieldDescriptor(oneof));
+
+    TestAllTypes message = builder.build();
+    assertSame(field, message.getOneofFieldDescriptor(oneof));
+  }
+
+  public void testReflectionClearOneof() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    reflectionTester.setAllFieldsViaReflection(builder);
+    Descriptors.OneofDescriptor oneof =
+        TestAllTypes.getDescriptor().getOneofs().get(0);
+    Descriptors.FieldDescriptor field =
+        TestAllTypes.getDescriptor().findFieldByName("oneof_bytes");
+
+    assertTrue(builder.hasOneof(oneof));
+    assertTrue(builder.hasField(field));
+    builder.clearOneof(oneof);
+    assertFalse(builder.hasOneof(oneof));
+    assertFalse(builder.hasField(field));
+  }
+
+  public void testEnumInterface() throws Exception {
+    assertTrue(TestAllTypes.getDefaultInstance().getDefaultNestedEnum()
+        instanceof ProtocolMessageEnum);
+  }
+
+  public void testEnumMap() throws Exception {
+    Internal.EnumLiteMap<ForeignEnum> map = ForeignEnum.internalGetValueMap();
+
+    for (ForeignEnum value : ForeignEnum.values()) {
+      assertEquals(value, map.findValueByNumber(value.getNumber()));
+    }
+
+    assertTrue(map.findValueByNumber(12345) == null);
+  }
+
+  public void testParsePackedToUnpacked() throws Exception {
+    TestUnpackedTypes.Builder builder = TestUnpackedTypes.newBuilder();
+    TestUnpackedTypes message =
+      builder.mergeFrom(TestUtil.getPackedSet().toByteString()).build();
+    TestUtil.assertUnpackedFieldsSet(message);
+  }
+
+  public void testParseUnpackedToPacked() throws Exception {
+    TestPackedTypes.Builder builder = TestPackedTypes.newBuilder();
+    TestPackedTypes message =
+      builder.mergeFrom(TestUtil.getUnpackedSet().toByteString()).build();
+    TestUtil.assertPackedFieldsSet(message);
+  }
+
+  // =================================================================
+  // Extensions.
+
+  TestUtil.ReflectionTester extensionsReflectionTester =
+    new TestUtil.ReflectionTester(TestAllExtensions.getDescriptor(),
+                                  TestUtil.getExtensionRegistry());
+
+  public void testExtensionMessageOrBuilder() throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    TestUtil.setAllExtensions(builder);
+    TestAllExtensions message = builder.build();
+    TestUtil.assertAllExtensionsSet(message);
+  }
+
+  public void testExtensionRepeatedSetters() throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    TestUtil.setAllExtensions(builder);
+    TestUtil.modifyRepeatedExtensions(builder);
+    TestAllExtensions message = builder.build();
+    TestUtil.assertRepeatedExtensionsModified(message);
+  }
+
+  public void testExtensionDefaults() throws Exception {
+    TestUtil.assertExtensionsClear(TestAllExtensions.getDefaultInstance());
+    TestUtil.assertExtensionsClear(TestAllExtensions.newBuilder().build());
+  }
+
+  public void testExtensionReflectionGetters() throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    TestUtil.setAllExtensions(builder);
+    extensionsReflectionTester.assertAllFieldsSetViaReflection(builder);
+
+    TestAllExtensions message = builder.build();
+    extensionsReflectionTester.assertAllFieldsSetViaReflection(message);
+  }
+
+  public void testExtensionReflectionSetters() throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    extensionsReflectionTester.setAllFieldsViaReflection(builder);
+    TestUtil.assertAllExtensionsSet(builder);
+
+    TestAllExtensions message = builder.build();
+    TestUtil.assertAllExtensionsSet(message);
+  }
+
+  public void testExtensionReflectionSettersRejectNull() throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    extensionsReflectionTester.assertReflectionSettersRejectNull(builder);
+  }
+
+  public void testExtensionReflectionRepeatedSetters() throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    extensionsReflectionTester.setAllFieldsViaReflection(builder);
+    extensionsReflectionTester.modifyRepeatedFieldsViaReflection(builder);
+    TestUtil.assertRepeatedExtensionsModified(builder);
+
+    TestAllExtensions message = builder.build();
+    TestUtil.assertRepeatedExtensionsModified(message);
+  }
+
+  public void testExtensionReflectionRepeatedSettersRejectNull()
+      throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    extensionsReflectionTester.assertReflectionRepeatedSettersRejectNull(
+        builder);
+  }
+
+  public void testExtensionReflectionDefaults() throws Exception {
+    extensionsReflectionTester.assertClearViaReflection(
+      TestAllExtensions.getDefaultInstance());
+    extensionsReflectionTester.assertClearViaReflection(
+      TestAllExtensions.newBuilder().build());
+  }
+
+  public void testClearExtension() throws Exception {
+    // clearExtension() is not actually used in TestUtil, so try it manually.
+    assertFalse(
+      TestAllExtensions.newBuilder()
+        .setExtension(UnittestProto.optionalInt32Extension, 1)
+        .clearExtension(UnittestProto.optionalInt32Extension)
+        .hasExtension(UnittestProto.optionalInt32Extension));
+    assertEquals(0,
+      TestAllExtensions.newBuilder()
+        .addExtension(UnittestProto.repeatedInt32Extension, 1)
+        .clearExtension(UnittestProto.repeatedInt32Extension)
+        .getExtensionCount(UnittestProto.repeatedInt32Extension));
+  }
+
+  public void testExtensionCopy() throws Exception {
+    TestAllExtensions original = TestUtil.getAllExtensionsSet();
+    TestAllExtensions copy = TestAllExtensions.newBuilder(original).build();
+    TestUtil.assertAllExtensionsSet(copy);
+  }
+
+  public void testExtensionMergeFrom() throws Exception {
+    TestAllExtensions original =
+      TestAllExtensions.newBuilder()
+        .setExtension(UnittestProto.optionalInt32Extension, 1).build();
+    TestAllExtensions merged =
+        TestAllExtensions.newBuilder().mergeFrom(original).build();
+    assertTrue(merged.hasExtension(UnittestProto.optionalInt32Extension));
+    assertEquals(
+        1, (int) merged.getExtension(UnittestProto.optionalInt32Extension));
+  }
+
+  // =================================================================
+  // Lite Extensions.
+
+  // We test lite extensions directly because they have a separate
+  // implementation from full extensions.  In contrast, we do not test
+  // lite fields directly since they are implemented exactly the same as
+  // regular fields.
+
+  public void testLiteExtensionMessageOrBuilder() throws Exception {
+    TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.newBuilder();
+    TestUtil.setAllExtensions(builder);
+    TestUtil.assertAllExtensionsSet(builder);
+
+    TestAllExtensionsLite message = builder.build();
+    TestUtil.assertAllExtensionsSet(message);
+  }
+
+  public void testLiteExtensionRepeatedSetters() throws Exception {
+    TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.newBuilder();
+    TestUtil.setAllExtensions(builder);
+    TestUtil.modifyRepeatedExtensions(builder);
+    TestUtil.assertRepeatedExtensionsModified(builder);
+
+    TestAllExtensionsLite message = builder.build();
+    TestUtil.assertRepeatedExtensionsModified(message);
+  }
+
+  public void testLiteExtensionDefaults() throws Exception {
+    TestUtil.assertExtensionsClear(TestAllExtensionsLite.getDefaultInstance());
+    TestUtil.assertExtensionsClear(TestAllExtensionsLite.newBuilder().build());
+  }
+
+  public void testClearLiteExtension() throws Exception {
+    // clearExtension() is not actually used in TestUtil, so try it manually.
+    assertFalse(
+      TestAllExtensionsLite.newBuilder()
+        .setExtension(UnittestLite.optionalInt32ExtensionLite, 1)
+        .clearExtension(UnittestLite.optionalInt32ExtensionLite)
+        .hasExtension(UnittestLite.optionalInt32ExtensionLite));
+    assertEquals(0,
+      TestAllExtensionsLite.newBuilder()
+        .addExtension(UnittestLite.repeatedInt32ExtensionLite, 1)
+        .clearExtension(UnittestLite.repeatedInt32ExtensionLite)
+        .getExtensionCount(UnittestLite.repeatedInt32ExtensionLite));
+  }
+
+  public void testLiteExtensionCopy() throws Exception {
+    TestAllExtensionsLite original = TestUtil.getAllLiteExtensionsSet();
+    TestAllExtensionsLite copy =
+        TestAllExtensionsLite.newBuilder(original).build();
+    TestUtil.assertAllExtensionsSet(copy);
+  }
+
+  public void testLiteExtensionMergeFrom() throws Exception {
+    TestAllExtensionsLite original =
+      TestAllExtensionsLite.newBuilder()
+        .setExtension(UnittestLite.optionalInt32ExtensionLite, 1).build();
+    TestAllExtensionsLite merged =
+        TestAllExtensionsLite.newBuilder().mergeFrom(original).build();
+    assertTrue(merged.hasExtension(UnittestLite.optionalInt32ExtensionLite));
+    assertEquals(
+        1, (int) merged.getExtension(UnittestLite.optionalInt32ExtensionLite));
+  }
+
+  // =================================================================
+  // multiple_files_test
+
+  // Test that custom options of an file level enum are properly initialized.
+  // This test needs to be put before any other access to MultipleFilesTestProto
+  // or messages defined in multiple_files_test.proto because the class loading
+  // order affects initialization process of custom options.
+  public void testEnumValueOptionsInMultipleFilesMode() throws Exception {
+    assertEquals(12345, EnumWithNoOuter.FOO.getValueDescriptor().getOptions()
+        .getExtension(MultipleFilesTestProto.enumValueOption).intValue());
+  }
+
+  public void testMultipleFilesOption() throws Exception {
+    // We mostly just want to check that things compile.
+    MessageWithNoOuter message =
+      MessageWithNoOuter.newBuilder()
+        .setNested(MessageWithNoOuter.NestedMessage.newBuilder().setI(1))
+        .addForeign(TestAllTypes.newBuilder().setOptionalInt32(1))
+        .setNestedEnum(MessageWithNoOuter.NestedEnum.BAZ)
+        .setForeignEnum(EnumWithNoOuter.BAR)
+        .build();
+    assertEquals(message, MessageWithNoOuter.parseFrom(message.toByteString()));
+
+    assertEquals(MultipleFilesTestProto.getDescriptor(),
+                 MessageWithNoOuter.getDescriptor().getFile());
+
+    Descriptors.FieldDescriptor field =
+      MessageWithNoOuter.getDescriptor().findFieldByName("foreign_enum");
+    assertEquals(EnumWithNoOuter.BAR.getValueDescriptor(),
+                 message.getField(field));
+
+    assertEquals(MultipleFilesTestProto.getDescriptor(),
+                 ServiceWithNoOuter.getDescriptor().getFile());
+
+    assertFalse(
+      TestAllExtensions.getDefaultInstance().hasExtension(
+        MultipleFilesTestProto.extensionWithOuter));
+  }
+
+  public void testOptionalFieldWithRequiredSubfieldsOptimizedForSize()
+    throws Exception {
+    TestOptionalOptimizedForSize message =
+        TestOptionalOptimizedForSize.getDefaultInstance();
+    assertTrue(message.isInitialized());
+
+    message = TestOptionalOptimizedForSize.newBuilder().setO(
+        TestRequiredOptimizedForSize.newBuilder().buildPartial()
+        ).buildPartial();
+    assertFalse(message.isInitialized());
+
+    message = TestOptionalOptimizedForSize.newBuilder().setO(
+        TestRequiredOptimizedForSize.newBuilder().setX(5).buildPartial()
+        ).buildPartial();
+    assertTrue(message.isInitialized());
+  }
+
+  public void testUninitializedExtensionInOptimizedForSize()
+      throws Exception {
+    TestOptimizedForSize.Builder builder = TestOptimizedForSize.newBuilder();
+    builder.setExtension(TestOptimizedForSize.testExtension2,
+        TestRequiredOptimizedForSize.newBuilder().buildPartial());
+    assertFalse(builder.isInitialized());
+    assertFalse(builder.buildPartial().isInitialized());
+
+    builder = TestOptimizedForSize.newBuilder();
+    builder.setExtension(TestOptimizedForSize.testExtension2,
+        TestRequiredOptimizedForSize.newBuilder().setX(10).buildPartial());
+    assertTrue(builder.isInitialized());
+    assertTrue(builder.buildPartial().isInitialized());
+  }
+
+  public void testToBuilder() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestAllTypes message = builder.build();
+    TestUtil.assertAllFieldsSet(message);
+    TestUtil.assertAllFieldsSet(message.toBuilder().build());
+  }
+
+  public void testFieldConstantValues() throws Exception {
+    assertEquals(TestAllTypes.NestedMessage.BB_FIELD_NUMBER, 1);
+    assertEquals(TestAllTypes.OPTIONAL_INT32_FIELD_NUMBER, 1);
+    assertEquals(TestAllTypes.OPTIONALGROUP_FIELD_NUMBER, 16);
+    assertEquals(TestAllTypes.OPTIONAL_NESTED_MESSAGE_FIELD_NUMBER, 18);
+    assertEquals(TestAllTypes.OPTIONAL_NESTED_ENUM_FIELD_NUMBER, 21);
+    assertEquals(TestAllTypes.REPEATED_INT32_FIELD_NUMBER, 31);
+    assertEquals(TestAllTypes.REPEATEDGROUP_FIELD_NUMBER, 46);
+    assertEquals(TestAllTypes.REPEATED_NESTED_MESSAGE_FIELD_NUMBER, 48);
+    assertEquals(TestAllTypes.REPEATED_NESTED_ENUM_FIELD_NUMBER, 51);
+  }
+
+  public void testExtensionConstantValues() throws Exception {
+    assertEquals(UnittestProto.TestRequired.SINGLE_FIELD_NUMBER, 1000);
+    assertEquals(UnittestProto.TestRequired.MULTI_FIELD_NUMBER, 1001);
+    assertEquals(UnittestProto.OPTIONAL_INT32_EXTENSION_FIELD_NUMBER, 1);
+    assertEquals(UnittestProto.OPTIONALGROUP_EXTENSION_FIELD_NUMBER, 16);
+    assertEquals(
+      UnittestProto.OPTIONAL_NESTED_MESSAGE_EXTENSION_FIELD_NUMBER, 18);
+    assertEquals(UnittestProto.OPTIONAL_NESTED_ENUM_EXTENSION_FIELD_NUMBER, 21);
+    assertEquals(UnittestProto.REPEATED_INT32_EXTENSION_FIELD_NUMBER, 31);
+    assertEquals(UnittestProto.REPEATEDGROUP_EXTENSION_FIELD_NUMBER, 46);
+    assertEquals(
+      UnittestProto.REPEATED_NESTED_MESSAGE_EXTENSION_FIELD_NUMBER, 48);
+    assertEquals(UnittestProto.REPEATED_NESTED_ENUM_EXTENSION_FIELD_NUMBER, 51);
+  }
+
+  public void testRecursiveMessageDefaultInstance() throws Exception {
+    UnittestProto.TestRecursiveMessage message =
+        UnittestProto.TestRecursiveMessage.getDefaultInstance();
+    assertTrue(message != null);
+    assertNotNull(message.getA());
+    assertTrue(message.getA() == message);
+  }
+
+  public void testSerialize() throws Exception {
+    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestUtil.setAllFields(builder);
+    TestAllTypes expected = builder.build();
+    ObjectOutputStream out = new ObjectOutputStream(baos);
+    try {
+      out.writeObject(expected);
+    } finally {
+      out.close();
+    }
+    ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
+    ObjectInputStream in = new ObjectInputStream(bais);
+    TestAllTypes actual = (TestAllTypes) in.readObject();
+    assertEquals(expected, actual);
+  }
+
+  public void testSerializePartial() throws Exception {
+    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestAllTypes expected = builder.buildPartial();
+    ObjectOutputStream out = new ObjectOutputStream(baos);
+    try {
+      out.writeObject(expected);
+    } finally {
+      out.close();
+    }
+    ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
+    ObjectInputStream in = new ObjectInputStream(bais);
+    TestAllTypes actual = (TestAllTypes) in.readObject();
+    assertEquals(expected, actual);
+  }
+
+  public void testEnumValues() {
+     assertEquals(
+         TestAllTypes.NestedEnum.BAR.getNumber(),
+         TestAllTypes.NestedEnum.BAR_VALUE);
+    assertEquals(
+        TestAllTypes.NestedEnum.BAZ.getNumber(),
+        TestAllTypes.NestedEnum.BAZ_VALUE);
+    assertEquals(
+        TestAllTypes.NestedEnum.FOO.getNumber(),
+        TestAllTypes.NestedEnum.FOO_VALUE);
+  }
+
+  public void testNonNestedExtensionInitialization() {
+    assertTrue(NonNestedExtension.nonNestedExtension
+               .getMessageDefaultInstance() instanceof MyNonNestedExtension);
+    assertEquals("nonNestedExtension",
+                 NonNestedExtension.nonNestedExtension.getDescriptor().getName());
+  }
+
+  public void testNestedExtensionInitialization() {
+    assertTrue(MyNestedExtension.recursiveExtension.getMessageDefaultInstance()
+               instanceof MessageToBeExtended);
+    assertEquals("recursiveExtension",
+                 MyNestedExtension.recursiveExtension.getDescriptor().getName());
+  }
+
+  public void testNonNestedExtensionLiteInitialization() {
+    assertTrue(NonNestedExtensionLite.nonNestedExtensionLite
+               .getMessageDefaultInstance() instanceof MyNonNestedExtensionLite);
+  }
+
+  public void testNestedExtensionLiteInitialization() {
+    assertTrue(MyNestedExtensionLite.recursiveExtensionLite
+               .getMessageDefaultInstance() instanceof MessageLiteToBeExtended);
+  }
+
+  public void testInvalidations() throws Exception {
+    GeneratedMessage.enableAlwaysUseFieldBuildersForTesting();
+    TestAllTypes.NestedMessage nestedMessage1 =
+        TestAllTypes.NestedMessage.newBuilder().build();
+    TestAllTypes.NestedMessage nestedMessage2 =
+        TestAllTypes.NestedMessage.newBuilder().build();
+
+    // Set all three flavors (enum, primitive, message and singular/repeated)
+    // and verify no invalidations fired
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+
+    TestAllTypes.Builder builder = (TestAllTypes.Builder)
+        ((GeneratedMessage) TestAllTypes.getDefaultInstance()).
+            newBuilderForType(mockParent);
+    builder.setOptionalInt32(1);
+    builder.setOptionalNestedEnum(TestAllTypes.NestedEnum.BAR);
+    builder.setOptionalNestedMessage(nestedMessage1);
+    builder.addRepeatedInt32(1);
+    builder.addRepeatedNestedEnum(TestAllTypes.NestedEnum.BAR);
+    builder.addRepeatedNestedMessage(nestedMessage1);
+    assertEquals(0, mockParent.getInvalidationCount());
+
+    // Now tell it we want changes and make sure it's only fired once
+    // And do this for each flavor
+
+    // primitive single
+    builder.buildPartial();
+    builder.setOptionalInt32(2);
+    builder.setOptionalInt32(3);
+    assertEquals(1, mockParent.getInvalidationCount());
+
+    // enum single
+    builder.buildPartial();
+    builder.setOptionalNestedEnum(TestAllTypes.NestedEnum.BAZ);
+    builder.setOptionalNestedEnum(TestAllTypes.NestedEnum.BAR);
+    assertEquals(2, mockParent.getInvalidationCount());
+
+    // message single
+    builder.buildPartial();
+    builder.setOptionalNestedMessage(nestedMessage2);
+    builder.setOptionalNestedMessage(nestedMessage1);
+    assertEquals(3, mockParent.getInvalidationCount());
+
+    // primitive repeated
+    builder.buildPartial();
+    builder.addRepeatedInt32(2);
+    builder.addRepeatedInt32(3);
+    assertEquals(4, mockParent.getInvalidationCount());
+
+    // enum repeated
+    builder.buildPartial();
+    builder.addRepeatedNestedEnum(TestAllTypes.NestedEnum.BAZ);
+    builder.addRepeatedNestedEnum(TestAllTypes.NestedEnum.BAZ);
+    assertEquals(5, mockParent.getInvalidationCount());
+
+    // message repeated
+    builder.buildPartial();
+    builder.addRepeatedNestedMessage(nestedMessage2);
+    builder.addRepeatedNestedMessage(nestedMessage1);
+    assertEquals(6, mockParent.getInvalidationCount());
+
+  }
+
+  public void testInvalidations_Extensions() throws Exception {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+
+    TestAllExtensions.Builder builder = (TestAllExtensions.Builder)
+        ((GeneratedMessage) TestAllExtensions.getDefaultInstance()).
+            newBuilderForType(mockParent);
+
+    builder.addExtension(UnittestProto.repeatedInt32Extension, 1);
+    builder.setExtension(UnittestProto.repeatedInt32Extension, 0, 2);
+    builder.clearExtension(UnittestProto.repeatedInt32Extension);
+    assertEquals(0, mockParent.getInvalidationCount());
+
+    // Now tell it we want changes and make sure it's only fired once
+    builder.buildPartial();
+    builder.addExtension(UnittestProto.repeatedInt32Extension, 2);
+    builder.addExtension(UnittestProto.repeatedInt32Extension, 3);
+    assertEquals(1, mockParent.getInvalidationCount());
+
+    builder.buildPartial();
+    builder.setExtension(UnittestProto.repeatedInt32Extension, 0, 4);
+    builder.setExtension(UnittestProto.repeatedInt32Extension, 1, 5);
+    assertEquals(2, mockParent.getInvalidationCount());
+
+    builder.buildPartial();
+    builder.clearExtension(UnittestProto.repeatedInt32Extension);
+    builder.clearExtension(UnittestProto.repeatedInt32Extension);
+    assertEquals(3, mockParent.getInvalidationCount());
+  }
+
+  public void testBaseMessageOrBuilder() {
+    // Mostly just makes sure the base interface exists and has some methods.
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestAllTypes message = builder.buildPartial();
+    TestAllTypesOrBuilder builderAsInterface = (TestAllTypesOrBuilder) builder;
+    TestAllTypesOrBuilder messageAsInterface = (TestAllTypesOrBuilder) message;
+
+    assertEquals(
+        messageAsInterface.getDefaultBool(),
+        messageAsInterface.getDefaultBool());
+    assertEquals(
+        messageAsInterface.getOptionalDouble(),
+        messageAsInterface.getOptionalDouble());
+  }
+
+  public void testMessageOrBuilderGetters() {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+
+    // single fields
+    assertSame(ForeignMessage.getDefaultInstance(),
+        builder.getOptionalForeignMessageOrBuilder());
+    ForeignMessage.Builder subBuilder =
+        builder.getOptionalForeignMessageBuilder();
+    assertSame(subBuilder, builder.getOptionalForeignMessageOrBuilder());
+
+    // repeated fields
+    ForeignMessage m0 = ForeignMessage.newBuilder().buildPartial();
+    ForeignMessage m1 = ForeignMessage.newBuilder().buildPartial();
+    ForeignMessage m2 = ForeignMessage.newBuilder().buildPartial();
+    builder.addRepeatedForeignMessage(m0);
+    builder.addRepeatedForeignMessage(m1);
+    builder.addRepeatedForeignMessage(m2);
+    assertSame(m0, builder.getRepeatedForeignMessageOrBuilder(0));
+    assertSame(m1, builder.getRepeatedForeignMessageOrBuilder(1));
+    assertSame(m2, builder.getRepeatedForeignMessageOrBuilder(2));
+    ForeignMessage.Builder b0 = builder.getRepeatedForeignMessageBuilder(0);
+    ForeignMessage.Builder b1 = builder.getRepeatedForeignMessageBuilder(1);
+    assertSame(b0, builder.getRepeatedForeignMessageOrBuilder(0));
+    assertSame(b1, builder.getRepeatedForeignMessageOrBuilder(1));
+    assertSame(m2, builder.getRepeatedForeignMessageOrBuilder(2));
+
+    List<? extends ForeignMessageOrBuilder> messageOrBuilderList =
+        builder.getRepeatedForeignMessageOrBuilderList();
+    assertSame(b0, messageOrBuilderList.get(0));
+    assertSame(b1, messageOrBuilderList.get(1));
+    assertSame(m2, messageOrBuilderList.get(2));
+  }
+
+  public void testGetFieldBuilder() {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+
+    FieldDescriptor fieldDescriptor =
+        descriptor.findFieldByName("optional_nested_message");
+    FieldDescriptor foreignFieldDescriptor =
+        descriptor.findFieldByName("optional_foreign_message");
+    FieldDescriptor importFieldDescriptor =
+        descriptor.findFieldByName("optional_import_message");
+
+    // Mutate the message with new field builder
+    // Mutate nested message
+    TestAllTypes.Builder builder1 = TestAllTypes.newBuilder();
+    Message.Builder fieldBuilder1 = builder1.newBuilderForField(fieldDescriptor)
+        .mergeFrom((Message) builder1.getField(fieldDescriptor));
+    FieldDescriptor subFieldDescriptor1 =
+        fieldBuilder1.getDescriptorForType().findFieldByName("bb");
+    fieldBuilder1.setField(subFieldDescriptor1, 1);
+    builder1.setField(fieldDescriptor, fieldBuilder1.build());
+
+    // Mutate foreign message
+    Message.Builder foreignFieldBuilder1 = builder1.newBuilderForField(
+        foreignFieldDescriptor)
+        .mergeFrom((Message) builder1.getField(foreignFieldDescriptor));
+    FieldDescriptor subForeignFieldDescriptor1 =
+        foreignFieldBuilder1.getDescriptorForType().findFieldByName("c");
+    foreignFieldBuilder1.setField(subForeignFieldDescriptor1, 2);
+    builder1.setField(foreignFieldDescriptor, foreignFieldBuilder1.build());
+
+    // Mutate import message
+    Message.Builder importFieldBuilder1 = builder1.newBuilderForField(
+        importFieldDescriptor)
+        .mergeFrom((Message) builder1.getField(importFieldDescriptor));
+    FieldDescriptor subImportFieldDescriptor1 =
+        importFieldBuilder1.getDescriptorForType().findFieldByName("d");
+    importFieldBuilder1.setField(subImportFieldDescriptor1, 3);
+    builder1.setField(importFieldDescriptor, importFieldBuilder1.build());
+
+    Message newMessage1 = builder1.build();
+
+    // Mutate the message with existing field builder
+    // Mutate nested message
+    TestAllTypes.Builder builder2 = TestAllTypes.newBuilder();
+    Message.Builder fieldBuilder2 = builder2.getFieldBuilder(fieldDescriptor);
+    FieldDescriptor subFieldDescriptor2 =
+        fieldBuilder2.getDescriptorForType().findFieldByName("bb");
+    fieldBuilder2.setField(subFieldDescriptor2, 1);
+    builder2.setField(fieldDescriptor, fieldBuilder2.build());
+
+    // Mutate foreign message
+    Message.Builder foreignFieldBuilder2 = builder2.newBuilderForField(
+        foreignFieldDescriptor)
+        .mergeFrom((Message) builder2.getField(foreignFieldDescriptor));
+    FieldDescriptor subForeignFieldDescriptor2 =
+        foreignFieldBuilder2.getDescriptorForType().findFieldByName("c");
+    foreignFieldBuilder2.setField(subForeignFieldDescriptor2, 2);
+    builder2.setField(foreignFieldDescriptor, foreignFieldBuilder2.build());
+
+    // Mutate import message
+    Message.Builder importFieldBuilder2 = builder2.newBuilderForField(
+        importFieldDescriptor)
+        .mergeFrom((Message) builder2.getField(importFieldDescriptor));
+    FieldDescriptor subImportFieldDescriptor2 =
+        importFieldBuilder2.getDescriptorForType().findFieldByName("d");
+    importFieldBuilder2.setField(subImportFieldDescriptor2, 3);
+    builder2.setField(importFieldDescriptor, importFieldBuilder2.build());
+
+    Message newMessage2 = builder2.build();
+
+    // These two messages should be equal.
+    assertEquals(newMessage1, newMessage2);
+  }
+
+  public void testGetFieldBuilderWithInitializedValue() {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+    FieldDescriptor fieldDescriptor =
+        descriptor.findFieldByName("optional_nested_message");
+
+    // Before setting field, builder is initialized by default value. 
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    NestedMessage.Builder fieldBuilder =
+        (NestedMessage.Builder) builder.getFieldBuilder(fieldDescriptor);
+    assertEquals(0, fieldBuilder.getBb());
+
+    // Setting field value with new field builder instance.
+    builder = TestAllTypes.newBuilder();
+    NestedMessage.Builder newFieldBuilder =
+        builder.getOptionalNestedMessageBuilder();
+    newFieldBuilder.setBb(2);
+    // Then get the field builder instance by getFieldBuilder().
+    fieldBuilder =
+        (NestedMessage.Builder) builder.getFieldBuilder(fieldDescriptor);
+    // It should contain new value.
+    assertEquals(2, fieldBuilder.getBb());
+    // These two builder should be equal.
+    assertSame(fieldBuilder, newFieldBuilder);
+  }
+
+  public void testGetFieldBuilderNotSupportedException() {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    try {
+      builder.getFieldBuilder(descriptor.findFieldByName("optional_int32"));
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.getFieldBuilder(
+          descriptor.findFieldByName("optional_nested_enum"));
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.getFieldBuilder(descriptor.findFieldByName("repeated_int32"));
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.getFieldBuilder(
+          descriptor.findFieldByName("repeated_nested_enum"));
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.getFieldBuilder(
+          descriptor.findFieldByName("repeated_nested_message"));
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+  }
+
+  // Test that when the default outer class name conflicts with another type
+  // defined in the proto the compiler will append a suffix to avoid the
+  // conflict.
+  public void testConflictingOuterClassName() {
+    // We just need to make sure we can refer to the outer class with the
+    // expected name. There is nothing else to test.
+    OuterClassNameTestOuterClass.OuterClassNameTest message =
+        OuterClassNameTestOuterClass.OuterClassNameTest.newBuilder().build();
+    assertTrue(message.getDescriptorForType() ==
+        OuterClassNameTestOuterClass.OuterClassNameTest.getDescriptor());
+
+    OuterClassNameTest2OuterClass.TestMessage2.NestedMessage.OuterClassNameTest2
+        message2 = OuterClassNameTest2OuterClass.TestMessage2.NestedMessage
+            .OuterClassNameTest2.newBuilder().build();
+    assertEquals(0, message2.getSerializedSize());
+
+    OuterClassNameTest3OuterClass.TestMessage3.NestedMessage.OuterClassNameTest3
+        enumValue = OuterClassNameTest3OuterClass.TestMessage3.NestedMessage
+            .OuterClassNameTest3.DUMMY_VALUE;
+    assertEquals(1, enumValue.getNumber());
+  }
+
+  // =================================================================
+  // oneof generated code test
+  public void testOneofEnumCase() throws Exception {
+    TestOneof2 message = TestOneof2.newBuilder()
+        .setFooInt(123).setFooString("foo").setFooCord("bar").build();
+    TestUtil.assertAtMostOneFieldSetOneof(message);
+  }
+
+  public void testClearOneof() throws Exception {
+    TestOneof2.Builder builder = TestOneof2.newBuilder().setFooInt(123);
+    assertEquals(TestOneof2.FooCase.FOO_INT, builder.getFooCase());
+    builder.clearFoo();
+    assertEquals(TestOneof2.FooCase.FOO_NOT_SET, builder.getFooCase());
+  }
+
+  public void testSetOneofClearsOthers() throws Exception {
+    TestOneof2.Builder builder = TestOneof2.newBuilder();
+    TestOneof2 message =
+        builder.setFooInt(123).setFooString("foo").buildPartial();
+    assertTrue(message.hasFooString());
+    TestUtil.assertAtMostOneFieldSetOneof(message);
+
+    message = builder.setFooCord("bar").buildPartial();
+    assertTrue(message.hasFooCord());
+    TestUtil.assertAtMostOneFieldSetOneof(message);
+
+    message = builder.setFooStringPiece("baz").buildPartial();
+    assertTrue(message.hasFooStringPiece());
+    TestUtil.assertAtMostOneFieldSetOneof(message);
+
+    message = builder.setFooBytes(TestUtil.toBytes("qux")).buildPartial();
+    assertTrue(message.hasFooBytes());
+    TestUtil.assertAtMostOneFieldSetOneof(message);
+
+    message = builder.setFooEnum(TestOneof2.NestedEnum.FOO).buildPartial();
+    assertTrue(message.hasFooEnum());
+    TestUtil.assertAtMostOneFieldSetOneof(message);
+
+    message = builder.setFooMessage(
+        TestOneof2.NestedMessage.newBuilder().setQuxInt(234).build()).buildPartial();
+    assertTrue(message.hasFooMessage());
+    TestUtil.assertAtMostOneFieldSetOneof(message);
+
+    message = builder.setFooInt(123).buildPartial();
+    assertTrue(message.hasFooInt());
+    TestUtil.assertAtMostOneFieldSetOneof(message);
+  }
+
+  public void testOneofTypes() throws Exception {
+    // Primitive
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      assertEquals(builder.getFooInt(), 0);
+      assertFalse(builder.hasFooInt());
+      assertTrue(builder.setFooInt(123).hasFooInt());
+      assertEquals(builder.getFooInt(), 123);
+      TestOneof2 message = builder.buildPartial();
+      assertTrue(message.hasFooInt());
+      assertEquals(message.getFooInt(), 123);
+
+      assertFalse(builder.clearFooInt().hasFooInt());
+      TestOneof2 message2 = builder.build();
+      assertFalse(message2.hasFooInt());
+      assertEquals(message2.getFooInt(), 0);
+    }
+
+    // Enum
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      assertEquals(builder.getFooEnum(), TestOneof2.NestedEnum.FOO);
+      assertTrue(builder.setFooEnum(TestOneof2.NestedEnum.BAR).hasFooEnum());
+      assertEquals(builder.getFooEnum(), TestOneof2.NestedEnum.BAR);
+      TestOneof2 message = builder.buildPartial();
+      assertTrue(message.hasFooEnum());
+      assertEquals(message.getFooEnum(), TestOneof2.NestedEnum.BAR);
+
+      assertFalse(builder.clearFooEnum().hasFooEnum());
+      TestOneof2 message2 = builder.build();
+      assertFalse(message2.hasFooEnum());
+      assertEquals(message2.getFooEnum(), TestOneof2.NestedEnum.FOO);
+    }
+
+    // String
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      assertEquals(builder.getFooString(), "");
+      builder.setFooString("foo");
+      assertTrue(builder.hasFooString());
+      assertEquals(builder.getFooString(), "foo");
+      TestOneof2 message = builder.buildPartial();
+      assertTrue(message.hasFooString());
+      assertEquals(message.getFooString(), "foo");
+      assertEquals(message.getFooStringBytes(), TestUtil.toBytes("foo"));
+
+      assertFalse(builder.clearFooString().hasFooString());
+      TestOneof2 message2 = builder.buildPartial();
+      assertFalse(message2.hasFooString());
+      assertEquals(message2.getFooString(), "");
+      assertEquals(message2.getFooStringBytes(), TestUtil.toBytes(""));
+
+      // Get method should not change the oneof value.
+      builder.setFooInt(123);
+      assertEquals(builder.getFooString(), "");
+      assertEquals(builder.getFooStringBytes(), TestUtil.toBytes(""));
+      assertEquals(123, builder.getFooInt());
+
+      message = builder.build();
+      assertEquals(message.getFooString(), "");
+      assertEquals(message.getFooStringBytes(), TestUtil.toBytes(""));
+      assertEquals(123, message.getFooInt());
+    }
+
+    // Cord
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      assertEquals(builder.getFooCord(), "");
+      builder.setFooCord("foo");
+      assertTrue(builder.hasFooCord());
+      assertEquals(builder.getFooCord(), "foo");
+      TestOneof2 message = builder.buildPartial();
+      assertTrue(message.hasFooCord());
+      assertEquals(message.getFooCord(), "foo");
+      assertEquals(message.getFooCordBytes(), TestUtil.toBytes("foo"));
+
+      assertFalse(builder.clearFooCord().hasFooCord());
+      TestOneof2 message2 = builder.build();
+      assertFalse(message2.hasFooCord());
+      assertEquals(message2.getFooCord(), "");
+      assertEquals(message2.getFooCordBytes(), TestUtil.toBytes(""));
+    }
+
+    // StringPiece
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      assertEquals(builder.getFooStringPiece(), "");
+      builder.setFooStringPiece("foo");
+      assertTrue(builder.hasFooStringPiece());
+      assertEquals(builder.getFooStringPiece(), "foo");
+      TestOneof2 message = builder.buildPartial();
+      assertTrue(message.hasFooStringPiece());
+      assertEquals(message.getFooStringPiece(), "foo");
+      assertEquals(message.getFooStringPieceBytes(), TestUtil.toBytes("foo"));
+
+      assertFalse(builder.clearFooStringPiece().hasFooStringPiece());
+      TestOneof2 message2 = builder.build();
+      assertFalse(message2.hasFooStringPiece());
+      assertEquals(message2.getFooStringPiece(), "");
+      assertEquals(message2.getFooStringPieceBytes(), TestUtil.toBytes(""));
+    }
+
+    // Message
+    {
+      // set
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      assertEquals(builder.getFooMessage().getQuxInt(), 0);
+      builder.setFooMessage(
+          TestOneof2.NestedMessage.newBuilder().setQuxInt(234).build());
+      assertTrue(builder.hasFooMessage());
+      assertEquals(builder.getFooMessage().getQuxInt(), 234);
+      TestOneof2 message = builder.buildPartial();
+      assertTrue(message.hasFooMessage());
+      assertEquals(message.getFooMessage().getQuxInt(), 234);
+
+      // clear
+      assertFalse(builder.clearFooMessage().hasFooString());
+      message = builder.build();
+      assertFalse(message.hasFooMessage());
+      assertEquals(message.getFooMessage().getQuxInt(), 0);
+
+      // nested builder
+      builder = TestOneof2.newBuilder();
+      assertSame(builder.getFooMessageOrBuilder(),
+          TestOneof2.NestedMessage.getDefaultInstance());
+      assertFalse(builder.hasFooMessage());
+      builder.getFooMessageBuilder().setQuxInt(123);
+      assertTrue(builder.hasFooMessage());
+      assertEquals(builder.getFooMessage().getQuxInt(), 123);
+      message = builder.build();
+      assertTrue(message.hasFooMessage());
+      assertEquals(message.getFooMessage().getQuxInt(), 123);
+    }
+
+    // LazyMessage is tested in LazyMessageLiteTest.java
+  }
+
+  public void testOneofMerge() throws Exception {
+    // Primitive Type
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      TestOneof2 message = builder.setFooInt(123).build();
+      TestOneof2 message2 = TestOneof2.newBuilder().mergeFrom(message).build();
+      assertTrue(message2.hasFooInt());
+      assertEquals(message2.getFooInt(), 123);
+    }
+
+    // String
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      TestOneof2 message = builder.setFooString("foo").build();
+      TestOneof2 message2 = TestOneof2.newBuilder().mergeFrom(message).build();
+      assertTrue(message2.hasFooString());
+      assertEquals(message2.getFooString(), "foo");
+    }
+
+    // Enum
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      TestOneof2 message = builder.setFooEnum(TestOneof2.NestedEnum.BAR).build();
+      TestOneof2 message2 = TestOneof2.newBuilder().mergeFrom(message).build();
+      assertTrue(message2.hasFooEnum());
+      assertEquals(message2.getFooEnum(), TestOneof2.NestedEnum.BAR);
+    }
+
+    // Message
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      TestOneof2 message = builder.setFooMessage(
+          TestOneof2.NestedMessage.newBuilder().setQuxInt(234).build()).build();
+      TestOneof2 message2 = TestOneof2.newBuilder().mergeFrom(message).build();
+      assertTrue(message2.hasFooMessage());
+      assertEquals(message2.getFooMessage().getQuxInt(), 234);
+    }
+  }
+
+  public void testOneofSerialization() throws Exception {
+    // Primitive Type
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      TestOneof2 message = builder.setFooInt(123).build();
+      ByteString serialized = message.toByteString();
+      TestOneof2 message2 = TestOneof2.parseFrom(serialized);
+      assertTrue(message2.hasFooInt());
+      assertEquals(message2.getFooInt(), 123);
+    }
+
+    // String
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      TestOneof2 message = builder.setFooString("foo").build();
+      ByteString serialized = message.toByteString();
+      TestOneof2 message2 = TestOneof2.parseFrom(serialized);
+      assertTrue(message2.hasFooString());
+      assertEquals(message2.getFooString(), "foo");
+    }
+
+    // Enum
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      TestOneof2 message = builder.setFooEnum(TestOneof2.NestedEnum.BAR).build();
+      ByteString serialized = message.toByteString();
+      TestOneof2 message2 = TestOneof2.parseFrom(serialized);
+      assertTrue(message2.hasFooEnum());
+      assertEquals(message2.getFooEnum(), TestOneof2.NestedEnum.BAR);
+    }
+
+    // Message
+    {
+      TestOneof2.Builder builder = TestOneof2.newBuilder();
+      TestOneof2 message = builder.setFooMessage(
+          TestOneof2.NestedMessage.newBuilder().setQuxInt(234).build()).build();
+      ByteString serialized = message.toByteString();
+      TestOneof2 message2 = TestOneof2.parseFrom(serialized);
+      assertTrue(message2.hasFooMessage());
+      assertEquals(message2.getFooMessage().getQuxInt(), 234);
+    }
+  }
+
+  public void testOneofNestedBuilderOnChangePropagation() {
+    NestedTestAllTypes.Builder parentBuilder = NestedTestAllTypes.newBuilder();
+    TestAllTypes.Builder builder = parentBuilder.getPayloadBuilder();
+    builder.getOneofNestedMessageBuilder();
+    assertTrue(builder.hasOneofNestedMessage());
+    assertTrue(parentBuilder.hasPayload());
+    NestedTestAllTypes message = parentBuilder.build();
+    assertTrue(message.hasPayload());
+    assertTrue(message.getPayload().hasOneofNestedMessage());
+  }
+
+  public void testGetRepeatedFieldBuilder() {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+
+    FieldDescriptor fieldDescriptor =
+        descriptor.findFieldByName("repeated_nested_message");
+    FieldDescriptor foreignFieldDescriptor =
+        descriptor.findFieldByName("repeated_foreign_message");
+    FieldDescriptor importFieldDescriptor =
+        descriptor.findFieldByName("repeated_import_message");
+
+    // Mutate the message with new field builder
+    // Mutate nested message
+    TestAllTypes.Builder builder1 = TestAllTypes.newBuilder();
+    Message.Builder fieldBuilder1 = builder1.newBuilderForField(
+        fieldDescriptor);
+    FieldDescriptor subFieldDescriptor1 =
+        fieldBuilder1.getDescriptorForType().findFieldByName("bb");
+    fieldBuilder1.setField(subFieldDescriptor1, 1);
+    builder1.addRepeatedField(fieldDescriptor, fieldBuilder1.build());
+
+    // Mutate foreign message
+    Message.Builder foreignFieldBuilder1 = builder1.newBuilderForField(
+        foreignFieldDescriptor);
+    FieldDescriptor subForeignFieldDescriptor1 =
+        foreignFieldBuilder1.getDescriptorForType().findFieldByName("c");
+    foreignFieldBuilder1.setField(subForeignFieldDescriptor1, 2);
+    builder1.addRepeatedField(foreignFieldDescriptor,
+        foreignFieldBuilder1.build());
+
+    // Mutate import message
+    Message.Builder importFieldBuilder1 = builder1.newBuilderForField(
+        importFieldDescriptor);
+    FieldDescriptor subImportFieldDescriptor1 =
+        importFieldBuilder1.getDescriptorForType().findFieldByName("d");
+    importFieldBuilder1.setField(subImportFieldDescriptor1, 3);
+    builder1.addRepeatedField(importFieldDescriptor,
+        importFieldBuilder1.build());
+
+    Message newMessage1 = builder1.build();
+
+    // Mutate the message with existing field builder
+    // Mutate nested message
+    TestAllTypes.Builder builder2 = TestAllTypes.newBuilder();
+    builder2.addRepeatedNestedMessageBuilder();
+    Message.Builder fieldBuilder2 = builder2.getRepeatedFieldBuilder(
+        fieldDescriptor, 0);
+    FieldDescriptor subFieldDescriptor2 =
+        fieldBuilder2.getDescriptorForType().findFieldByName("bb");
+    fieldBuilder2.setField(subFieldDescriptor2, 1);
+
+    // Mutate foreign message
+    Message.Builder foreignFieldBuilder2 = builder2.newBuilderForField(
+        foreignFieldDescriptor);
+    FieldDescriptor subForeignFieldDescriptor2 =
+        foreignFieldBuilder2.getDescriptorForType().findFieldByName("c");
+    foreignFieldBuilder2.setField(subForeignFieldDescriptor2, 2);
+    builder2.addRepeatedField(foreignFieldDescriptor,
+        foreignFieldBuilder2.build());
+
+    // Mutate import message
+    Message.Builder importFieldBuilder2 = builder2.newBuilderForField(
+        importFieldDescriptor);
+    FieldDescriptor subImportFieldDescriptor2 =
+        importFieldBuilder2.getDescriptorForType().findFieldByName("d");
+    importFieldBuilder2.setField(subImportFieldDescriptor2, 3);
+    builder2.addRepeatedField(importFieldDescriptor,
+        importFieldBuilder2.build());
+
+    Message newMessage2 = builder2.build();
+
+    // These two messages should be equal.
+    assertEquals(newMessage1, newMessage2);
+  }
+
+  public void testGetRepeatedFieldBuilderWithInitializedValue() {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+    FieldDescriptor fieldDescriptor =
+        descriptor.findFieldByName("repeated_nested_message");
+
+    // Before setting field, builder is initialized by default value. 
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.addRepeatedNestedMessageBuilder();
+    NestedMessage.Builder fieldBuilder =
+        (NestedMessage.Builder) builder.getRepeatedFieldBuilder(fieldDescriptor, 0);
+    assertEquals(0, fieldBuilder.getBb());
+
+    // Setting field value with new field builder instance.
+    builder = TestAllTypes.newBuilder();
+    NestedMessage.Builder newFieldBuilder =
+        builder.addRepeatedNestedMessageBuilder();
+    newFieldBuilder.setBb(2);
+    // Then get the field builder instance by getRepeatedFieldBuilder().
+    fieldBuilder =
+        (NestedMessage.Builder) builder.getRepeatedFieldBuilder(fieldDescriptor, 0);
+    // It should contain new value.
+    assertEquals(2, fieldBuilder.getBb());
+    // These two builder should be equal.
+    assertSame(fieldBuilder, newFieldBuilder);
+  }
+
+  public void testGetRepeatedFieldBuilderNotSupportedException() {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    try {
+      builder.getRepeatedFieldBuilder(descriptor.findFieldByName("repeated_int32"), 0);
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.getRepeatedFieldBuilder(
+          descriptor.findFieldByName("repeated_nested_enum"), 0);
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.getRepeatedFieldBuilder(descriptor.findFieldByName("optional_int32"), 0);
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.getRepeatedFieldBuilder(
+          descriptor.findFieldByName("optional_nested_enum"), 0);
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+    try {
+      builder.getRepeatedFieldBuilder(
+          descriptor.findFieldByName("optional_nested_message"), 0);
+      fail("Exception was not thrown");
+    } catch (UnsupportedOperationException e) {
+      // We expect this exception.
+    }
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/IntArrayListTest.java b/java/core/src/test/java/com/google/protobuf/IntArrayListTest.java
new file mode 100644
index 00000000..3733eb30
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/IntArrayListTest.java
@@ -0,0 +1,473 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.util.Arrays.asList;
+
+import junit.framework.TestCase;
+
+import java.util.Collections;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+
+/**
+ * Tests for {@link IntArrayList}.
+ * 
+ * @author dweis@google.com (Daniel Weis)
+ */
+public class IntArrayListTest extends TestCase {
+  
+  private static final IntArrayList UNARY_LIST = newImmutableIntArrayList(1);
+  private static final IntArrayList TERTIARY_LIST =
+      newImmutableIntArrayList(1, 2, 3);
+  
+  private IntArrayList list;
+  
+  @Override
+  protected void setUp() throws Exception {
+    list = new IntArrayList();
+  }
+  
+  public void testEmptyListReturnsSameInstance() {
+    assertSame(IntArrayList.emptyList(), IntArrayList.emptyList());
+  }
+  
+  public void testEmptyListIsImmutable() {
+    assertImmutable(IntArrayList.emptyList());
+  }
+  
+  public void testMakeImmutable() {
+    list.addInt(2);
+    list.addInt(4);
+    list.addInt(6);
+    list.addInt(8);
+    list.makeImmutable();
+    assertImmutable(list);
+  }
+  
+  public void testCopyConstructor() {
+    IntArrayList copy = new IntArrayList(TERTIARY_LIST);
+    assertEquals(TERTIARY_LIST, copy);
+
+    copy = new IntArrayList(IntArrayList.emptyList());
+    assertEquals(IntArrayList.emptyList(), copy);
+    
+    copy = new IntArrayList(asList(1, 2, 3));
+    assertEquals(asList(1, 2, 3), copy);
+
+    copy = new IntArrayList(Collections.<Integer>emptyList());
+    assertEquals(IntArrayList.emptyList(), copy);
+  }
+
+  public void testModificationWithIteration() {
+    list.addAll(asList(1, 2, 3, 4));
+    Iterator<Integer> iterator = list.iterator();
+    assertEquals(4, list.size());
+    assertEquals(1, (int) list.get(0));
+    assertEquals(1, (int) iterator.next());
+    list.set(0, 1);
+    assertEquals(2, (int) iterator.next());
+    
+    list.remove(0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+
+    iterator = list.iterator();
+    list.add(0, 0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+  }
+  
+  public void testGet() {
+    assertEquals(1, (int) TERTIARY_LIST.get(0));
+    assertEquals(2, (int) TERTIARY_LIST.get(1));
+    assertEquals(3, (int) TERTIARY_LIST.get(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testGetInt() {
+    assertEquals(1, TERTIARY_LIST.getInt(0));
+    assertEquals(2, TERTIARY_LIST.getInt(1));
+    assertEquals(3, TERTIARY_LIST.getInt(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSize() {
+    assertEquals(0, IntArrayList.emptyList().size());
+    assertEquals(1, UNARY_LIST.size());
+    assertEquals(3, TERTIARY_LIST.size());
+
+    list.addInt(2);
+    list.addInt(4);
+    list.addInt(6);
+    list.addInt(8);
+    assertEquals(4, list.size());
+    
+    list.remove(0);
+    assertEquals(3, list.size());
+    
+    list.add(16);
+    assertEquals(4, list.size());
+  }
+  
+  public void testSet() {
+    list.addInt(2);
+    list.addInt(4);
+    
+    assertEquals(2, (int) list.set(0, 0));
+    assertEquals(0, list.getInt(0));
+
+    assertEquals(4, (int) list.set(1, 0));
+    assertEquals(0, list.getInt(1));
+    
+    try {
+      list.set(-1, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.set(2, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSetInt() {
+    list.addInt(2);
+    list.addInt(4);
+    
+    assertEquals(2, list.setInt(0, 0));
+    assertEquals(0, list.getInt(0));
+
+    assertEquals(4, list.setInt(1, 0));
+    assertEquals(0, list.getInt(1));
+    
+    try {
+      list.setInt(-1, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.setInt(2, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAdd() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.add(2));
+    assertEquals(asList(2), list);
+
+    assertTrue(list.add(3));
+    list.add(0, 4);
+    assertEquals(asList(4, 2, 3), list);
+    
+    list.add(0, 1);
+    list.add(0, 0);
+    // Force a resize by getting up to 11 elements.
+    for (int i = 0; i < 6; i++) {
+      list.add(5 + i);
+    }
+    assertEquals(asList(0, 1, 4, 2, 3, 5, 6, 7, 8, 9, 10), list);
+    
+    try {
+      list.add(-1, 5);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.add(4, 5);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAddInt() {
+    assertEquals(0, list.size());
+
+    list.addInt(2);
+    assertEquals(asList(2), list);
+
+    list.addInt(3);
+    assertEquals(asList(2, 3), list);
+  }
+  
+  public void testAddAll() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.addAll(Collections.singleton(1)));
+    assertEquals(1, list.size());
+    assertEquals(1, (int) list.get(0));
+    assertEquals(1, list.getInt(0));
+    
+    assertTrue(list.addAll(asList(2, 3, 4, 5, 6)));
+    assertEquals(asList(1, 2, 3, 4, 5, 6), list);
+    
+    assertTrue(list.addAll(TERTIARY_LIST));
+    assertEquals(asList(1, 2, 3, 4, 5, 6, 1, 2, 3), list);
+
+    assertFalse(list.addAll(Collections.<Integer>emptyList()));
+    assertFalse(list.addAll(IntArrayList.emptyList()));
+  }
+  
+  public void testRemove() {
+    list.addAll(TERTIARY_LIST);
+    assertEquals(1, (int) list.remove(0));
+    assertEquals(asList(2, 3), list);
+
+    assertTrue(list.remove(Integer.valueOf(3)));
+    assertEquals(asList(2), list);
+
+    assertFalse(list.remove(Integer.valueOf(3)));
+    assertEquals(asList(2), list);
+
+    assertEquals(2, (int) list.remove(0));
+    assertEquals(asList(), list);
+    
+    try {
+      list.remove(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(0);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  private void assertImmutable(IntArrayList list) {
+    if (list.contains(1)) {
+      throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
+    }
+    
+    try {
+      list.add(1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.add(0, 1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.<Integer>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.singletonList(1));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(new IntArrayList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.singleton(1));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.<Integer>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addInt(0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.clear();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+
+    try {
+      list.remove(1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.<Integer>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.singleton(1));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.<Integer>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.singleton(1));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, 0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.setInt(0, 0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+  }
+  
+  private static IntArrayList newImmutableIntArrayList(int... elements) {
+    IntArrayList list = new IntArrayList();
+    for (int element : elements) {
+      list.addInt(element);
+    }
+    list.makeImmutable();
+    return list;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/IsValidUtf8Test.java b/java/core/src/test/java/com/google/protobuf/IsValidUtf8Test.java
new file mode 100644
index 00000000..8751baae
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/IsValidUtf8Test.java
@@ -0,0 +1,183 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.IsValidUtf8TestUtil.Shard;
+
+import junit.framework.TestCase;
+
+import java.io.UnsupportedEncodingException;
+
+/**
+ * Tests cases for {@link ByteString#isValidUtf8()}. This includes three
+ * brute force tests that actually test every permutation of one byte, two byte,
+ * and three byte sequences to ensure that the method produces the right result
+ * for every possible byte encoding where "right" means it's consistent with
+ * java's UTF-8 string encoding/decoding such that the method returns true for
+ * any sequence that will round trip when converted to a String and then back to
+ * bytes and will return false for any sequence that will not round trip.
+ * See also {@link IsValidUtf8FourByteTest}. It also includes some
+ * other more targeted tests.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ * @author martinrb@google.com (Martin Buchholz)
+ */
+public class IsValidUtf8Test extends TestCase {
+
+  /**
+   * Tests that round tripping of all two byte permutations work.
+   */
+  public void testIsValidUtf8_1Byte() throws UnsupportedEncodingException {
+    IsValidUtf8TestUtil.testBytes(1,
+        IsValidUtf8TestUtil.EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT);
+  }
+
+  /**
+   * Tests that round tripping of all two byte permutations work.
+   */
+  public void testIsValidUtf8_2Bytes() throws UnsupportedEncodingException {
+    IsValidUtf8TestUtil.testBytes(2,
+        IsValidUtf8TestUtil.EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT);
+  }
+
+  /**
+   * Tests that round tripping of all three byte permutations work.
+   */
+  public void testIsValidUtf8_3Bytes() throws UnsupportedEncodingException {
+    // Travis' OOM killer doesn't like this test
+    if (System.getenv("TRAVIS") == null) {
+      IsValidUtf8TestUtil.testBytes(3,
+          IsValidUtf8TestUtil.EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT);
+    }
+  }
+
+  /**
+   * Tests that round tripping of a sample of four byte permutations work.
+   * All permutations are prohibitively expensive to test for automated runs;
+   * {@link IsValidUtf8FourByteTest} is used for full coverage. This method
+   * tests specific four-byte cases.
+   */
+  public void testIsValidUtf8_4BytesSamples()
+      throws UnsupportedEncodingException {
+    // Valid 4 byte.
+    assertValidUtf8(0xF0, 0xA4, 0xAD, 0xA2);
+
+    // Bad trailing bytes
+    assertInvalidUtf8(0xF0, 0xA4, 0xAD, 0x7F);
+    assertInvalidUtf8(0xF0, 0xA4, 0xAD, 0xC0);
+
+    // Special cases for byte2
+    assertInvalidUtf8(0xF0, 0x8F, 0xAD, 0xA2);
+    assertInvalidUtf8(0xF4, 0x90, 0xAD, 0xA2);
+  }
+
+  /**
+   * Tests some hard-coded test cases.
+   */
+  public void testSomeSequences() {
+    // Empty
+    assertTrue(asBytes("").isValidUtf8());
+
+    // One-byte characters, including control characters
+    assertTrue(asBytes("\u0000abc\u007f").isValidUtf8());
+
+    // Two-byte characters
+    assertTrue(asBytes("\u00a2\u00a2").isValidUtf8());
+
+    // Three-byte characters
+    assertTrue(asBytes("\u020ac\u020ac").isValidUtf8());
+
+    // Four-byte characters
+    assertTrue(asBytes("\u024B62\u024B62").isValidUtf8());
+
+    // Mixed string
+    assertTrue(
+        asBytes("a\u020ac\u00a2b\\u024B62u020acc\u00a2de\u024B62")
+        .isValidUtf8());
+
+    // Not a valid string
+    assertInvalidUtf8(-1, 0, -1, 0);
+  }
+
+  private byte[] toByteArray(int... bytes) {
+    byte[] realBytes = new byte[bytes.length];
+    for (int i = 0; i < bytes.length; i++) {
+      realBytes[i] = (byte) bytes[i];
+    }
+    return realBytes;
+  }
+
+  private ByteString toByteString(int... bytes) {
+    return ByteString.copyFrom(toByteArray(bytes));
+  }
+
+  private void assertValidUtf8(int[] bytes, boolean not) {
+    byte[] realBytes = toByteArray(bytes);
+    assertTrue(not ^ Utf8.isValidUtf8(realBytes));
+    assertTrue(not ^ Utf8.isValidUtf8(realBytes, 0, bytes.length));
+    ByteString lit = ByteString.copyFrom(realBytes);
+    ByteString sub = lit.substring(0, bytes.length);
+    assertTrue(not ^ lit.isValidUtf8());
+    assertTrue(not ^ sub.isValidUtf8());
+    ByteString[] ropes = {
+      RopeByteString.newInstanceForTest(ByteString.EMPTY, lit),
+      RopeByteString.newInstanceForTest(ByteString.EMPTY, sub),
+      RopeByteString.newInstanceForTest(lit, ByteString.EMPTY),
+      RopeByteString.newInstanceForTest(sub, ByteString.EMPTY),
+      RopeByteString.newInstanceForTest(sub, lit)
+    };
+    for (ByteString rope : ropes) {
+      assertTrue(not ^ rope.isValidUtf8());
+    }
+  }
+
+  private void assertValidUtf8(int... bytes) {
+    assertValidUtf8(bytes, false);
+  }
+
+  private void assertInvalidUtf8(int... bytes) {
+    assertValidUtf8(bytes, true);
+  }
+
+  private static ByteString asBytes(String s) {
+    return ByteString.copyFromUtf8(s);
+  }
+
+  public void testShardsHaveExpectedRoundTrippables() {
+    // A sanity check.
+    int actual = 0;
+    for (Shard shard : IsValidUtf8TestUtil.FOUR_BYTE_SHARDS) {
+      actual += shard.expected;
+    }
+    assertEquals(IsValidUtf8TestUtil.EXPECTED_FOUR_BYTE_ROUNDTRIPPABLE_COUNT,
+        actual);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java b/java/core/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java
new file mode 100644
index 00000000..321669f3
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java
@@ -0,0 +1,420 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static junit.framework.Assert.*;
+
+import java.io.UnsupportedEncodingException;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.CharsetEncoder;
+import java.nio.charset.CoderResult;
+import java.nio.charset.CodingErrorAction;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+import java.util.logging.Logger;
+
+/**
+ * Shared testing code for {@link IsValidUtf8Test} and
+ * {@link IsValidUtf8FourByteTest}.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ * @author martinrb@google.com (Martin Buchholz)
+ */
+class IsValidUtf8TestUtil {
+  private static Logger logger = Logger.getLogger(
+      IsValidUtf8TestUtil.class.getName());
+
+  // 128 - [chars 0x0000 to 0x007f]
+  static long ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x007f - 0x0000 + 1;
+
+  // 128
+  static long EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT =
+      ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS;
+
+  // 1920 [chars 0x0080 to 0x07FF]
+  static long TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x07FF - 0x0080 + 1;
+
+  // 18,304
+  static long EXPECTED_TWO_BYTE_ROUNDTRIPPABLE_COUNT =
+      // Both bytes are one byte characters
+      (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 2) +
+      // The possible number of two byte characters
+      TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS;
+
+  // 2048
+  static long THREE_BYTE_SURROGATES = 2 * 1024;
+
+  // 61,440 [chars 0x0800 to 0xFFFF, minus surrogates]
+  static long THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS =
+      0xFFFF - 0x0800 + 1 - THREE_BYTE_SURROGATES;
+
+  // 2,650,112
+  static long EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT =
+      // All one byte characters
+      (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 3) +
+      // One two byte character and a one byte character
+      2 * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS *
+          ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS +
+       // Three byte characters
+      THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS;
+
+  // 1,048,576 [chars 0x10000L to 0x10FFFF]
+  static long FOUR_BYTE_ROUNDTRIPPABLE_CHARACTERS = 0x10FFFF - 0x10000L + 1;
+
+  // 289,571,839
+  static long EXPECTED_FOUR_BYTE_ROUNDTRIPPABLE_COUNT =
+      // All one byte characters
+      (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 4) +
+      // One and three byte characters
+      2 * THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS *
+          ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS +
+      // Two two byte characters
+      TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS +
+      // Permutations of one and two byte characters
+      3 * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS *
+          ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS *
+          ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS +
+      // Four byte characters
+      FOUR_BYTE_ROUNDTRIPPABLE_CHARACTERS;
+
+  static class Shard {
+    final long index;
+    final long start;
+    final long lim;
+    final long expected;
+
+
+    public Shard(long index, long start, long lim, long expected) {
+      assertTrue(start < lim);
+      this.index = index;
+      this.start = start;
+      this.lim = lim;
+      this.expected = expected;
+    }
+  }
+
+  static final long[] FOUR_BYTE_SHARDS_EXPECTED_ROUNTRIPPABLES =
+      generateFourByteShardsExpectedRunnables();
+
+  private static long[] generateFourByteShardsExpectedRunnables() {
+    long[] expected = new long[128];
+
+    // 0-63 are all 5300224
+    for (int i = 0; i <= 63; i++) {
+      expected[i] = 5300224;
+    }
+
+    // 97-111 are all 2342912
+    for (int i = 97; i <= 111; i++) {
+     expected[i] = 2342912;
+    }
+
+    // 113-117 are all 1048576
+    for (int i = 113; i <= 117; i++) {
+      expected[i] = 1048576;
+    }
+
+    // One offs
+    expected[112] = 786432;
+    expected[118] = 786432;
+    expected[119] = 1048576;
+    expected[120] = 458752;
+    expected[121] = 524288;
+    expected[122] = 65536;
+
+    // Anything not assigned was the default 0.
+    return expected;
+  }
+
+  static final List<Shard> FOUR_BYTE_SHARDS = generateFourByteShards(
+      128, FOUR_BYTE_SHARDS_EXPECTED_ROUNTRIPPABLES);
+
+
+  private static List<Shard> generateFourByteShards(
+      int numShards, long[] expected) {
+    assertEquals(numShards, expected.length);
+    List<Shard> shards = new ArrayList<Shard>(numShards);
+    long LIM = 1L << 32;
+    long increment = LIM / numShards;
+    assertTrue(LIM % numShards == 0);
+    for (int i = 0; i < numShards; i++) {
+      shards.add(new Shard(i,
+          increment * i,
+          increment * (i + 1),
+          expected[i]));
+    }
+    return shards;
+  }
+
+  /**
+   * Helper to run the loop to test all the permutations for the number of bytes
+   * specified.
+   *
+   * @param numBytes the number of bytes in the byte array
+   * @param expectedCount the expected number of roundtrippable permutations
+   */
+  static void testBytes(int numBytes, long expectedCount)
+      throws UnsupportedEncodingException {
+    testBytes(numBytes, expectedCount, 0, -1);
+  }
+
+  /**
+   * Helper to run the loop to test all the permutations for the number of bytes
+   * specified. This overload is useful for debugging to get the loop to start
+   * at a certain character.
+   *
+   * @param numBytes the number of bytes in the byte array
+   * @param expectedCount the expected number of roundtrippable permutations
+   * @param start the starting bytes encoded as a long as big-endian
+   * @param lim the limit of bytes to process encoded as a long as big-endian,
+   *     or -1 to mean the max limit for numBytes
+   */
+  static void testBytes(int numBytes, long expectedCount, long start, long lim)
+      throws UnsupportedEncodingException {
+    Random rnd = new Random();
+    byte[] bytes = new byte[numBytes];
+
+    if (lim == -1) {
+      lim = 1L << (numBytes * 8);
+    }
+    long count = 0;
+    long countRoundTripped = 0;
+    for (long byteChar = start; byteChar < lim; byteChar++) {
+      long tmpByteChar = byteChar;
+      for (int i = 0; i < numBytes; i++) {
+        bytes[bytes.length - i - 1] = (byte) tmpByteChar;
+        tmpByteChar = tmpByteChar >> 8;
+      }
+      ByteString bs = ByteString.copyFrom(bytes);
+      boolean isRoundTrippable = bs.isValidUtf8();
+      String s = new String(bytes, Internal.UTF_8);
+      byte[] bytesReencoded = s.getBytes(Internal.UTF_8);
+      boolean bytesEqual = Arrays.equals(bytes, bytesReencoded);
+
+      if (bytesEqual != isRoundTrippable) {
+        outputFailure(byteChar, bytes, bytesReencoded);
+      }
+
+      // Check agreement with static Utf8 methods.
+      assertEquals(isRoundTrippable, Utf8.isValidUtf8(bytes));
+      assertEquals(isRoundTrippable, Utf8.isValidUtf8(bytes, 0, numBytes));
+
+      // Test partial sequences.
+      // Partition numBytes into three segments (not necessarily non-empty).
+      int i = rnd.nextInt(numBytes);
+      int j = rnd.nextInt(numBytes);
+      if (j < i) {
+        int tmp = i; i = j; j = tmp;
+      }
+      int state1 = Utf8.partialIsValidUtf8(Utf8.COMPLETE, bytes, 0, i);
+      int state2 = Utf8.partialIsValidUtf8(state1, bytes, i, j);
+      int state3 = Utf8.partialIsValidUtf8(state2, bytes, j, numBytes);
+      if (isRoundTrippable != (state3 == Utf8.COMPLETE)) {
+        System.out.printf("state=%04x %04x %04x i=%d j=%d%n",
+                          state1, state2, state3, i, j);
+        outputFailure(byteChar, bytes, bytesReencoded);
+      }
+      assertEquals(isRoundTrippable, (state3 == Utf8.COMPLETE));
+
+      // Test ropes built out of small partial sequences
+      ByteString rope = RopeByteString.newInstanceForTest(
+          bs.substring(0, i),
+          RopeByteString.newInstanceForTest(
+              bs.substring(i, j),
+              bs.substring(j, numBytes)));
+      assertSame(RopeByteString.class, rope.getClass());
+
+      ByteString[] byteStrings = { bs, bs.substring(0, numBytes), rope };
+      for (ByteString x : byteStrings) {
+        assertEquals(isRoundTrippable,
+                     x.isValidUtf8());
+        assertEquals(state3,
+                     x.partialIsValidUtf8(Utf8.COMPLETE, 0, numBytes));
+
+        assertEquals(state1,
+                     x.partialIsValidUtf8(Utf8.COMPLETE, 0, i));
+        assertEquals(state1,
+                     x.substring(0, i).partialIsValidUtf8(Utf8.COMPLETE, 0, i));
+        assertEquals(state2,
+                     x.partialIsValidUtf8(state1, i, j - i));
+        assertEquals(state2,
+                     x.substring(i, j).partialIsValidUtf8(state1, 0, j - i));
+        assertEquals(state3,
+                     x.partialIsValidUtf8(state2, j, numBytes - j));
+        assertEquals(state3,
+                     x.substring(j, numBytes)
+                     .partialIsValidUtf8(state2, 0, numBytes - j));
+      }
+
+      // ByteString reduplication should not affect its UTF-8 validity.
+      ByteString ropeADope =
+          RopeByteString.newInstanceForTest(bs, bs.substring(0, numBytes));
+      assertEquals(isRoundTrippable, ropeADope.isValidUtf8());
+
+      if (isRoundTrippable) {
+        countRoundTripped++;
+      }
+      count++;
+      if (byteChar != 0 && byteChar % 1000000L == 0) {
+        logger.info("Processed " + (byteChar / 1000000L) +
+            " million characters");
+      }
+    }
+    logger.info("Round tripped " + countRoundTripped + " of " + count);
+    assertEquals(expectedCount, countRoundTripped);
+  }
+
+  /**
+   * Variation of {@link #testBytes} that does less allocation using the
+   * low-level encoders/decoders directly. Checked in because it's useful for
+   * debugging when trying to process bytes faster, but since it doesn't use the
+   * actual String class, it's possible for incompatibilities to develop
+   * (although unlikely).
+   *
+   * @param numBytes the number of bytes in the byte array
+   * @param expectedCount the expected number of roundtrippable permutations
+   * @param start the starting bytes encoded as a long as big-endian
+   * @param lim the limit of bytes to process encoded as a long as big-endian,
+   *     or -1 to mean the max limit for numBytes
+   */
+  void testBytesUsingByteBuffers(
+      int numBytes, long expectedCount, long start, long lim)
+      throws UnsupportedEncodingException {
+    CharsetDecoder decoder = Internal.UTF_8.newDecoder()
+        .onMalformedInput(CodingErrorAction.REPLACE)
+        .onUnmappableCharacter(CodingErrorAction.REPLACE);
+    CharsetEncoder encoder = Internal.UTF_8.newEncoder()
+        .onMalformedInput(CodingErrorAction.REPLACE)
+        .onUnmappableCharacter(CodingErrorAction.REPLACE);
+    byte[] bytes = new byte[numBytes];
+    int maxChars = (int) (decoder.maxCharsPerByte() * numBytes) + 1;
+    char[] charsDecoded =
+        new char[(int) (decoder.maxCharsPerByte() * numBytes) + 1];
+    int maxBytes = (int) (encoder.maxBytesPerChar() * maxChars) + 1;
+    byte[] bytesReencoded = new byte[maxBytes];
+
+    ByteBuffer bb = ByteBuffer.wrap(bytes);
+    CharBuffer cb = CharBuffer.wrap(charsDecoded);
+    ByteBuffer bbReencoded = ByteBuffer.wrap(bytesReencoded);
+    if (lim == -1) {
+      lim = 1L << (numBytes * 8);
+    }
+    long count = 0;
+    long countRoundTripped = 0;
+    for (long byteChar = start; byteChar < lim; byteChar++) {
+      bb.rewind();
+      bb.limit(bytes.length);
+      cb.rewind();
+      cb.limit(charsDecoded.length);
+      bbReencoded.rewind();
+      bbReencoded.limit(bytesReencoded.length);
+      encoder.reset();
+      decoder.reset();
+      long tmpByteChar = byteChar;
+      for (int i = 0; i < bytes.length; i++) {
+        bytes[bytes.length - i - 1] = (byte) tmpByteChar;
+        tmpByteChar = tmpByteChar >> 8;
+      }
+      boolean isRoundTrippable = ByteString.copyFrom(bytes).isValidUtf8();
+      CoderResult result = decoder.decode(bb, cb, true);
+      assertFalse(result.isError());
+      result = decoder.flush(cb);
+      assertFalse(result.isError());
+
+      int charLen = cb.position();
+      cb.rewind();
+      cb.limit(charLen);
+      result = encoder.encode(cb, bbReencoded, true);
+      assertFalse(result.isError());
+      result = encoder.flush(bbReencoded);
+      assertFalse(result.isError());
+
+      boolean bytesEqual = true;
+      int bytesLen = bbReencoded.position();
+      if (bytesLen != numBytes) {
+        bytesEqual = false;
+      } else {
+        for (int i = 0; i < numBytes; i++) {
+          if (bytes[i] != bytesReencoded[i]) {
+            bytesEqual = false;
+            break;
+          }
+        }
+      }
+      if (bytesEqual != isRoundTrippable) {
+        outputFailure(byteChar, bytes, bytesReencoded, bytesLen);
+      }
+
+      count++;
+      if (isRoundTrippable) {
+        countRoundTripped++;
+      }
+      if (byteChar != 0 && byteChar % 1000000 == 0) {
+        logger.info("Processed " + (byteChar / 1000000) +
+            " million characters");
+      }
+    }
+    logger.info("Round tripped " + countRoundTripped + " of " + count);
+    assertEquals(expectedCount, countRoundTripped);
+  }
+
+  private static void outputFailure(long byteChar, byte[] bytes, byte[] after) {
+    outputFailure(byteChar, bytes, after, after.length);
+  }
+
+  private static void outputFailure(long byteChar, byte[] bytes, byte[] after,
+      int len) {
+    fail("Failure: (" + Long.toHexString(byteChar) + ") " +
+        toHexString(bytes) + " => " + toHexString(after, len));
+  }
+
+  private static String toHexString(byte[] b) {
+    return toHexString(b, b.length);
+  }
+
+  private static String toHexString(byte[] b, int len) {
+    StringBuilder s = new StringBuilder();
+    s.append("\"");
+    for (int i = 0; i < len; i++) {
+      if (i > 0) {
+        s.append(" ");
+      }
+      s.append(String.format("%02x", b[i] & 0xFF));
+    }
+    s.append("\"");
+    return s.toString();
+  }
+
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java b/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
new file mode 100644
index 00000000..211b5697
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
@@ -0,0 +1,271 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static protobuf_unittest.UnittestProto.optionalInt32Extension;
+import static protobuf_unittest.UnittestProto.optionalInt64Extension;
+
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+
+import java.io.IOException;
+import junit.framework.TestCase;
+
+/**
+ * Unit test for {@link LazyFieldLite}.
+ *
+ * @author xiangl@google.com (Xiang Li)
+ */
+public class LazyFieldLiteTest extends TestCase {
+
+  public void testGetValue() {
+    MessageLite message = TestUtil.getAllSet();
+    LazyFieldLite lazyField = createLazyFieldLiteFromMessage(message);
+    assertEquals(message, lazyField.getValue(TestAllTypes.getDefaultInstance()));
+    changeValue(lazyField);
+    assertNotEqual(message, lazyField.getValue(TestAllTypes.getDefaultInstance()));
+  }
+
+  public void testGetValueEx() throws Exception {
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    LazyFieldLite lazyField = createLazyFieldLiteFromMessage(message);
+    assertEquals(message, lazyField.getValue(TestAllExtensions.getDefaultInstance()));
+    changeValue(lazyField);
+    assertNotEqual(message, lazyField.getValue(TestAllExtensions.getDefaultInstance()));
+  }
+
+  public void testSetValue() {
+    MessageLite message = TestUtil.getAllSet();
+    LazyFieldLite lazyField = createLazyFieldLiteFromMessage(message);
+    changeValue(lazyField);
+    assertNotEqual(message, lazyField.getValue(TestAllTypes.getDefaultInstance()));
+    message = lazyField.getValue(TestAllTypes.getDefaultInstance());
+    changeValue(lazyField);
+    assertEquals(message, lazyField.getValue(TestAllTypes.getDefaultInstance()));
+  }
+
+  public void testSetValueEx() throws Exception {
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    LazyFieldLite lazyField = createLazyFieldLiteFromMessage(message);
+    changeValue(lazyField);
+    assertNotEqual(message, lazyField.getValue(TestAllExtensions.getDefaultInstance()));
+    MessageLite value = lazyField.getValue(TestAllExtensions.getDefaultInstance());
+    changeValue(lazyField);
+    assertEquals(value, lazyField.getValue(TestAllExtensions.getDefaultInstance()));
+  }
+
+  public void testGetSerializedSize() {
+    MessageLite message = TestUtil.getAllSet();
+    LazyFieldLite lazyField = createLazyFieldLiteFromMessage(message);
+    assertEquals(message.getSerializedSize(), lazyField.getSerializedSize());
+    changeValue(lazyField);
+    assertNotEqual(message.getSerializedSize(), lazyField.getSerializedSize());
+  }
+
+  public void testGetSerializedSizeEx() throws Exception {
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    LazyFieldLite lazyField = createLazyFieldLiteFromMessage(message);
+    assertEquals(message.getSerializedSize(), lazyField.getSerializedSize());
+    changeValue(lazyField);
+    assertNotEqual(message.getSerializedSize(), lazyField.getSerializedSize());
+  }
+
+  public void testGetByteString() {
+    MessageLite message = TestUtil.getAllSet();
+    LazyFieldLite lazyField = createLazyFieldLiteFromMessage(message);
+    assertEquals(message.toByteString(), lazyField.toByteString());
+    changeValue(lazyField);
+    assertNotEqual(message.toByteString(), lazyField.toByteString());
+  }
+
+  public void testGetByteStringEx() throws Exception {
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    LazyFieldLite lazyField = createLazyFieldLiteFromMessage(message);
+    assertEquals(message.toByteString(), lazyField.toByteString());
+    changeValue(lazyField);
+    assertNotEqual(message.toByteString(), lazyField.toByteString());
+  }
+
+  public void testMergeExtensions() throws Exception {
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    LazyFieldLite original = createLazyFieldLiteFromMessage(message);
+    LazyFieldLite merged = new LazyFieldLite();
+    merged.merge(original);
+    TestAllExtensions value = (TestAllExtensions) merged.getValue(
+        TestAllExtensions.getDefaultInstance());
+    assertEquals(message, value);
+  }
+
+  public void testEmptyLazyField() throws Exception {
+    LazyFieldLite field = new LazyFieldLite();
+    assertEquals(0, field.getSerializedSize());
+    assertEquals(ByteString.EMPTY, field.toByteString());
+  }
+
+  public void testInvalidProto() throws Exception {
+    // Silently fails and uses the default instance.
+    LazyFieldLite field = new LazyFieldLite(
+        TestUtil.getExtensionRegistry(), ByteString.copyFromUtf8("invalid"));
+    assertEquals(
+        TestAllTypes.getDefaultInstance(), field.getValue(TestAllTypes.getDefaultInstance()));
+    assertEquals(0, field.getSerializedSize());
+    assertEquals(ByteString.EMPTY, field.toByteString());
+  }
+
+  public void testMergeBeforeParsing() throws Exception {
+    TestAllTypes message1 = TestAllTypes.newBuilder().setOptionalInt32(1).build();
+    LazyFieldLite field1 = createLazyFieldLiteFromMessage(message1);
+    TestAllTypes message2 = TestAllTypes.newBuilder().setOptionalInt64(2).build();
+    LazyFieldLite field2 = createLazyFieldLiteFromMessage(message2);
+
+    field1.merge(field2);
+    TestAllTypes expected =
+        TestAllTypes.newBuilder().setOptionalInt32(1).setOptionalInt64(2).build();
+    assertEquals(expected, field1.getValue(TestAllTypes.getDefaultInstance()));
+  }
+
+  public void testMergeOneNotParsed() throws Exception {
+    // Test a few different paths that involve one message that was not parsed.
+    TestAllTypes message1 = TestAllTypes.newBuilder().setOptionalInt32(1).build();
+    TestAllTypes message2 = TestAllTypes.newBuilder().setOptionalInt64(2).build();
+    TestAllTypes expected =
+        TestAllTypes.newBuilder().setOptionalInt32(1).setOptionalInt64(2).build();
+
+    LazyFieldLite field1 = LazyFieldLite.fromValue(message1);
+    field1.getValue(TestAllTypes.getDefaultInstance());  // Force parsing.
+    LazyFieldLite field2 = createLazyFieldLiteFromMessage(message2);
+    field1.merge(field2);
+    assertEquals(expected, field1.getValue(TestAllTypes.getDefaultInstance()));
+
+    // Now reverse which one is parsed first.
+    field1 = LazyFieldLite.fromValue(message1);
+    field2 = createLazyFieldLiteFromMessage(message2);
+    field2.getValue(TestAllTypes.getDefaultInstance());  // Force parsing.
+    field1.merge(field2);
+    assertEquals(expected, field1.getValue(TestAllTypes.getDefaultInstance()));
+  }
+
+  public void testMergeInvalid() throws Exception {
+    // Test a few different paths that involve one message that was not parsed.
+    TestAllTypes message = TestAllTypes.newBuilder().setOptionalInt32(1).build();
+    LazyFieldLite valid = LazyFieldLite.fromValue(message);
+    LazyFieldLite invalid = new LazyFieldLite(
+        TestUtil.getExtensionRegistry(), ByteString.copyFromUtf8("invalid"));
+    invalid.merge(valid);
+
+    // We swallow the exception and just use the set field.
+    assertEquals(message, invalid.getValue(TestAllTypes.getDefaultInstance()));
+  }
+
+  public void testMergeKeepsExtensionsWhenPossible() throws Exception {
+    // In this test we attempt to only use the empty registry, which will strip out all extensions
+    // when serializing and then parsing. We verify that each code path will attempt to not
+    // serialize and parse a message that was set directly without going through the
+    // extensionRegistry.
+    TestAllExtensions messageWithExtensions =
+        TestAllExtensions.newBuilder().setExtension(optionalInt32Extension, 42).build();
+    TestAllExtensions emptyMessage = TestAllExtensions.newBuilder().build();
+
+    ExtensionRegistryLite emptyRegistry = ExtensionRegistryLite.getEmptyRegistry();
+
+    LazyFieldLite field = LazyFieldLite.fromValue(messageWithExtensions);
+    field.merge(createLazyFieldLiteFromMessage(emptyRegistry, emptyMessage));
+    assertEquals(messageWithExtensions, field.getValue(TestAllExtensions.getDefaultInstance()));
+
+    // Now reverse the order of the merging.
+    field = createLazyFieldLiteFromMessage(emptyRegistry, emptyMessage);
+    field.merge(LazyFieldLite.fromValue(messageWithExtensions));
+    assertEquals(messageWithExtensions, field.getValue(TestAllExtensions.getDefaultInstance()));
+
+    // Now try parsing the empty field first.
+    field = LazyFieldLite.fromValue(messageWithExtensions);
+    LazyFieldLite other = createLazyFieldLiteFromMessage(emptyRegistry, emptyMessage);
+    other.getValue(TestAllExtensions.getDefaultInstance());  // Force parsing.
+    field.merge(other);
+    assertEquals(messageWithExtensions, field.getValue(TestAllExtensions.getDefaultInstance()));
+
+    // And again reverse.
+    field = createLazyFieldLiteFromMessage(emptyRegistry, emptyMessage);
+    field.getValue(TestAllExtensions.getDefaultInstance());  // Force parsing.
+    other = LazyFieldLite.fromValue(messageWithExtensions);
+    field.merge(other);
+    assertEquals(messageWithExtensions, field.getValue(TestAllExtensions.getDefaultInstance()));
+  }
+
+  public void testMergeMightLoseExtensions() throws Exception {
+    // Test that we don't know about the extensions when parsing.
+    TestAllExtensions message1 =
+        TestAllExtensions.newBuilder().setExtension(optionalInt32Extension, 1).build();
+    TestAllExtensions message2 =
+        TestAllExtensions.newBuilder().setExtension(optionalInt64Extension, 2L).build();
+
+    LazyFieldLite field = LazyFieldLite.fromValue(message1);
+    field.merge(LazyFieldLite.fromValue(message2));
+
+    // We lose the extensions from message 2 because we have to serialize it and then parse it
+    // again, using the empty registry this time.
+    TestAllExtensions value =
+        (TestAllExtensions) field.getValue(TestAllExtensions.getDefaultInstance());
+    assertTrue(value.hasExtension(optionalInt32Extension));
+    assertEquals(Integer.valueOf(1), value.getExtension(optionalInt32Extension));
+    assertFalse(value.hasExtension(optionalInt64Extension));
+
+    // The field is still there, it is just unknown.
+    assertTrue(value.getUnknownFields()
+        .hasField(optionalInt64Extension.getDescriptor().getNumber()));
+  }
+
+
+  // Help methods.
+
+  private LazyFieldLite createLazyFieldLiteFromMessage(MessageLite message) {
+    return createLazyFieldLiteFromMessage(TestUtil.getExtensionRegistry(), message);
+  }
+
+  private LazyFieldLite createLazyFieldLiteFromMessage(
+      ExtensionRegistryLite extensionRegistry, MessageLite message) {
+    ByteString bytes = message.toByteString();
+    return new LazyFieldLite(extensionRegistry, bytes);
+  }
+
+  private void changeValue(LazyFieldLite lazyField) {
+    TestAllTypes.Builder builder = TestUtil.getAllSet().toBuilder();
+    builder.addRepeatedBool(true);
+    MessageLite newMessage = builder.build();
+    lazyField.setValue(newMessage);
+  }
+
+  private void assertNotEqual(Object unexpected, Object actual) {
+    assertFalse(unexpected == actual
+        || (unexpected != null && unexpected.equals(actual)));
+  }
+
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java b/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
new file mode 100644
index 00000000..2b900065
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
@@ -0,0 +1,121 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+
+import java.io.IOException;
+import junit.framework.TestCase;
+
+/**
+ * Unit test for {@link LazyField}.
+ *
+ * @author xiangl@google.com (Xiang Li)
+ */
+public class LazyFieldTest extends TestCase {
+  public void testHashCode() {
+    MessageLite message = TestUtil.getAllSet();
+    LazyField lazyField =
+        createLazyFieldFromMessage(message);
+    assertEquals(message.hashCode(), lazyField.hashCode());
+    lazyField.getValue();
+    assertEquals(message.hashCode(), lazyField.hashCode());
+    changeValue(lazyField);
+    // make sure two messages have different hash code
+    assertNotEqual(message.hashCode(), lazyField.hashCode());
+  }
+
+  public void testHashCodeEx() throws Exception {
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    LazyField lazyField = createLazyFieldFromMessage(message);
+    assertEquals(message.hashCode(), lazyField.hashCode());
+    lazyField.getValue();
+    assertEquals(message.hashCode(), lazyField.hashCode());
+    changeValue(lazyField);
+    // make sure two messages have different hash code
+    assertNotEqual(message.hashCode(), lazyField.hashCode());
+  }
+
+  public void testGetValue() {
+    MessageLite message = TestUtil.getAllSet();
+    LazyField lazyField = createLazyFieldFromMessage(message);
+    assertEquals(message, lazyField.getValue());
+    changeValue(lazyField);
+    assertNotEqual(message, lazyField.getValue());
+  }
+
+  public void testGetValueEx() throws Exception {
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    LazyField lazyField = createLazyFieldFromMessage(message);
+    assertEquals(message, lazyField.getValue());
+    changeValue(lazyField);
+    assertNotEqual(message, lazyField.getValue());
+  }
+
+  public void testEqualsObject() {
+    MessageLite message = TestUtil.getAllSet();
+    LazyField lazyField = createLazyFieldFromMessage(message);
+    assertTrue(lazyField.equals(message));
+    changeValue(lazyField);
+    assertFalse(lazyField.equals(message));
+    assertFalse(message.equals(lazyField.getValue()));
+  }
+
+  public void testEqualsObjectEx() throws Exception {
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    LazyField lazyField = createLazyFieldFromMessage(message);
+    assertTrue(lazyField.equals(message));
+    changeValue(lazyField);
+    assertFalse(lazyField.equals(message));
+    assertFalse(message.equals(lazyField.getValue()));
+  }
+
+  // Help methods.
+
+  private LazyField createLazyFieldFromMessage(MessageLite message) {
+    ByteString bytes = message.toByteString();
+    return new LazyField(message.getDefaultInstanceForType(),
+        TestUtil.getExtensionRegistry(), bytes);
+  }
+
+  private void changeValue(LazyField lazyField) {
+    TestAllTypes.Builder builder = TestUtil.getAllSet().toBuilder();
+    builder.addRepeatedBool(true);
+    MessageLite newMessage = builder.build();
+    lazyField.setValue(newMessage);
+  }
+
+  private void assertNotEqual(Object unexpected, Object actual) {
+    assertFalse(unexpected == actual
+        || (unexpected != null && unexpected.equals(actual)));
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LazyMessageLiteTest.java b/java/core/src/test/java/com/google/protobuf/LazyMessageLiteTest.java
new file mode 100644
index 00000000..afe0fffd
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LazyMessageLiteTest.java
@@ -0,0 +1,307 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.LazyFieldsLite.LazyExtension;
+import protobuf_unittest.LazyFieldsLite.LazyInnerMessageLite;
+import protobuf_unittest.LazyFieldsLite.LazyMessageLite;
+import protobuf_unittest.LazyFieldsLite.LazyNestedInnerMessageLite;
+
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+
+/**
+ * Unit test for messages with lazy fields.
+ *
+ * @author niwasaki@google.com (Naoki Iwasaki)
+ */
+public class LazyMessageLiteTest extends TestCase {
+
+  private Parser<LazyInnerMessageLite> originalLazyInnerMessageLiteParser;
+
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+  }
+
+  @Override
+  protected void tearDown() throws Exception {
+    super.tearDown();
+  }
+
+  public void testSetValues() {
+    LazyNestedInnerMessageLite nested = LazyNestedInnerMessageLite.newBuilder()
+        .setNum(3)
+        .build();
+    LazyInnerMessageLite inner = LazyInnerMessageLite.newBuilder()
+        .setNum(2)
+        .setNested(nested)
+        .build();
+    LazyMessageLite outer = LazyMessageLite.newBuilder()
+        .setNum(1)
+        .setInner(inner)
+        .setOneofNum(123)
+        .setOneofInner(inner)
+        .build();
+
+    assertEquals(1, outer.getNum());
+    assertEquals(421, outer.getNumWithDefault());
+
+    assertEquals(2, outer.getInner().getNum());
+    assertEquals(42, outer.getInner().getNumWithDefault());
+
+    assertEquals(3, outer.getInner().getNested().getNum());
+    assertEquals(4, outer.getInner().getNested().getNumWithDefault());
+
+    assertFalse(outer.hasOneofNum());
+    assertTrue(outer.hasOneofInner());
+
+    assertEquals(2, outer.getOneofInner().getNum());
+    assertEquals(42, outer.getOneofInner().getNumWithDefault());
+    assertEquals(3, outer.getOneofInner().getNested().getNum());
+    assertEquals(4, outer.getOneofInner().getNested().getNumWithDefault());
+  }
+
+  public void testSetRepeatedValues() {
+    LazyMessageLite outer = LazyMessageLite.newBuilder()
+        .setNum(1)
+        .addRepeatedInner(LazyInnerMessageLite.newBuilder().setNum(119))
+        .addRepeatedInner(LazyInnerMessageLite.newBuilder().setNum(122))
+        .build();
+
+    assertEquals(1, outer.getNum());
+    assertEquals(2, outer.getRepeatedInnerCount());
+    assertEquals(119, outer.getRepeatedInner(0).getNum());
+    assertEquals(122, outer.getRepeatedInner(1).getNum());
+  }
+
+  public void testAddAll() {
+    ArrayList<LazyInnerMessageLite> inners = new ArrayList<LazyInnerMessageLite>();
+    int count = 4;
+    for (int i = 0; i < count; i++) {
+      LazyInnerMessageLite inner = LazyInnerMessageLite.newBuilder()
+          .setNum(i)
+          .build();
+      inners.add(inner);
+    }
+
+    LazyMessageLite outer = LazyMessageLite.newBuilder()
+        .addAllRepeatedInner(inners)
+        .build();
+    assertEquals(count, outer.getRepeatedInnerCount());
+    for (int i = 0; i < count; i++) {
+      assertEquals(i, outer.getRepeatedInner(i).getNum());
+    }
+  }
+
+  public void testGetDefaultValues() {
+    LazyMessageLite outer = LazyMessageLite.newBuilder()
+        .build();
+
+    assertEquals(0, outer.getNum());
+    assertEquals(421, outer.getNumWithDefault());
+
+    assertEquals(0, outer.getInner().getNum());
+    assertEquals(42, outer.getInner().getNumWithDefault());
+
+    assertEquals(0, outer.getInner().getNested().getNum());
+    assertEquals(4, outer.getInner().getNested().getNumWithDefault());
+
+    assertEquals(0, outer.getOneofNum());
+
+    assertEquals(0, outer.getOneofInner().getNum());
+    assertEquals(42, outer.getOneofInner().getNumWithDefault());
+    assertEquals(0, outer.getOneofInner().getNested().getNum());
+    assertEquals(4, outer.getOneofInner().getNested().getNumWithDefault());
+  }
+
+  public void testClearValues() {
+    LazyInnerMessageLite inner = LazyInnerMessageLite.newBuilder()
+        .setNum(115)
+        .build();
+
+    LazyMessageLite.Builder outerBuilder = LazyMessageLite.newBuilder();
+
+    assertEquals(0, outerBuilder.build().getNum());
+
+
+    // Set/Clear num
+    outerBuilder.setNum(100);
+
+    assertEquals(100, outerBuilder.build().getNum());
+    assertEquals(421, outerBuilder.build().getNumWithDefault());
+    assertFalse(outerBuilder.build().hasInner());
+
+    outerBuilder.clearNum();
+
+    assertEquals(0, outerBuilder.build().getNum());
+    assertEquals(421, outerBuilder.build().getNumWithDefault());
+    assertFalse(outerBuilder.build().hasInner());
+
+
+    // Set/Clear all
+    outerBuilder.setNum(100)
+        .setInner(inner)
+        .addRepeatedInner(LazyInnerMessageLite.newBuilder().setNum(119))
+        .addRepeatedInner(LazyInnerMessageLite.newBuilder().setNum(122))
+        .setOneofInner(LazyInnerMessageLite.newBuilder().setNum(123));
+
+    LazyMessageLite outer = outerBuilder.build();
+    assertEquals(100, outer.getNum());
+    assertEquals(421, outer.getNumWithDefault());
+    assertTrue(outer.hasInner());
+    assertEquals(115, outer.getInner().getNum());
+    assertEquals(2, outer.getRepeatedInnerCount());
+    assertEquals(119, outer.getRepeatedInner(0).getNum());
+    assertEquals(122, outer.getRepeatedInner(1).getNum());
+    assertTrue(outer.hasOneofInner());
+    assertEquals(123, outer.getOneofInner().getNum());
+
+    outerBuilder.clear();
+
+    outer = outerBuilder.build();
+
+    assertEquals(0, outer.getNum());
+    assertEquals(421, outer.getNumWithDefault());
+    assertFalse(outer.hasInner());
+    assertEquals(0, outer.getRepeatedInnerCount());
+    assertFalse(outer.hasOneofInner());
+    assertEquals(0, outer.getOneofInner().getNum());
+  }
+
+  public void testMergeValues() {
+    LazyMessageLite outerBase = LazyMessageLite.newBuilder()
+        .setNumWithDefault(122)
+        .build();
+
+    LazyInnerMessageLite innerMerging = LazyInnerMessageLite.newBuilder()
+        .setNum(115)
+        .build();
+    LazyMessageLite outerMerging = LazyMessageLite.newBuilder()
+        .setNum(119)
+        .setInner(innerMerging)
+        .setOneofInner(innerMerging)
+        .build();
+
+    LazyMessageLite merged = LazyMessageLite
+        .newBuilder(outerBase)
+        .mergeFrom(outerMerging)
+        .build();
+    assertEquals(119, merged.getNum());
+    assertEquals(122, merged.getNumWithDefault());
+    assertEquals(115, merged.getInner().getNum());
+    assertEquals(42, merged.getInner().getNumWithDefault());
+    assertEquals(115, merged.getOneofInner().getNum());
+    assertEquals(42, merged.getOneofInner().getNumWithDefault());
+  }
+
+  public void testMergeDefaultValues() {
+    LazyInnerMessageLite innerBase = LazyInnerMessageLite.newBuilder()
+        .setNum(115)
+        .build();
+    LazyMessageLite outerBase = LazyMessageLite.newBuilder()
+        .setNum(119)
+        .setNumWithDefault(122)
+        .setInner(innerBase)
+        .setOneofInner(innerBase)
+        .build();
+
+    LazyMessageLite outerMerging = LazyMessageLite.newBuilder()
+        .build();
+
+    LazyMessageLite merged = LazyMessageLite
+        .newBuilder(outerBase)
+        .mergeFrom(outerMerging)
+        .build();
+    // Merging default-instance shouldn't overwrite values in the base message.
+    assertEquals(119, merged.getNum());
+    assertEquals(122, merged.getNumWithDefault());
+    assertEquals(115, merged.getInner().getNum());
+    assertEquals(42, merged.getInner().getNumWithDefault());
+    assertEquals(115, merged.getOneofInner().getNum());
+    assertEquals(42, merged.getOneofInner().getNumWithDefault());
+  }
+
+  public void testSerialize() throws InvalidProtocolBufferException {
+    LazyNestedInnerMessageLite nested = LazyNestedInnerMessageLite.newBuilder()
+        .setNum(3)
+        .build();
+    LazyInnerMessageLite inner = LazyInnerMessageLite.newBuilder()
+        .setNum(2)
+        .setNested(nested)
+        .build();
+    LazyMessageLite outer = LazyMessageLite.newBuilder()
+        .setNum(1)
+        .setInner(inner)
+        .setOneofInner(inner)
+        .build();
+
+    ByteString bytes = outer.toByteString();
+    assertEquals(bytes.size(), outer.getSerializedSize());
+
+    LazyMessageLite deserialized = LazyMessageLite.parseFrom(bytes);
+
+    assertEquals(1, deserialized.getNum());
+    assertEquals(421,  deserialized.getNumWithDefault());
+
+    assertEquals(2,  deserialized.getInner().getNum());
+    assertEquals(42,  deserialized.getInner().getNumWithDefault());
+
+    assertEquals(3,  deserialized.getInner().getNested().getNum());
+    assertEquals(4,  deserialized.getInner().getNested().getNumWithDefault());
+
+    assertEquals(2,  deserialized.getOneofInner().getNum());
+    assertEquals(42,  deserialized.getOneofInner().getNumWithDefault());
+    assertEquals(3,  deserialized.getOneofInner().getNested().getNum());
+    assertEquals(4,  deserialized.getOneofInner().getNested().getNumWithDefault());
+
+    assertEquals(bytes, deserialized.toByteString());
+  }
+
+  public void testExtensions() throws Exception {
+    LazyInnerMessageLite.Builder innerBuilder = LazyInnerMessageLite.newBuilder();
+    innerBuilder.setExtension(
+        LazyExtension.extension, LazyExtension.newBuilder()
+        .setName("name").build());
+    assertTrue(innerBuilder.hasExtension(LazyExtension.extension));
+    assertEquals("name", innerBuilder.getExtension(LazyExtension.extension).getName());
+
+    LazyInnerMessageLite innerMessage = innerBuilder.build();
+    assertTrue(innerMessage.hasExtension(LazyExtension.extension));
+    assertEquals("name", innerMessage.getExtension(LazyExtension.extension).getName());
+
+    LazyMessageLite lite = LazyMessageLite.newBuilder()
+        .setInner(innerMessage).build();
+    assertTrue(lite.getInner().hasExtension(LazyExtension.extension));
+    assertEquals("name", lite.getInner().getExtension(LazyExtension.extension).getName());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java b/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
new file mode 100644
index 00000000..0f42ac50
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
@@ -0,0 +1,362 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.util.Arrays.asList;
+
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Tests for {@link LazyStringArrayList}.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ */
+public class LazyStringArrayListTest extends TestCase {
+
+  private static String STRING_A = "A";
+  private static String STRING_B = "B";
+  private static String STRING_C = "C";
+
+  private static ByteString BYTE_STRING_A = ByteString.copyFromUtf8("A");
+  private static ByteString BYTE_STRING_B = ByteString.copyFromUtf8("B");
+  private static ByteString BYTE_STRING_C = ByteString.copyFromUtf8("C");
+
+  public void testJustStrings() {
+    LazyStringArrayList list = new LazyStringArrayList();
+    list.add(STRING_A);
+    list.add(STRING_B);
+    list.add(STRING_C);
+
+    assertEquals(3, list.size());
+    assertSame(STRING_A, list.get(0));
+    assertSame(STRING_B, list.get(1));
+    assertSame(STRING_C, list.get(2));
+
+    list.set(1, STRING_C);
+    assertSame(STRING_C, list.get(1));
+
+    list.remove(1);
+    assertSame(STRING_A, list.get(0));
+    assertSame(STRING_C, list.get(1));
+
+    List<ByteString> byteStringList = list.asByteStringList();
+    assertEquals(BYTE_STRING_A, byteStringList.get(0));
+    assertEquals(BYTE_STRING_C, byteStringList.get(1));
+
+    // Underlying list should be transformed.
+    assertSame(byteStringList.get(0), list.getByteString(0));
+    assertSame(byteStringList.get(1), list.getByteString(1));
+  }
+
+  public void testJustByteString() {
+    LazyStringArrayList list = new LazyStringArrayList();
+    list.add(BYTE_STRING_A);
+    list.add(BYTE_STRING_B);
+    list.add(BYTE_STRING_C);
+
+    assertEquals(3, list.size());
+    assertSame(BYTE_STRING_A, list.getByteString(0));
+    assertSame(BYTE_STRING_B, list.getByteString(1));
+    assertSame(BYTE_STRING_C, list.getByteString(2));
+
+    list.remove(1);
+    assertSame(BYTE_STRING_A, list.getByteString(0));
+    assertSame(BYTE_STRING_C, list.getByteString(1));
+
+    List<ByteString> byteStringList = list.asByteStringList();
+    assertSame(BYTE_STRING_A, byteStringList.get(0));
+    assertSame(BYTE_STRING_C, byteStringList.get(1));
+  }
+
+  public void testConversionBackAndForth() {
+    LazyStringArrayList list = new LazyStringArrayList();
+    list.add(STRING_A);
+    list.add(BYTE_STRING_B);
+    list.add(BYTE_STRING_C);
+
+    // String a should be the same because it was originally a string
+    assertSame(STRING_A, list.get(0));
+
+    // String b and c should be different because the string has to be computed
+    // from the ByteString
+    String bPrime = list.get(1);
+    assertNotSame(STRING_B, bPrime);
+    assertEquals(STRING_B, bPrime);
+    String cPrime = list.get(2);
+    assertNotSame(STRING_C, cPrime);
+    assertEquals(STRING_C, cPrime);
+
+    // String c and c should stay the same once cached.
+    assertSame(bPrime, list.get(1));
+    assertSame(cPrime, list.get(2));
+
+    // ByteString needs to be computed from string for both a and b
+    ByteString aPrimeByteString = list.getByteString(0);
+    assertEquals(BYTE_STRING_A, aPrimeByteString);
+    ByteString bPrimeByteString = list.getByteString(1);
+    assertNotSame(BYTE_STRING_B, bPrimeByteString);
+    assertEquals(BYTE_STRING_B, list.getByteString(1));
+
+    // Once cached, ByteString should stay cached.
+    assertSame(aPrimeByteString, list.getByteString(0));
+    assertSame(bPrimeByteString, list.getByteString(1));
+  }
+
+  public void testCopyConstructorCopiesByReference() {
+    LazyStringArrayList list1 = new LazyStringArrayList();
+    list1.add(STRING_A);
+    list1.add(BYTE_STRING_B);
+    list1.add(BYTE_STRING_C);
+
+    LazyStringArrayList list2 = new LazyStringArrayList(list1);
+    assertEquals(3, list2.size());
+    assertSame(STRING_A, list2.get(0));
+    assertSame(BYTE_STRING_B, list2.getByteString(1));
+    assertSame(BYTE_STRING_C, list2.getByteString(2));
+  }
+
+  public void testListCopyConstructor() {
+    List<String> list1 = new ArrayList<String>();
+    list1.add(STRING_A);
+    list1.add(STRING_B);
+    list1.add(STRING_C);
+
+    LazyStringArrayList list2 = new LazyStringArrayList(list1);
+    assertEquals(3, list2.size());
+    assertSame(STRING_A, list2.get(0));
+    assertSame(STRING_B, list2.get(1));
+    assertSame(STRING_C, list2.get(2));
+  }
+
+  public void testAddAllCopiesByReferenceIfPossible() {
+    LazyStringArrayList list1 = new LazyStringArrayList();
+    list1.add(STRING_A);
+    list1.add(BYTE_STRING_B);
+    list1.add(BYTE_STRING_C);
+
+    LazyStringArrayList list2 = new LazyStringArrayList();
+    list2.addAll(list1);
+
+    assertEquals(3, list2.size());
+    assertSame(STRING_A, list2.get(0));
+    assertSame(BYTE_STRING_B, list2.getByteString(1));
+    assertSame(BYTE_STRING_C, list2.getByteString(2));
+  }
+  
+  public void testModificationWithIteration() {
+    LazyStringArrayList list = new LazyStringArrayList();
+    list.addAll(asList(STRING_A, STRING_B, STRING_C));
+    Iterator<String> iterator = list.iterator();
+    assertEquals(3, list.size());
+    assertEquals(STRING_A, list.get(0));
+    assertEquals(STRING_A, iterator.next());
+    
+    // Does not structurally modify.
+    iterator = list.iterator();
+    list.set(0, STRING_B);
+    iterator.next();
+    
+    list.remove(0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+    
+    iterator = list.iterator();
+    list.add(0, STRING_C);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+  }
+  
+  public void testMakeImmutable() {
+    LazyStringArrayList list = new LazyStringArrayList();
+    list.add(STRING_A);
+    list.add(STRING_B);
+    list.add(STRING_C);
+    list.makeImmutable();
+    assertGenericListImmutable(list, STRING_A);
+    
+    // LazyStringArrayList has extra methods not covered in the generic
+    // assertion.
+    
+    try {
+      list.add(BYTE_STRING_A.toByteArray());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.add(BYTE_STRING_A);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAllByteArray(asList(BYTE_STRING_A.toByteArray()));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAllByteString(asList(BYTE_STRING_A));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.mergeFrom(new LazyStringArrayList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, BYTE_STRING_A.toByteArray());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, BYTE_STRING_A);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+  }
+  
+  public void testImmutabilityPropagation() {
+    LazyStringArrayList list = new LazyStringArrayList();
+    list.add(STRING_A);
+    list.makeImmutable();
+
+    assertGenericListImmutable(list.asByteStringList(), BYTE_STRING_A);
+    
+    // Arrays use reference equality so need to retrieve the underlying value
+    // to properly test deep immutability.
+    List<byte[]> byteArrayList = list.asByteArrayList();
+    assertGenericListImmutable(byteArrayList, byteArrayList.get(0));
+  }
+  
+  private static <T> void assertGenericListImmutable(List<T> list, T value) {
+    try {
+      list.add(value);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.add(0, value);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(asList(value));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, asList(value));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+
+    try {
+      list.clear();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(value);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(asList(value));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(asList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(asList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, value);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java b/java/core/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java
new file mode 100644
index 00000000..0ef414aa
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java
@@ -0,0 +1,132 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+
+import protobuf_unittest.UnittestProto;
+
+import junit.framework.TestCase;
+
+import java.io.IOException;
+
+/**
+ * Tests to make sure the lazy conversion of UTF8-encoded byte arrays to
+ * strings works correctly.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ */
+public class LazyStringEndToEndTest extends TestCase {
+
+  private static ByteString TEST_ALL_TYPES_SERIALIZED_WITH_ILLEGAL_UTF8 =
+      ByteString.copyFrom(new byte[] {
+          114, 4, -1, 0, -1, 0, -30, 2, 4, -1,
+          0, -1, 0, -30, 2, 4, -1, 0, -1, 0, });
+
+  private ByteString encodedTestAllTypes;
+
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+    this.encodedTestAllTypes = UnittestProto.TestAllTypes.newBuilder()
+        .setOptionalString("foo")
+        .addRepeatedString("bar")
+        .addRepeatedString("baz")
+        .build()
+        .toByteString();
+  }
+
+  /**
+   * Tests that an invalid UTF8 string will roundtrip through a parse
+   * and serialization.
+   */
+  public void testParseAndSerialize() throws InvalidProtocolBufferException {
+    UnittestProto.TestAllTypes tV2 = UnittestProto.TestAllTypes.parseFrom(
+        TEST_ALL_TYPES_SERIALIZED_WITH_ILLEGAL_UTF8);
+    ByteString bytes = tV2.toByteString();
+    assertEquals(TEST_ALL_TYPES_SERIALIZED_WITH_ILLEGAL_UTF8, bytes);
+
+    tV2.getOptionalString();
+    bytes = tV2.toByteString();
+    assertEquals(TEST_ALL_TYPES_SERIALIZED_WITH_ILLEGAL_UTF8, bytes);
+  }
+
+  public void testParseAndWrite() throws IOException {
+    UnittestProto.TestAllTypes tV2 = UnittestProto.TestAllTypes.parseFrom(
+        TEST_ALL_TYPES_SERIALIZED_WITH_ILLEGAL_UTF8);
+    byte[] sink = new byte[TEST_ALL_TYPES_SERIALIZED_WITH_ILLEGAL_UTF8.size()];
+    CodedOutputStream outputStream = CodedOutputStream.newInstance(sink);
+    tV2.writeTo(outputStream);
+    outputStream.flush();
+    assertEquals(
+        TEST_ALL_TYPES_SERIALIZED_WITH_ILLEGAL_UTF8,
+        ByteString.copyFrom(sink));
+  }
+  
+  public void testCaching() {
+    String a = "a";
+    String b = "b";
+    String c = "c";
+    UnittestProto.TestAllTypes proto = UnittestProto.TestAllTypes.newBuilder()
+        .setOptionalString(a)
+        .addRepeatedString(b)
+        .addRepeatedString(c)
+        .build();
+
+    // String should be the one we passed it.
+    assertSame(a, proto.getOptionalString());
+    assertSame(b, proto.getRepeatedString(0));
+    assertSame(c, proto.getRepeatedString(1));
+
+
+    // Ensure serialization keeps strings cached.
+    proto.toByteString();
+
+    // And now the string should stay cached.
+    assertSame(a, proto.getOptionalString());
+    assertSame(b, proto.getRepeatedString(0));
+    assertSame(c, proto.getRepeatedString(1));
+  }
+
+  public void testNoStringCachingIfOnlyBytesAccessed() throws Exception {
+    UnittestProto.TestAllTypes proto =
+        UnittestProto.TestAllTypes.parseFrom(encodedTestAllTypes);
+    ByteString optional = proto.getOptionalStringBytes();
+    assertSame(optional, proto.getOptionalStringBytes());
+    assertSame(optional, proto.toBuilder().getOptionalStringBytes());
+
+    ByteString repeated0 = proto.getRepeatedStringBytes(0);
+    ByteString repeated1 = proto.getRepeatedStringBytes(1);
+    assertSame(repeated0, proto.getRepeatedStringBytes(0));
+    assertSame(repeated1, proto.getRepeatedStringBytes(1));
+    assertSame(repeated0, proto.toBuilder().getRepeatedStringBytes(0));
+    assertSame(repeated1, proto.toBuilder().getRepeatedStringBytes(1));
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java b/java/core/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java
new file mode 100644
index 00000000..035917c8
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java
@@ -0,0 +1,108 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Bar;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.BarPrime;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Foo;
+
+import junit.framework.TestCase;
+
+/**
+ * Test generate equal and hash methods for the lite runtime.
+ *
+ * @author pbogle@google.com Phil Bogle
+ */
+public class LiteEqualsAndHashTest extends TestCase {
+
+  public void testEquals() throws Exception {
+    // Since the generated equals and hashCode methods for lite messages are a
+    // mostly complete subset of those for regular messages, we can mostly assume
+    // that the generated methods are already thoroughly tested by the regular tests.
+
+    // This test mostly just verifies is that a proto with
+    // optimize_for = LITE_RUNTIME and java_generates_equals_and_hash_compiles
+    // correctly when linked only against the lite library.
+
+    // We do however do some basic testing to make sure that equals is actually
+    // overriden to test for value equality rather than simple object equality.
+
+    // Check that two identical objs are equal.
+    Foo foo1a = Foo.newBuilder()
+        .setValue(1)
+        .addBar(Bar.newBuilder().setName("foo1"))
+        .build();
+    Foo foo1b = Foo.newBuilder()
+        .setValue(1)
+        .addBar(Bar.newBuilder().setName("foo1"))
+        .build();
+    Foo foo2 = Foo.newBuilder()
+        .setValue(1)
+        .addBar(Bar.newBuilder().setName("foo2"))
+        .build();
+
+    // Check that equals is doing value rather than object equality.
+    assertEquals(foo1a, foo1b);
+    assertEquals(foo1a.hashCode(), foo1b.hashCode());
+
+    // Check that a diffeent object is not equal.
+    assertFalse(foo1a.equals(foo2));
+
+    // Check that two objects which have different types but the same field values are not
+    // considered to be equal.
+    Bar bar = Bar.newBuilder().setName("bar").build();
+    BarPrime barPrime = BarPrime.newBuilder().setName("bar").build();
+    assertFalse(bar.equals(barPrime));
+  }
+
+  public void testEqualsAndHashCodeWithUnknownFields() throws InvalidProtocolBufferException {
+    Foo fooWithOnlyValue = Foo.newBuilder()
+        .setValue(1)
+        .build();
+
+    Foo fooWithValueAndExtension = fooWithOnlyValue.toBuilder()
+        .setValue(1)
+        .setExtension(Bar.fooExt, Bar.newBuilder()
+            .setName("name")
+            .build())
+        .build();
+
+    Foo fooWithValueAndUnknownFields = Foo.parseFrom(fooWithValueAndExtension.toByteArray());
+
+    assertEqualsAndHashCodeAreFalse(fooWithOnlyValue, fooWithValueAndUnknownFields);
+    assertEqualsAndHashCodeAreFalse(fooWithValueAndExtension, fooWithValueAndUnknownFields);
+  }
+
+  private void assertEqualsAndHashCodeAreFalse(Object o1, Object o2) {
+    assertFalse(o1.equals(o2));
+    assertFalse(o1.hashCode() == o2.hashCode());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LiteTest.java b/java/core/src/test/java/com/google/protobuf/LiteTest.java
new file mode 100644
index 00000000..b1f298ff
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LiteTest.java
@@ -0,0 +1,1462 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+
+import com.google.protobuf.UnittestLite;
+import com.google.protobuf.UnittestLite.ForeignEnumLite;
+import com.google.protobuf.UnittestLite.ForeignMessageLite;
+import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
+import com.google.protobuf.UnittestLite.TestAllTypesLite;
+import com.google.protobuf.UnittestLite.TestAllTypesLite.NestedMessage;
+import com.google.protobuf.UnittestLite.TestAllTypesLite.OneofFieldCase;
+import com.google.protobuf.UnittestLite.TestAllTypesLite.OptionalGroup;
+import com.google.protobuf.UnittestLite.TestAllTypesLite.RepeatedGroup;
+import com.google.protobuf.UnittestLite.TestAllTypesLiteOrBuilder;
+import com.google.protobuf.UnittestLite.TestNestedExtensionLite;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+/**
+ * Test lite runtime.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class LiteTest extends TestCase {
+  public void setUp() throws Exception {
+    // Test that nested extensions are initialized correctly even if the outer
+    // class has not been accessed directly.  This was once a bug with lite
+    // messages.
+    //
+    // We put this in setUp() rather than in its own test method because we
+    // need to make sure it runs before any actual tests.
+    assertTrue(TestNestedExtensionLite.nestedExtension != null);
+  }
+
+  public void testLite() throws Exception {
+    // Since lite messages are a subset of regular messages, we can mostly
+    // assume that the functionality of lite messages is already thoroughly
+    // tested by the regular tests.  All this test really verifies is that
+    // a proto with optimize_for = LITE_RUNTIME compiles correctly when
+    // linked only against the lite library.  That is all tested at compile
+    // time, leaving not much to do in this method.  Let's just do some random
+    // stuff to make sure the lite message is actually here and usable.
+
+    TestAllTypesLite message =
+      TestAllTypesLite.newBuilder()
+                      .setOptionalInt32(123)
+                      .addRepeatedString("hello")
+                      .setOptionalNestedMessage(
+                          TestAllTypesLite.NestedMessage.newBuilder().setBb(7))
+                      .build();
+
+    ByteString data = message.toByteString();
+
+    TestAllTypesLite message2 = TestAllTypesLite.parseFrom(data);
+
+    assertEquals(123, message2.getOptionalInt32());
+    assertEquals(1, message2.getRepeatedStringCount());
+    assertEquals("hello", message2.getRepeatedString(0));
+    assertEquals(7, message2.getOptionalNestedMessage().getBb());
+  }
+
+  public void testLiteExtensions() throws Exception {
+    // TODO(kenton):  Unlike other features of the lite library, extensions are
+    //   implemented completely differently from the regular library.  We
+    //   should probably test them more thoroughly.
+
+    TestAllExtensionsLite message =
+      TestAllExtensionsLite.newBuilder()
+        .setExtension(UnittestLite.optionalInt32ExtensionLite, 123)
+        .addExtension(UnittestLite.repeatedStringExtensionLite, "hello")
+        .setExtension(UnittestLite.optionalNestedEnumExtensionLite,
+            TestAllTypesLite.NestedEnum.BAZ)
+        .setExtension(UnittestLite.optionalNestedMessageExtensionLite,
+            TestAllTypesLite.NestedMessage.newBuilder().setBb(7).build())
+        .build();
+
+    // Test copying a message, since coping extensions actually does use a
+    // different code path between lite and regular libraries, and as of this
+    // writing, parsing hasn't been implemented yet.
+    TestAllExtensionsLite message2 = message.toBuilder().build();
+
+    assertEquals(123, (int) message2.getExtension(
+        UnittestLite.optionalInt32ExtensionLite));
+    assertEquals(1, message2.getExtensionCount(
+        UnittestLite.repeatedStringExtensionLite));
+    assertEquals(1, message2.getExtension(
+        UnittestLite.repeatedStringExtensionLite).size());
+    assertEquals("hello", message2.getExtension(
+        UnittestLite.repeatedStringExtensionLite, 0));
+    assertEquals(TestAllTypesLite.NestedEnum.BAZ, message2.getExtension(
+        UnittestLite.optionalNestedEnumExtensionLite));
+    assertEquals(7, message2.getExtension(
+        UnittestLite.optionalNestedMessageExtensionLite).getBb());
+  }
+
+  public void testSerialize() throws Exception {
+    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    TestAllTypesLite expected =
+      TestAllTypesLite.newBuilder()
+                      .setOptionalInt32(123)
+                      .addRepeatedString("hello")
+                      .setOptionalNestedMessage(
+                          TestAllTypesLite.NestedMessage.newBuilder().setBb(7))
+                      .build();
+    ObjectOutputStream out = new ObjectOutputStream(baos);
+    try {
+      out.writeObject(expected);
+    } finally {
+      out.close();
+    }
+    ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
+    ObjectInputStream in = new ObjectInputStream(bais);
+    TestAllTypesLite actual = (TestAllTypesLite) in.readObject();
+    assertEquals(expected.getOptionalInt32(), actual.getOptionalInt32());
+    assertEquals(expected.getRepeatedStringCount(),
+        actual.getRepeatedStringCount());
+    assertEquals(expected.getRepeatedString(0),
+        actual.getRepeatedString(0));
+    assertEquals(expected.getOptionalNestedMessage().getBb(),
+        actual.getOptionalNestedMessage().getBb());
+  }
+  
+  public void testClone() {
+    TestAllTypesLite.Builder expected = TestAllTypesLite.newBuilder()
+        .setOptionalInt32(123);
+    assertEquals(
+        expected.getOptionalInt32(), expected.clone().getOptionalInt32());
+   
+    TestAllExtensionsLite.Builder expected2 = TestAllExtensionsLite.newBuilder()
+        .setExtension(UnittestLite.optionalInt32ExtensionLite, 123);
+    assertEquals(
+        expected2.getExtension(UnittestLite.optionalInt32ExtensionLite),
+        expected2.clone().getExtension(UnittestLite.optionalInt32ExtensionLite));
+  }
+  
+  public void testAddAll() {
+    try {
+      TestAllTypesLite.newBuilder()
+          .addAllRepeatedBytes(null);
+      fail();
+    } catch (NullPointerException e) {
+      // expected.
+    }
+  }
+  
+  public void testSanityCopyOnWrite() throws InvalidProtocolBufferException {
+    // Since builders are implemented as a thin wrapper around a message
+    // instance, we attempt to verify that we can't cause the builder to modify
+    // a produced message.
+
+    TestAllTypesLite.Builder builder = TestAllTypesLite.newBuilder();
+    TestAllTypesLite message = builder.build();
+    TestAllTypesLite messageAfterBuild;
+    builder.setOptionalBool(true);
+    assertEquals(false, message.getOptionalBool());
+    assertEquals(true, builder.getOptionalBool());
+    messageAfterBuild = builder.build();
+    assertEquals(true, messageAfterBuild.getOptionalBool());
+    assertEquals(false, message.getOptionalBool());
+    builder.clearOptionalBool();
+    assertEquals(false, builder.getOptionalBool());
+    assertEquals(true, messageAfterBuild.getOptionalBool());
+
+    message = builder.build();
+    builder.setOptionalBytes(ByteString.copyFromUtf8("hi"));
+    assertEquals(ByteString.EMPTY, message.getOptionalBytes());
+    assertEquals(ByteString.copyFromUtf8("hi"), builder.getOptionalBytes());
+    messageAfterBuild = builder.build();
+    assertEquals(
+        ByteString.copyFromUtf8("hi"), messageAfterBuild.getOptionalBytes());
+    assertEquals(ByteString.EMPTY, message.getOptionalBytes());
+    builder.clearOptionalBytes();
+    assertEquals(ByteString.EMPTY, builder.getOptionalBytes());
+    assertEquals(
+        ByteString.copyFromUtf8("hi"), messageAfterBuild.getOptionalBytes());
+
+    message = builder.build();
+    builder.setOptionalCord("hi");
+    assertEquals("", message.getOptionalCord());
+    assertEquals("hi", builder.getOptionalCord());
+    messageAfterBuild = builder.build();
+    assertEquals("hi", messageAfterBuild.getOptionalCord());
+    assertEquals("", message.getOptionalCord());
+    builder.clearOptionalCord();
+    assertEquals("", builder.getOptionalCord());
+    assertEquals("hi", messageAfterBuild.getOptionalCord());
+
+    message = builder.build();
+    builder.setOptionalCordBytes(ByteString.copyFromUtf8("no"));
+    assertEquals(ByteString.EMPTY, message.getOptionalCordBytes());
+    assertEquals(ByteString.copyFromUtf8("no"), builder.getOptionalCordBytes());
+    messageAfterBuild = builder.build();
+    assertEquals(
+        ByteString.copyFromUtf8("no"),
+        messageAfterBuild.getOptionalCordBytes());
+    assertEquals(ByteString.EMPTY, message.getOptionalCordBytes());
+    builder.clearOptionalCord();
+    assertEquals(ByteString.EMPTY, builder.getOptionalCordBytes());
+    assertEquals(
+        ByteString.copyFromUtf8("no"),
+        messageAfterBuild.getOptionalCordBytes());
+    
+    message = builder.build();
+    builder.setOptionalDouble(1);
+    assertEquals(0D, message.getOptionalDouble());
+    assertEquals(1D, builder.getOptionalDouble());
+    messageAfterBuild = builder.build();
+    assertEquals(1D, messageAfterBuild.getOptionalDouble());
+    assertEquals(0D, message.getOptionalDouble());
+    builder.clearOptionalDouble();
+    assertEquals(0D, builder.getOptionalDouble());
+    assertEquals(1D, messageAfterBuild.getOptionalDouble());
+    
+    message = builder.build();
+    builder.setOptionalFixed32(1);
+    assertEquals(0, message.getOptionalFixed32());
+    assertEquals(1, builder.getOptionalFixed32());
+    messageAfterBuild = builder.build();
+    assertEquals(1, messageAfterBuild.getOptionalFixed32());
+    assertEquals(0, message.getOptionalFixed32());
+    builder.clearOptionalFixed32();
+    assertEquals(0, builder.getOptionalFixed32());
+    assertEquals(1, messageAfterBuild.getOptionalFixed32());
+    
+    message = builder.build();
+    builder.setOptionalFixed64(1);
+    assertEquals(0L, message.getOptionalFixed64());
+    assertEquals(1L, builder.getOptionalFixed64());
+    messageAfterBuild = builder.build();
+    assertEquals(1L, messageAfterBuild.getOptionalFixed64());
+    assertEquals(0L, message.getOptionalFixed64());
+    builder.clearOptionalFixed64();
+    assertEquals(0L, builder.getOptionalFixed64());
+    assertEquals(1L, messageAfterBuild.getOptionalFixed64());
+
+    message = builder.build();
+    builder.setOptionalFloat(1);
+    assertEquals(0F, message.getOptionalFloat());
+    assertEquals(1F, builder.getOptionalFloat());
+    messageAfterBuild = builder.build();
+    assertEquals(1F, messageAfterBuild.getOptionalFloat());
+    assertEquals(0F, message.getOptionalFloat());
+    builder.clearOptionalFloat();
+    assertEquals(0F, builder.getOptionalFloat());
+    assertEquals(1F, messageAfterBuild.getOptionalFloat());
+
+    message = builder.build();
+    builder.setOptionalForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR);
+    assertEquals(
+        ForeignEnumLite.FOREIGN_LITE_FOO, message.getOptionalForeignEnum());
+    assertEquals(
+        ForeignEnumLite.FOREIGN_LITE_BAR, builder.getOptionalForeignEnum());
+    messageAfterBuild = builder.build();
+    assertEquals(
+        ForeignEnumLite.FOREIGN_LITE_BAR,
+        messageAfterBuild.getOptionalForeignEnum());
+    assertEquals(
+        ForeignEnumLite.FOREIGN_LITE_FOO, message.getOptionalForeignEnum());
+    builder.clearOptionalForeignEnum();
+    assertEquals(
+        ForeignEnumLite.FOREIGN_LITE_FOO, builder.getOptionalForeignEnum());
+    assertEquals(
+        ForeignEnumLite.FOREIGN_LITE_BAR,
+        messageAfterBuild.getOptionalForeignEnum());
+
+    message = builder.build();
+    ForeignMessageLite foreignMessage = ForeignMessageLite.newBuilder()
+        .setC(1)
+        .build();
+    builder.setOptionalForeignMessage(foreignMessage);
+    assertEquals(
+        ForeignMessageLite.getDefaultInstance(),
+        message.getOptionalForeignMessage());
+    assertEquals(foreignMessage, builder.getOptionalForeignMessage());
+    messageAfterBuild = builder.build();
+    assertEquals(foreignMessage, messageAfterBuild.getOptionalForeignMessage());
+    assertEquals(
+        ForeignMessageLite.getDefaultInstance(),
+        message.getOptionalForeignMessage());
+    builder.clearOptionalForeignMessage();
+    assertEquals(
+        ForeignMessageLite.getDefaultInstance(),
+        builder.getOptionalForeignMessage());
+    assertEquals(foreignMessage, messageAfterBuild.getOptionalForeignMessage());
+
+    message = builder.build();
+    ForeignMessageLite.Builder foreignMessageBuilder =
+        ForeignMessageLite.newBuilder()
+            .setC(3);
+    builder.setOptionalForeignMessage(foreignMessageBuilder);
+    assertEquals(
+        ForeignMessageLite.getDefaultInstance(),
+        message.getOptionalForeignMessage());
+    // LITE_RUNTIME doesn't implement equals so we compare on a property and
+    // ensure the property isn't set on foreignMessage.
+    assertEquals(3, builder.getOptionalForeignMessage().getC());
+    messageAfterBuild = builder.build();
+    assertEquals(3, messageAfterBuild.getOptionalForeignMessage().getC());
+    assertEquals(
+        ForeignMessageLite.getDefaultInstance(),
+        message.getOptionalForeignMessage());
+    builder.clearOptionalForeignMessage();
+    assertEquals(
+        ForeignMessageLite.getDefaultInstance(),
+        builder.getOptionalForeignMessage());
+    assertEquals(3, messageAfterBuild.getOptionalForeignMessage().getC());
+
+    message = builder.build();
+    OptionalGroup optionalGroup = OptionalGroup.newBuilder()
+        .setA(1)
+        .build();
+    builder.setOptionalGroup(optionalGroup);
+    assertEquals(
+        OptionalGroup.getDefaultInstance(), message.getOptionalGroup());
+    assertEquals(optionalGroup, builder.getOptionalGroup());
+    messageAfterBuild = builder.build();
+    assertEquals(optionalGroup, messageAfterBuild.getOptionalGroup());
+    assertEquals(
+        OptionalGroup.getDefaultInstance(), message.getOptionalGroup());
+    builder.clearOptionalGroup();
+    assertEquals(
+        OptionalGroup.getDefaultInstance(), builder.getOptionalGroup());
+    assertEquals(optionalGroup, messageAfterBuild.getOptionalGroup());
+
+    message = builder.build();
+    OptionalGroup.Builder optionalGroupBuilder = OptionalGroup.newBuilder()
+        .setA(3);
+    builder.setOptionalGroup(optionalGroupBuilder);
+    assertEquals(
+        OptionalGroup.getDefaultInstance(), message.getOptionalGroup());
+    // LITE_RUNTIME doesn't implement equals so we compare on a property and
+    // ensure the property isn't set on optionalGroup.
+    assertEquals(3, builder.getOptionalGroup().getA());
+    messageAfterBuild = builder.build();
+    assertEquals(3, messageAfterBuild.getOptionalGroup().getA());
+    assertEquals(
+        OptionalGroup.getDefaultInstance(), message.getOptionalGroup());
+    builder.clearOptionalGroup();
+    assertEquals(
+        OptionalGroup.getDefaultInstance(), builder.getOptionalGroup());
+    assertEquals(3, messageAfterBuild.getOptionalGroup().getA());
+
+    message = builder.build();
+    builder.setOptionalInt32(1);
+    assertEquals(0, message.getOptionalInt32());
+    assertEquals(1, builder.getOptionalInt32());
+    messageAfterBuild = builder.build();
+    assertEquals(1, messageAfterBuild.getOptionalInt32());
+    assertEquals(0, message.getOptionalInt32());
+    builder.clearOptionalInt32();
+    assertEquals(0, builder.getOptionalInt32());
+    assertEquals(1, messageAfterBuild.getOptionalInt32());
+
+    message = builder.build();
+    builder.setOptionalInt64(1);
+    assertEquals(0L, message.getOptionalInt64());
+    assertEquals(1L, builder.getOptionalInt64());
+    messageAfterBuild = builder.build();
+    assertEquals(1L, messageAfterBuild.getOptionalInt64());
+    assertEquals(0L, message.getOptionalInt64());
+    builder.clearOptionalInt64();
+    assertEquals(0L, builder.getOptionalInt64());
+    assertEquals(1L, messageAfterBuild.getOptionalInt64());
+    
+    message = builder.build();
+    NestedMessage nestedMessage = NestedMessage.newBuilder()
+        .setBb(1)
+        .build();
+    builder.setOptionalLazyMessage(nestedMessage);
+    assertEquals(
+        NestedMessage.getDefaultInstance(),
+        message.getOptionalLazyMessage());
+    assertEquals(nestedMessage, builder.getOptionalLazyMessage());
+    messageAfterBuild = builder.build();
+    assertEquals(nestedMessage, messageAfterBuild.getOptionalLazyMessage());
+    assertEquals(
+        NestedMessage.getDefaultInstance(),
+        message.getOptionalLazyMessage());
+    builder.clearOptionalLazyMessage();
+    assertEquals(
+        NestedMessage.getDefaultInstance(), builder.getOptionalLazyMessage());
+    assertEquals(nestedMessage, messageAfterBuild.getOptionalLazyMessage());
+
+    message = builder.build();
+    NestedMessage.Builder nestedMessageBuilder =
+        NestedMessage.newBuilder()
+            .setBb(3);
+    builder.setOptionalLazyMessage(nestedMessageBuilder);
+    assertEquals(
+        NestedMessage.getDefaultInstance(),
+        message.getOptionalLazyMessage());
+    // LITE_RUNTIME doesn't implement equals so we compare on a property.
+    assertEquals(3, builder.getOptionalLazyMessage().getBb());
+    messageAfterBuild = builder.build();
+    assertEquals(3, messageAfterBuild.getOptionalLazyMessage().getBb());
+    assertEquals(
+        NestedMessage.getDefaultInstance(),
+        message.getOptionalLazyMessage());
+    builder.clearOptionalLazyMessage();
+    assertEquals(
+        NestedMessage.getDefaultInstance(), builder.getOptionalLazyMessage());
+    assertEquals(3, messageAfterBuild.getOptionalLazyMessage().getBb());
+
+    message = builder.build();
+    builder.setOptionalSfixed32(1);
+    assertEquals(0, message.getOptionalSfixed32());
+    assertEquals(1, builder.getOptionalSfixed32());
+    messageAfterBuild = builder.build();
+    assertEquals(1, messageAfterBuild.getOptionalSfixed32());
+    assertEquals(0, message.getOptionalSfixed32());
+    builder.clearOptionalSfixed32();
+    assertEquals(0, builder.getOptionalSfixed32());
+    assertEquals(1, messageAfterBuild.getOptionalSfixed32());
+
+    message = builder.build();
+    builder.setOptionalSfixed64(1);
+    assertEquals(0L, message.getOptionalSfixed64());
+    assertEquals(1L, builder.getOptionalSfixed64());
+    messageAfterBuild = builder.build();
+    assertEquals(1L, messageAfterBuild.getOptionalSfixed64());
+    assertEquals(0L, message.getOptionalSfixed64());
+    builder.clearOptionalSfixed64();
+    assertEquals(0L, builder.getOptionalSfixed64());
+    assertEquals(1L, messageAfterBuild.getOptionalSfixed64());
+
+    message = builder.build();
+    builder.setOptionalSint32(1);
+    assertEquals(0, message.getOptionalSint32());
+    assertEquals(1, builder.getOptionalSint32());
+    messageAfterBuild = builder.build();
+    assertEquals(1, messageAfterBuild.getOptionalSint32());
+    builder.clearOptionalSint32();
+    assertEquals(0, builder.getOptionalSint32());
+    assertEquals(1, messageAfterBuild.getOptionalSint32());
+
+    message = builder.build();
+    builder.setOptionalSint64(1);
+    assertEquals(0L, message.getOptionalSint64());
+    assertEquals(1L, builder.getOptionalSint64());
+    messageAfterBuild = builder.build();
+    assertEquals(1L, messageAfterBuild.getOptionalSint64());
+    assertEquals(0L, message.getOptionalSint64());
+    builder.clearOptionalSint64();
+    assertEquals(0L, builder.getOptionalSint64());
+    assertEquals(1L, messageAfterBuild.getOptionalSint64());
+
+    message = builder.build();
+    builder.setOptionalString("hi");
+    assertEquals("", message.getOptionalString());
+    assertEquals("hi", builder.getOptionalString());
+    messageAfterBuild = builder.build();
+    assertEquals("hi", messageAfterBuild.getOptionalString());
+    assertEquals("", message.getOptionalString());
+    builder.clearOptionalString();
+    assertEquals("", builder.getOptionalString());
+    assertEquals("hi", messageAfterBuild.getOptionalString());
+
+    message = builder.build();
+    builder.setOptionalStringBytes(ByteString.copyFromUtf8("no"));
+    assertEquals(ByteString.EMPTY, message.getOptionalStringBytes());
+    assertEquals(
+        ByteString.copyFromUtf8("no"), builder.getOptionalStringBytes());
+    messageAfterBuild = builder.build();
+    assertEquals(
+        ByteString.copyFromUtf8("no"),
+        messageAfterBuild.getOptionalStringBytes());
+    assertEquals(ByteString.EMPTY, message.getOptionalStringBytes());
+    builder.clearOptionalString();
+    assertEquals(ByteString.EMPTY, builder.getOptionalStringBytes());
+    assertEquals(
+        ByteString.copyFromUtf8("no"),
+        messageAfterBuild.getOptionalStringBytes());
+    
+    message = builder.build();
+    builder.setOptionalStringPiece("hi");
+    assertEquals("", message.getOptionalStringPiece());
+    assertEquals("hi", builder.getOptionalStringPiece());
+    messageAfterBuild = builder.build();
+    assertEquals("hi", messageAfterBuild.getOptionalStringPiece());
+    assertEquals("", message.getOptionalStringPiece());
+    builder.clearOptionalStringPiece();
+    assertEquals("", builder.getOptionalStringPiece());
+    assertEquals("hi", messageAfterBuild.getOptionalStringPiece());
+
+    message = builder.build();
+    builder.setOptionalStringPieceBytes(ByteString.copyFromUtf8("no"));
+    assertEquals(ByteString.EMPTY, message.getOptionalStringPieceBytes());
+    assertEquals(
+        ByteString.copyFromUtf8("no"), builder.getOptionalStringPieceBytes());
+    messageAfterBuild = builder.build();
+    assertEquals(
+        ByteString.copyFromUtf8("no"),
+        messageAfterBuild.getOptionalStringPieceBytes());
+    assertEquals(ByteString.EMPTY, message.getOptionalStringPieceBytes());
+    builder.clearOptionalStringPiece();
+    assertEquals(ByteString.EMPTY, builder.getOptionalStringPieceBytes());
+    assertEquals(
+        ByteString.copyFromUtf8("no"),
+        messageAfterBuild.getOptionalStringPieceBytes());
+
+    message = builder.build();
+    builder.setOptionalUint32(1);
+    assertEquals(0, message.getOptionalUint32());
+    assertEquals(1, builder.getOptionalUint32());
+    messageAfterBuild = builder.build();
+    assertEquals(1, messageAfterBuild.getOptionalUint32());
+    assertEquals(0, message.getOptionalUint32());
+    builder.clearOptionalUint32();
+    assertEquals(0, builder.getOptionalUint32());
+    assertEquals(1, messageAfterBuild.getOptionalUint32());
+
+    message = builder.build();
+    builder.setOptionalUint64(1);
+    assertEquals(0L, message.getOptionalUint64());
+    assertEquals(1L, builder.getOptionalUint64());
+    messageAfterBuild = builder.build();
+    assertEquals(1L, messageAfterBuild.getOptionalUint64());
+    assertEquals(0L, message.getOptionalUint64());
+    builder.clearOptionalUint64();
+    assertEquals(0L, builder.getOptionalUint64());
+    assertEquals(1L, messageAfterBuild.getOptionalUint64());
+
+    message = builder.build();
+    builder.addAllRepeatedBool(singletonList(true));
+    assertEquals(emptyList(), message.getRepeatedBoolList());
+    assertEquals(singletonList(true), builder.getRepeatedBoolList());
+    assertEquals(emptyList(), message.getRepeatedBoolList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedBool();
+    assertEquals(emptyList(), builder.getRepeatedBoolList());
+    assertEquals(singletonList(true), messageAfterBuild.getRepeatedBoolList());
+
+    message = builder.build();
+    builder.addAllRepeatedBytes(singletonList(ByteString.copyFromUtf8("hi")));
+    assertEquals(emptyList(), message.getRepeatedBytesList());
+    assertEquals(
+        singletonList(ByteString.copyFromUtf8("hi")),
+        builder.getRepeatedBytesList());
+    assertEquals(emptyList(), message.getRepeatedBytesList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedBytes();
+    assertEquals(emptyList(), builder.getRepeatedBytesList());
+    assertEquals(
+        singletonList(ByteString.copyFromUtf8("hi")),
+        messageAfterBuild.getRepeatedBytesList());
+
+    message = builder.build();
+    builder.addAllRepeatedCord(singletonList("hi"));
+    assertEquals(emptyList(), message.getRepeatedCordList());
+    assertEquals(singletonList("hi"), builder.getRepeatedCordList());
+    assertEquals(emptyList(), message.getRepeatedCordList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedCord();
+    assertEquals(emptyList(), builder.getRepeatedCordList());
+    assertEquals(singletonList("hi"), messageAfterBuild.getRepeatedCordList());
+
+    message = builder.build();
+    builder.addAllRepeatedDouble(singletonList(1D));
+    assertEquals(emptyList(), message.getRepeatedDoubleList());
+    assertEquals(singletonList(1D), builder.getRepeatedDoubleList());
+    assertEquals(emptyList(), message.getRepeatedDoubleList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedDouble();
+    assertEquals(emptyList(), builder.getRepeatedDoubleList());
+    assertEquals(singletonList(1D), messageAfterBuild.getRepeatedDoubleList());
+
+    message = builder.build();
+    builder.addAllRepeatedFixed32(singletonList(1));
+    assertEquals(emptyList(), message.getRepeatedFixed32List());
+    assertEquals(singletonList(1), builder.getRepeatedFixed32List());
+    assertEquals(emptyList(), message.getRepeatedFixed32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedFixed32();
+    assertEquals(emptyList(), builder.getRepeatedFixed32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedFixed32List());
+
+    message = builder.build();
+    builder.addAllRepeatedFixed64(singletonList(1L));
+    assertEquals(emptyList(), message.getRepeatedFixed64List());
+    assertEquals(singletonList(1L), builder.getRepeatedFixed64List());
+    assertEquals(emptyList(), message.getRepeatedFixed64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedFixed64();
+    assertEquals(emptyList(), builder.getRepeatedFixed64List());
+    assertEquals(singletonList(1L), messageAfterBuild.getRepeatedFixed64List());
+
+    message = builder.build();
+    builder.addAllRepeatedFloat(singletonList(1F));
+    assertEquals(emptyList(), message.getRepeatedFloatList());
+    assertEquals(singletonList(1F), builder.getRepeatedFloatList());
+    assertEquals(emptyList(), message.getRepeatedFloatList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedFloat();
+    assertEquals(emptyList(), builder.getRepeatedFloatList());
+    assertEquals(singletonList(1F), messageAfterBuild.getRepeatedFloatList());
+
+    message = builder.build();
+    builder.addAllRepeatedForeignEnum(
+        singletonList(ForeignEnumLite.FOREIGN_LITE_BAR));
+    assertEquals(emptyList(), message.getRepeatedForeignEnumList());
+    assertEquals(
+        singletonList(ForeignEnumLite.FOREIGN_LITE_BAR),
+        builder.getRepeatedForeignEnumList());
+    assertEquals(emptyList(), message.getRepeatedForeignEnumList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedForeignEnum();
+    assertEquals(emptyList(), builder.getRepeatedForeignEnumList());
+    assertEquals(
+        singletonList(ForeignEnumLite.FOREIGN_LITE_BAR),
+        messageAfterBuild.getRepeatedForeignEnumList());
+
+    message = builder.build();
+    builder.addAllRepeatedForeignMessage(singletonList(foreignMessage));
+    assertEquals(emptyList(), message.getRepeatedForeignMessageList());
+    assertEquals(
+        singletonList(foreignMessage), builder.getRepeatedForeignMessageList());
+    assertEquals(emptyList(), message.getRepeatedForeignMessageList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedForeignMessage();
+    assertEquals(emptyList(), builder.getRepeatedForeignMessageList());
+    assertEquals(
+        singletonList(foreignMessage),
+        messageAfterBuild.getRepeatedForeignMessageList());
+
+    message = builder.build();
+    builder.addAllRepeatedGroup(
+        singletonList(RepeatedGroup.getDefaultInstance()));
+    assertEquals(emptyList(), message.getRepeatedGroupList());
+    assertEquals(
+        singletonList(RepeatedGroup.getDefaultInstance()),
+        builder.getRepeatedGroupList());
+    assertEquals(emptyList(), message.getRepeatedGroupList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedGroup();
+    assertEquals(emptyList(), builder.getRepeatedGroupList());
+    assertEquals(
+        singletonList(RepeatedGroup.getDefaultInstance()),
+        messageAfterBuild.getRepeatedGroupList());
+
+    message = builder.build();
+    builder.addAllRepeatedInt32(singletonList(1));
+    assertEquals(emptyList(), message.getRepeatedInt32List());
+    assertEquals(singletonList(1), builder.getRepeatedInt32List());
+    assertEquals(emptyList(), message.getRepeatedInt32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedInt32();
+    assertEquals(emptyList(), builder.getRepeatedInt32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedInt32List());
+
+    message = builder.build();
+    builder.addAllRepeatedInt64(singletonList(1L));
+    assertEquals(emptyList(), message.getRepeatedInt64List());
+    assertEquals(singletonList(1L), builder.getRepeatedInt64List());
+    assertEquals(emptyList(), message.getRepeatedInt64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedInt64();
+    assertEquals(emptyList(), builder.getRepeatedInt64List());
+    assertEquals(singletonList(1L), messageAfterBuild.getRepeatedInt64List());
+
+    message = builder.build();
+    builder.addAllRepeatedLazyMessage(singletonList(nestedMessage));
+    assertEquals(emptyList(), message.getRepeatedLazyMessageList());
+    assertEquals(
+        singletonList(nestedMessage), builder.getRepeatedLazyMessageList());
+    assertEquals(emptyList(), message.getRepeatedLazyMessageList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedLazyMessage();
+    assertEquals(emptyList(), builder.getRepeatedLazyMessageList());
+    assertEquals(
+        singletonList(nestedMessage),
+        messageAfterBuild.getRepeatedLazyMessageList());
+
+    message = builder.build();
+    builder.addAllRepeatedSfixed32(singletonList(1));
+    assertEquals(emptyList(), message.getRepeatedSfixed32List());
+    assertEquals(singletonList(1), builder.getRepeatedSfixed32List());
+    assertEquals(emptyList(), message.getRepeatedSfixed32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedSfixed32();
+    assertEquals(emptyList(), builder.getRepeatedSfixed32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedSfixed32List());
+
+    message = builder.build();
+    builder.addAllRepeatedSfixed64(singletonList(1L));
+    assertEquals(emptyList(), message.getRepeatedSfixed64List());
+    assertEquals(singletonList(1L), builder.getRepeatedSfixed64List());
+    assertEquals(emptyList(), message.getRepeatedSfixed64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedSfixed64();
+    assertEquals(emptyList(), builder.getRepeatedSfixed64List());
+    assertEquals(
+        singletonList(1L), messageAfterBuild.getRepeatedSfixed64List());
+
+    message = builder.build();
+    builder.addAllRepeatedSint32(singletonList(1));
+    assertEquals(emptyList(), message.getRepeatedSint32List());
+    assertEquals(singletonList(1), builder.getRepeatedSint32List());
+    assertEquals(emptyList(), message.getRepeatedSint32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedSint32();
+    assertEquals(emptyList(), builder.getRepeatedSint32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedSint32List());
+
+    message = builder.build();
+    builder.addAllRepeatedSint64(singletonList(1L));
+    assertEquals(emptyList(), message.getRepeatedSint64List());
+    assertEquals(singletonList(1L), builder.getRepeatedSint64List());
+    assertEquals(emptyList(), message.getRepeatedSint64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedSint64();
+    assertEquals(emptyList(), builder.getRepeatedSint64List());
+    assertEquals(singletonList(1L), messageAfterBuild.getRepeatedSint64List());
+
+    message = builder.build();
+    builder.addAllRepeatedString(singletonList("hi"));
+    assertEquals(emptyList(), message.getRepeatedStringList());
+    assertEquals(singletonList("hi"), builder.getRepeatedStringList());
+    assertEquals(emptyList(), message.getRepeatedStringList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedString();
+    assertEquals(emptyList(), builder.getRepeatedStringList());
+    assertEquals(
+        singletonList("hi"), messageAfterBuild.getRepeatedStringList());
+
+    message = builder.build();
+    builder.addAllRepeatedStringPiece(singletonList("hi"));
+    assertEquals(emptyList(), message.getRepeatedStringPieceList());
+    assertEquals(singletonList("hi"), builder.getRepeatedStringPieceList());
+    assertEquals(emptyList(), message.getRepeatedStringPieceList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedStringPiece();
+    assertEquals(emptyList(), builder.getRepeatedStringPieceList());
+    assertEquals(
+        singletonList("hi"), messageAfterBuild.getRepeatedStringPieceList());
+
+    message = builder.build();
+    builder.addAllRepeatedUint32(singletonList(1));
+    assertEquals(emptyList(), message.getRepeatedUint32List());
+    assertEquals(singletonList(1), builder.getRepeatedUint32List());
+    assertEquals(emptyList(), message.getRepeatedUint32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedUint32();
+    assertEquals(emptyList(), builder.getRepeatedUint32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedUint32List());
+
+    message = builder.build();
+    builder.addAllRepeatedUint64(singletonList(1L));
+    assertEquals(emptyList(), message.getRepeatedUint64List());
+    assertEquals(singletonList(1L), builder.getRepeatedUint64List());
+    assertEquals(emptyList(), message.getRepeatedUint64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedUint64();
+    assertEquals(emptyList(), builder.getRepeatedUint64List());
+    assertEquals(singletonList(1L), messageAfterBuild.getRepeatedUint64List());
+
+    message = builder.build();
+    builder.addRepeatedBool(true);
+    assertEquals(emptyList(), message.getRepeatedBoolList());
+    assertEquals(singletonList(true), builder.getRepeatedBoolList());
+    assertEquals(emptyList(), message.getRepeatedBoolList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedBool();
+    assertEquals(emptyList(), builder.getRepeatedBoolList());
+    assertEquals(singletonList(true), messageAfterBuild.getRepeatedBoolList());
+
+    message = builder.build();
+    builder.addRepeatedBytes(ByteString.copyFromUtf8("hi"));
+    assertEquals(emptyList(), message.getRepeatedBytesList());
+    assertEquals(
+        singletonList(ByteString.copyFromUtf8("hi")),
+        builder.getRepeatedBytesList());
+    assertEquals(emptyList(), message.getRepeatedBytesList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedBytes();
+    assertEquals(emptyList(), builder.getRepeatedBytesList());
+    assertEquals(
+        singletonList(ByteString.copyFromUtf8("hi")),
+        messageAfterBuild.getRepeatedBytesList());
+
+    message = builder.build();
+    builder.addRepeatedCord("hi");
+    assertEquals(emptyList(), message.getRepeatedCordList());
+    assertEquals(singletonList("hi"), builder.getRepeatedCordList());
+    assertEquals(emptyList(), message.getRepeatedCordList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedCord();
+    assertEquals(emptyList(), builder.getRepeatedCordList());
+    assertEquals(singletonList("hi"), messageAfterBuild.getRepeatedCordList());
+
+    message = builder.build();
+    builder.addRepeatedDouble(1D);
+    assertEquals(emptyList(), message.getRepeatedDoubleList());
+    assertEquals(singletonList(1D), builder.getRepeatedDoubleList());
+    assertEquals(emptyList(), message.getRepeatedDoubleList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedDouble();
+    assertEquals(emptyList(), builder.getRepeatedDoubleList());
+    assertEquals(singletonList(1D), messageAfterBuild.getRepeatedDoubleList());
+
+    message = builder.build();
+    builder.addRepeatedFixed32(1);
+    assertEquals(emptyList(), message.getRepeatedFixed32List());
+    assertEquals(singletonList(1), builder.getRepeatedFixed32List());
+    assertEquals(emptyList(), message.getRepeatedFixed32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedFixed32();
+    assertEquals(emptyList(), builder.getRepeatedFixed32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedFixed32List());
+
+    message = builder.build();
+    builder.addRepeatedFixed64(1L);
+    assertEquals(emptyList(), message.getRepeatedFixed64List());
+    assertEquals(singletonList(1L), builder.getRepeatedFixed64List());
+    assertEquals(emptyList(), message.getRepeatedFixed64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedFixed64();
+    assertEquals(emptyList(), builder.getRepeatedFixed64List());
+    assertEquals(singletonList(1L), messageAfterBuild.getRepeatedFixed64List());
+
+    message = builder.build();
+    builder.addRepeatedFloat(1F);
+    assertEquals(emptyList(), message.getRepeatedFloatList());
+    assertEquals(singletonList(1F), builder.getRepeatedFloatList());
+    assertEquals(emptyList(), message.getRepeatedFloatList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedFloat();
+    assertEquals(emptyList(), builder.getRepeatedFloatList());
+    assertEquals(singletonList(1F), messageAfterBuild.getRepeatedFloatList());
+
+    message = builder.build();
+    builder.addRepeatedForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR);
+    assertEquals(emptyList(), message.getRepeatedForeignEnumList());
+    assertEquals(
+        singletonList(ForeignEnumLite.FOREIGN_LITE_BAR),
+        builder.getRepeatedForeignEnumList());
+    assertEquals(emptyList(), message.getRepeatedForeignEnumList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedForeignEnum();
+    assertEquals(emptyList(), builder.getRepeatedForeignEnumList());
+    assertEquals(
+        singletonList(ForeignEnumLite.FOREIGN_LITE_BAR),
+        messageAfterBuild.getRepeatedForeignEnumList());
+
+    message = builder.build();
+    builder.addRepeatedForeignMessage(foreignMessage);
+    assertEquals(emptyList(), message.getRepeatedForeignMessageList());
+    assertEquals(
+        singletonList(foreignMessage), builder.getRepeatedForeignMessageList());
+    assertEquals(emptyList(), message.getRepeatedForeignMessageList());
+    messageAfterBuild = builder.build();
+    builder.removeRepeatedForeignMessage(0);
+    assertEquals(emptyList(), builder.getRepeatedForeignMessageList());
+    assertEquals(
+        singletonList(foreignMessage),
+        messageAfterBuild.getRepeatedForeignMessageList());
+
+    message = builder.build();
+    builder.addRepeatedGroup(RepeatedGroup.getDefaultInstance());
+    assertEquals(emptyList(), message.getRepeatedGroupList());
+    assertEquals(
+        singletonList(RepeatedGroup.getDefaultInstance()),
+        builder.getRepeatedGroupList());
+    assertEquals(emptyList(), message.getRepeatedGroupList());
+    messageAfterBuild = builder.build();
+    builder.removeRepeatedGroup(0);
+    assertEquals(emptyList(), builder.getRepeatedGroupList());
+    assertEquals(
+        singletonList(RepeatedGroup.getDefaultInstance()),
+        messageAfterBuild.getRepeatedGroupList());
+
+    message = builder.build();
+    builder.addRepeatedInt32(1);
+    assertEquals(emptyList(), message.getRepeatedInt32List());
+    assertEquals(singletonList(1), builder.getRepeatedInt32List());
+    assertEquals(emptyList(), message.getRepeatedInt32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedInt32();
+    assertEquals(emptyList(), builder.getRepeatedInt32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedInt32List());
+
+    message = builder.build();
+    builder.addRepeatedInt64(1L);
+    assertEquals(emptyList(), message.getRepeatedInt64List());
+    assertEquals(singletonList(1L), builder.getRepeatedInt64List());
+    assertEquals(emptyList(), message.getRepeatedInt64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedInt64();
+    assertEquals(emptyList(), builder.getRepeatedInt64List());
+    assertEquals(singletonList(1L), messageAfterBuild.getRepeatedInt64List());
+
+    message = builder.build();
+    builder.addRepeatedLazyMessage(nestedMessage);
+    assertEquals(emptyList(), message.getRepeatedLazyMessageList());
+    assertEquals(
+        singletonList(nestedMessage), builder.getRepeatedLazyMessageList());
+    assertEquals(emptyList(), message.getRepeatedLazyMessageList());
+    messageAfterBuild = builder.build();
+    builder.removeRepeatedLazyMessage(0);
+    assertEquals(emptyList(), builder.getRepeatedLazyMessageList());
+    assertEquals(
+        singletonList(nestedMessage),
+        messageAfterBuild.getRepeatedLazyMessageList());
+
+    message = builder.build();
+    builder.addRepeatedSfixed32(1);
+    assertEquals(emptyList(), message.getRepeatedSfixed32List());
+    assertEquals(singletonList(1), builder.getRepeatedSfixed32List());
+    assertEquals(emptyList(), message.getRepeatedSfixed32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedSfixed32();
+    assertEquals(emptyList(), builder.getRepeatedSfixed32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedSfixed32List());
+
+    message = builder.build();
+    builder.addRepeatedSfixed64(1L);
+    assertEquals(emptyList(), message.getRepeatedSfixed64List());
+    assertEquals(singletonList(1L), builder.getRepeatedSfixed64List());
+    assertEquals(emptyList(), message.getRepeatedSfixed64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedSfixed64();
+    assertEquals(emptyList(), builder.getRepeatedSfixed64List());
+    assertEquals(
+        singletonList(1L), messageAfterBuild.getRepeatedSfixed64List());
+
+    message = builder.build();
+    builder.addRepeatedSint32(1);
+    assertEquals(emptyList(), message.getRepeatedSint32List());
+    assertEquals(singletonList(1), builder.getRepeatedSint32List());
+    assertEquals(emptyList(), message.getRepeatedSint32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedSint32();
+    assertEquals(emptyList(), builder.getRepeatedSint32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedSint32List());
+
+    message = builder.build();
+    builder.addRepeatedSint64(1L);
+    assertEquals(emptyList(), message.getRepeatedSint64List());
+    assertEquals(singletonList(1L), builder.getRepeatedSint64List());
+    assertEquals(emptyList(), message.getRepeatedSint64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedSint64();
+    assertEquals(emptyList(), builder.getRepeatedSint64List());
+    assertEquals(singletonList(1L), messageAfterBuild.getRepeatedSint64List());
+
+    message = builder.build();
+    builder.addRepeatedString("hi");
+    assertEquals(emptyList(), message.getRepeatedStringList());
+    assertEquals(singletonList("hi"), builder.getRepeatedStringList());
+    assertEquals(emptyList(), message.getRepeatedStringList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedString();
+    assertEquals(emptyList(), builder.getRepeatedStringList());
+    assertEquals(
+        singletonList("hi"), messageAfterBuild.getRepeatedStringList());
+
+    message = builder.build();
+    builder.addRepeatedStringPiece("hi");
+    assertEquals(emptyList(), message.getRepeatedStringPieceList());
+    assertEquals(singletonList("hi"), builder.getRepeatedStringPieceList());
+    assertEquals(emptyList(), message.getRepeatedStringPieceList());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedStringPiece();
+    assertEquals(emptyList(), builder.getRepeatedStringPieceList());
+    assertEquals(
+        singletonList("hi"), messageAfterBuild.getRepeatedStringPieceList());
+
+    message = builder.build();
+    builder.addRepeatedUint32(1);
+    assertEquals(emptyList(), message.getRepeatedUint32List());
+    assertEquals(singletonList(1), builder.getRepeatedUint32List());
+    assertEquals(emptyList(), message.getRepeatedUint32List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedUint32();
+    assertEquals(emptyList(), builder.getRepeatedUint32List());
+    assertEquals(singletonList(1), messageAfterBuild.getRepeatedUint32List());
+
+    message = builder.build();
+    builder.addRepeatedUint64(1L);
+    assertEquals(emptyList(), message.getRepeatedUint64List());
+    assertEquals(singletonList(1L), builder.getRepeatedUint64List());
+    assertEquals(emptyList(), message.getRepeatedUint64List());
+    messageAfterBuild = builder.build();
+    builder.clearRepeatedUint64();
+    assertEquals(emptyList(), builder.getRepeatedUint64List());
+    assertEquals(singletonList(1L), messageAfterBuild.getRepeatedUint64List());
+    
+    message = builder.build();
+    builder.addRepeatedBool(true);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedBoolCount());
+    builder.setRepeatedBool(0, false);
+    assertEquals(true, messageAfterBuild.getRepeatedBool(0));
+    assertEquals(false, builder.getRepeatedBool(0));
+    builder.clearRepeatedBool();
+    
+    message = builder.build();
+    builder.addRepeatedBytes(ByteString.copyFromUtf8("hi"));
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedBytesCount());
+    builder.setRepeatedBytes(0, ByteString.EMPTY);
+    assertEquals(
+        ByteString.copyFromUtf8("hi"), messageAfterBuild.getRepeatedBytes(0));
+    assertEquals(ByteString.EMPTY, builder.getRepeatedBytes(0));
+    builder.clearRepeatedBytes();
+
+    message = builder.build();
+    builder.addRepeatedCord("hi");
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedCordCount());
+    builder.setRepeatedCord(0, "");
+    assertEquals("hi", messageAfterBuild.getRepeatedCord(0));
+    assertEquals("", builder.getRepeatedCord(0));
+    builder.clearRepeatedCord();
+    message = builder.build();
+
+    builder.addRepeatedCordBytes(ByteString.copyFromUtf8("hi"));
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedCordCount());
+    builder.setRepeatedCord(0, "");
+    assertEquals(
+        ByteString.copyFromUtf8("hi"), messageAfterBuild.getRepeatedCordBytes(0));
+    assertEquals(ByteString.EMPTY, builder.getRepeatedCordBytes(0));
+    builder.clearRepeatedCord();
+
+    message = builder.build();
+    builder.addRepeatedDouble(1D);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedDoubleCount());
+    builder.setRepeatedDouble(0, 0D);
+    assertEquals(1D, messageAfterBuild.getRepeatedDouble(0));
+    assertEquals(0D, builder.getRepeatedDouble(0));
+    builder.clearRepeatedDouble();
+
+    message = builder.build();
+    builder.addRepeatedFixed32(1);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedFixed32Count());
+    builder.setRepeatedFixed32(0, 0);
+    assertEquals(1, messageAfterBuild.getRepeatedFixed32(0));
+    assertEquals(0, builder.getRepeatedFixed32(0));
+    builder.clearRepeatedFixed32();
+
+    message = builder.build();
+    builder.addRepeatedFixed64(1L);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedFixed64Count());
+    builder.setRepeatedFixed64(0, 0L);
+    assertEquals(1L, messageAfterBuild.getRepeatedFixed64(0));
+    assertEquals(0L, builder.getRepeatedFixed64(0));
+    builder.clearRepeatedFixed64();
+
+    message = builder.build();
+    builder.addRepeatedFloat(1F);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedFloatCount());
+    builder.setRepeatedFloat(0, 0F);
+    assertEquals(1F, messageAfterBuild.getRepeatedFloat(0));
+    assertEquals(0F, builder.getRepeatedFloat(0));
+    builder.clearRepeatedFloat();
+
+    message = builder.build();
+    builder.addRepeatedForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedForeignEnumCount());
+    builder.setRepeatedForeignEnum(0, ForeignEnumLite.FOREIGN_LITE_FOO);
+    assertEquals(
+        ForeignEnumLite.FOREIGN_LITE_BAR,
+        messageAfterBuild.getRepeatedForeignEnum(0));
+    assertEquals(
+        ForeignEnumLite.FOREIGN_LITE_FOO, builder.getRepeatedForeignEnum(0));
+    builder.clearRepeatedForeignEnum();
+
+    message = builder.build();
+    builder.addRepeatedForeignMessage(foreignMessage);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedForeignMessageCount());
+    builder.setRepeatedForeignMessage(
+        0, ForeignMessageLite.getDefaultInstance());
+    assertEquals(
+        foreignMessage, messageAfterBuild.getRepeatedForeignMessage(0));
+    assertEquals(
+        ForeignMessageLite.getDefaultInstance(),
+        builder.getRepeatedForeignMessage(0));
+    builder.clearRepeatedForeignMessage();
+    
+    message = builder.build();
+    builder.addRepeatedForeignMessage(foreignMessageBuilder);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedForeignMessageCount());
+    builder.setRepeatedForeignMessage(
+        0, ForeignMessageLite.getDefaultInstance());
+    // LITE_RUNTIME doesn't implement equals so we compare on a property.
+    assertEquals(3, messageAfterBuild.getRepeatedForeignMessage(0).getC());
+    assertEquals(
+        ForeignMessageLite.getDefaultInstance(),
+        builder.getRepeatedForeignMessage(0));
+    builder.clearRepeatedForeignMessage();
+
+    message = builder.build();
+    builder.addRepeatedForeignMessage(0, foreignMessage);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedForeignMessageCount());
+    builder.setRepeatedForeignMessage(0, foreignMessageBuilder);
+    assertEquals(
+        foreignMessage, messageAfterBuild.getRepeatedForeignMessage(0));
+    // LITE_RUNTIME doesn't implement equals so we compare on a property.
+    assertEquals(3, builder.getRepeatedForeignMessage(0).getC());
+    builder.clearRepeatedForeignMessage();
+
+    message = builder.build();
+    RepeatedGroup repeatedGroup = RepeatedGroup.newBuilder()
+        .setA(1)
+        .build();
+    builder.addRepeatedGroup(repeatedGroup);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedGroupCount());
+    builder.setRepeatedGroup(0, RepeatedGroup.getDefaultInstance());
+    assertEquals(repeatedGroup, messageAfterBuild.getRepeatedGroup(0));
+    assertEquals(
+        RepeatedGroup.getDefaultInstance(), builder.getRepeatedGroup(0));
+    builder.clearRepeatedGroup();
+    
+    message = builder.build();
+    builder.addRepeatedGroup(0, repeatedGroup);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedGroupCount());
+    builder.setRepeatedGroup(0, RepeatedGroup.getDefaultInstance());
+    assertEquals(repeatedGroup, messageAfterBuild.getRepeatedGroup(0));
+    assertEquals(
+        RepeatedGroup.getDefaultInstance(), builder.getRepeatedGroup(0));
+    builder.clearRepeatedGroup();
+    
+    message = builder.build();
+    RepeatedGroup.Builder repeatedGroupBuilder = RepeatedGroup.newBuilder()
+        .setA(3);
+    builder.addRepeatedGroup(repeatedGroupBuilder);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedGroupCount());
+    builder.setRepeatedGroup(0, RepeatedGroup.getDefaultInstance());
+    // LITE_RUNTIME doesn't implement equals so we compare on a property and
+    // ensure the property isn't set on repeatedGroup.
+    assertEquals(3, messageAfterBuild.getRepeatedGroup(0).getA());
+    assertEquals(
+        RepeatedGroup.getDefaultInstance(), builder.getRepeatedGroup(0));
+    builder.clearRepeatedGroup();
+    
+    message = builder.build();
+    builder.addRepeatedGroup(0, repeatedGroupBuilder);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedGroupCount());
+    builder.setRepeatedGroup(0, RepeatedGroup.getDefaultInstance());
+    // LITE_RUNTIME doesn't implement equals so we compare on a property and
+    // ensure the property isn't set on repeatedGroup.
+    assertEquals(3, messageAfterBuild.getRepeatedGroup(0).getA());
+    assertEquals(
+        RepeatedGroup.getDefaultInstance(), builder.getRepeatedGroup(0));
+    builder.clearRepeatedGroup();
+
+    message = builder.build();
+    builder.addRepeatedInt32(1);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedInt32Count());
+    builder.setRepeatedInt32(0, 0);
+    assertEquals(1, messageAfterBuild.getRepeatedInt32(0));
+    assertEquals(0, builder.getRepeatedInt32(0));
+    builder.clearRepeatedInt32();
+
+    message = builder.build();
+    builder.addRepeatedInt64(1L);
+    messageAfterBuild = builder.build();
+    assertEquals(0L, message.getRepeatedInt64Count());
+    builder.setRepeatedInt64(0, 0L);
+    assertEquals(1L, messageAfterBuild.getRepeatedInt64(0));
+    assertEquals(0L, builder.getRepeatedInt64(0));
+    builder.clearRepeatedInt64();
+    
+    message = builder.build();
+    builder.addRepeatedLazyMessage(nestedMessage);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedLazyMessageCount());
+    builder.setRepeatedLazyMessage(0, NestedMessage.getDefaultInstance());
+    assertEquals(nestedMessage, messageAfterBuild.getRepeatedLazyMessage(0));
+    assertEquals(
+        NestedMessage.getDefaultInstance(), builder.getRepeatedLazyMessage(0));
+    builder.clearRepeatedLazyMessage();
+    
+    message = builder.build();
+    builder.addRepeatedLazyMessage(0, nestedMessage);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedLazyMessageCount());
+    builder.setRepeatedLazyMessage(0, NestedMessage.getDefaultInstance());
+    assertEquals(nestedMessage, messageAfterBuild.getRepeatedLazyMessage(0));
+    assertEquals(
+        NestedMessage.getDefaultInstance(), builder.getRepeatedLazyMessage(0));
+    builder.clearRepeatedLazyMessage();
+    
+    message = builder.build();
+    builder.addRepeatedLazyMessage(nestedMessageBuilder);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedLazyMessageCount());
+    builder.setRepeatedLazyMessage(0, NestedMessage.getDefaultInstance());
+    // LITE_RUNTIME doesn't implement equals so we compare on a property and
+    // ensure the property isn't set on repeatedGroup.
+    assertEquals(3, messageAfterBuild.getRepeatedLazyMessage(0).getBb());
+    assertEquals(
+        NestedMessage.getDefaultInstance(), builder.getRepeatedLazyMessage(0));
+    builder.clearRepeatedLazyMessage();
+    
+    message = builder.build();
+    builder.addRepeatedLazyMessage(0, nestedMessageBuilder);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedLazyMessageCount());
+    builder.setRepeatedLazyMessage(0, NestedMessage.getDefaultInstance());
+    // LITE_RUNTIME doesn't implement equals so we compare on a property and
+    // ensure the property isn't set on repeatedGroup.
+    assertEquals(3, messageAfterBuild.getRepeatedLazyMessage(0).getBb());
+    assertEquals(
+        NestedMessage.getDefaultInstance(), builder.getRepeatedLazyMessage(0));
+    builder.clearRepeatedLazyMessage();
+
+    message = builder.build();
+    builder.addRepeatedSfixed32(1);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedSfixed32Count());
+    builder.setRepeatedSfixed32(0, 0);
+    assertEquals(1, messageAfterBuild.getRepeatedSfixed32(0));
+    assertEquals(0, builder.getRepeatedSfixed32(0));
+    builder.clearRepeatedSfixed32();
+
+    message = builder.build();
+    builder.addRepeatedSfixed64(1L);
+    messageAfterBuild = builder.build();
+    assertEquals(0L, message.getRepeatedSfixed64Count());
+    builder.setRepeatedSfixed64(0, 0L);
+    assertEquals(1L, messageAfterBuild.getRepeatedSfixed64(0));
+    assertEquals(0L, builder.getRepeatedSfixed64(0));
+    builder.clearRepeatedSfixed64();
+
+    message = builder.build();
+    builder.addRepeatedSint32(1);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedSint32Count());
+    builder.setRepeatedSint32(0, 0);
+    assertEquals(1, messageAfterBuild.getRepeatedSint32(0));
+    assertEquals(0, builder.getRepeatedSint32(0));
+    builder.clearRepeatedSint32();
+
+    message = builder.build();
+    builder.addRepeatedSint64(1L);
+    messageAfterBuild = builder.build();
+    assertEquals(0L, message.getRepeatedSint64Count());
+    builder.setRepeatedSint64(0, 0L);
+    assertEquals(1L, messageAfterBuild.getRepeatedSint64(0));
+    assertEquals(0L, builder.getRepeatedSint64(0));
+    builder.clearRepeatedSint64();
+
+    message = builder.build();
+    builder.addRepeatedString("hi");
+    messageAfterBuild = builder.build();
+    assertEquals(0L, message.getRepeatedStringCount());
+    builder.setRepeatedString(0, "");
+    assertEquals("hi", messageAfterBuild.getRepeatedString(0));
+    assertEquals("", builder.getRepeatedString(0));
+    builder.clearRepeatedString();
+
+    message = builder.build();
+    builder.addRepeatedStringBytes(ByteString.copyFromUtf8("hi"));
+    messageAfterBuild = builder.build();
+    assertEquals(0L, message.getRepeatedStringCount());
+    builder.setRepeatedString(0, "");
+    assertEquals(
+        ByteString.copyFromUtf8("hi"),
+        messageAfterBuild.getRepeatedStringBytes(0));
+    assertEquals(ByteString.EMPTY, builder.getRepeatedStringBytes(0));
+    builder.clearRepeatedString();
+
+    message = builder.build();
+    builder.addRepeatedStringPiece("hi");
+    messageAfterBuild = builder.build();
+    assertEquals(0L, message.getRepeatedStringPieceCount());
+    builder.setRepeatedStringPiece(0, "");
+    assertEquals("hi", messageAfterBuild.getRepeatedStringPiece(0));
+    assertEquals("", builder.getRepeatedStringPiece(0));
+    builder.clearRepeatedStringPiece();
+
+    message = builder.build();
+    builder.addRepeatedStringPieceBytes(ByteString.copyFromUtf8("hi"));
+    messageAfterBuild = builder.build();
+    assertEquals(0L, message.getRepeatedStringPieceCount());
+    builder.setRepeatedStringPiece(0, "");
+    assertEquals(
+        ByteString.copyFromUtf8("hi"),
+        messageAfterBuild.getRepeatedStringPieceBytes(0));
+    assertEquals(ByteString.EMPTY, builder.getRepeatedStringPieceBytes(0));
+    builder.clearRepeatedStringPiece();
+
+    message = builder.build();
+    builder.addRepeatedUint32(1);
+    messageAfterBuild = builder.build();
+    assertEquals(0, message.getRepeatedUint32Count());
+    builder.setRepeatedUint32(0, 0);
+    assertEquals(1, messageAfterBuild.getRepeatedUint32(0));
+    assertEquals(0, builder.getRepeatedUint32(0));
+    builder.clearRepeatedUint32();
+
+    message = builder.build();
+    builder.addRepeatedUint64(1L);
+    messageAfterBuild = builder.build();
+    assertEquals(0L, message.getRepeatedUint64Count());
+    builder.setRepeatedUint64(0, 0L);
+    assertEquals(1L, messageAfterBuild.getRepeatedUint64(0));
+    assertEquals(0L, builder.getRepeatedUint64(0));
+    builder.clearRepeatedUint64();
+
+    message = builder.build();
+    assertEquals(0, message.getSerializedSize());
+    builder.mergeFrom(TestAllTypesLite.newBuilder()
+        .setOptionalBool(true)
+        .build());
+    assertEquals(0, message.getSerializedSize());
+    assertEquals(true, builder.build().getOptionalBool());
+    builder.clearOptionalBool();
+
+    message = builder.build();
+    assertEquals(0, message.getSerializedSize());
+    builder.mergeFrom(TestAllTypesLite.newBuilder()
+        .setOptionalBool(true)
+        .build());
+    assertEquals(0, message.getSerializedSize());
+    assertEquals(true, builder.build().getOptionalBool());
+    builder.clear();
+    assertEquals(0, builder.build().getSerializedSize());
+
+    message = builder.build();
+    assertEquals(0, message.getSerializedSize());
+    builder.mergeOptionalForeignMessage(foreignMessage);
+    assertEquals(0, message.getSerializedSize());
+    assertEquals(
+        foreignMessage.getC(),
+        builder.build().getOptionalForeignMessage().getC());
+    builder.clearOptionalForeignMessage();
+
+    message = builder.build();
+    assertEquals(0, message.getSerializedSize());
+    builder.mergeOptionalLazyMessage(nestedMessage);
+    assertEquals(0, message.getSerializedSize());
+    assertEquals(
+        nestedMessage.getBb(),
+        builder.build().getOptionalLazyMessage().getBb());
+    builder.clearOptionalLazyMessage();
+    
+    message = builder.build();
+    builder.setOneofString("hi");
+    assertEquals(
+        OneofFieldCase.ONEOFFIELD_NOT_SET, message.getOneofFieldCase());
+    assertEquals(OneofFieldCase.ONEOF_STRING, builder.getOneofFieldCase());
+    assertEquals("hi", builder.getOneofString());
+    messageAfterBuild = builder.build();
+    assertEquals(
+        OneofFieldCase.ONEOF_STRING, messageAfterBuild.getOneofFieldCase());
+    assertEquals("hi", messageAfterBuild.getOneofString());
+    builder.setOneofUint32(1);
+    assertEquals(
+        OneofFieldCase.ONEOF_STRING, messageAfterBuild.getOneofFieldCase());
+    assertEquals("hi", messageAfterBuild.getOneofString());
+    assertEquals(OneofFieldCase.ONEOF_UINT32, builder.getOneofFieldCase());
+    assertEquals(1, builder.getOneofUint32());
+    TestAllTypesLiteOrBuilder messageOrBuilder = builder;
+    assertEquals(OneofFieldCase.ONEOF_UINT32, messageOrBuilder.getOneofFieldCase());
+    
+    TestAllExtensionsLite.Builder extendableMessageBuilder =
+        TestAllExtensionsLite.newBuilder();
+    TestAllExtensionsLite extendableMessage = extendableMessageBuilder.build();
+    extendableMessageBuilder.setExtension(
+        UnittestLite.optionalInt32ExtensionLite, 1);
+    assertFalse(extendableMessage.hasExtension(
+        UnittestLite.optionalInt32ExtensionLite));
+    extendableMessage = extendableMessageBuilder.build();
+    assertEquals(
+        1, (int) extendableMessageBuilder.getExtension(
+            UnittestLite.optionalInt32ExtensionLite));
+    assertEquals(
+        1, (int) extendableMessage.getExtension(
+            UnittestLite.optionalInt32ExtensionLite));
+    extendableMessageBuilder.setExtension(
+        UnittestLite.optionalInt32ExtensionLite, 3);
+    assertEquals(
+        3, (int) extendableMessageBuilder.getExtension(
+            UnittestLite.optionalInt32ExtensionLite));
+    assertEquals(
+        1, (int) extendableMessage.getExtension(
+            UnittestLite.optionalInt32ExtensionLite));
+    extendableMessage = extendableMessageBuilder.build();
+    assertEquals(
+        3, (int) extendableMessageBuilder.getExtension(
+            UnittestLite.optionalInt32ExtensionLite));
+    assertEquals(
+        3, (int) extendableMessage.getExtension(
+            UnittestLite.optionalInt32ExtensionLite));
+    
+    // No extension registry, so it should be in unknown fields.
+    extendableMessage =
+        TestAllExtensionsLite.parseFrom(extendableMessage.toByteArray());
+    assertFalse(extendableMessage.hasExtension(
+        UnittestLite.optionalInt32ExtensionLite));
+    
+    extendableMessageBuilder = extendableMessage.toBuilder();
+    extendableMessageBuilder.mergeFrom(TestAllExtensionsLite.newBuilder()
+        .setExtension(UnittestLite.optionalFixed32ExtensionLite, 11)
+        .build());
+    
+    extendableMessage = extendableMessageBuilder.build();
+    ExtensionRegistryLite registry = ExtensionRegistryLite.newInstance();
+    UnittestLite.registerAllExtensions(registry);
+    extendableMessage = TestAllExtensionsLite.parseFrom(
+        extendableMessage.toByteArray(), registry);
+    
+    // The unknown field was preserved.
+    assertEquals(
+        3, (int) extendableMessage.getExtension(
+            UnittestLite.optionalInt32ExtensionLite));
+    assertEquals(
+        11, (int) extendableMessage.getExtension(
+            UnittestLite.optionalFixed32ExtensionLite));
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LiteralByteStringTest.java b/java/core/src/test/java/com/google/protobuf/LiteralByteStringTest.java
new file mode 100644
index 00000000..68b55ceb
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LiteralByteStringTest.java
@@ -0,0 +1,495 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.OutputStream;
+import java.io.UnsupportedEncodingException;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+/**
+ * Test {@link LiteralByteString} by setting up a reference string in {@link #setUp()}.
+ * This class is designed to be extended for testing extensions of {@link LiteralByteString}
+ * such as {@link BoundedByteString}, see {@link BoundedByteStringTest}.
+ *
+ * @author carlanton@google.com (Carl Haverl)
+ */
+public class LiteralByteStringTest extends TestCase {
+  protected static final String UTF_8 = "UTF-8";
+
+  protected String classUnderTest;
+  protected byte[] referenceBytes;
+  protected ByteString stringUnderTest;
+  protected int expectedHashCode;
+
+  @Override
+  protected void setUp() throws Exception {
+    classUnderTest = "LiteralByteString";
+    referenceBytes = ByteStringTest.getTestBytes(1234, 11337766L);
+    stringUnderTest = ByteString.copyFrom(referenceBytes);
+    expectedHashCode = 331161852;
+  }
+
+  public void testExpectedType() {
+    String actualClassName = getActualClassName(stringUnderTest);
+    assertEquals(classUnderTest + " should match type exactly", classUnderTest, actualClassName);
+  }
+
+  protected String getActualClassName(Object object) {
+    return object.getClass().getSimpleName();
+  }
+
+  public void testByteAt() {
+    boolean stillEqual = true;
+    for (int i = 0; stillEqual && i < referenceBytes.length; ++i) {
+      stillEqual = (referenceBytes[i] == stringUnderTest.byteAt(i));
+    }
+    assertTrue(classUnderTest + " must capture the right bytes", stillEqual);
+  }
+
+  public void testByteIterator() {
+    boolean stillEqual = true;
+    ByteString.ByteIterator iter = stringUnderTest.iterator();
+    for (int i = 0; stillEqual && i < referenceBytes.length; ++i) {
+      stillEqual = (iter.hasNext() && referenceBytes[i] == iter.nextByte());
+    }
+    assertTrue(classUnderTest + " must capture the right bytes", stillEqual);
+    assertFalse(classUnderTest + " must have exhausted the itertor", iter.hasNext());
+
+    try {
+      iter.nextByte();
+      fail("Should have thrown an exception.");
+    } catch (NoSuchElementException e) {
+      // This is success
+    }
+  }
+
+  public void testByteIterable() {
+    boolean stillEqual = true;
+    int j = 0;
+    for (byte quantum : stringUnderTest) {
+      stillEqual = (referenceBytes[j] == quantum);
+      ++j;
+    }
+    assertTrue(classUnderTest + " must capture the right bytes as Bytes", stillEqual);
+    assertEquals(classUnderTest + " iterable character count", referenceBytes.length, j);
+  }
+
+  public void testSize() {
+    assertEquals(classUnderTest + " must have the expected size", referenceBytes.length,
+        stringUnderTest.size());
+  }
+
+  public void testGetTreeDepth() {
+    assertEquals(classUnderTest + " must have depth 0", 0, stringUnderTest.getTreeDepth());
+  }
+
+  public void testIsBalanced() {
+    assertTrue(classUnderTest + " is technically balanced", stringUnderTest.isBalanced());
+  }
+
+  public void testCopyTo_ByteArrayOffsetLength() {
+    int destinationOffset = 50;
+    int length = 100;
+    byte[] destination = new byte[destinationOffset + length];
+    int sourceOffset = 213;
+    stringUnderTest.copyTo(destination, sourceOffset, destinationOffset, length);
+    boolean stillEqual = true;
+    for (int i = 0; stillEqual && i < length; ++i) {
+      stillEqual = referenceBytes[i + sourceOffset] == destination[i + destinationOffset];
+    }
+    assertTrue(classUnderTest + ".copyTo(4 arg) must give the expected bytes", stillEqual);
+  }
+
+  public void testCopyTo_ByteArrayOffsetLengthErrors() {
+    int destinationOffset = 50;
+    int length = 100;
+    byte[] destination = new byte[destinationOffset + length];
+
+    try {
+      // Copy one too many bytes
+      stringUnderTest.copyTo(destination, stringUnderTest.size() + 1 - length,
+          destinationOffset, length);
+      fail("Should have thrown an exception when copying too many bytes of a "
+          + classUnderTest);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative sourceOffset
+      stringUnderTest.copyTo(destination, -1, destinationOffset, length);
+      fail("Should have thrown an exception when given a negative sourceOffset in "
+          + classUnderTest);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative destinationOffset
+      stringUnderTest.copyTo(destination, 0, -1, length);
+      fail("Should have thrown an exception when given a negative destinationOffset in "
+          + classUnderTest);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative size
+      stringUnderTest.copyTo(destination, 0, 0, -1);
+      fail("Should have thrown an exception when given a negative size in "
+          + classUnderTest);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal too-large sourceOffset
+      stringUnderTest.copyTo(destination, 2 * stringUnderTest.size(), 0, length);
+      fail("Should have thrown an exception when the destinationOffset is too large in "
+          + classUnderTest);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal too-large destinationOffset
+      stringUnderTest.copyTo(destination, 0, 2 * destination.length, length);
+      fail("Should have thrown an exception when the destinationOffset is too large in "
+          + classUnderTest);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+  }
+
+  public void testCopyTo_ByteBuffer() {
+    ByteBuffer myBuffer = ByteBuffer.allocate(referenceBytes.length);
+    stringUnderTest.copyTo(myBuffer);
+    assertTrue(classUnderTest + ".copyTo(ByteBuffer) must give back the same bytes",
+        Arrays.equals(referenceBytes, myBuffer.array()));
+  }
+
+  public void testMarkSupported() {
+    InputStream stream = stringUnderTest.newInput();
+    assertTrue(classUnderTest + ".newInput() must support marking", stream.markSupported());
+  }
+
+  public void testMarkAndReset() throws IOException {
+    int fraction = stringUnderTest.size() / 3;
+
+    InputStream stream = stringUnderTest.newInput();
+    stream.mark(stringUnderTest.size()); // First, mark() the end.
+
+    skipFully(stream, fraction); // Skip a large fraction, but not all.
+    int available = stream.available();
+    assertTrue(
+        classUnderTest + ": after skipping to the 'middle', half the bytes are available",
+        (stringUnderTest.size() - fraction) == available);
+    stream.reset();
+
+    skipFully(stream, stringUnderTest.size()); // Skip to the end.
+    available = stream.available();
+    assertTrue(
+        classUnderTest + ": after skipping to the end, no more bytes are available",
+        0 == available);
+  }
+
+  /**
+   * Discards {@code n} bytes of data from the input stream. This method
+   * will block until the full amount has been skipped. Does not close the
+   * stream.
+   * <p>Copied from com.google.common.io.ByteStreams to avoid adding dependency.
+   *
+   * @param in the input stream to read from
+   * @param n the number of bytes to skip
+   * @throws EOFException if this stream reaches the end before skipping all
+   *     the bytes
+   * @throws IOException if an I/O error occurs, or the stream does not
+   *     support skipping
+   */
+  static void skipFully(InputStream in, long n) throws IOException {
+    long toSkip = n;
+    while (n > 0) {
+      long amt = in.skip(n);
+      if (amt == 0) {
+        // Force a blocking read to avoid infinite loop
+        if (in.read() == -1) {
+          long skipped = toSkip - n;
+          throw new EOFException("reached end of stream after skipping "
+              + skipped + " bytes; " + toSkip + " bytes expected");
+        }
+        n--;
+      } else {
+        n -= amt;
+      }
+    }
+  }
+
+  public void testAsReadOnlyByteBuffer() {
+    ByteBuffer byteBuffer = stringUnderTest.asReadOnlyByteBuffer();
+    byte[] roundTripBytes = new byte[referenceBytes.length];
+    assertTrue(byteBuffer.remaining() == referenceBytes.length);
+    assertTrue(byteBuffer.isReadOnly());
+    byteBuffer.get(roundTripBytes);
+    assertTrue(classUnderTest + ".asReadOnlyByteBuffer() must give back the same bytes",
+        Arrays.equals(referenceBytes, roundTripBytes));
+  }
+
+  public void testAsReadOnlyByteBufferList() {
+    List<ByteBuffer> byteBuffers = stringUnderTest.asReadOnlyByteBufferList();
+    int bytesSeen = 0;
+    byte[] roundTripBytes = new byte[referenceBytes.length];
+    for (ByteBuffer byteBuffer : byteBuffers) {
+      int thisLength = byteBuffer.remaining();
+      assertTrue(byteBuffer.isReadOnly());
+      assertTrue(bytesSeen + thisLength <= referenceBytes.length);
+      byteBuffer.get(roundTripBytes, bytesSeen, thisLength);
+      bytesSeen += thisLength;
+    }
+    assertTrue(bytesSeen == referenceBytes.length);
+    assertTrue(classUnderTest + ".asReadOnlyByteBufferTest() must give back the same bytes",
+        Arrays.equals(referenceBytes, roundTripBytes));
+  }
+
+  public void testToByteArray() {
+    byte[] roundTripBytes = stringUnderTest.toByteArray();
+    assertTrue(classUnderTest + ".toByteArray() must give back the same bytes",
+        Arrays.equals(referenceBytes, roundTripBytes));
+  }
+
+  public void testWriteTo() throws IOException {
+    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+    stringUnderTest.writeTo(bos);
+    byte[] roundTripBytes = bos.toByteArray();
+    assertTrue(classUnderTest + ".writeTo() must give back the same bytes",
+        Arrays.equals(referenceBytes, roundTripBytes));
+  }
+
+  public void testWriteTo_mutating() throws IOException {
+    OutputStream os = new OutputStream() {
+      @Override
+      public void write(byte[] b, int off, int len) {
+        for (int x = 0; x < len; ++x) {
+          b[off + x] = (byte) 0;
+        }
+      }
+
+      @Override
+      public void write(int b) {
+        // Purposefully left blank.
+      }
+    };
+
+    stringUnderTest.writeTo(os);
+    byte[] newBytes = stringUnderTest.toByteArray();
+    assertTrue(classUnderTest + ".writeTo() must not grant access to underlying array",
+        Arrays.equals(referenceBytes, newBytes));
+  }
+
+  public void testNewOutput() throws IOException {
+    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+    ByteString.Output output = ByteString.newOutput();
+    stringUnderTest.writeTo(output);
+    assertEquals("Output Size returns correct result",
+        output.size(), stringUnderTest.size());
+    output.writeTo(bos);
+    assertTrue("Output.writeTo() must give back the same bytes",
+        Arrays.equals(referenceBytes, bos.toByteArray()));
+
+    // write the output stream to itself! This should cause it to double
+    output.writeTo(output);
+    assertEquals("Writing an output stream to itself is successful",
+        stringUnderTest.concat(stringUnderTest), output.toByteString());
+
+    output.reset();
+    assertEquals("Output.reset() resets the output", 0, output.size());
+    assertEquals("Output.reset() resets the output",
+        ByteString.EMPTY, output.toByteString());
+  }
+
+  public void testToString() throws UnsupportedEncodingException {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString unicode = ByteString.wrap(testString.getBytes(Internal.UTF_8));
+    String roundTripString = unicode.toString(UTF_8);
+    assertEquals(classUnderTest + " unicode must match", testString, roundTripString);
+  }
+
+  public void testCharsetToString() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString unicode = ByteString.wrap(testString.getBytes(Internal.UTF_8));
+    String roundTripString = unicode.toString(Internal.UTF_8);
+    assertEquals(classUnderTest + " unicode must match", testString, roundTripString);
+  }
+
+  public void testToString_returnsCanonicalEmptyString() {
+    assertSame(classUnderTest + " must be the same string references",
+        ByteString.EMPTY.toString(Internal.UTF_8),
+        ByteString.wrap(new byte[]{}).toString(Internal.UTF_8));
+  }
+
+  public void testToString_raisesException() {
+    try {
+      ByteString.EMPTY.toString("invalid");
+      fail("Should have thrown an exception.");
+    } catch (UnsupportedEncodingException expected) {
+      // This is success
+    }
+
+    try {
+      ByteString.wrap(referenceBytes).toString("invalid");
+      fail("Should have thrown an exception.");
+    } catch (UnsupportedEncodingException expected) {
+      // This is success
+    }
+  }
+
+  public void testEquals() {
+    assertEquals(classUnderTest + " must not equal null", false, stringUnderTest.equals(null));
+    assertEquals(classUnderTest + " must equal self", stringUnderTest, stringUnderTest);
+    assertFalse(classUnderTest + " must not equal the empty string",
+        stringUnderTest.equals(ByteString.EMPTY));
+    assertEquals(classUnderTest + " empty strings must be equal",
+        ByteString.wrap(new byte[]{}), stringUnderTest.substring(55, 55));
+    assertEquals(classUnderTest + " must equal another string with the same value",
+        stringUnderTest, ByteString.wrap(referenceBytes));
+
+    byte[] mungedBytes = new byte[referenceBytes.length];
+    System.arraycopy(referenceBytes, 0, mungedBytes, 0, referenceBytes.length);
+    mungedBytes[mungedBytes.length - 5] = (byte) (mungedBytes[mungedBytes.length - 5] ^ 0xFF);
+    assertFalse(classUnderTest + " must not equal every string with the same length",
+        stringUnderTest.equals(ByteString.wrap(mungedBytes)));
+  }
+
+  public void testHashCode() {
+    int hash = stringUnderTest.hashCode();
+    assertEquals(classUnderTest + " must have expected hashCode", expectedHashCode, hash);
+  }
+
+  public void testPeekCachedHashCode() {
+    assertEquals(classUnderTest + ".peekCachedHashCode() should return zero at first", 0,
+        stringUnderTest.peekCachedHashCode());
+    stringUnderTest.hashCode();
+    assertEquals(classUnderTest + ".peekCachedHashCode should return zero at first",
+        expectedHashCode, stringUnderTest.peekCachedHashCode());
+  }
+
+  public void testPartialHash() {
+    // partialHash() is more strenuously tested elsewhere by testing hashes of substrings.
+    // This test would fail if the expected hash were 1.  It's not.
+    int hash = stringUnderTest.partialHash(stringUnderTest.size(), 0, stringUnderTest.size());
+    assertEquals(classUnderTest + ".partialHash() must yield expected hashCode",
+        expectedHashCode, hash);
+  }
+
+  public void testNewInput() throws IOException {
+    InputStream input = stringUnderTest.newInput();
+    assertEquals("InputStream.available() returns correct value",
+        stringUnderTest.size(), input.available());
+    boolean stillEqual = true;
+    for (byte referenceByte : referenceBytes) {
+      int expectedInt = (referenceByte & 0xFF);
+      stillEqual = (expectedInt == input.read());
+    }
+    assertEquals("InputStream.available() returns correct value",
+        0, input.available());
+    assertTrue(classUnderTest + " must give the same bytes from the InputStream", stillEqual);
+    assertEquals(classUnderTest + " InputStream must now be exhausted", -1, input.read());
+  }
+
+  public void testNewInput_skip() throws IOException {
+    InputStream input = stringUnderTest.newInput();
+    int stringSize = stringUnderTest.size();
+    int nearEndIndex = stringSize * 2 / 3;
+    long skipped1 = input.skip(nearEndIndex);
+    assertEquals("InputStream.skip()", skipped1, nearEndIndex);
+    assertEquals("InputStream.available()",
+        stringSize - skipped1, input.available());
+    assertTrue("InputStream.mark() is available", input.markSupported());
+    input.mark(0);
+    assertEquals("InputStream.skip(), read()",
+        stringUnderTest.byteAt(nearEndIndex) & 0xFF, input.read());
+    assertEquals("InputStream.available()",
+                 stringSize - skipped1 - 1, input.available());
+    long skipped2 = input.skip(stringSize);
+    assertEquals("InputStream.skip() incomplete",
+        skipped2, stringSize - skipped1 - 1);
+    assertEquals("InputStream.skip(), no more input", 0, input.available());
+    assertEquals("InputStream.skip(), no more input", -1, input.read());
+    input.reset();
+    assertEquals("InputStream.reset() succeded",
+                 stringSize - skipped1, input.available());
+    assertEquals("InputStream.reset(), read()",
+        stringUnderTest.byteAt(nearEndIndex) & 0xFF, input.read());
+  }
+
+  public void testNewCodedInput() throws IOException {
+    CodedInputStream cis = stringUnderTest.newCodedInput();
+    byte[] roundTripBytes = cis.readRawBytes(referenceBytes.length);
+    assertTrue(classUnderTest + " must give the same bytes back from the CodedInputStream",
+        Arrays.equals(referenceBytes, roundTripBytes));
+    assertTrue(classUnderTest + " CodedInputStream must now be exhausted", cis.isAtEnd());
+  }
+
+  /**
+   * Make sure we keep things simple when concatenating with empty. See also
+   * {@link ByteStringTest#testConcat_empty()}.
+   */
+  public void testConcat_empty() {
+    assertSame(classUnderTest + " concatenated with empty must give " + classUnderTest,
+        stringUnderTest.concat(ByteString.EMPTY), stringUnderTest);
+    assertSame("empty concatenated with " + classUnderTest + " must give " + classUnderTest,
+        ByteString.EMPTY.concat(stringUnderTest), stringUnderTest);
+  }
+
+  public void testJavaSerialization() throws Exception {
+    ByteArrayOutputStream out = new ByteArrayOutputStream();
+    ObjectOutputStream oos = new ObjectOutputStream(out);
+    oos.writeObject(stringUnderTest);
+    oos.close();
+    byte[] pickled = out.toByteArray();
+    InputStream in = new ByteArrayInputStream(pickled);
+    ObjectInputStream ois = new ObjectInputStream(in);
+    Object o = ois.readObject();
+    assertTrue("Didn't get a ByteString back", o instanceof ByteString);
+    assertEquals("Should get an equal ByteString back", stringUnderTest, o);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/LongArrayListTest.java b/java/core/src/test/java/com/google/protobuf/LongArrayListTest.java
new file mode 100644
index 00000000..1bd094f7
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/LongArrayListTest.java
@@ -0,0 +1,473 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.util.Arrays.asList;
+
+import junit.framework.TestCase;
+
+import java.util.Collections;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+
+/**
+ * Tests for {@link LongArrayList}.
+ * 
+ * @author dweis@google.com (Daniel Weis)
+ */
+public class LongArrayListTest extends TestCase {
+  
+  private static final LongArrayList UNARY_LIST = newImmutableLongArrayList(1);
+  private static final LongArrayList TERTIARY_LIST =
+      newImmutableLongArrayList(1, 2, 3);
+  
+  private LongArrayList list;
+  
+  @Override
+  protected void setUp() throws Exception {
+    list = new LongArrayList();
+  }
+  
+  public void testEmptyListReturnsSameInstance() {
+    assertSame(LongArrayList.emptyList(), LongArrayList.emptyList());
+  }
+  
+  public void testEmptyListIsImmutable() {
+    assertImmutable(LongArrayList.emptyList());
+  }
+  
+  public void testMakeImmutable() {
+    list.addLong(2);
+    list.addLong(4);
+    list.addLong(6);
+    list.addLong(8);
+    list.makeImmutable();
+    assertImmutable(list);
+  }
+  
+  public void testCopyConstructor() {
+    LongArrayList copy = new LongArrayList(TERTIARY_LIST);
+    assertEquals(TERTIARY_LIST, copy);
+
+    copy = new LongArrayList(LongArrayList.emptyList());
+    assertEquals(LongArrayList.emptyList(), copy);
+    
+    copy = new LongArrayList(asList(1L, 2L, 3L));
+    assertEquals(asList(1L, 2L, 3L), copy);
+
+    copy = new LongArrayList(Collections.<Long>emptyList());
+    assertEquals(LongArrayList.emptyList(), copy);
+  }
+  
+  public void testModificationWithIteration() {
+    list.addAll(asList(1L, 2L, 3L, 4L));
+    Iterator<Long> iterator = list.iterator();
+    assertEquals(4, list.size());
+    assertEquals(1, (long) list.get(0));
+    assertEquals(1, (long) iterator.next());
+    list.set(0, 1L);
+    assertEquals(2, (long) iterator.next());
+    
+    list.remove(0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+    
+    iterator = list.iterator();
+    list.add(0, 0L);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+  }
+  
+  public void testGet() {
+    assertEquals(1, (long) TERTIARY_LIST.get(0));
+    assertEquals(2, (long) TERTIARY_LIST.get(1));
+    assertEquals(3, (long) TERTIARY_LIST.get(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testGetLong() {
+    assertEquals(1, TERTIARY_LIST.getLong(0));
+    assertEquals(2, TERTIARY_LIST.getLong(1));
+    assertEquals(3, TERTIARY_LIST.getLong(2));
+    
+    try {
+      TERTIARY_LIST.get(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      TERTIARY_LIST.get(3);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSize() {
+    assertEquals(0, LongArrayList.emptyList().size());
+    assertEquals(1, UNARY_LIST.size());
+    assertEquals(3, TERTIARY_LIST.size());
+
+    list.addLong(2);
+    list.addLong(4);
+    list.addLong(6);
+    list.addLong(8);
+    assertEquals(4, list.size());
+    
+    list.remove(0);
+    assertEquals(3, list.size());
+    
+    list.add(16L);
+    assertEquals(4, list.size());
+  }
+  
+  public void testSet() {
+    list.addLong(2);
+    list.addLong(4);
+    
+    assertEquals(2, (long) list.set(0, 0L));
+    assertEquals(0, list.getLong(0));
+
+    assertEquals(4, (long) list.set(1, 0L));
+    assertEquals(0, list.getLong(1));
+    
+    try {
+      list.set(-1, 0L);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.set(2, 0L);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testSetLong() {
+    list.addLong(2);
+    list.addLong(4);
+    
+    assertEquals(2, list.setLong(0, 0));
+    assertEquals(0, list.getLong(0));
+
+    assertEquals(4, list.setLong(1, 0));
+    assertEquals(0, list.getLong(1));
+    
+    try {
+      list.setLong(-1, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+
+    try {
+      list.setLong(2, 0);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAdd() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.add(2L));
+    assertEquals(asList(2L), list);
+
+    assertTrue(list.add(3L));
+    list.add(0, 4L);
+    assertEquals(asList(4L, 2L, 3L), list);
+    
+    list.add(0, 1L);
+    list.add(0, 0L);
+    // Force a resize by getting up to 11 elements.
+    for (int i = 0; i < 6; i++) {
+      list.add(Long.valueOf(5 + i));
+    }
+    assertEquals(asList(0L, 1L, 4L, 2L, 3L, 5L, 6L, 7L, 8L, 9L, 10L), list);
+    
+    try {
+      list.add(-1, 5L);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.add(4, 5L);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  public void testAddLong() {
+    assertEquals(0, list.size());
+
+    list.addLong(2);
+    assertEquals(asList(2L), list);
+
+    list.addLong(3);
+    assertEquals(asList(2L, 3L), list);
+  }
+  
+  public void testAddAll() {
+    assertEquals(0, list.size());
+
+    assertTrue(list.addAll(Collections.singleton(1L)));
+    assertEquals(1, list.size());
+    assertEquals(1, (long) list.get(0));
+    assertEquals(1, list.getLong(0));
+    
+    assertTrue(list.addAll(asList(2L, 3L, 4L, 5L, 6L)));
+    assertEquals(asList(1L, 2L, 3L, 4L, 5L, 6L), list);
+    
+    assertTrue(list.addAll(TERTIARY_LIST));
+    assertEquals(asList(1L, 2L, 3L, 4L, 5L, 6L, 1L, 2L, 3L), list);
+
+    assertFalse(list.addAll(Collections.<Long>emptyList()));
+    assertFalse(list.addAll(LongArrayList.emptyList()));
+  }
+  
+  public void testRemove() {
+    list.addAll(TERTIARY_LIST);
+    assertEquals(1, (long) list.remove(0));
+    assertEquals(asList(2L, 3L), list);
+
+    assertTrue(list.remove(3L));
+    assertEquals(asList(2L), list);
+
+    assertFalse(list.remove(3L));
+    assertEquals(asList(2L), list);
+
+    assertEquals(2, (long) list.remove(0));
+    assertEquals(asList(), list);
+    
+    try {
+      list.remove(-1);
+      fail();
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(0);
+    } catch (IndexOutOfBoundsException e) {
+      // expected
+    }
+  }
+  
+  private void assertImmutable(LongArrayList list) {
+    if (list.contains(1L)) {
+      throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
+    }
+    
+    try {
+      list.add(1L);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.add(0, 1L);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.<Long>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.singletonList(1L));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(new LongArrayList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.singleton(1L));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.<Long>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addLong(0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.clear();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+
+    try {
+      list.remove(1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.<Long>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.singleton(1L));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.<Long>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.singleton(1L));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, 0L);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.setLong(0, 0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+  }
+  
+  private static LongArrayList newImmutableLongArrayList(long... elements) {
+    LongArrayList list = new LongArrayList();
+    for (long element : elements) {
+      list.addLong(element);
+    }
+    list.makeImmutable();
+    return list;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/MapForProto2LiteTest.java b/java/core/src/test/java/com/google/protobuf/MapForProto2LiteTest.java
new file mode 100644
index 00000000..3d8c9bc4
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/MapForProto2LiteTest.java
@@ -0,0 +1,458 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import map_lite_test.MapForProto2TestProto.TestMap;
+import map_lite_test.MapForProto2TestProto.TestMap.MessageValue;
+import map_lite_test.MapForProto2TestProto.TestUnknownEnumValue;
+
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Unit tests for map fields.
+ */
+public class MapForProto2LiteTest extends TestCase {
+  private void setMapValues(TestMap.Builder builder) {
+    builder.getMutableInt32ToInt32Field().put(1, 11);
+    builder.getMutableInt32ToInt32Field().put(2, 22);
+    builder.getMutableInt32ToInt32Field().put(3, 33);
+
+    builder.getMutableInt32ToStringField().put(1, "11");
+    builder.getMutableInt32ToStringField().put(2, "22");
+    builder.getMutableInt32ToStringField().put(3, "33");
+    
+    builder.getMutableInt32ToBytesField().put(1, TestUtil.toBytes("11"));
+    builder.getMutableInt32ToBytesField().put(2, TestUtil.toBytes("22"));
+    builder.getMutableInt32ToBytesField().put(3, TestUtil.toBytes("33"));
+    
+    builder.getMutableInt32ToEnumField().put(1, TestMap.EnumValue.FOO);
+    builder.getMutableInt32ToEnumField().put(2, TestMap.EnumValue.BAR);
+    builder.getMutableInt32ToEnumField().put(3, TestMap.EnumValue.BAZ);
+    
+    builder.getMutableInt32ToMessageField().put(
+        1, MessageValue.newBuilder().setValue(11).build());
+    builder.getMutableInt32ToMessageField().put(
+        2, MessageValue.newBuilder().setValue(22).build());
+    builder.getMutableInt32ToMessageField().put(
+        3, MessageValue.newBuilder().setValue(33).build());
+    
+    builder.getMutableStringToInt32Field().put("1", 11);
+    builder.getMutableStringToInt32Field().put("2", 22);
+    builder.getMutableStringToInt32Field().put("3", 33);
+  }
+
+  private void copyMapValues(TestMap source, TestMap.Builder destination) {
+    destination
+        .putAllInt32ToInt32Field(source.getInt32ToInt32Field())
+        .putAllInt32ToStringField(source.getInt32ToStringField())
+        .putAllInt32ToBytesField(source.getInt32ToBytesField())
+        .putAllInt32ToEnumField(source.getInt32ToEnumField())
+        .putAllInt32ToMessageField(source.getInt32ToMessageField())
+        .putAllStringToInt32Field(source.getStringToInt32Field());
+  }
+
+  private void assertMapValuesSet(TestMap message) {
+    assertEquals(3, message.getInt32ToInt32Field().size());
+    assertEquals(11, message.getInt32ToInt32Field().get(1).intValue());
+    assertEquals(22, message.getInt32ToInt32Field().get(2).intValue());
+    assertEquals(33, message.getInt32ToInt32Field().get(3).intValue());
+
+    assertEquals(3, message.getInt32ToStringField().size());
+    assertEquals("11", message.getInt32ToStringField().get(1));
+    assertEquals("22", message.getInt32ToStringField().get(2));
+    assertEquals("33", message.getInt32ToStringField().get(3));
+    
+    assertEquals(3, message.getInt32ToBytesField().size());
+    assertEquals(TestUtil.toBytes("11"), message.getInt32ToBytesField().get(1));
+    assertEquals(TestUtil.toBytes("22"), message.getInt32ToBytesField().get(2));
+    assertEquals(TestUtil.toBytes("33"), message.getInt32ToBytesField().get(3));
+    
+    assertEquals(3, message.getInt32ToEnumField().size());
+    assertEquals(TestMap.EnumValue.FOO, message.getInt32ToEnumField().get(1));
+    assertEquals(TestMap.EnumValue.BAR, message.getInt32ToEnumField().get(2));
+    assertEquals(TestMap.EnumValue.BAZ, message.getInt32ToEnumField().get(3));
+    
+    assertEquals(3, message.getInt32ToMessageField().size());
+    assertEquals(11, message.getInt32ToMessageField().get(1).getValue());
+    assertEquals(22, message.getInt32ToMessageField().get(2).getValue());
+    assertEquals(33, message.getInt32ToMessageField().get(3).getValue());
+    
+    assertEquals(3, message.getStringToInt32Field().size());
+    assertEquals(11, message.getStringToInt32Field().get("1").intValue());
+    assertEquals(22, message.getStringToInt32Field().get("2").intValue());
+    assertEquals(33, message.getStringToInt32Field().get("3").intValue());
+  }
+
+  private void updateMapValues(TestMap.Builder builder) {
+    builder.getMutableInt32ToInt32Field().put(1, 111);
+    builder.getMutableInt32ToInt32Field().remove(2);
+    builder.getMutableInt32ToInt32Field().put(4, 44);
+
+    builder.getMutableInt32ToStringField().put(1, "111");
+    builder.getMutableInt32ToStringField().remove(2);
+    builder.getMutableInt32ToStringField().put(4, "44");
+    
+    builder.getMutableInt32ToBytesField().put(1, TestUtil.toBytes("111"));
+    builder.getMutableInt32ToBytesField().remove(2);
+    builder.getMutableInt32ToBytesField().put(4, TestUtil.toBytes("44"));
+    
+    builder.getMutableInt32ToEnumField().put(1, TestMap.EnumValue.BAR);
+    builder.getMutableInt32ToEnumField().remove(2);
+    builder.getMutableInt32ToEnumField().put(4, TestMap.EnumValue.QUX);
+    
+    builder.getMutableInt32ToMessageField().put(
+        1, MessageValue.newBuilder().setValue(111).build());
+    builder.getMutableInt32ToMessageField().remove(2);
+    builder.getMutableInt32ToMessageField().put(
+        4, MessageValue.newBuilder().setValue(44).build());
+    
+    builder.getMutableStringToInt32Field().put("1", 111);
+    builder.getMutableStringToInt32Field().remove("2");
+    builder.getMutableStringToInt32Field().put("4", 44);
+  }
+
+  private void assertMapValuesUpdated(TestMap message) {
+    assertEquals(3, message.getInt32ToInt32Field().size());
+    assertEquals(111, message.getInt32ToInt32Field().get(1).intValue());
+    assertEquals(33, message.getInt32ToInt32Field().get(3).intValue());
+    assertEquals(44, message.getInt32ToInt32Field().get(4).intValue());
+
+    assertEquals(3, message.getInt32ToStringField().size());
+    assertEquals("111", message.getInt32ToStringField().get(1));
+    assertEquals("33", message.getInt32ToStringField().get(3));
+    assertEquals("44", message.getInt32ToStringField().get(4));
+    
+    assertEquals(3, message.getInt32ToBytesField().size());
+    assertEquals(TestUtil.toBytes("111"), message.getInt32ToBytesField().get(1));
+    assertEquals(TestUtil.toBytes("33"), message.getInt32ToBytesField().get(3));
+    assertEquals(TestUtil.toBytes("44"), message.getInt32ToBytesField().get(4));
+    
+    assertEquals(3, message.getInt32ToEnumField().size());
+    assertEquals(TestMap.EnumValue.BAR, message.getInt32ToEnumField().get(1));
+    assertEquals(TestMap.EnumValue.BAZ, message.getInt32ToEnumField().get(3));
+    assertEquals(TestMap.EnumValue.QUX, message.getInt32ToEnumField().get(4));
+    
+    assertEquals(3, message.getInt32ToMessageField().size());
+    assertEquals(111, message.getInt32ToMessageField().get(1).getValue());
+    assertEquals(33, message.getInt32ToMessageField().get(3).getValue());
+    assertEquals(44, message.getInt32ToMessageField().get(4).getValue());
+    
+    assertEquals(3, message.getStringToInt32Field().size());
+    assertEquals(111, message.getStringToInt32Field().get("1").intValue());
+    assertEquals(33, message.getStringToInt32Field().get("3").intValue());
+    assertEquals(44, message.getStringToInt32Field().get("4").intValue());
+  }
+
+  private void assertMapValuesCleared(TestMap message) {
+    assertEquals(0, message.getInt32ToInt32Field().size());
+    assertEquals(0, message.getInt32ToStringField().size());
+    assertEquals(0, message.getInt32ToBytesField().size());
+    assertEquals(0, message.getInt32ToEnumField().size());
+    assertEquals(0, message.getInt32ToMessageField().size());
+    assertEquals(0, message.getStringToInt32Field().size());
+  }
+
+  public void testSanityCopyOnWrite() throws InvalidProtocolBufferException {
+    // Since builders are implemented as a thin wrapper around a message
+    // instance, we attempt to verify that we can't cause the builder to modify
+    // a produced message.
+    
+    TestMap.Builder builder = TestMap.newBuilder();
+    TestMap message = builder.build();
+    Map<Integer, Integer> intMap = builder.getMutableInt32ToInt32Field();
+    intMap.put(1, 2);
+    assertTrue(message.getInt32ToInt32Field().isEmpty());
+    message = builder.build();
+    try {
+      intMap.put(2, 3);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, 2), message.getInt32ToInt32Field());
+    assertEquals(newMap(1, 2), builder.getInt32ToInt32Field());
+    builder.getMutableInt32ToInt32Field().put(2, 3);
+    assertEquals(newMap(1, 2), message.getInt32ToInt32Field());
+    assertEquals(newMap(1, 2, 2, 3), builder.getInt32ToInt32Field());
+  }
+  
+  public void testMutableMapLifecycle() {
+    TestMap.Builder builder = TestMap.newBuilder();
+    Map<Integer, Integer> intMap = builder.getMutableInt32ToInt32Field();
+    intMap.put(1, 2);
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+    try {
+      intMap.put(2, 3);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, 2), builder.getInt32ToInt32Field());
+    builder.getMutableInt32ToInt32Field().put(2, 3);
+    assertEquals(newMap(1, 2, 2, 3), builder.getInt32ToInt32Field());
+
+    Map<Integer, TestMap.EnumValue> enumMap = builder.getMutableInt32ToEnumField();
+    enumMap.put(1, TestMap.EnumValue.BAR);
+    assertEquals(newMap(1, TestMap.EnumValue.BAR), builder.build().getInt32ToEnumField());
+    try {
+      enumMap.put(2, TestMap.EnumValue.FOO);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, TestMap.EnumValue.BAR), builder.getInt32ToEnumField());
+    builder.getMutableInt32ToEnumField().put(2, TestMap.EnumValue.FOO);
+    assertEquals(
+        newMap(1, TestMap.EnumValue.BAR, 2, TestMap.EnumValue.FOO),
+        builder.getInt32ToEnumField());
+    
+    Map<Integer, String> stringMap = builder.getMutableInt32ToStringField();
+    stringMap.put(1, "1");
+    assertEquals(newMap(1, "1"), builder.build().getInt32ToStringField());
+    try {
+      stringMap.put(2, "2");
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, "1"), builder.getInt32ToStringField());
+    builder.getMutableInt32ToStringField().put(2, "2");
+    assertEquals(
+        newMap(1, "1", 2, "2"),
+        builder.getInt32ToStringField());
+    
+    Map<Integer, TestMap.MessageValue> messageMap = builder.getMutableInt32ToMessageField();
+    messageMap.put(1, TestMap.MessageValue.getDefaultInstance());
+    assertEquals(newMap(1, TestMap.MessageValue.getDefaultInstance()),
+        builder.build().getInt32ToMessageField());
+    try {
+      messageMap.put(2, TestMap.MessageValue.getDefaultInstance());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, TestMap.MessageValue.getDefaultInstance()),
+        builder.getInt32ToMessageField());
+    builder.getMutableInt32ToMessageField().put(2, TestMap.MessageValue.getDefaultInstance());
+    assertEquals(
+        newMap(1, TestMap.MessageValue.getDefaultInstance(),
+            2, TestMap.MessageValue.getDefaultInstance()),
+        builder.getInt32ToMessageField());
+  }
+
+  public void testMutableMapLifecycle_collections() {
+    TestMap.Builder builder = TestMap.newBuilder();
+    Map<Integer, Integer> intMap = builder.getMutableInt32ToInt32Field();
+    intMap.put(1, 2);
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+    try {
+      intMap.remove(2);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.entrySet().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.entrySet().iterator().remove();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.keySet().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.values().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.values().iterator().remove();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, 2), intMap);
+    assertEquals(newMap(1, 2), builder.getInt32ToInt32Field());
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+  }
+
+  public void testGettersAndSetters() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    TestMap message = builder.build();
+    assertMapValuesCleared(message);
+    
+    builder = message.toBuilder();
+    setMapValues(builder);
+    message = builder.build();
+    assertMapValuesSet(message);
+    
+    builder = message.toBuilder();
+    updateMapValues(builder);
+    message = builder.build();
+    assertMapValuesUpdated(message);
+    
+    builder = message.toBuilder();
+    builder.clear();
+    message = builder.build();
+    assertMapValuesCleared(message);
+  }
+
+  public void testPutAll() throws Exception {
+    TestMap.Builder sourceBuilder = TestMap.newBuilder();
+    setMapValues(sourceBuilder);
+    TestMap source = sourceBuilder.build();
+
+    TestMap.Builder destination = TestMap.newBuilder();
+    copyMapValues(source, destination);
+    assertMapValuesSet(destination.build());
+  }
+
+  public void testSerializeAndParse() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesSet(message);
+    
+    builder = message.toBuilder();
+    updateMapValues(builder);
+    message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesUpdated(message);
+    
+    builder = message.toBuilder();
+    builder.clear();
+    message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesCleared(message);
+  }
+  
+  public void testMergeFrom() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+    
+    TestMap.Builder other = TestMap.newBuilder();
+    other.mergeFrom(message);
+    assertMapValuesSet(other.build());
+  }
+
+  public void testEqualsAndHashCode() throws Exception {
+    // Test that generated equals() and hashCode() will disregard the order
+    // of map entries when comparing/hashing map fields.
+    
+    // We can't control the order of elements in a HashMap. The best we can do
+    // here is to add elements in different order.
+    TestMap.Builder b1 = TestMap.newBuilder();
+    b1.getMutableInt32ToInt32Field().put(1, 2);
+    b1.getMutableInt32ToInt32Field().put(3, 4);
+    b1.getMutableInt32ToInt32Field().put(5, 6);
+    TestMap m1 = b1.build();
+    
+    TestMap.Builder b2 = TestMap.newBuilder();
+    b2.getMutableInt32ToInt32Field().put(5, 6);
+    b2.getMutableInt32ToInt32Field().put(1, 2);
+    b2.getMutableInt32ToInt32Field().put(3, 4);
+    TestMap m2 = b2.build();
+    
+    assertEquals(m1, m2);
+    assertEquals(m1.hashCode(), m2.hashCode());
+    
+    // Make sure we did compare map fields.
+    b2.getMutableInt32ToInt32Field().put(1, 0);
+    m2 = b2.build();
+    assertFalse(m1.equals(m2));
+    // Don't check m1.hashCode() != m2.hashCode() because it's not guaranteed
+    // to be different.
+  }
+
+  public void testUnknownEnumValues() throws Exception {
+    TestUnknownEnumValue.Builder builder =
+        TestUnknownEnumValue.newBuilder();
+    builder.getMutableInt32ToInt32Field().put(1, 1);
+    builder.getMutableInt32ToInt32Field().put(2, 54321);
+    ByteString data = builder.build().toByteString();
+
+    TestMap message = TestMap.parseFrom(data);
+    // Entries with unknown enum values will be stored into UnknownFieldSet so
+    // there is only one entry in the map.
+    assertEquals(1, message.getInt32ToEnumField().size());
+    assertEquals(TestMap.EnumValue.BAR, message.getInt32ToEnumField().get(1));
+    // Serializing and parsing should preserve the unknown entry.
+    data = message.toByteString();
+    TestUnknownEnumValue messageWithUnknownEnums =
+        TestUnknownEnumValue.parseFrom(data);
+    assertEquals(2, messageWithUnknownEnums.getInt32ToInt32Field().size());
+    assertEquals(1, messageWithUnknownEnums.getInt32ToInt32Field().get(1).intValue());
+    assertEquals(54321, messageWithUnknownEnums.getInt32ToInt32Field().get(2).intValue());
+  }
+  
+
+  public void testIterationOrder() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+
+    assertEquals(Arrays.asList("1", "2", "3"),
+        new ArrayList<String>(message.getStringToInt32Field().keySet()));
+  }
+  
+  private static <K, V> Map<K, V> newMap(K key1, V value1) {
+    Map<K, V> map = new HashMap<K, V>();
+    map.put(key1, value1);
+    return map;
+  }
+  
+  private static <K, V> Map<K, V> newMap(K key1, V value1, K key2, V value2) {
+    Map<K, V> map = new HashMap<K, V>();
+    map.put(key1, value1);
+    map.put(key2, value2);
+    return map;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
new file mode 100644
index 00000000..1fa3cbdb
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
@@ -0,0 +1,684 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import map_test.MapForProto2TestProto.TestMap;
+import map_test.MapForProto2TestProto.TestMap.MessageValue;
+import map_test.MapForProto2TestProto.TestMap.MessageWithRequiredFields;
+import map_test.MapForProto2TestProto.TestRecursiveMap;
+import map_test.MapForProto2TestProto.TestUnknownEnumValue;
+
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Unit tests for map fields in proto2 protos.
+ */
+public class MapForProto2Test extends TestCase {
+  private void setMapValues(TestMap.Builder builder) {
+    builder.getMutableInt32ToInt32Field().put(1, 11);
+    builder.getMutableInt32ToInt32Field().put(2, 22);
+    builder.getMutableInt32ToInt32Field().put(3, 33);
+
+    builder.getMutableInt32ToStringField().put(1, "11");
+    builder.getMutableInt32ToStringField().put(2, "22");
+    builder.getMutableInt32ToStringField().put(3, "33");
+    
+    builder.getMutableInt32ToBytesField().put(1, TestUtil.toBytes("11"));
+    builder.getMutableInt32ToBytesField().put(2, TestUtil.toBytes("22"));
+    builder.getMutableInt32ToBytesField().put(3, TestUtil.toBytes("33"));
+    
+    builder.getMutableInt32ToEnumField().put(1, TestMap.EnumValue.FOO);
+    builder.getMutableInt32ToEnumField().put(2, TestMap.EnumValue.BAR);
+    builder.getMutableInt32ToEnumField().put(3, TestMap.EnumValue.BAZ);
+    
+    builder.getMutableInt32ToMessageField().put(
+        1, MessageValue.newBuilder().setValue(11).build());
+    builder.getMutableInt32ToMessageField().put(
+        2, MessageValue.newBuilder().setValue(22).build());
+    builder.getMutableInt32ToMessageField().put(
+        3, MessageValue.newBuilder().setValue(33).build());
+    
+    builder.getMutableStringToInt32Field().put("1", 11);
+    builder.getMutableStringToInt32Field().put("2", 22);
+    builder.getMutableStringToInt32Field().put("3", 33);
+  }
+
+  private void copyMapValues(TestMap source, TestMap.Builder destination) {
+    destination
+        .putAllInt32ToInt32Field(source.getInt32ToInt32Field())
+        .putAllInt32ToStringField(source.getInt32ToStringField())
+        .putAllInt32ToBytesField(source.getInt32ToBytesField())
+        .putAllInt32ToEnumField(source.getInt32ToEnumField())
+        .putAllInt32ToMessageField(source.getInt32ToMessageField())
+        .putAllStringToInt32Field(source.getStringToInt32Field());
+  }
+
+  private void assertMapValuesSet(TestMap message) {
+    assertEquals(3, message.getInt32ToInt32Field().size());
+    assertEquals(11, message.getInt32ToInt32Field().get(1).intValue());
+    assertEquals(22, message.getInt32ToInt32Field().get(2).intValue());
+    assertEquals(33, message.getInt32ToInt32Field().get(3).intValue());
+
+    assertEquals(3, message.getInt32ToStringField().size());
+    assertEquals("11", message.getInt32ToStringField().get(1));
+    assertEquals("22", message.getInt32ToStringField().get(2));
+    assertEquals("33", message.getInt32ToStringField().get(3));
+    
+    assertEquals(3, message.getInt32ToBytesField().size());
+    assertEquals(TestUtil.toBytes("11"), message.getInt32ToBytesField().get(1));
+    assertEquals(TestUtil.toBytes("22"), message.getInt32ToBytesField().get(2));
+    assertEquals(TestUtil.toBytes("33"), message.getInt32ToBytesField().get(3));
+    
+    assertEquals(3, message.getInt32ToEnumField().size());
+    assertEquals(TestMap.EnumValue.FOO, message.getInt32ToEnumField().get(1));
+    assertEquals(TestMap.EnumValue.BAR, message.getInt32ToEnumField().get(2));
+    assertEquals(TestMap.EnumValue.BAZ, message.getInt32ToEnumField().get(3));
+    
+    assertEquals(3, message.getInt32ToMessageField().size());
+    assertEquals(11, message.getInt32ToMessageField().get(1).getValue());
+    assertEquals(22, message.getInt32ToMessageField().get(2).getValue());
+    assertEquals(33, message.getInt32ToMessageField().get(3).getValue());
+    
+    assertEquals(3, message.getStringToInt32Field().size());
+    assertEquals(11, message.getStringToInt32Field().get("1").intValue());
+    assertEquals(22, message.getStringToInt32Field().get("2").intValue());
+    assertEquals(33, message.getStringToInt32Field().get("3").intValue());
+  }
+
+  private void updateMapValues(TestMap.Builder builder) {
+    builder.getMutableInt32ToInt32Field().put(1, 111);
+    builder.getMutableInt32ToInt32Field().remove(2);
+    builder.getMutableInt32ToInt32Field().put(4, 44);
+
+    builder.getMutableInt32ToStringField().put(1, "111");
+    builder.getMutableInt32ToStringField().remove(2);
+    builder.getMutableInt32ToStringField().put(4, "44");
+    
+    builder.getMutableInt32ToBytesField().put(1, TestUtil.toBytes("111"));
+    builder.getMutableInt32ToBytesField().remove(2);
+    builder.getMutableInt32ToBytesField().put(4, TestUtil.toBytes("44"));
+    
+    builder.getMutableInt32ToEnumField().put(1, TestMap.EnumValue.BAR);
+    builder.getMutableInt32ToEnumField().remove(2);
+    builder.getMutableInt32ToEnumField().put(4, TestMap.EnumValue.QUX);
+    
+    builder.getMutableInt32ToMessageField().put(
+        1, MessageValue.newBuilder().setValue(111).build());
+    builder.getMutableInt32ToMessageField().remove(2);
+    builder.getMutableInt32ToMessageField().put(
+        4, MessageValue.newBuilder().setValue(44).build());
+    
+    builder.getMutableStringToInt32Field().put("1", 111);
+    builder.getMutableStringToInt32Field().remove("2");
+    builder.getMutableStringToInt32Field().put("4", 44);
+  }
+
+  private void assertMapValuesUpdated(TestMap message) {
+    assertEquals(3, message.getInt32ToInt32Field().size());
+    assertEquals(111, message.getInt32ToInt32Field().get(1).intValue());
+    assertEquals(33, message.getInt32ToInt32Field().get(3).intValue());
+    assertEquals(44, message.getInt32ToInt32Field().get(4).intValue());
+
+    assertEquals(3, message.getInt32ToStringField().size());
+    assertEquals("111", message.getInt32ToStringField().get(1));
+    assertEquals("33", message.getInt32ToStringField().get(3));
+    assertEquals("44", message.getInt32ToStringField().get(4));
+    
+    assertEquals(3, message.getInt32ToBytesField().size());
+    assertEquals(TestUtil.toBytes("111"), message.getInt32ToBytesField().get(1));
+    assertEquals(TestUtil.toBytes("33"), message.getInt32ToBytesField().get(3));
+    assertEquals(TestUtil.toBytes("44"), message.getInt32ToBytesField().get(4));
+    
+    assertEquals(3, message.getInt32ToEnumField().size());
+    assertEquals(TestMap.EnumValue.BAR, message.getInt32ToEnumField().get(1));
+    assertEquals(TestMap.EnumValue.BAZ, message.getInt32ToEnumField().get(3));
+    assertEquals(TestMap.EnumValue.QUX, message.getInt32ToEnumField().get(4));
+    
+    assertEquals(3, message.getInt32ToMessageField().size());
+    assertEquals(111, message.getInt32ToMessageField().get(1).getValue());
+    assertEquals(33, message.getInt32ToMessageField().get(3).getValue());
+    assertEquals(44, message.getInt32ToMessageField().get(4).getValue());
+    
+    assertEquals(3, message.getStringToInt32Field().size());
+    assertEquals(111, message.getStringToInt32Field().get("1").intValue());
+    assertEquals(33, message.getStringToInt32Field().get("3").intValue());
+    assertEquals(44, message.getStringToInt32Field().get("4").intValue());
+  }
+
+  private void assertMapValuesCleared(TestMap message) {
+    assertEquals(0, message.getInt32ToInt32Field().size());
+    assertEquals(0, message.getInt32ToStringField().size());
+    assertEquals(0, message.getInt32ToBytesField().size());
+    assertEquals(0, message.getInt32ToEnumField().size());
+    assertEquals(0, message.getInt32ToMessageField().size());
+    assertEquals(0, message.getStringToInt32Field().size());
+  }
+  
+  public void testMutableMapLifecycle() {
+    TestMap.Builder builder = TestMap.newBuilder();
+    Map<Integer, Integer> intMap = builder.getMutableInt32ToInt32Field();
+    intMap.put(1, 2);
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+    try {
+      intMap.put(2, 3);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, 2), builder.getInt32ToInt32Field());
+    builder.getMutableInt32ToInt32Field().put(2, 3);
+    assertEquals(newMap(1, 2, 2, 3), builder.getInt32ToInt32Field());
+
+    Map<Integer, TestMap.EnumValue> enumMap = builder.getMutableInt32ToEnumField();
+    enumMap.put(1, TestMap.EnumValue.BAR);
+    assertEquals(newMap(1, TestMap.EnumValue.BAR), builder.build().getInt32ToEnumField());
+    try {
+      enumMap.put(2, TestMap.EnumValue.FOO);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, TestMap.EnumValue.BAR), builder.getInt32ToEnumField());
+    builder.getMutableInt32ToEnumField().put(2, TestMap.EnumValue.FOO);
+    assertEquals(
+        newMap(1, TestMap.EnumValue.BAR, 2, TestMap.EnumValue.FOO),
+        builder.getInt32ToEnumField());
+    
+    Map<Integer, String> stringMap = builder.getMutableInt32ToStringField();
+    stringMap.put(1, "1");
+    assertEquals(newMap(1, "1"), builder.build().getInt32ToStringField());
+    try {
+      stringMap.put(2, "2");
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, "1"), builder.getInt32ToStringField());
+    builder.getMutableInt32ToStringField().put(2, "2");
+    assertEquals(
+        newMap(1, "1", 2, "2"),
+        builder.getInt32ToStringField());
+    
+    Map<Integer, TestMap.MessageValue> messageMap = builder.getMutableInt32ToMessageField();
+    messageMap.put(1, TestMap.MessageValue.getDefaultInstance());
+    assertEquals(newMap(1, TestMap.MessageValue.getDefaultInstance()),
+        builder.build().getInt32ToMessageField());
+    try {
+      messageMap.put(2, TestMap.MessageValue.getDefaultInstance());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, TestMap.MessageValue.getDefaultInstance()),
+        builder.getInt32ToMessageField());
+    builder.getMutableInt32ToMessageField().put(2, TestMap.MessageValue.getDefaultInstance());
+    assertEquals(
+        newMap(1, TestMap.MessageValue.getDefaultInstance(),
+            2, TestMap.MessageValue.getDefaultInstance()),
+        builder.getInt32ToMessageField());
+  }
+
+  public void testMutableMapLifecycle_collections() {
+    TestMap.Builder builder = TestMap.newBuilder();
+    Map<Integer, Integer> intMap = builder.getMutableInt32ToInt32Field();
+    intMap.put(1, 2);
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+    try {
+      intMap.remove(2);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.entrySet().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.entrySet().iterator().remove();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.keySet().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.values().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.values().iterator().remove();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, 2), intMap);
+    assertEquals(newMap(1, 2), builder.getInt32ToInt32Field());
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+  }
+
+  public void testGettersAndSetters() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    TestMap message = builder.build();
+    assertMapValuesCleared(message);
+    
+    builder = message.toBuilder();
+    setMapValues(builder);
+    message = builder.build();
+    assertMapValuesSet(message);
+    
+    builder = message.toBuilder();
+    updateMapValues(builder);
+    message = builder.build();
+    assertMapValuesUpdated(message);
+    
+    builder = message.toBuilder();
+    builder.clear();
+    message = builder.build();
+    assertMapValuesCleared(message);
+  }
+
+  public void testPutAll() throws Exception {
+    TestMap.Builder sourceBuilder = TestMap.newBuilder();
+    setMapValues(sourceBuilder);
+    TestMap source = sourceBuilder.build();
+
+    TestMap.Builder destination = TestMap.newBuilder();
+    copyMapValues(source, destination);
+    assertMapValuesSet(destination.build());
+  }
+
+  public void testSerializeAndParse() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesSet(message);
+    
+    builder = message.toBuilder();
+    updateMapValues(builder);
+    message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesUpdated(message);
+    
+    builder = message.toBuilder();
+    builder.clear();
+    message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesCleared(message);
+  }
+  
+  public void testMergeFrom() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+    
+    TestMap.Builder other = TestMap.newBuilder();
+    other.mergeFrom(message);
+    assertMapValuesSet(other.build());
+  }
+
+  public void testEqualsAndHashCode() throws Exception {
+    // Test that generated equals() and hashCode() will disregard the order
+    // of map entries when comparing/hashing map fields.
+    
+    // We can't control the order of elements in a HashMap. The best we can do
+    // here is to add elements in different order.
+    TestMap.Builder b1 = TestMap.newBuilder();
+    b1.getMutableInt32ToInt32Field().put(1, 2);
+    b1.getMutableInt32ToInt32Field().put(3, 4);
+    b1.getMutableInt32ToInt32Field().put(5, 6);
+    TestMap m1 = b1.build();
+    
+    TestMap.Builder b2 = TestMap.newBuilder();
+    b2.getMutableInt32ToInt32Field().put(5, 6);
+    b2.getMutableInt32ToInt32Field().put(1, 2);
+    b2.getMutableInt32ToInt32Field().put(3, 4);
+    TestMap m2 = b2.build();
+    
+    assertEquals(m1, m2);
+    assertEquals(m1.hashCode(), m2.hashCode());
+    
+    // Make sure we did compare map fields.
+    b2.getMutableInt32ToInt32Field().put(1, 0);
+    m2 = b2.build();
+    assertFalse(m1.equals(m2));
+    // Don't check m1.hashCode() != m2.hashCode() because it's not guaranteed
+    // to be different.
+  }
+  
+  
+  // The following methods are used to test reflection API.
+  
+  private static FieldDescriptor f(String name) {
+    return TestMap.getDescriptor().findFieldByName(name);
+  }
+  
+  private static Object getFieldValue(Message mapEntry, String name) {
+    FieldDescriptor field = mapEntry.getDescriptorForType().findFieldByName(name);
+    return mapEntry.getField(field);
+  }
+  
+  private static Message.Builder setFieldValue(
+      Message.Builder mapEntry, String name, Object value) {
+    FieldDescriptor field = mapEntry.getDescriptorForType().findFieldByName(name);
+    mapEntry.setField(field, value);
+    return mapEntry;
+  }
+  
+  private static void assertHasMapValues(Message message, String name, Map<?, ?> values) {
+    FieldDescriptor field = f(name);
+    for (Object entry : (List<?>) message.getField(field)) {
+      Message mapEntry = (Message) entry;
+      Object key = getFieldValue(mapEntry, "key");
+      Object value = getFieldValue(mapEntry, "value");
+      assertTrue(values.containsKey(key));
+      assertEquals(value, values.get(key));
+    }
+    assertEquals(values.size(), message.getRepeatedFieldCount(field));
+    for (int i = 0; i < message.getRepeatedFieldCount(field); i++) {
+      Message mapEntry = (Message) message.getRepeatedField(field, i);
+      Object key = getFieldValue(mapEntry, "key");
+      Object value = getFieldValue(mapEntry, "value");
+      assertTrue(values.containsKey(key));
+      assertEquals(value, values.get(key));
+    }
+  }
+  
+  private static <KeyType, ValueType>
+  Message newMapEntry(Message.Builder builder, String name, KeyType key, ValueType value) {
+    FieldDescriptor field = builder.getDescriptorForType().findFieldByName(name);
+    Message.Builder entryBuilder = builder.newBuilderForField(field);
+    FieldDescriptor keyField = entryBuilder.getDescriptorForType().findFieldByName("key");
+    FieldDescriptor valueField = entryBuilder.getDescriptorForType().findFieldByName("value");
+    entryBuilder.setField(keyField, key);
+    entryBuilder.setField(valueField, value);
+    return entryBuilder.build();
+  }
+  
+  private static void setMapValues(Message.Builder builder, String name, Map<?, ?> values) {
+    List<Message> entryList = new ArrayList<Message>();
+    for (Map.Entry<?, ?> entry : values.entrySet()) {
+      entryList.add(newMapEntry(builder, name, entry.getKey(), entry.getValue()));
+    }
+    FieldDescriptor field = builder.getDescriptorForType().findFieldByName(name);
+    builder.setField(field, entryList);
+  }
+  
+  private static <KeyType, ValueType>
+  Map<KeyType, ValueType> mapForValues(
+      KeyType key1, ValueType value1, KeyType key2, ValueType value2) {
+    Map<KeyType, ValueType> map = new HashMap<KeyType, ValueType>();
+    map.put(key1, value1);
+    map.put(key2, value2);
+    return map;
+  }
+
+  public void testReflectionApi() throws Exception {
+    // In reflection API, map fields are just repeated message fields.
+    TestMap.Builder builder = TestMap.newBuilder();
+    builder.getMutableInt32ToInt32Field().put(1, 2);
+    builder.getMutableInt32ToInt32Field().put(3, 4);
+    builder.getMutableInt32ToMessageField().put(
+        11, MessageValue.newBuilder().setValue(22).build());
+    builder.getMutableInt32ToMessageField().put(
+        33, MessageValue.newBuilder().setValue(44).build());
+    TestMap message = builder.build();
+
+    // Test getField(), getRepeatedFieldCount(), getRepeatedField().
+    assertHasMapValues(message, "int32_to_int32_field",
+        mapForValues(1, 2, 3, 4));
+    assertHasMapValues(message, "int32_to_message_field",
+        mapForValues(
+            11, MessageValue.newBuilder().setValue(22).build(),
+            33, MessageValue.newBuilder().setValue(44).build()));
+    
+    // Test clearField()
+    builder.clearField(f("int32_to_int32_field"));
+    builder.clearField(f("int32_to_message_field"));
+    message = builder.build();
+    assertEquals(0, message.getInt32ToInt32Field().size());
+    assertEquals(0, message.getInt32ToMessageField().size());
+    
+    // Test setField()
+    setMapValues(builder, "int32_to_int32_field",
+        mapForValues(11, 22, 33, 44));
+    setMapValues(builder, "int32_to_message_field",
+        mapForValues(
+            111, MessageValue.newBuilder().setValue(222).build(),
+            333, MessageValue.newBuilder().setValue(444).build()));
+    message = builder.build();
+    assertEquals(22, message.getInt32ToInt32Field().get(11).intValue());
+    assertEquals(44, message.getInt32ToInt32Field().get(33).intValue());
+    assertEquals(222, message.getInt32ToMessageField().get(111).getValue());
+    assertEquals(444, message.getInt32ToMessageField().get(333).getValue());
+    
+    // Test addRepeatedField
+    builder.addRepeatedField(f("int32_to_int32_field"),
+        newMapEntry(builder, "int32_to_int32_field", 55, 66));
+    builder.addRepeatedField(f("int32_to_message_field"),
+        newMapEntry(builder, "int32_to_message_field", 555,
+            MessageValue.newBuilder().setValue(666).build()));
+    message = builder.build();
+    assertEquals(66, message.getInt32ToInt32Field().get(55).intValue());
+    assertEquals(666, message.getInt32ToMessageField().get(555).getValue());
+
+    // Test addRepeatedField (overriding existing values)
+    builder.addRepeatedField(f("int32_to_int32_field"),
+        newMapEntry(builder, "int32_to_int32_field", 55, 55));
+    builder.addRepeatedField(f("int32_to_message_field"),
+        newMapEntry(builder, "int32_to_message_field", 555,
+            MessageValue.newBuilder().setValue(555).build()));
+    message = builder.build();
+    assertEquals(55, message.getInt32ToInt32Field().get(55).intValue());
+    assertEquals(555, message.getInt32ToMessageField().get(555).getValue());
+    
+    // Test setRepeatedField
+    for (int i = 0; i < builder.getRepeatedFieldCount(f("int32_to_int32_field")); i++) {
+      Message mapEntry = (Message) builder.getRepeatedField(f("int32_to_int32_field"), i);
+      int oldKey = ((Integer) getFieldValue(mapEntry, "key")).intValue();
+      int oldValue = ((Integer) getFieldValue(mapEntry, "value")).intValue();
+      // Swap key with value for each entry.
+      Message.Builder mapEntryBuilder = mapEntry.toBuilder();
+      setFieldValue(mapEntryBuilder, "key", oldValue);
+      setFieldValue(mapEntryBuilder, "value", oldKey);
+      builder.setRepeatedField(f("int32_to_int32_field"), i, mapEntryBuilder.build());
+    }
+    message = builder.build();
+    assertEquals(11, message.getInt32ToInt32Field().get(22).intValue());
+    assertEquals(33, message.getInt32ToInt32Field().get(44).intValue());
+    assertEquals(55, message.getInt32ToInt32Field().get(55).intValue());
+  }
+  
+  public void testTextFormat() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+    
+    String textData = TextFormat.printToString(message);
+    
+    builder = TestMap.newBuilder();
+    TextFormat.merge(textData, builder);
+    message = builder.build();
+    
+    assertMapValuesSet(message);
+  }
+  
+  public void testDynamicMessage() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+    
+    Message dynamicDefaultInstance =
+        DynamicMessage.getDefaultInstance(TestMap.getDescriptor());
+    Message dynamicMessage = dynamicDefaultInstance
+        .newBuilderForType().mergeFrom(message.toByteString()).build();
+    
+    assertEquals(message, dynamicMessage);
+    assertEquals(message.hashCode(), dynamicMessage.hashCode());
+  }
+  
+  public void testReflectionEqualsAndHashCode() throws Exception {
+    // Test that generated equals() and hashCode() will disregard the order
+    // of map entries when comparing/hashing map fields.
+
+    // We use DynamicMessage to test reflection based equals()/hashCode().
+    Message dynamicDefaultInstance =
+        DynamicMessage.getDefaultInstance(TestMap.getDescriptor());
+    FieldDescriptor field = f("int32_to_int32_field");
+    
+    Message.Builder b1 = dynamicDefaultInstance.newBuilderForType();
+    b1.addRepeatedField(field, newMapEntry(b1, "int32_to_int32_field", 1, 2));
+    b1.addRepeatedField(field, newMapEntry(b1, "int32_to_int32_field", 3, 4));
+    b1.addRepeatedField(field, newMapEntry(b1, "int32_to_int32_field", 5, 6));
+    Message m1 = b1.build();
+    
+    Message.Builder b2 = dynamicDefaultInstance.newBuilderForType();
+    b2.addRepeatedField(field, newMapEntry(b2, "int32_to_int32_field", 5, 6));
+    b2.addRepeatedField(field, newMapEntry(b2, "int32_to_int32_field", 1, 2));
+    b2.addRepeatedField(field, newMapEntry(b2, "int32_to_int32_field", 3, 4));
+    Message m2 = b2.build();
+    
+    assertEquals(m1, m2);
+    assertEquals(m1.hashCode(), m2.hashCode());
+    
+    // Make sure we did compare map fields.
+    b2.setRepeatedField(field, 0, newMapEntry(b1, "int32_to_int32_field", 0, 0));
+    m2 = b2.build();
+    assertFalse(m1.equals(m2));
+    // Don't check m1.hashCode() != m2.hashCode() because it's not guaranteed
+    // to be different.
+  }
+  
+  public void testUnknownEnumValues() throws Exception {
+    TestUnknownEnumValue.Builder builder =
+        TestUnknownEnumValue.newBuilder();
+    builder.getMutableInt32ToInt32Field().put(1, 1);
+    builder.getMutableInt32ToInt32Field().put(2, 54321);
+    ByteString data = builder.build().toByteString();
+
+    TestMap message = TestMap.parseFrom(data);
+    // Entries with unknown enum values will be stored into UnknownFieldSet so
+    // there is only one entry in the map.
+    assertEquals(1, message.getInt32ToEnumField().size());
+    assertEquals(TestMap.EnumValue.BAR, message.getInt32ToEnumField().get(1));
+    // UnknownFieldSet should not be empty.
+    assertFalse(message.getUnknownFields().asMap().isEmpty());
+    // Serializing and parsing should preserve the unknown entry.
+    data = message.toByteString();
+    TestUnknownEnumValue messageWithUnknownEnums =
+        TestUnknownEnumValue.parseFrom(data);
+    assertEquals(2, messageWithUnknownEnums.getInt32ToInt32Field().size());
+    assertEquals(1, messageWithUnknownEnums.getInt32ToInt32Field().get(1).intValue());
+    assertEquals(54321, messageWithUnknownEnums.getInt32ToInt32Field().get(2).intValue());
+  }
+
+
+  public void testRequiredMessage() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    builder.getMutableRequiredMessageMap().put(0,
+        MessageWithRequiredFields.newBuilder().buildPartial());
+    TestMap message = builder.buildPartial();
+    assertFalse(message.isInitialized());
+
+    builder.getMutableRequiredMessageMap().put(0,
+        MessageWithRequiredFields.newBuilder().setValue(1).build());
+    message = builder.build();
+    assertTrue(message.isInitialized());
+  }
+
+  public void testRecursiveMap() throws Exception {
+    TestRecursiveMap.Builder builder = TestRecursiveMap.newBuilder();
+    builder.getMutableRecursiveMapField().put(
+        1, TestRecursiveMap.newBuilder().setValue(2).build());
+    builder.getMutableRecursiveMapField().put(
+        3, TestRecursiveMap.newBuilder().setValue(4).build());
+    ByteString data = builder.build().toByteString();
+
+    TestRecursiveMap message = TestRecursiveMap.parseFrom(data);
+    assertEquals(2, message.getRecursiveMapField().get(1).getValue());
+    assertEquals(4, message.getRecursiveMapField().get(3).getValue());
+  }
+
+  public void testIterationOrder() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+
+    assertEquals(Arrays.asList("1", "2", "3"),
+        new ArrayList<String>(message.getStringToInt32Field().keySet()));
+  }
+
+  // Regression test for b/20494788
+  public void testMapInitializationOrder() throws Exception {
+    assertEquals("RedactAllTypes", map_test.RedactAllTypes
+        .getDefaultInstance().getDescriptorForType().getName());
+
+    map_test.Message1.Builder builder =
+        map_test.Message1.newBuilder();
+    builder.getMutableMapField().put("key", true);
+    map_test.Message1 message = builder.build();
+    Message mapEntry = (Message) message.getRepeatedField(
+        message.getDescriptorForType().findFieldByName("map_field"), 0);
+    assertEquals(2, mapEntry.getAllFields().size());
+  }
+  
+  private static <K, V> Map<K, V> newMap(K key1, V value1) {
+    Map<K, V> map = new HashMap<K, V>();
+    map.put(key1, value1);
+    return map;
+  }
+  
+  private static <K, V> Map<K, V> newMap(K key1, V value1, K key2, V value2) {
+    Map<K, V> map = new HashMap<K, V>();
+    map.put(key1, value1);
+    map.put(key2, value2);
+    return map;
+  }
+}
+
diff --git a/java/core/src/test/java/com/google/protobuf/MapTest.java b/java/core/src/test/java/com/google/protobuf/MapTest.java
new file mode 100644
index 00000000..0e5c1284
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/MapTest.java
@@ -0,0 +1,783 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.Descriptor;
+import com.google.protobuf.Descriptors.EnumDescriptor;
+import com.google.protobuf.Descriptors.EnumValueDescriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import map_test.MapTestProto.TestMap;
+import map_test.MapTestProto.TestMap.MessageValue;
+import map_test.MapTestProto.TestOnChangeEventPropagation;
+
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Unit tests for map fields.
+ */
+public class MapTest extends TestCase {
+  private void setMapValues(TestMap.Builder builder) {
+    builder.getMutableInt32ToInt32Field().put(1, 11);
+    builder.getMutableInt32ToInt32Field().put(2, 22);
+    builder.getMutableInt32ToInt32Field().put(3, 33);
+
+    builder.getMutableInt32ToStringField().put(1, "11");
+    builder.getMutableInt32ToStringField().put(2, "22");
+    builder.getMutableInt32ToStringField().put(3, "33");
+
+    builder.getMutableInt32ToBytesField().put(1, TestUtil.toBytes("11"));
+    builder.getMutableInt32ToBytesField().put(2, TestUtil.toBytes("22"));
+    builder.getMutableInt32ToBytesField().put(3, TestUtil.toBytes("33"));
+
+    builder.getMutableInt32ToEnumField().put(1, TestMap.EnumValue.FOO);
+    builder.getMutableInt32ToEnumField().put(2, TestMap.EnumValue.BAR);
+    builder.getMutableInt32ToEnumField().put(3, TestMap.EnumValue.BAZ);
+
+    builder.getMutableInt32ToMessageField().put(
+        1, MessageValue.newBuilder().setValue(11).build());
+    builder.getMutableInt32ToMessageField().put(
+        2, MessageValue.newBuilder().setValue(22).build());
+    builder.getMutableInt32ToMessageField().put(
+        3, MessageValue.newBuilder().setValue(33).build());
+
+    builder.getMutableStringToInt32Field().put("1", 11);
+    builder.getMutableStringToInt32Field().put("2", 22);
+    builder.getMutableStringToInt32Field().put("3", 33);
+  }
+
+  private void copyMapValues(TestMap source, TestMap.Builder destination) {
+    destination
+        .putAllInt32ToInt32Field(source.getInt32ToInt32Field())
+        .putAllInt32ToStringField(source.getInt32ToStringField())
+        .putAllInt32ToBytesField(source.getInt32ToBytesField())
+        .putAllInt32ToEnumField(source.getInt32ToEnumField())
+        .putAllInt32ToMessageField(source.getInt32ToMessageField())
+        .putAllStringToInt32Field(source.getStringToInt32Field());
+  }
+
+  private void assertMapValuesSet(TestMap message) {
+    assertEquals(3, message.getInt32ToInt32Field().size());
+    assertEquals(11, message.getInt32ToInt32Field().get(1).intValue());
+    assertEquals(22, message.getInt32ToInt32Field().get(2).intValue());
+    assertEquals(33, message.getInt32ToInt32Field().get(3).intValue());
+
+    assertEquals(3, message.getInt32ToStringField().size());
+    assertEquals("11", message.getInt32ToStringField().get(1));
+    assertEquals("22", message.getInt32ToStringField().get(2));
+    assertEquals("33", message.getInt32ToStringField().get(3));
+
+    assertEquals(3, message.getInt32ToBytesField().size());
+    assertEquals(TestUtil.toBytes("11"), message.getInt32ToBytesField().get(1));
+    assertEquals(TestUtil.toBytes("22"), message.getInt32ToBytesField().get(2));
+    assertEquals(TestUtil.toBytes("33"), message.getInt32ToBytesField().get(3));
+
+    assertEquals(3, message.getInt32ToEnumField().size());
+    assertEquals(TestMap.EnumValue.FOO, message.getInt32ToEnumField().get(1));
+    assertEquals(TestMap.EnumValue.BAR, message.getInt32ToEnumField().get(2));
+    assertEquals(TestMap.EnumValue.BAZ, message.getInt32ToEnumField().get(3));
+
+    assertEquals(3, message.getInt32ToMessageField().size());
+    assertEquals(11, message.getInt32ToMessageField().get(1).getValue());
+    assertEquals(22, message.getInt32ToMessageField().get(2).getValue());
+    assertEquals(33, message.getInt32ToMessageField().get(3).getValue());
+
+    assertEquals(3, message.getStringToInt32Field().size());
+    assertEquals(11, message.getStringToInt32Field().get("1").intValue());
+    assertEquals(22, message.getStringToInt32Field().get("2").intValue());
+    assertEquals(33, message.getStringToInt32Field().get("3").intValue());
+  }
+
+  private void updateMapValues(TestMap.Builder builder) {
+    builder.getMutableInt32ToInt32Field().put(1, 111);
+    builder.getMutableInt32ToInt32Field().remove(2);
+    builder.getMutableInt32ToInt32Field().put(4, 44);
+
+    builder.getMutableInt32ToStringField().put(1, "111");
+    builder.getMutableInt32ToStringField().remove(2);
+    builder.getMutableInt32ToStringField().put(4, "44");
+
+    builder.getMutableInt32ToBytesField().put(1, TestUtil.toBytes("111"));
+    builder.getMutableInt32ToBytesField().remove(2);
+    builder.getMutableInt32ToBytesField().put(4, TestUtil.toBytes("44"));
+
+    builder.getMutableInt32ToEnumField().put(1, TestMap.EnumValue.BAR);
+    builder.getMutableInt32ToEnumField().remove(2);
+    builder.getMutableInt32ToEnumField().put(4, TestMap.EnumValue.QUX);
+
+    builder.getMutableInt32ToMessageField().put(
+        1, MessageValue.newBuilder().setValue(111).build());
+    builder.getMutableInt32ToMessageField().remove(2);
+    builder.getMutableInt32ToMessageField().put(
+        4, MessageValue.newBuilder().setValue(44).build());
+
+    builder.getMutableStringToInt32Field().put("1", 111);
+    builder.getMutableStringToInt32Field().remove("2");
+    builder.getMutableStringToInt32Field().put("4", 44);
+  }
+
+  private void assertMapValuesUpdated(TestMap message) {
+    assertEquals(3, message.getInt32ToInt32Field().size());
+    assertEquals(111, message.getInt32ToInt32Field().get(1).intValue());
+    assertEquals(33, message.getInt32ToInt32Field().get(3).intValue());
+    assertEquals(44, message.getInt32ToInt32Field().get(4).intValue());
+
+    assertEquals(3, message.getInt32ToStringField().size());
+    assertEquals("111", message.getInt32ToStringField().get(1));
+    assertEquals("33", message.getInt32ToStringField().get(3));
+    assertEquals("44", message.getInt32ToStringField().get(4));
+
+    assertEquals(3, message.getInt32ToBytesField().size());
+    assertEquals(TestUtil.toBytes("111"), message.getInt32ToBytesField().get(1));
+    assertEquals(TestUtil.toBytes("33"), message.getInt32ToBytesField().get(3));
+    assertEquals(TestUtil.toBytes("44"), message.getInt32ToBytesField().get(4));
+
+    assertEquals(3, message.getInt32ToEnumField().size());
+    assertEquals(TestMap.EnumValue.BAR, message.getInt32ToEnumField().get(1));
+    assertEquals(TestMap.EnumValue.BAZ, message.getInt32ToEnumField().get(3));
+    assertEquals(TestMap.EnumValue.QUX, message.getInt32ToEnumField().get(4));
+
+    assertEquals(3, message.getInt32ToMessageField().size());
+    assertEquals(111, message.getInt32ToMessageField().get(1).getValue());
+    assertEquals(33, message.getInt32ToMessageField().get(3).getValue());
+    assertEquals(44, message.getInt32ToMessageField().get(4).getValue());
+
+    assertEquals(3, message.getStringToInt32Field().size());
+    assertEquals(111, message.getStringToInt32Field().get("1").intValue());
+    assertEquals(33, message.getStringToInt32Field().get("3").intValue());
+    assertEquals(44, message.getStringToInt32Field().get("4").intValue());
+  }
+
+  private void assertMapValuesCleared(TestMap message) {
+    assertEquals(0, message.getInt32ToInt32Field().size());
+    assertEquals(0, message.getInt32ToStringField().size());
+    assertEquals(0, message.getInt32ToBytesField().size());
+    assertEquals(0, message.getInt32ToEnumField().size());
+    assertEquals(0, message.getInt32ToMessageField().size());
+    assertEquals(0, message.getStringToInt32Field().size());
+  }
+  
+  public void testMutableMapLifecycle() {
+    TestMap.Builder builder = TestMap.newBuilder();
+    Map<Integer, Integer> intMap = builder.getMutableInt32ToInt32Field();
+    intMap.put(1, 2);
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+    try {
+      intMap.put(2, 3);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, 2), builder.getInt32ToInt32Field());
+    builder.getMutableInt32ToInt32Field().put(2, 3);
+    assertEquals(newMap(1, 2, 2, 3), builder.getInt32ToInt32Field());
+
+    Map<Integer, TestMap.EnumValue> enumMap = builder.getMutableInt32ToEnumField();
+    enumMap.put(1, TestMap.EnumValue.BAR);
+    assertEquals(newMap(1, TestMap.EnumValue.BAR), builder.build().getInt32ToEnumField());
+    try {
+      enumMap.put(2, TestMap.EnumValue.FOO);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, TestMap.EnumValue.BAR), builder.getInt32ToEnumField());
+    builder.getMutableInt32ToEnumField().put(2, TestMap.EnumValue.FOO);
+    assertEquals(
+        newMap(1, TestMap.EnumValue.BAR, 2, TestMap.EnumValue.FOO),
+        builder.getInt32ToEnumField());
+    
+    Map<Integer, String> stringMap = builder.getMutableInt32ToStringField();
+    stringMap.put(1, "1");
+    assertEquals(newMap(1, "1"), builder.build().getInt32ToStringField());
+    try {
+      stringMap.put(2, "2");
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, "1"), builder.getInt32ToStringField());
+    builder.getMutableInt32ToStringField().put(2, "2");
+    assertEquals(
+        newMap(1, "1", 2, "2"),
+        builder.getInt32ToStringField());
+    
+    Map<Integer, TestMap.MessageValue> messageMap = builder.getMutableInt32ToMessageField();
+    messageMap.put(1, TestMap.MessageValue.getDefaultInstance());
+    assertEquals(newMap(1, TestMap.MessageValue.getDefaultInstance()),
+        builder.build().getInt32ToMessageField());
+    try {
+      messageMap.put(2, TestMap.MessageValue.getDefaultInstance());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, TestMap.MessageValue.getDefaultInstance()),
+        builder.getInt32ToMessageField());
+    builder.getMutableInt32ToMessageField().put(2, TestMap.MessageValue.getDefaultInstance());
+    assertEquals(
+        newMap(1, TestMap.MessageValue.getDefaultInstance(),
+            2, TestMap.MessageValue.getDefaultInstance()),
+        builder.getInt32ToMessageField());
+  }
+
+  public void testMutableMapLifecycle_collections() {
+    TestMap.Builder builder = TestMap.newBuilder();
+    Map<Integer, Integer> intMap = builder.getMutableInt32ToInt32Field();
+    intMap.put(1, 2);
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+    try {
+      intMap.remove(2);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.entrySet().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.entrySet().iterator().remove();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.keySet().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.values().remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    try {
+      intMap.values().iterator().remove();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(newMap(1, 2), intMap);
+    assertEquals(newMap(1, 2), builder.getInt32ToInt32Field());
+    assertEquals(newMap(1, 2), builder.build().getInt32ToInt32Field());
+  }
+  
+  public void testGettersAndSetters() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    TestMap message = builder.build();
+    assertMapValuesCleared(message);
+
+    builder = message.toBuilder();
+    setMapValues(builder);
+    message = builder.build();
+    assertMapValuesSet(message);
+
+    builder = message.toBuilder();
+    updateMapValues(builder);
+    message = builder.build();
+    assertMapValuesUpdated(message);
+
+    builder = message.toBuilder();
+    builder.clear();
+    message = builder.build();
+    assertMapValuesCleared(message);
+  }
+
+  public void testPutAll() throws Exception {
+    TestMap.Builder sourceBuilder = TestMap.newBuilder();
+    setMapValues(sourceBuilder);
+    TestMap source = sourceBuilder.build();
+
+    TestMap.Builder destination = TestMap.newBuilder();
+    copyMapValues(source, destination);
+    assertMapValuesSet(destination.build());
+  }
+
+  public void testPutAllForUnknownEnumValues() throws Exception {
+    TestMap.Builder sourceBuilder = TestMap.newBuilder();
+    sourceBuilder.getMutableInt32ToEnumFieldValue().put(0, 0);
+    sourceBuilder.getMutableInt32ToEnumFieldValue().put(1, 1);
+    sourceBuilder.getMutableInt32ToEnumFieldValue().put(2, 1000);  // unknown value.
+    TestMap source = sourceBuilder.build();
+
+    TestMap.Builder destinationBuilder = TestMap.newBuilder();
+    destinationBuilder.putAllInt32ToEnumFieldValue(source.getInt32ToEnumFieldValue());
+    TestMap destination = destinationBuilder.build();
+
+    assertEquals(0, destination.getInt32ToEnumFieldValue().get(0).intValue());
+    assertEquals(1, destination.getInt32ToEnumFieldValue().get(1).intValue());
+    assertEquals(1000, destination.getInt32ToEnumFieldValue().get(2).intValue());
+  }
+
+  public void testSerializeAndParse() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesSet(message);
+
+    builder = message.toBuilder();
+    updateMapValues(builder);
+    message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesUpdated(message);
+
+    builder = message.toBuilder();
+    builder.clear();
+    message = builder.build();
+    assertEquals(message.getSerializedSize(), message.toByteString().size());
+    message = TestMap.parser().parseFrom(message.toByteString());
+    assertMapValuesCleared(message);
+  }
+
+  public void testMergeFrom() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+
+    TestMap.Builder other = TestMap.newBuilder();
+    other.mergeFrom(message);
+    assertMapValuesSet(other.build());
+  }
+
+  public void testEqualsAndHashCode() throws Exception {
+    // Test that generated equals() and hashCode() will disregard the order
+    // of map entries when comparing/hashing map fields.
+
+    // We can't control the order of elements in a HashMap. The best we can do
+    // here is to add elements in different order.
+    TestMap.Builder b1 = TestMap.newBuilder();
+    b1.getMutableInt32ToInt32Field().put(1, 2);
+    b1.getMutableInt32ToInt32Field().put(3, 4);
+    b1.getMutableInt32ToInt32Field().put(5, 6);
+    TestMap m1 = b1.build();
+
+    TestMap.Builder b2 = TestMap.newBuilder();
+    b2.getMutableInt32ToInt32Field().put(5, 6);
+    b2.getMutableInt32ToInt32Field().put(1, 2);
+    b2.getMutableInt32ToInt32Field().put(3, 4);
+    TestMap m2 = b2.build();
+
+    assertEquals(m1, m2);
+    assertEquals(m1.hashCode(), m2.hashCode());
+
+    // Make sure we did compare map fields.
+    b2.getMutableInt32ToInt32Field().put(1, 0);
+    m2 = b2.build();
+    assertFalse(m1.equals(m2));
+    // Don't check m1.hashCode() != m2.hashCode() because it's not guaranteed
+    // to be different.
+
+    // Regression test for b/18549190: if a map is a subset of the other map,
+    // equals() should return false.
+    b2.getMutableInt32ToInt32Field().remove(1);
+    m2 = b2.build();
+    assertFalse(m1.equals(m2));
+    assertFalse(m2.equals(m1));
+  }
+
+  public void testNestedBuilderOnChangeEventPropagation() {
+    TestOnChangeEventPropagation.Builder parent =
+        TestOnChangeEventPropagation.newBuilder();
+    parent.getOptionalMessageBuilder().getMutableInt32ToInt32Field().put(1, 2);
+    TestOnChangeEventPropagation message = parent.build();
+    assertEquals(2, message.getOptionalMessage().getInt32ToInt32Field().get(1).intValue());
+
+    // Make a change using nested builder.
+    parent.getOptionalMessageBuilder().getMutableInt32ToInt32Field().put(1, 3);
+
+    // Should be able to observe the change.
+    message = parent.build();
+    assertEquals(3, message.getOptionalMessage().getInt32ToInt32Field().get(1).intValue());
+
+    // Make another change using mergeFrom()
+    TestMap.Builder other = TestMap.newBuilder();
+    other.getMutableInt32ToInt32Field().put(1, 4);
+    parent.getOptionalMessageBuilder().mergeFrom(other.build());
+
+    // Should be able to observe the change.
+    message = parent.build();
+    assertEquals(4, message.getOptionalMessage().getInt32ToInt32Field().get(1).intValue());
+
+    // Make yet another change by clearing the nested builder.
+    parent.getOptionalMessageBuilder().clear();
+
+    // Should be able to observe the change.
+    message = parent.build();
+    assertEquals(0, message.getOptionalMessage().getInt32ToInt32Field().size());
+  }
+
+  public void testNestedBuilderOnChangeEventPropagationReflection() {
+    FieldDescriptor intMapField = f("int32_to_int32_field");
+    // Create an outer message builder with nested builder.
+    TestOnChangeEventPropagation.Builder parentBuilder =
+        TestOnChangeEventPropagation.newBuilder();
+    TestMap.Builder testMapBuilder = parentBuilder.getOptionalMessageBuilder();
+
+    // Create a map entry message.
+    TestMap.Builder entryBuilder = TestMap.newBuilder();
+    entryBuilder.getMutableInt32ToInt32Field().put(1, 1);
+
+    // Put the entry into the nested builder.
+    testMapBuilder.addRepeatedField(
+        intMapField, entryBuilder.getRepeatedField(intMapField, 0));
+
+    // Should be able to observe the change.
+    TestOnChangeEventPropagation message = parentBuilder.build();
+    assertEquals(1, message.getOptionalMessage().getInt32ToInt32Field().size());
+
+    // Change the entry value.
+    entryBuilder.getMutableInt32ToInt32Field().put(1, 4);
+    testMapBuilder = parentBuilder.getOptionalMessageBuilder();
+    testMapBuilder.setRepeatedField(
+        intMapField, 0, entryBuilder.getRepeatedField(intMapField, 0));
+
+    // Should be able to observe the change.
+    message = parentBuilder.build();
+    assertEquals(4,
+        message.getOptionalMessage().getInt32ToInt32Field().get(1).intValue());
+
+    // Clear the nested builder.
+    testMapBuilder = parentBuilder.getOptionalMessageBuilder();
+    testMapBuilder.clearField(intMapField);
+
+    // Should be able to observe the change.
+    message = parentBuilder.build();
+    assertEquals(0, message.getOptionalMessage().getInt32ToInt32Field().size());
+  }
+
+  // The following methods are used to test reflection API.
+
+  private static FieldDescriptor f(String name) {
+    return TestMap.getDescriptor().findFieldByName(name);
+  }
+
+  private static Object getFieldValue(Message mapEntry, String name) {
+    FieldDescriptor field = mapEntry.getDescriptorForType().findFieldByName(name);
+    return mapEntry.getField(field);
+  }
+
+  private static Message.Builder setFieldValue(
+      Message.Builder mapEntry, String name, Object value) {
+    FieldDescriptor field = mapEntry.getDescriptorForType().findFieldByName(name);
+    mapEntry.setField(field, value);
+    return mapEntry;
+  }
+
+  private static void assertHasMapValues(Message message, String name, Map<?, ?> values) {
+    FieldDescriptor field = f(name);
+    for (Object entry : (List<?>) message.getField(field)) {
+      Message mapEntry = (Message) entry;
+      Object key = getFieldValue(mapEntry, "key");
+      Object value = getFieldValue(mapEntry, "value");
+      assertTrue(values.containsKey(key));
+      assertEquals(value, values.get(key));
+    }
+    assertEquals(values.size(), message.getRepeatedFieldCount(field));
+    for (int i = 0; i < message.getRepeatedFieldCount(field); i++) {
+      Message mapEntry = (Message) message.getRepeatedField(field, i);
+      Object key = getFieldValue(mapEntry, "key");
+      Object value = getFieldValue(mapEntry, "value");
+      assertTrue(values.containsKey(key));
+      assertEquals(value, values.get(key));
+    }
+  }
+
+  private static <KeyType, ValueType>
+  Message newMapEntry(Message.Builder builder, String name, KeyType key, ValueType value) {
+    FieldDescriptor field = builder.getDescriptorForType().findFieldByName(name);
+    Message.Builder entryBuilder = builder.newBuilderForField(field);
+    FieldDescriptor keyField = entryBuilder.getDescriptorForType().findFieldByName("key");
+    FieldDescriptor valueField = entryBuilder.getDescriptorForType().findFieldByName("value");
+    entryBuilder.setField(keyField, key);
+    entryBuilder.setField(valueField, value);
+    return entryBuilder.build();
+  }
+
+  private static void setMapValues(Message.Builder builder, String name, Map<?, ?> values) {
+    List<Message> entryList = new ArrayList<Message>();
+    for (Map.Entry<?, ?> entry : values.entrySet()) {
+      entryList.add(newMapEntry(builder, name, entry.getKey(), entry.getValue()));
+    }
+    FieldDescriptor field = builder.getDescriptorForType().findFieldByName(name);
+    builder.setField(field, entryList);
+  }
+
+  private static <KeyType, ValueType>
+  Map<KeyType, ValueType> mapForValues(
+      KeyType key1, ValueType value1, KeyType key2, ValueType value2) {
+    Map<KeyType, ValueType> map = new HashMap<KeyType, ValueType>();
+    map.put(key1, value1);
+    map.put(key2, value2);
+    return map;
+  }
+
+  public void testReflectionApi() throws Exception {
+    // In reflection API, map fields are just repeated message fields.
+    TestMap.Builder builder = TestMap.newBuilder();
+    builder.getMutableInt32ToInt32Field().put(1, 2);
+    builder.getMutableInt32ToInt32Field().put(3, 4);
+    builder.getMutableInt32ToMessageField().put(
+        11, MessageValue.newBuilder().setValue(22).build());
+    builder.getMutableInt32ToMessageField().put(
+        33, MessageValue.newBuilder().setValue(44).build());
+    TestMap message = builder.build();
+
+    // Test getField(), getRepeatedFieldCount(), getRepeatedField().
+    assertHasMapValues(message, "int32_to_int32_field",
+        mapForValues(1, 2, 3, 4));
+    assertHasMapValues(message, "int32_to_message_field",
+        mapForValues(
+            11, MessageValue.newBuilder().setValue(22).build(),
+            33, MessageValue.newBuilder().setValue(44).build()));
+
+    // Test clearField()
+    builder.clearField(f("int32_to_int32_field"));
+    builder.clearField(f("int32_to_message_field"));
+    message = builder.build();
+    assertEquals(0, message.getInt32ToInt32Field().size());
+    assertEquals(0, message.getInt32ToMessageField().size());
+
+    // Test setField()
+    setMapValues(builder, "int32_to_int32_field",
+        mapForValues(11, 22, 33, 44));
+    setMapValues(builder, "int32_to_message_field",
+        mapForValues(
+            111, MessageValue.newBuilder().setValue(222).build(),
+            333, MessageValue.newBuilder().setValue(444).build()));
+    message = builder.build();
+    assertEquals(22, message.getInt32ToInt32Field().get(11).intValue());
+    assertEquals(44, message.getInt32ToInt32Field().get(33).intValue());
+    assertEquals(222, message.getInt32ToMessageField().get(111).getValue());
+    assertEquals(444, message.getInt32ToMessageField().get(333).getValue());
+
+    // Test addRepeatedField
+    builder.addRepeatedField(f("int32_to_int32_field"),
+        newMapEntry(builder, "int32_to_int32_field", 55, 66));
+    builder.addRepeatedField(f("int32_to_message_field"),
+        newMapEntry(builder, "int32_to_message_field", 555,
+            MessageValue.newBuilder().setValue(666).build()));
+    message = builder.build();
+    assertEquals(66, message.getInt32ToInt32Field().get(55).intValue());
+    assertEquals(666, message.getInt32ToMessageField().get(555).getValue());
+
+    // Test addRepeatedField (overriding existing values)
+    builder.addRepeatedField(f("int32_to_int32_field"),
+        newMapEntry(builder, "int32_to_int32_field", 55, 55));
+    builder.addRepeatedField(f("int32_to_message_field"),
+        newMapEntry(builder, "int32_to_message_field", 555,
+            MessageValue.newBuilder().setValue(555).build()));
+    message = builder.build();
+    assertEquals(55, message.getInt32ToInt32Field().get(55).intValue());
+    assertEquals(555, message.getInt32ToMessageField().get(555).getValue());
+
+    // Test setRepeatedField
+    for (int i = 0; i < builder.getRepeatedFieldCount(f("int32_to_int32_field")); i++) {
+      Message mapEntry = (Message) builder.getRepeatedField(f("int32_to_int32_field"), i);
+      int oldKey = ((Integer) getFieldValue(mapEntry, "key")).intValue();
+      int oldValue = ((Integer) getFieldValue(mapEntry, "value")).intValue();
+      // Swap key with value for each entry.
+      Message.Builder mapEntryBuilder = mapEntry.toBuilder();
+      setFieldValue(mapEntryBuilder, "key", oldValue);
+      setFieldValue(mapEntryBuilder, "value", oldKey);
+      builder.setRepeatedField(f("int32_to_int32_field"), i, mapEntryBuilder.build());
+    }
+    message = builder.build();
+    assertEquals(11, message.getInt32ToInt32Field().get(22).intValue());
+    assertEquals(33, message.getInt32ToInt32Field().get(44).intValue());
+    assertEquals(55, message.getInt32ToInt32Field().get(55).intValue());
+  }
+
+  public void testTextFormat() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+
+    String textData = TextFormat.printToString(message);
+
+    builder = TestMap.newBuilder();
+    TextFormat.merge(textData, builder);
+    message = builder.build();
+
+    assertMapValuesSet(message);
+  }
+
+  public void testDynamicMessage() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+
+    Message dynamicDefaultInstance =
+        DynamicMessage.getDefaultInstance(TestMap.getDescriptor());
+    Message dynamicMessage = dynamicDefaultInstance
+        .newBuilderForType().mergeFrom(message.toByteString()).build();
+
+    assertEquals(message, dynamicMessage);
+    assertEquals(message.hashCode(), dynamicMessage.hashCode());
+  }
+
+  public void testReflectionEqualsAndHashCode() throws Exception {
+    // Test that generated equals() and hashCode() will disregard the order
+    // of map entries when comparing/hashing map fields.
+
+    // We use DynamicMessage to test reflection based equals()/hashCode().
+    Message dynamicDefaultInstance =
+        DynamicMessage.getDefaultInstance(TestMap.getDescriptor());
+    FieldDescriptor field = f("int32_to_int32_field");
+
+    Message.Builder b1 = dynamicDefaultInstance.newBuilderForType();
+    b1.addRepeatedField(field, newMapEntry(b1, "int32_to_int32_field", 1, 2));
+    b1.addRepeatedField(field, newMapEntry(b1, "int32_to_int32_field", 3, 4));
+    b1.addRepeatedField(field, newMapEntry(b1, "int32_to_int32_field", 5, 6));
+    Message m1 = b1.build();
+
+    Message.Builder b2 = dynamicDefaultInstance.newBuilderForType();
+    b2.addRepeatedField(field, newMapEntry(b2, "int32_to_int32_field", 5, 6));
+    b2.addRepeatedField(field, newMapEntry(b2, "int32_to_int32_field", 1, 2));
+    b2.addRepeatedField(field, newMapEntry(b2, "int32_to_int32_field", 3, 4));
+    Message m2 = b2.build();
+
+    assertEquals(m1, m2);
+    assertEquals(m1.hashCode(), m2.hashCode());
+
+    // Make sure we did compare map fields.
+    b2.setRepeatedField(field, 0, newMapEntry(b1, "int32_to_int32_field", 0, 0));
+    m2 = b2.build();
+    assertFalse(m1.equals(m2));
+    // Don't check m1.hashCode() != m2.hashCode() because it's not guaranteed
+    // to be different.
+  }
+
+  public void testUnknownEnumValues() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    builder.getMutableInt32ToEnumFieldValue().put(0, 0);
+    builder.getMutableInt32ToEnumFieldValue().put(1, 1);
+    builder.getMutableInt32ToEnumFieldValue().put(2, 1000);  // unknown value.
+    TestMap message = builder.build();
+
+    assertEquals(TestMap.EnumValue.FOO,
+        message.getInt32ToEnumField().get(0));
+    assertEquals(TestMap.EnumValue.BAR,
+        message.getInt32ToEnumField().get(1));
+    assertEquals(TestMap.EnumValue.UNRECOGNIZED,
+        message.getInt32ToEnumField().get(2));
+    assertEquals(1000, message.getInt32ToEnumFieldValue().get(2).intValue());
+
+    // Unknown enum values should be preserved after:
+    //   1. Serialization and parsing.
+    //   2. toBuild().
+    //   3. mergeFrom().
+    message = TestMap.parseFrom(message.toByteString());
+    assertEquals(1000, message.getInt32ToEnumFieldValue().get(2).intValue());
+    builder = message.toBuilder();
+    assertEquals(1000, builder.getInt32ToEnumFieldValue().get(2).intValue());
+    builder = TestMap.newBuilder().mergeFrom(message);
+    assertEquals(1000, builder.getInt32ToEnumFieldValue().get(2).intValue());
+
+    // hashCode()/equals() should take unknown enum values into account.
+    builder.getMutableInt32ToEnumFieldValue().put(2, 1001);
+    TestMap message2 = builder.build();
+    assertFalse(message.hashCode() == message2.hashCode());
+    assertFalse(message.equals(message2));
+    // Unknown values will be converted to UNRECOGNIZED so the resulted enum map
+    // should be the same.
+    assertTrue(message.getInt32ToEnumField().equals(message2.getInt32ToEnumField()));
+  }
+
+  public void testUnknownEnumValuesInReflectionApi() throws Exception {
+    Descriptor descriptor = TestMap.getDescriptor();
+    EnumDescriptor enumDescriptor = TestMap.EnumValue.getDescriptor();
+    FieldDescriptor field = descriptor.findFieldByName("int32_to_enum_field");
+
+    Map<Integer, Integer> data = new HashMap<Integer, Integer>();
+    data.put(0, 0);
+    data.put(1, 1);
+    data.put(2, 1000);  // unknown value.
+
+    TestMap.Builder builder = TestMap.newBuilder();
+    for (Map.Entry<Integer, Integer> entry : data.entrySet()) {
+      builder.getMutableInt32ToEnumFieldValue().put(entry.getKey(), entry.getValue());
+    }
+
+    // Try to read unknown enum values using reflection API.
+    for (int i = 0; i < builder.getRepeatedFieldCount(field); i++) {
+      Message mapEntry = (Message) builder.getRepeatedField(field, i);
+      int key = ((Integer) getFieldValue(mapEntry, "key")).intValue();
+      int value = ((EnumValueDescriptor) getFieldValue(mapEntry, "value")).getNumber();
+      assertEquals(data.get(key).intValue(), value);
+      Message.Builder mapEntryBuilder = mapEntry.toBuilder();
+      // Increase the value by 1.
+      setFieldValue(mapEntryBuilder, "value",
+          enumDescriptor.findValueByNumberCreatingIfUnknown(value + 1));
+      builder.setRepeatedField(field, i, mapEntryBuilder.build());
+    }
+
+    // Verify that enum values have been successfully updated.
+    TestMap message = builder.build();
+    for (Map.Entry<Integer, Integer> entry : message.getInt32ToEnumFieldValue().entrySet()) {
+      assertEquals(data.get(entry.getKey()) + 1, entry.getValue().intValue());
+    }
+  }
+
+  public void testIterationOrder() throws Exception {
+    TestMap.Builder builder = TestMap.newBuilder();
+    setMapValues(builder);
+    TestMap message = builder.build();
+
+    assertEquals(Arrays.asList("1", "2", "3"),
+        new ArrayList<String>(message.getStringToInt32Field().keySet()));
+  }
+  
+  private static <K, V> Map<K, V> newMap(K key1, V value1) {
+    Map<K, V> map = new HashMap<K, V>();
+    map.put(key1, value1);
+    return map;
+  }
+  
+  private static <K, V> Map<K, V> newMap(K key1, V value1, K key2, V value2) {
+    Map<K, V> map = new HashMap<K, V>();
+    map.put(key1, value1);
+    map.put(key2, value2);
+    return map;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/MessageTest.java b/java/core/src/test/java/com/google/protobuf/MessageTest.java
new file mode 100644
index 00000000..abcd3a1d
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/MessageTest.java
@@ -0,0 +1,353 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestRequired;
+import protobuf_unittest.UnittestProto.TestRequiredForeign;
+import protobuf_unittest.UnittestProto.ForeignMessage;
+
+import junit.framework.TestCase;
+
+import java.util.List;
+
+/**
+ * Misc. unit tests for message operations that apply to both generated
+ * and dynamic messages.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class MessageTest extends TestCase {
+  // =================================================================
+  // Message-merging tests.
+
+  static final TestAllTypes MERGE_SOURCE =
+    TestAllTypes.newBuilder()
+      .setOptionalInt32(1)
+      .setOptionalString("foo")
+      .setOptionalForeignMessage(ForeignMessage.getDefaultInstance())
+      .addRepeatedString("bar")
+      .build();
+
+  static final TestAllTypes MERGE_DEST =
+    TestAllTypes.newBuilder()
+      .setOptionalInt64(2)
+      .setOptionalString("baz")
+      .setOptionalForeignMessage(ForeignMessage.newBuilder().setC(3).build())
+      .addRepeatedString("qux")
+      .build();
+
+  static final String MERGE_RESULT_TEXT =
+      "optional_int32: 1\n" +
+      "optional_int64: 2\n" +
+      "optional_string: \"foo\"\n" +
+      "optional_foreign_message {\n" +
+      "  c: 3\n" +
+      "}\n" +
+      "repeated_string: \"qux\"\n" +
+      "repeated_string: \"bar\"\n";
+
+  public void testMergeFrom() throws Exception {
+    TestAllTypes result =
+      TestAllTypes.newBuilder(MERGE_DEST)
+        .mergeFrom(MERGE_SOURCE).build();
+
+    assertEquals(MERGE_RESULT_TEXT, result.toString());
+  }
+
+  /**
+   * Test merging a DynamicMessage into a GeneratedMessage.  As long as they
+   * have the same descriptor, this should work, but it is an entirely different
+   * code path.
+   */
+  public void testMergeFromDynamic() throws Exception {
+    TestAllTypes result =
+      TestAllTypes.newBuilder(MERGE_DEST)
+        .mergeFrom(DynamicMessage.newBuilder(MERGE_SOURCE).build())
+        .build();
+
+    assertEquals(MERGE_RESULT_TEXT, result.toString());
+  }
+
+  /** Test merging two DynamicMessages. */
+  public void testDynamicMergeFrom() throws Exception {
+    DynamicMessage result =
+      DynamicMessage.newBuilder(MERGE_DEST)
+        .mergeFrom(DynamicMessage.newBuilder(MERGE_SOURCE).build())
+        .build();
+
+    assertEquals(MERGE_RESULT_TEXT, result.toString());
+  }
+
+  // =================================================================
+  // Required-field-related tests.
+
+  private static final TestRequired TEST_REQUIRED_UNINITIALIZED =
+    TestRequired.getDefaultInstance();
+  private static final TestRequired TEST_REQUIRED_INITIALIZED =
+    TestRequired.newBuilder().setA(1).setB(2).setC(3).build();
+
+  public void testRequired() throws Exception {
+    TestRequired.Builder builder = TestRequired.newBuilder();
+
+    assertFalse(builder.isInitialized());
+    builder.setA(1);
+    assertFalse(builder.isInitialized());
+    builder.setB(1);
+    assertFalse(builder.isInitialized());
+    builder.setC(1);
+    assertTrue(builder.isInitialized());
+  }
+
+  public void testRequiredForeign() throws Exception {
+    TestRequiredForeign.Builder builder = TestRequiredForeign.newBuilder();
+
+    assertTrue(builder.isInitialized());
+
+    builder.setOptionalMessage(TEST_REQUIRED_UNINITIALIZED);
+    assertFalse(builder.isInitialized());
+
+    builder.setOptionalMessage(TEST_REQUIRED_INITIALIZED);
+    assertTrue(builder.isInitialized());
+
+    builder.addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED);
+    assertFalse(builder.isInitialized());
+
+    builder.setRepeatedMessage(0, TEST_REQUIRED_INITIALIZED);
+    assertTrue(builder.isInitialized());
+  }
+
+  public void testRequiredExtension() throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+
+    assertTrue(builder.isInitialized());
+
+    builder.setExtension(TestRequired.single, TEST_REQUIRED_UNINITIALIZED);
+    assertFalse(builder.isInitialized());
+
+    builder.setExtension(TestRequired.single, TEST_REQUIRED_INITIALIZED);
+    assertTrue(builder.isInitialized());
+
+    builder.addExtension(TestRequired.multi, TEST_REQUIRED_UNINITIALIZED);
+    assertFalse(builder.isInitialized());
+
+    builder.setExtension(TestRequired.multi, 0, TEST_REQUIRED_INITIALIZED);
+    assertTrue(builder.isInitialized());
+  }
+
+  public void testRequiredDynamic() throws Exception {
+    Descriptors.Descriptor descriptor = TestRequired.getDescriptor();
+    DynamicMessage.Builder builder = DynamicMessage.newBuilder(descriptor);
+
+    assertFalse(builder.isInitialized());
+    builder.setField(descriptor.findFieldByName("a"), 1);
+    assertFalse(builder.isInitialized());
+    builder.setField(descriptor.findFieldByName("b"), 1);
+    assertFalse(builder.isInitialized());
+    builder.setField(descriptor.findFieldByName("c"), 1);
+    assertTrue(builder.isInitialized());
+  }
+
+  public void testRequiredDynamicForeign() throws Exception {
+    Descriptors.Descriptor descriptor = TestRequiredForeign.getDescriptor();
+    DynamicMessage.Builder builder = DynamicMessage.newBuilder(descriptor);
+
+    assertTrue(builder.isInitialized());
+
+    builder.setField(descriptor.findFieldByName("optional_message"),
+                     TEST_REQUIRED_UNINITIALIZED);
+    assertFalse(builder.isInitialized());
+
+    builder.setField(descriptor.findFieldByName("optional_message"),
+                     TEST_REQUIRED_INITIALIZED);
+    assertTrue(builder.isInitialized());
+
+    builder.addRepeatedField(descriptor.findFieldByName("repeated_message"),
+                             TEST_REQUIRED_UNINITIALIZED);
+    assertFalse(builder.isInitialized());
+
+    builder.setRepeatedField(descriptor.findFieldByName("repeated_message"), 0,
+                             TEST_REQUIRED_INITIALIZED);
+    assertTrue(builder.isInitialized());
+  }
+
+  public void testUninitializedException() throws Exception {
+    try {
+      TestRequired.newBuilder().build();
+      fail("Should have thrown an exception.");
+    } catch (UninitializedMessageException e) {
+      assertEquals("Message missing required fields: a, b, c", e.getMessage());
+    }
+  }
+
+  public void testBuildPartial() throws Exception {
+    // We're mostly testing that no exception is thrown.
+    TestRequired message = TestRequired.newBuilder().buildPartial();
+    assertFalse(message.isInitialized());
+  }
+
+  public void testNestedUninitializedException() throws Exception {
+    try {
+      TestRequiredForeign.newBuilder()
+        .setOptionalMessage(TEST_REQUIRED_UNINITIALIZED)
+        .addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED)
+        .addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED)
+        .build();
+      fail("Should have thrown an exception.");
+    } catch (UninitializedMessageException e) {
+      assertEquals(
+        "Message missing required fields: " +
+        "optional_message.a, " +
+        "optional_message.b, " +
+        "optional_message.c, " +
+        "repeated_message[0].a, " +
+        "repeated_message[0].b, " +
+        "repeated_message[0].c, " +
+        "repeated_message[1].a, " +
+        "repeated_message[1].b, " +
+        "repeated_message[1].c",
+        e.getMessage());
+    }
+  }
+
+  public void testBuildNestedPartial() throws Exception {
+    // We're mostly testing that no exception is thrown.
+    TestRequiredForeign message =
+      TestRequiredForeign.newBuilder()
+        .setOptionalMessage(TEST_REQUIRED_UNINITIALIZED)
+        .addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED)
+        .addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED)
+        .buildPartial();
+    assertFalse(message.isInitialized());
+  }
+
+  public void testParseUnititialized() throws Exception {
+    try {
+      TestRequired.parseFrom(ByteString.EMPTY);
+      fail("Should have thrown an exception.");
+    } catch (InvalidProtocolBufferException e) {
+      assertEquals("Message missing required fields: a, b, c", e.getMessage());
+    }
+  }
+
+  public void testParseNestedUnititialized() throws Exception {
+    ByteString data =
+      TestRequiredForeign.newBuilder()
+        .setOptionalMessage(TEST_REQUIRED_UNINITIALIZED)
+        .addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED)
+        .addRepeatedMessage(TEST_REQUIRED_UNINITIALIZED)
+        .buildPartial().toByteString();
+
+    try {
+      TestRequiredForeign.parseFrom(data);
+      fail("Should have thrown an exception.");
+    } catch (InvalidProtocolBufferException e) {
+      assertEquals(
+        "Message missing required fields: " +
+        "optional_message.a, " +
+        "optional_message.b, " +
+        "optional_message.c, " +
+        "repeated_message[0].a, " +
+        "repeated_message[0].b, " +
+        "repeated_message[0].c, " +
+        "repeated_message[1].a, " +
+        "repeated_message[1].b, " +
+        "repeated_message[1].c",
+        e.getMessage());
+    }
+  }
+
+  public void testDynamicUninitializedException() throws Exception {
+    try {
+      DynamicMessage.newBuilder(TestRequired.getDescriptor()).build();
+      fail("Should have thrown an exception.");
+    } catch (UninitializedMessageException e) {
+      assertEquals("Message missing required fields: a, b, c", e.getMessage());
+    }
+  }
+
+  public void testDynamicBuildPartial() throws Exception {
+    // We're mostly testing that no exception is thrown.
+    DynamicMessage message =
+      DynamicMessage.newBuilder(TestRequired.getDescriptor())
+        .buildPartial();
+    assertFalse(message.isInitialized());
+  }
+
+  public void testDynamicParseUnititialized() throws Exception {
+    try {
+      Descriptors.Descriptor descriptor = TestRequired.getDescriptor();
+      DynamicMessage.parseFrom(descriptor, ByteString.EMPTY);
+      fail("Should have thrown an exception.");
+    } catch (InvalidProtocolBufferException e) {
+      assertEquals("Message missing required fields: a, b, c", e.getMessage());
+    }
+  }
+  
+  /** Test reading unset repeated message from DynamicMessage. */
+  public void testDynamicRepeatedMessageNull() throws Exception {
+    Descriptors.Descriptor descriptor = TestRequired.getDescriptor();
+    DynamicMessage result =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor())
+        .mergeFrom(DynamicMessage.newBuilder(MERGE_SOURCE).build())
+        .build();
+
+    assertTrue(result.getField(result.getDescriptorForType()
+        .findFieldByName("repeated_foreign_message")) instanceof List<?>);
+    assertEquals(result.getRepeatedFieldCount(result.getDescriptorForType()
+        .findFieldByName("repeated_foreign_message")), 0);
+  }
+  
+  /** Test reading repeated message from DynamicMessage. */
+  public void testDynamicRepeatedMessageNotNull() throws Exception {
+
+    TestAllTypes REPEATED_NESTED =
+      TestAllTypes.newBuilder()
+        .setOptionalInt32(1)
+        .setOptionalString("foo")
+        .setOptionalForeignMessage(ForeignMessage.getDefaultInstance())
+        .addRepeatedString("bar")
+        .addRepeatedForeignMessage(ForeignMessage.getDefaultInstance())
+        .addRepeatedForeignMessage(ForeignMessage.getDefaultInstance())
+        .build();
+    Descriptors.Descriptor descriptor = TestRequired.getDescriptor();
+    DynamicMessage result =
+      DynamicMessage.newBuilder(TestAllTypes.getDescriptor())
+        .mergeFrom(DynamicMessage.newBuilder(REPEATED_NESTED).build())
+        .build();
+
+    assertTrue(result.getField(result.getDescriptorForType()
+        .findFieldByName("repeated_foreign_message")) instanceof List<?>);
+    assertEquals(result.getRepeatedFieldCount(result.getDescriptorForType()
+        .findFieldByName("repeated_foreign_message")), 2);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java b/java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java
new file mode 100644
index 00000000..23653126
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java
@@ -0,0 +1,185 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.Vehicle;
+import protobuf_unittest.Wheel;
+
+import junit.framework.TestCase;
+
+import java.util.List;
+import java.util.ArrayList;
+
+/**
+ * Test cases that exercise end-to-end use cases involving
+ * {@link SingleFieldBuilder} and {@link RepeatedFieldBuilder}.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ */
+public class NestedBuildersTest extends TestCase {
+
+  public void testMessagesAndBuilders() {
+    Vehicle.Builder vehicleBuilder = Vehicle.newBuilder();
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(4)
+        .setWidth(1);
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(4)
+        .setWidth(2);
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(4)
+        .setWidth(3);
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(4)
+        .setWidth(4);
+    vehicleBuilder.getEngineBuilder()
+        .setLiters(10);
+
+    Vehicle vehicle = vehicleBuilder.build();
+    assertEquals(4, vehicle.getWheelCount());
+    for (int i = 0; i < 4; i++) {
+      Wheel wheel = vehicle.getWheel(i);
+      assertEquals(4, wheel.getRadius());
+      assertEquals(i + 1, wheel.getWidth());
+    }
+    assertEquals(10, vehicle.getEngine().getLiters());
+
+    for (int i = 0; i < 4; i++) {
+      vehicleBuilder.getWheelBuilder(i)
+          .setRadius(5)
+          .setWidth(i + 10);
+    }
+    vehicleBuilder.getEngineBuilder().setLiters(20);
+
+    vehicle = vehicleBuilder.build();
+    for (int i = 0; i < 4; i++) {
+      Wheel wheel = vehicle.getWheel(i);
+      assertEquals(5, wheel.getRadius());
+      assertEquals(i + 10, wheel.getWidth());
+    }
+    assertEquals(20, vehicle.getEngine().getLiters());
+    assertTrue(vehicle.hasEngine());
+  }
+
+  public void testMessagesAreCached() {
+    Vehicle.Builder vehicleBuilder = Vehicle.newBuilder();
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(1)
+        .setWidth(2);
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(3)
+        .setWidth(4);
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(5)
+        .setWidth(6);
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(7)
+        .setWidth(8);
+
+    // Make sure messages are cached.
+    List<Wheel> wheels = new ArrayList<Wheel>(vehicleBuilder.getWheelList());
+    for (int i = 0; i < wheels.size(); i++) {
+      assertSame(wheels.get(i), vehicleBuilder.getWheel(i));
+    }
+
+    // Now get builders and check they didn't change.
+    for (int i = 0; i < wheels.size(); i++) {
+      vehicleBuilder.getWheel(i);
+    }
+    for (int i = 0; i < wheels.size(); i++) {
+      assertSame(wheels.get(i), vehicleBuilder.getWheel(i));
+    }
+
+    // Change just one
+    vehicleBuilder.getWheelBuilder(3)
+        .setRadius(20).setWidth(20);
+
+    // Now get wheels and check that only that one changed
+    for (int i = 0; i < wheels.size(); i++) {
+      if (i < 3) {
+        assertSame(wheels.get(i), vehicleBuilder.getWheel(i));
+      } else {
+        assertNotSame(wheels.get(i), vehicleBuilder.getWheel(i));
+      }
+    }
+  }
+
+  public void testRemove_WithNestedBuilders() {
+    Vehicle.Builder vehicleBuilder = Vehicle.newBuilder();
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(1)
+        .setWidth(1);
+    vehicleBuilder.addWheelBuilder()
+        .setRadius(2)
+        .setWidth(2);
+    vehicleBuilder.removeWheel(0);
+
+    assertEquals(1, vehicleBuilder.getWheelCount());
+    assertEquals(2, vehicleBuilder.getWheel(0).getRadius());
+  }
+
+  public void testRemove_WithNestedMessages() {
+    Vehicle.Builder vehicleBuilder = Vehicle.newBuilder();
+    vehicleBuilder.addWheel(Wheel.newBuilder()
+        .setRadius(1)
+        .setWidth(1));
+    vehicleBuilder.addWheel(Wheel.newBuilder()
+        .setRadius(2)
+        .setWidth(2));
+    vehicleBuilder.removeWheel(0);
+
+    assertEquals(1, vehicleBuilder.getWheelCount());
+    assertEquals(2, vehicleBuilder.getWheel(0).getRadius());
+  }
+
+  public void testMerge() {
+    Vehicle vehicle1 = Vehicle.newBuilder()
+        .addWheel(Wheel.newBuilder().setRadius(1).build())
+        .addWheel(Wheel.newBuilder().setRadius(2).build())
+        .build();
+
+    Vehicle vehicle2 = Vehicle.newBuilder()
+        .mergeFrom(vehicle1)
+        .build();
+    // List should be the same -- no allocation
+    assertSame(vehicle1.getWheelList(), vehicle2.getWheelList());
+
+    Vehicle vehicle3 = vehicle1.toBuilder().build();
+    assertSame(vehicle1.getWheelList(), vehicle3.getWheelList());
+  }
+
+  public void testGettingBuilderMarksFieldAsHaving() {
+    Vehicle.Builder vehicleBuilder = Vehicle.newBuilder();
+    vehicleBuilder.getEngineBuilder();
+    Vehicle vehicle = vehicleBuilder.buildPartial();
+    assertTrue(vehicle.hasEngine());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/NioByteStringTest.java b/java/core/src/test/java/com/google/protobuf/NioByteStringTest.java
new file mode 100644
index 00000000..e40a3662
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/NioByteStringTest.java
@@ -0,0 +1,545 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static com.google.protobuf.Internal.UTF_8;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.UnsupportedEncodingException;
+import java.nio.BufferOverflowException;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+/**
+ * Tests for {@link NioByteString}.
+ */
+public class NioByteStringTest extends TestCase {
+  private static final ByteString EMPTY = new NioByteString(ByteBuffer.wrap(new byte[0]));
+  private static final String CLASSNAME = NioByteString.class.getSimpleName();
+  private static final byte[] BYTES = ByteStringTest.getTestBytes(1234, 11337766L);
+  private static final int EXPECTED_HASH = ByteString.wrap(BYTES).hashCode();
+  private static final ByteBuffer BUFFER = ByteBuffer.wrap(BYTES.clone());
+  private static final ByteString TEST_STRING = new NioByteString(BUFFER);
+
+  public void testExpectedType() {
+    String actualClassName = getActualClassName(TEST_STRING);
+    assertEquals(CLASSNAME + " should match type exactly", CLASSNAME, actualClassName);
+  }
+
+  protected String getActualClassName(Object object) {
+    String actualClassName = object.getClass().getName();
+    actualClassName = actualClassName.substring(actualClassName.lastIndexOf('.') + 1);
+    return actualClassName;
+  }
+
+  public void testByteAt() {
+    boolean stillEqual = true;
+    for (int i = 0; stillEqual && i < BYTES.length; ++i) {
+      stillEqual = (BYTES[i] == TEST_STRING.byteAt(i));
+    }
+    assertTrue(CLASSNAME + " must capture the right bytes", stillEqual);
+  }
+
+  public void testByteIterator() {
+    boolean stillEqual = true;
+    ByteString.ByteIterator iter = TEST_STRING.iterator();
+    for (int i = 0; stillEqual && i < BYTES.length; ++i) {
+      stillEqual = (iter.hasNext() && BYTES[i] == iter.nextByte());
+    }
+    assertTrue(CLASSNAME + " must capture the right bytes", stillEqual);
+    assertFalse(CLASSNAME + " must have exhausted the itertor", iter.hasNext());
+
+    try {
+      iter.nextByte();
+      fail("Should have thrown an exception.");
+    } catch (NoSuchElementException e) {
+      // This is success
+    }
+  }
+
+  public void testByteIterable() {
+    boolean stillEqual = true;
+    int j = 0;
+    for (byte quantum : TEST_STRING) {
+      stillEqual = (BYTES[j] == quantum);
+      ++j;
+    }
+    assertTrue(CLASSNAME + " must capture the right bytes as Bytes", stillEqual);
+    assertEquals(CLASSNAME + " iterable character count", BYTES.length, j);
+  }
+
+  public void testSize() {
+    assertEquals(CLASSNAME + " must have the expected size", BYTES.length,
+        TEST_STRING.size());
+  }
+
+  public void testGetTreeDepth() {
+    assertEquals(CLASSNAME + " must have depth 0", 0, TEST_STRING.getTreeDepth());
+  }
+
+  public void testIsBalanced() {
+    assertTrue(CLASSNAME + " is technically balanced", TEST_STRING.isBalanced());
+  }
+
+  public void testCopyTo_ByteArrayOffsetLength() {
+    int destinationOffset = 50;
+    int length = 100;
+    byte[] destination = new byte[destinationOffset + length];
+    int sourceOffset = 213;
+    TEST_STRING.copyTo(destination, sourceOffset, destinationOffset, length);
+    boolean stillEqual = true;
+    for (int i = 0; stillEqual && i < length; ++i) {
+      stillEqual = BYTES[i + sourceOffset] == destination[i + destinationOffset];
+    }
+    assertTrue(CLASSNAME + ".copyTo(4 arg) must give the expected bytes", stillEqual);
+  }
+
+  public void testCopyTo_ByteArrayOffsetLengthErrors() {
+    int destinationOffset = 50;
+    int length = 100;
+    byte[] destination = new byte[destinationOffset + length];
+
+    try {
+      // Copy one too many bytes
+      TEST_STRING.copyTo(destination, TEST_STRING.size() + 1 - length,
+          destinationOffset, length);
+      fail("Should have thrown an exception when copying too many bytes of a "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative sourceOffset
+      TEST_STRING.copyTo(destination, -1, destinationOffset, length);
+      fail("Should have thrown an exception when given a negative sourceOffset in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative destinationOffset
+      TEST_STRING.copyTo(destination, 0, -1, length);
+      fail("Should have thrown an exception when given a negative destinationOffset in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal negative size
+      TEST_STRING.copyTo(destination, 0, 0, -1);
+      fail("Should have thrown an exception when given a negative size in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal too-large sourceOffset
+      TEST_STRING.copyTo(destination, 2 * TEST_STRING.size(), 0, length);
+      fail("Should have thrown an exception when the destinationOffset is too large in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+
+    try {
+      // Copy with illegal too-large destinationOffset
+      TEST_STRING.copyTo(destination, 0, 2 * destination.length, length);
+      fail("Should have thrown an exception when the destinationOffset is too large in "
+          + CLASSNAME);
+    } catch (IndexOutOfBoundsException expected) {
+      // This is success
+    }
+  }
+
+  public void testCopyTo_ByteBuffer() {
+    // Same length.
+    ByteBuffer myBuffer = ByteBuffer.allocate(BYTES.length);
+    TEST_STRING.copyTo(myBuffer);
+    myBuffer.flip();
+    assertEquals(CLASSNAME + ".copyTo(ByteBuffer) must give back the same bytes",
+        BUFFER, myBuffer);
+
+    // Target buffer bigger than required.
+    myBuffer = ByteBuffer.allocate(TEST_STRING.size() + 1);
+    TEST_STRING.copyTo(myBuffer);
+    myBuffer.flip();
+    assertEquals(BUFFER, myBuffer);
+
+    // Target buffer has no space.
+    myBuffer = ByteBuffer.allocate(0);
+    try {
+      TEST_STRING.copyTo(myBuffer);
+      fail("Should have thrown an exception when target ByteBuffer has insufficient capacity");
+    } catch (BufferOverflowException e) {
+      // Expected.
+    }
+
+    // Target buffer too small.
+    myBuffer = ByteBuffer.allocate(1);
+    try {
+      TEST_STRING.copyTo(myBuffer);
+      fail("Should have thrown an exception when target ByteBuffer has insufficient capacity");
+    } catch (BufferOverflowException e) {
+      // Expected.
+    }
+  }
+
+  public void testMarkSupported() {
+    InputStream stream = TEST_STRING.newInput();
+    assertTrue(CLASSNAME + ".newInput() must support marking", stream.markSupported());
+  }
+
+  public void testMarkAndReset() throws IOException {
+    int fraction = TEST_STRING.size() / 3;
+
+    InputStream stream = TEST_STRING.newInput();
+    stream.mark(TEST_STRING.size()); // First, mark() the end.
+
+    skipFully(stream, fraction); // Skip a large fraction, but not all.
+    assertEquals(
+        CLASSNAME + ": after skipping to the 'middle', half the bytes are available",
+        (TEST_STRING.size() - fraction), stream.available());
+    stream.reset();
+    assertEquals(
+        CLASSNAME + ": after resetting, all bytes are available",
+        TEST_STRING.size(), stream.available());
+
+    skipFully(stream, TEST_STRING.size()); // Skip to the end.
+    assertEquals(
+        CLASSNAME + ": after skipping to the end, no more bytes are available",
+        0, stream.available());
+  }
+
+  /**
+   * Discards {@code n} bytes of data from the input stream. This method
+   * will block until the full amount has been skipped. Does not close the
+   * stream.
+   * <p>Copied from com.google.common.io.ByteStreams to avoid adding dependency.
+   *
+   * @param in the input stream to read from
+   * @param n the number of bytes to skip
+   * @throws EOFException if this stream reaches the end before skipping all
+   *     the bytes
+   * @throws IOException if an I/O error occurs, or the stream does not
+   *     support skipping
+   */
+  static void skipFully(InputStream in, long n) throws IOException {
+    long toSkip = n;
+    while (n > 0) {
+      long amt = in.skip(n);
+      if (amt == 0) {
+        // Force a blocking read to avoid infinite loop
+        if (in.read() == -1) {
+          long skipped = toSkip - n;
+          throw new EOFException("reached end of stream after skipping "
+              + skipped + " bytes; " + toSkip + " bytes expected");
+        }
+        n--;
+      } else {
+        n -= amt;
+      }
+    }
+  }
+
+  public void testAsReadOnlyByteBuffer() {
+    ByteBuffer byteBuffer = TEST_STRING.asReadOnlyByteBuffer();
+    byte[] roundTripBytes = new byte[BYTES.length];
+    assertTrue(byteBuffer.remaining() == BYTES.length);
+    assertTrue(byteBuffer.isReadOnly());
+    byteBuffer.get(roundTripBytes);
+    assertTrue(CLASSNAME + ".asReadOnlyByteBuffer() must give back the same bytes",
+        Arrays.equals(BYTES, roundTripBytes));
+  }
+
+  public void testAsReadOnlyByteBufferList() {
+    List<ByteBuffer> byteBuffers = TEST_STRING.asReadOnlyByteBufferList();
+    int bytesSeen = 0;
+    byte[] roundTripBytes = new byte[BYTES.length];
+    for (ByteBuffer byteBuffer : byteBuffers) {
+      int thisLength = byteBuffer.remaining();
+      assertTrue(byteBuffer.isReadOnly());
+      assertTrue(bytesSeen + thisLength <= BYTES.length);
+      byteBuffer.get(roundTripBytes, bytesSeen, thisLength);
+      bytesSeen += thisLength;
+    }
+    assertTrue(bytesSeen == BYTES.length);
+    assertTrue(CLASSNAME + ".asReadOnlyByteBufferTest() must give back the same bytes",
+        Arrays.equals(BYTES, roundTripBytes));
+  }
+
+  public void testToByteArray() {
+    byte[] roundTripBytes = TEST_STRING.toByteArray();
+    assertTrue(CLASSNAME + ".toByteArray() must give back the same bytes",
+        Arrays.equals(BYTES, roundTripBytes));
+  }
+
+  public void testWriteTo() throws IOException {
+    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+    TEST_STRING.writeTo(bos);
+    byte[] roundTripBytes = bos.toByteArray();
+    assertTrue(CLASSNAME + ".writeTo() must give back the same bytes",
+        Arrays.equals(BYTES, roundTripBytes));
+  }
+
+  public void testNewOutput() throws IOException {
+    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+    ByteString.Output output = ByteString.newOutput();
+    TEST_STRING.writeTo(output);
+    assertEquals("Output Size returns correct result",
+        output.size(), TEST_STRING.size());
+    output.writeTo(bos);
+    assertTrue("Output.writeTo() must give back the same bytes",
+        Arrays.equals(BYTES, bos.toByteArray()));
+
+    // write the output stream to itself! This should cause it to double
+    output.writeTo(output);
+    assertEquals("Writing an output stream to itself is successful",
+        TEST_STRING.concat(TEST_STRING), output.toByteString());
+
+    output.reset();
+    assertEquals("Output.reset() resets the output", 0, output.size());
+    assertEquals("Output.reset() resets the output",
+        EMPTY, output.toByteString());
+  }
+
+  public void testToString() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString unicode = forString(testString);
+    String roundTripString = unicode.toString(UTF_8);
+    assertEquals(CLASSNAME + " unicode must match", testString, roundTripString);
+  }
+
+  public void testCharsetToString() {
+    String testString = "I love unicode \u1234\u5678 characters";
+    ByteString unicode = forString(testString);
+    String roundTripString = unicode.toString(UTF_8);
+    assertEquals(CLASSNAME + " unicode must match", testString, roundTripString);
+  }
+
+  public void testToString_returnsCanonicalEmptyString() {
+    assertSame(CLASSNAME + " must be the same string references",
+        EMPTY.toString(UTF_8),
+        new NioByteString(ByteBuffer.wrap(new byte[0])).toString(UTF_8));
+  }
+
+  public void testToString_raisesException() {
+    try {
+      EMPTY.toString("invalid");
+      fail("Should have thrown an exception.");
+    } catch (UnsupportedEncodingException expected) {
+      // This is success
+    }
+
+    try {
+      TEST_STRING.toString("invalid");
+      fail("Should have thrown an exception.");
+    } catch (UnsupportedEncodingException expected) {
+      // This is success
+    }
+  }
+
+  public void testEquals() {
+    assertEquals(CLASSNAME + " must not equal null", false, TEST_STRING.equals(null));
+    assertEquals(CLASSNAME + " must equal self", TEST_STRING, TEST_STRING);
+    assertFalse(CLASSNAME + " must not equal the empty string",
+        TEST_STRING.equals(EMPTY));
+    assertEquals(CLASSNAME + " empty strings must be equal",
+        EMPTY, TEST_STRING.substring(55, 55));
+    assertEquals(CLASSNAME + " must equal another string with the same value",
+        TEST_STRING, new NioByteString(BUFFER));
+
+    byte[] mungedBytes = mungedBytes();
+    assertFalse(CLASSNAME + " must not equal every string with the same length",
+        TEST_STRING.equals(new NioByteString(ByteBuffer.wrap(mungedBytes))));
+  }
+
+  public void testEqualsLiteralByteString() {
+    ByteString literal = ByteString.copyFrom(BYTES);
+    assertEquals(CLASSNAME + " must equal LiteralByteString with same value", literal,
+        TEST_STRING);
+    assertEquals(CLASSNAME + " must equal LiteralByteString with same value", TEST_STRING,
+        literal);
+    assertFalse(CLASSNAME + " must not equal the empty string",
+        TEST_STRING.equals(ByteString.EMPTY));
+    assertEquals(CLASSNAME + " empty strings must be equal",
+        ByteString.EMPTY, TEST_STRING.substring(55, 55));
+
+    literal = ByteString.copyFrom(mungedBytes());
+    assertFalse(CLASSNAME + " must not equal every LiteralByteString with the same length",
+        TEST_STRING.equals(literal));
+    assertFalse(CLASSNAME + " must not equal every LiteralByteString with the same length",
+        literal.equals(TEST_STRING));
+  }
+
+  public void testEqualsRopeByteString() {
+    ByteString p1 = ByteString.copyFrom(BYTES, 0, 5);
+    ByteString p2 = ByteString.copyFrom(BYTES, 5, BYTES.length - 5);
+    ByteString rope = p1.concat(p2);
+
+    assertEquals(CLASSNAME + " must equal RopeByteString with same value", rope,
+        TEST_STRING);
+    assertEquals(CLASSNAME + " must equal RopeByteString with same value", TEST_STRING,
+        rope);
+    assertFalse(CLASSNAME + " must not equal the empty string",
+        TEST_STRING.equals(ByteString.EMPTY.concat(ByteString.EMPTY)));
+    assertEquals(CLASSNAME + " empty strings must be equal",
+        ByteString.EMPTY.concat(ByteString.EMPTY), TEST_STRING.substring(55, 55));
+
+    byte[] mungedBytes = mungedBytes();
+    p1 = ByteString.copyFrom(mungedBytes, 0, 5);
+    p2 = ByteString.copyFrom(mungedBytes, 5, mungedBytes.length - 5);
+    rope = p1.concat(p2);
+    assertFalse(CLASSNAME + " must not equal every RopeByteString with the same length",
+        TEST_STRING.equals(rope));
+    assertFalse(CLASSNAME + " must not equal every RopeByteString with the same length",
+        rope.equals(TEST_STRING));
+  }
+
+  private byte[] mungedBytes() {
+    byte[] mungedBytes = new byte[BYTES.length];
+    System.arraycopy(BYTES, 0, mungedBytes, 0, BYTES.length);
+    mungedBytes[mungedBytes.length - 5] = (byte) (mungedBytes[mungedBytes.length - 5] ^ 0xFF);
+    return mungedBytes;
+  }
+
+  public void testHashCode() {
+    int hash = TEST_STRING.hashCode();
+    assertEquals(CLASSNAME + " must have expected hashCode", EXPECTED_HASH, hash);
+  }
+
+  public void testPeekCachedHashCode() {
+    ByteString newString = new NioByteString(BUFFER);
+    assertEquals(CLASSNAME + ".peekCachedHashCode() should return zero at first", 0,
+        newString.peekCachedHashCode());
+    newString.hashCode();
+    assertEquals(CLASSNAME + ".peekCachedHashCode should return zero at first",
+        EXPECTED_HASH, newString.peekCachedHashCode());
+  }
+
+  public void testPartialHash() {
+    // partialHash() is more strenuously tested elsewhere by testing hashes of substrings.
+    // This test would fail if the expected hash were 1.  It's not.
+    int hash = TEST_STRING.partialHash(TEST_STRING.size(), 0, TEST_STRING.size());
+    assertEquals(CLASSNAME + ".partialHash() must yield expected hashCode",
+        EXPECTED_HASH, hash);
+  }
+
+  public void testNewInput() throws IOException {
+    InputStream input = TEST_STRING.newInput();
+    assertEquals("InputStream.available() returns correct value",
+        TEST_STRING.size(), input.available());
+    boolean stillEqual = true;
+    for (byte referenceByte : BYTES) {
+      int expectedInt = (referenceByte & 0xFF);
+      stillEqual = (expectedInt == input.read());
+    }
+    assertEquals("InputStream.available() returns correct value",
+        0, input.available());
+    assertTrue(CLASSNAME + " must give the same bytes from the InputStream", stillEqual);
+    assertEquals(CLASSNAME + " InputStream must now be exhausted", -1, input.read());
+  }
+
+  public void testNewInput_skip() throws IOException {
+    InputStream input = TEST_STRING.newInput();
+    int stringSize = TEST_STRING.size();
+    int nearEndIndex = stringSize * 2 / 3;
+    long skipped1 = input.skip(nearEndIndex);
+    assertEquals("InputStream.skip()", skipped1, nearEndIndex);
+    assertEquals("InputStream.available()",
+        stringSize - skipped1, input.available());
+    assertTrue("InputStream.mark() is available", input.markSupported());
+    input.mark(0);
+    assertEquals("InputStream.skip(), read()",
+        TEST_STRING.byteAt(nearEndIndex) & 0xFF, input.read());
+    assertEquals("InputStream.available()",
+        stringSize - skipped1 - 1, input.available());
+    long skipped2 = input.skip(stringSize);
+    assertEquals("InputStream.skip() incomplete",
+        skipped2, stringSize - skipped1 - 1);
+    assertEquals("InputStream.skip(), no more input", 0, input.available());
+    assertEquals("InputStream.skip(), no more input", -1, input.read());
+    input.reset();
+    assertEquals("InputStream.reset() succeded",
+        stringSize - skipped1, input.available());
+    assertEquals("InputStream.reset(), read()",
+        TEST_STRING.byteAt(nearEndIndex) & 0xFF, input.read());
+  }
+
+  public void testNewCodedInput() throws IOException {
+    CodedInputStream cis = TEST_STRING.newCodedInput();
+    byte[] roundTripBytes = cis.readRawBytes(BYTES.length);
+    assertTrue(CLASSNAME + " must give the same bytes back from the CodedInputStream",
+        Arrays.equals(BYTES, roundTripBytes));
+    assertTrue(CLASSNAME + " CodedInputStream must now be exhausted", cis.isAtEnd());
+  }
+
+  /**
+   * Make sure we keep things simple when concatenating with empty. See also
+   * {@link ByteStringTest#testConcat_empty()}.
+   */
+  public void testConcat_empty() {
+    assertSame(CLASSNAME + " concatenated with empty must give " + CLASSNAME,
+        TEST_STRING.concat(EMPTY), TEST_STRING);
+    assertSame("empty concatenated with " + CLASSNAME + " must give " + CLASSNAME,
+        EMPTY.concat(TEST_STRING), TEST_STRING);
+  }
+
+  public void testJavaSerialization() throws Exception {
+    ByteArrayOutputStream out = new ByteArrayOutputStream();
+    ObjectOutputStream oos = new ObjectOutputStream(out);
+    oos.writeObject(TEST_STRING);
+    oos.close();
+    byte[] pickled = out.toByteArray();
+    InputStream in = new ByteArrayInputStream(pickled);
+    ObjectInputStream ois = new ObjectInputStream(in);
+    Object o = ois.readObject();
+    assertTrue("Didn't get a ByteString back", o instanceof ByteString);
+    assertEquals("Should get an equal ByteString back", TEST_STRING, o);
+  }
+
+  private static ByteString forString(String str) {
+    return new NioByteString(ByteBuffer.wrap(str.getBytes(UTF_8)));
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java b/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java
new file mode 100644
index 00000000..03593413
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java
@@ -0,0 +1,212 @@
+package com.google.protobuf;
+
+import com.google.protobuf.DescriptorProtos.DescriptorProto;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+/**
+ * Tests the exceptions thrown when parsing from a stream. The methods on the {@link Parser}
+ * interface are specified to only throw {@link InvalidProtocolBufferException}. But we really want
+ * to distinguish between invalid protos vs. actual I/O errors (like failures reading from a
+ * socket, etc.). So, when we're not using the parser directly, an {@link IOException} should be
+ * thrown where appropriate, instead of always an {@link InvalidProtocolBufferException}.
+ *
+ * @author jh@squareup.com (Joshua Humphries)
+ */
+public class ParseExceptionsTest {
+
+// disable for now for update the maven local repo.
+//   private interface ParseTester {
+//     DescriptorProto parse(InputStream in) throws IOException;
+//   }
+// 
+//   private byte serializedProto[];
+// 
+//   private void setup() {
+//     serializedProto = DescriptorProto.getDescriptor().toProto().toByteArray();
+//   }
+// 
+//   private void setupDelimited() {
+//     ByteArrayOutputStream bos = new ByteArrayOutputStream();
+//     try {
+//       DescriptorProto.getDescriptor().toProto().writeDelimitedTo(bos);
+//     } catch (IOException e) {
+//       fail("Exception not expected: " + e);
+//     }
+//     serializedProto = bos.toByteArray();
+//   }
+// 
+//   @Test public void message_parseFrom_InputStream() {
+//     setup();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.parseFrom(in);
+//       }
+//     });
+//   }
+// 
+//   @Test public void message_parseFrom_InputStreamAndExtensionRegistry() {
+//     setup();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.parseFrom(in, ExtensionRegistry.newInstance());
+//       }
+//     });
+//   }
+// 
+//   @Test public void message_parseFrom_CodedInputStream() {
+//     setup();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.parseFrom(CodedInputStream.newInstance(in));
+//       }
+//     });
+//   }
+// 
+//   @Test public void message_parseFrom_CodedInputStreamAndExtensionRegistry() {
+//     setup();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.parseFrom(CodedInputStream.newInstance(in),
+//             ExtensionRegistry.newInstance());
+//       }
+//     });
+//   }
+// 
+//   @Test public void message_parseDelimitedFrom_InputStream() {
+//     setupDelimited();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.parseDelimitedFrom(in);
+//       }
+//     });
+//   }
+// 
+//   @Test public void message_parseDelimitedFrom_InputStreamAndExtensionRegistry() {
+//     setupDelimited();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.parseDelimitedFrom(in, ExtensionRegistry.newInstance());
+//       }
+//     });
+//   }
+// 
+//   @Test public void messageBuilder_mergeFrom_InputStream() {
+//     setup();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.newBuilder().mergeFrom(in).build();
+//       }
+//     });
+//   }
+// 
+//   @Test public void messageBuilder_mergeFrom_InputStreamAndExtensionRegistry() {
+//     setup();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.newBuilder().mergeFrom(in, ExtensionRegistry.newInstance()).build();
+//       }
+//     });
+//   }
+// 
+//   @Test public void messageBuilder_mergeFrom_CodedInputStream() {
+//     setup();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.newBuilder().mergeFrom(CodedInputStream.newInstance(in)).build();
+//       }
+//     });
+//   }
+// 
+//   @Test public void messageBuilder_mergeFrom_CodedInputStreamAndExtensionRegistry() {
+//     setup();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         return DescriptorProto.newBuilder()
+//             .mergeFrom(CodedInputStream.newInstance(in), ExtensionRegistry.newInstance()).build();
+//       }
+//     });
+//   }
+// 
+//   @Test public void messageBuilder_mergeDelimitedFrom_InputStream() {
+//     setupDelimited();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         DescriptorProto.Builder builder = DescriptorProto.newBuilder();
+//         builder.mergeDelimitedFrom(in);
+//         return builder.build();
+//       }
+//     });
+//   }
+// 
+//   @Test public void messageBuilder_mergeDelimitedFrom_InputStreamAndExtensionRegistry() {
+//     setupDelimited();
+//     verifyExceptions(new ParseTester() {
+//       public DescriptorProto parse(InputStream in) throws IOException {
+//         DescriptorProto.Builder builder = DescriptorProto.newBuilder();
+//         builder.mergeDelimitedFrom(in, ExtensionRegistry.newInstance());
+//         return builder.build();
+//       }
+//     });
+//   }
+// 
+//   private void verifyExceptions(ParseTester parseTester) {
+//     // No exception
+//     try {
+//       assertEquals(DescriptorProto.getDescriptor().toProto(),
+//           parseTester.parse(new ByteArrayInputStream(serializedProto)));
+//     } catch (IOException e) {
+//       fail("No exception expected: " + e);
+//     }
+// 
+//     // IOException
+//     try {
+//       // using a "broken" stream that will throw part-way through reading the message
+//       parseTester.parse(broken(new ByteArrayInputStream(serializedProto)));
+//       fail("IOException expected but not thrown");
+//     } catch (IOException e) {
+//       assertFalse(e instanceof InvalidProtocolBufferException);
+//     }
+// 
+//     // InvalidProtocolBufferException
+//     try {
+//       // make the serialized proto invalid
+//       for (int i = 0; i < 50; i++) {
+//         serializedProto[i] = -1;
+//       }
+//       parseTester.parse(new ByteArrayInputStream(serializedProto));
+//       fail("InvalidProtocolBufferException expected but not thrown");
+//     } catch (IOException e) {
+//       assertTrue(e instanceof InvalidProtocolBufferException);
+//     }
+//   }
+// 
+//   private InputStream broken(InputStream i) {
+//     return new FilterInputStream(i) {
+//       int count = 0;
+// 
+//       @Override public int read() throws IOException {
+//         if (count++ >= 50) {
+//           throw new IOException("I'm broken!");
+//         }
+//         return super.read();
+//       }
+// 
+//       @Override public int read(byte b[], int off, int len) throws IOException {
+//         if ((count += len) >= 50) {
+//           throw new IOException("I'm broken!");
+//         }
+//         return super.read(b, off, len);
+//       }
+//     };
+//   }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/ParserTest.java b/java/core/src/test/java/com/google/protobuf/ParserTest.java
new file mode 100644
index 00000000..5a92bacf
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ParserTest.java
@@ -0,0 +1,377 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.UnittestLite.TestAllTypesLite;
+import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
+import com.google.protobuf.UnittestLite.TestParsingMergeLite;
+import protobuf_unittest.UnittestOptimizeFor.TestOptimizedForSize;
+import protobuf_unittest.UnittestOptimizeFor.TestRequiredOptimizedForSize;
+import protobuf_unittest.UnittestOptimizeFor;
+import protobuf_unittest.UnittestProto.ForeignMessage;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestEmptyMessage;
+import protobuf_unittest.UnittestProto.TestParsingMerge;
+import protobuf_unittest.UnittestProto.TestRequired;
+import protobuf_unittest.UnittestProto;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Unit test for {@link Parser}.
+ *
+ * @author liujisi@google.com (Pherl Liu)
+ */
+public class ParserTest extends TestCase {
+  public void testGeneratedMessageParserSingleton() throws Exception {
+    for (int i = 0; i < 10; i++) {
+      assertEquals(TestAllTypes.parser(), TestUtil.getAllSet().getParserForType());
+    }
+  }
+
+  private void assertRoundTripEquals(MessageLite message,
+                                     ExtensionRegistryLite registry)
+      throws Exception {
+    final byte[] data = message.toByteArray();
+    final int offset = 20;
+    final int length = data.length;
+    final int padding = 30;
+    Parser<? extends MessageLite> parser = message.getParserForType();
+    assertMessageEquals(message, parser.parseFrom(data, registry));
+    assertMessageEquals(message, parser.parseFrom(
+        generatePaddingArray(data, offset, padding),
+        offset, length, registry));
+    assertMessageEquals(message, parser.parseFrom(
+        message.toByteString(), registry));
+    assertMessageEquals(message, parser.parseFrom(
+        new ByteArrayInputStream(data), registry));
+    assertMessageEquals(message, parser.parseFrom(
+        CodedInputStream.newInstance(data), registry));
+  }
+
+  @SuppressWarnings("unchecked")
+  private void assertRoundTripEquals(MessageLite message) throws Exception {
+    final byte[] data = message.toByteArray();
+    final int offset = 20;
+    final int length = data.length;
+    final int padding = 30;
+
+    Parser<MessageLite> parser =
+        (Parser<MessageLite>) message.getParserForType();
+    assertMessageEquals(message, parser.parseFrom(data));
+    assertMessageEquals(message, parser.parseFrom(
+        generatePaddingArray(data, offset, padding),
+        offset, length));
+    assertMessageEquals(message, parser.parseFrom(message.toByteString()));
+    assertMessageEquals(message, parser.parseFrom(
+        new ByteArrayInputStream(data)));
+    assertMessageEquals(message, parser.parseFrom(
+        CodedInputStream.newInstance(data)));
+  }
+
+  private void assertMessageEquals(
+      MessageLite expected, MessageLite actual)
+      throws Exception {
+    if (expected instanceof Message) {
+      assertEquals(expected, actual);
+    } else {
+      assertEquals(expected.toByteString(), actual.toByteString());
+    }
+  }
+
+  private byte[] generatePaddingArray(byte[] data, int offset, int padding) {
+    byte[] result = new byte[offset + data.length + padding];
+    System.arraycopy(data, 0, result, offset, data.length);
+    return result;
+  }
+
+  public void testNormalMessage() throws Exception {
+    assertRoundTripEquals(TestUtil.getAllSet());
+  }
+
+
+  public void testParsePartial() throws Exception {
+    assertParsePartial(TestRequired.parser(), TestRequired.newBuilder().setA(1).buildPartial());
+  }
+
+  private <T extends MessageLite> void assertParsePartial(
+      Parser<T> parser, T partialMessage) throws Exception {
+    final String errorString =
+        "Should throw exceptions when the parsed message isn't initialized.";
+
+    // parsePartialFrom should pass.
+    byte[] data = partialMessage.toByteArray();
+    assertEquals(partialMessage, parser.parsePartialFrom(data));
+    assertEquals(partialMessage, parser.parsePartialFrom(
+        partialMessage.toByteString()));
+    assertEquals(partialMessage, parser.parsePartialFrom(
+        new ByteArrayInputStream(data)));
+    assertEquals(partialMessage, parser.parsePartialFrom(
+        CodedInputStream.newInstance(data)));
+
+    // parseFrom(ByteArray)
+    try {
+      parser.parseFrom(partialMessage.toByteArray());
+      fail(errorString);
+    } catch (InvalidProtocolBufferException e) {
+      // pass.
+    }
+
+    // parseFrom(ByteString)
+    try {
+      parser.parseFrom(partialMessage.toByteString());
+      fail(errorString);
+    } catch (InvalidProtocolBufferException e) {
+      // pass.
+    }
+
+    // parseFrom(InputStream)
+    try {
+      parser.parseFrom(new ByteArrayInputStream(partialMessage.toByteArray()));
+      fail(errorString);
+    } catch (IOException e) {
+      // pass.
+    }
+
+    // parseFrom(CodedInputStream)
+    try {
+      parser.parseFrom(CodedInputStream.newInstance(
+          partialMessage.toByteArray()));
+      fail(errorString);
+    } catch (IOException e) {
+      // pass.
+    }
+  }
+
+  public void testParseExtensions() throws Exception {
+    assertRoundTripEquals(TestUtil.getAllExtensionsSet(),
+                          TestUtil.getExtensionRegistry());
+    assertRoundTripEquals(TestUtil.getAllLiteExtensionsSet(),
+                          TestUtil.getExtensionRegistryLite());
+  }
+
+  public void testParsePacked() throws Exception {
+    assertRoundTripEquals(TestUtil.getPackedSet());
+    assertRoundTripEquals(TestUtil.getPackedExtensionsSet(),
+                          TestUtil.getExtensionRegistry());
+    assertRoundTripEquals(TestUtil.getLitePackedExtensionsSet(),
+                          TestUtil.getExtensionRegistryLite());
+  }
+
+  public void testParseDelimitedTo() throws Exception {
+    // Write normal Message.
+    TestAllTypes normalMessage = TestUtil.getAllSet();
+    ByteArrayOutputStream output = new ByteArrayOutputStream();
+    normalMessage.writeDelimitedTo(output);
+
+    // Write MessageLite with packed extension fields.
+    TestPackedExtensionsLite packedMessage =
+        TestUtil.getLitePackedExtensionsSet();
+    packedMessage.writeDelimitedTo(output);
+
+    InputStream input = new ByteArrayInputStream(output.toByteArray());
+    assertMessageEquals(
+        normalMessage,
+        normalMessage.getParserForType().parseDelimitedFrom(input));
+    assertMessageEquals(
+        packedMessage,
+        packedMessage.getParserForType().parseDelimitedFrom(
+            input, TestUtil.getExtensionRegistryLite()));
+  }
+
+  public void testParseUnknownFields() throws Exception {
+    // All fields will be treated as unknown fields in emptyMessage.
+    TestEmptyMessage emptyMessage =
+        TestEmptyMessage.parser().parseFrom(TestUtil.getAllSet().toByteString());
+    assertEquals(
+        TestUtil.getAllSet().toByteString(),
+        emptyMessage.toByteString());
+  }
+
+
+  public void testOptimizeForSize() throws Exception {
+    TestOptimizedForSize.Builder builder = TestOptimizedForSize.newBuilder();
+    builder.setI(12).setMsg(ForeignMessage.newBuilder().setC(34).build());
+    builder.setExtension(TestOptimizedForSize.testExtension, 56);
+    builder.setExtension(TestOptimizedForSize.testExtension2,
+        TestRequiredOptimizedForSize.newBuilder().setX(78).build());
+
+    TestOptimizedForSize message = builder.build();
+    ExtensionRegistry registry = ExtensionRegistry.newInstance();
+    UnittestOptimizeFor.registerAllExtensions(registry);
+
+    assertRoundTripEquals(message, registry);
+  }
+
+  /** Helper method for {@link #testParsingMerge()}.*/
+  private void assertMessageMerged(TestAllTypes allTypes)
+      throws Exception {
+    assertEquals(3, allTypes.getOptionalInt32());
+    assertEquals(2, allTypes.getOptionalInt64());
+    assertEquals("hello", allTypes.getOptionalString());
+  }
+
+  /** Helper method for {@link #testParsingMergeLite()}.*/
+  private void assertMessageMerged(TestAllTypesLite allTypes)
+      throws Exception {
+    assertEquals(3, allTypes.getOptionalInt32());
+    assertEquals(2, allTypes.getOptionalInt64());
+    assertEquals("hello", allTypes.getOptionalString());
+  }
+
+  public void testParsingMerge() throws Exception {
+    // Build messages.
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TestAllTypes msg1 = builder.setOptionalInt32(1).build();
+    builder.clear();
+    TestAllTypes msg2 = builder.setOptionalInt64(2).build();
+    builder.clear();
+    TestAllTypes msg3 = builder.setOptionalInt32(3)
+        .setOptionalString("hello").build();
+
+    // Build groups.
+    TestParsingMerge.RepeatedFieldsGenerator.Group1 optionalG1 =
+        TestParsingMerge.RepeatedFieldsGenerator.Group1.newBuilder()
+        .setField1(msg1).build();
+    TestParsingMerge.RepeatedFieldsGenerator.Group1 optionalG2 =
+        TestParsingMerge.RepeatedFieldsGenerator.Group1.newBuilder()
+        .setField1(msg2).build();
+    TestParsingMerge.RepeatedFieldsGenerator.Group1 optionalG3 =
+        TestParsingMerge.RepeatedFieldsGenerator.Group1.newBuilder()
+        .setField1(msg3).build();
+    TestParsingMerge.RepeatedFieldsGenerator.Group2 repeatedG1 =
+        TestParsingMerge.RepeatedFieldsGenerator.Group2.newBuilder()
+        .setField1(msg1).build();
+    TestParsingMerge.RepeatedFieldsGenerator.Group2 repeatedG2 =
+        TestParsingMerge.RepeatedFieldsGenerator.Group2.newBuilder()
+        .setField1(msg2).build();
+    TestParsingMerge.RepeatedFieldsGenerator.Group2 repeatedG3 =
+        TestParsingMerge.RepeatedFieldsGenerator.Group2.newBuilder()
+        .setField1(msg3).build();
+
+    // Assign and serialize RepeatedFieldsGenerator.
+    ByteString data = TestParsingMerge.RepeatedFieldsGenerator.newBuilder()
+        .addField1(msg1).addField1(msg2).addField1(msg3)
+        .addField2(msg1).addField2(msg2).addField2(msg3)
+        .addField3(msg1).addField3(msg2).addField3(msg3)
+        .addGroup1(optionalG1).addGroup1(optionalG2).addGroup1(optionalG3)
+        .addGroup2(repeatedG1).addGroup2(repeatedG2).addGroup2(repeatedG3)
+        .addExt1(msg1).addExt1(msg2).addExt1(msg3)
+        .addExt2(msg1).addExt2(msg2).addExt2(msg3)
+        .build().toByteString();
+
+    // Parse TestParsingMerge.
+    ExtensionRegistry registry = ExtensionRegistry.newInstance();
+    UnittestProto.registerAllExtensions(registry);
+    TestParsingMerge parsingMerge = TestParsingMerge.parser().parseFrom(data, registry);
+
+    // Required and optional fields should be merged.
+    assertMessageMerged(parsingMerge.getRequiredAllTypes());
+    assertMessageMerged(parsingMerge.getOptionalAllTypes());
+    assertMessageMerged(
+        parsingMerge.getOptionalGroup().getOptionalGroupAllTypes());
+    assertMessageMerged(parsingMerge.getExtension(
+        TestParsingMerge.optionalExt));
+
+    // Repeated fields should not be merged.
+    assertEquals(3, parsingMerge.getRepeatedAllTypesCount());
+    assertEquals(3, parsingMerge.getRepeatedGroupCount());
+    assertEquals(3, parsingMerge.getExtensionCount(
+        TestParsingMerge.repeatedExt));
+  }
+
+  public void testParsingMergeLite() throws Exception {
+    // Build messages.
+    TestAllTypesLite.Builder builder =
+        TestAllTypesLite.newBuilder();
+    TestAllTypesLite msg1 = builder.setOptionalInt32(1).build();
+    builder.clear();
+    TestAllTypesLite msg2 = builder.setOptionalInt64(2).build();
+    builder.clear();
+    TestAllTypesLite msg3 = builder.setOptionalInt32(3)
+        .setOptionalString("hello").build();
+
+    // Build groups.
+    TestParsingMergeLite.RepeatedFieldsGenerator.Group1 optionalG1 =
+        TestParsingMergeLite.RepeatedFieldsGenerator.Group1.newBuilder()
+        .setField1(msg1).build();
+    TestParsingMergeLite.RepeatedFieldsGenerator.Group1 optionalG2 =
+        TestParsingMergeLite.RepeatedFieldsGenerator.Group1.newBuilder()
+        .setField1(msg2).build();
+    TestParsingMergeLite.RepeatedFieldsGenerator.Group1 optionalG3 =
+        TestParsingMergeLite.RepeatedFieldsGenerator.Group1.newBuilder()
+        .setField1(msg3).build();
+    TestParsingMergeLite.RepeatedFieldsGenerator.Group2 repeatedG1 =
+        TestParsingMergeLite.RepeatedFieldsGenerator.Group2.newBuilder()
+        .setField1(msg1).build();
+    TestParsingMergeLite.RepeatedFieldsGenerator.Group2 repeatedG2 =
+        TestParsingMergeLite.RepeatedFieldsGenerator.Group2.newBuilder()
+        .setField1(msg2).build();
+    TestParsingMergeLite.RepeatedFieldsGenerator.Group2 repeatedG3 =
+        TestParsingMergeLite.RepeatedFieldsGenerator.Group2.newBuilder()
+        .setField1(msg3).build();
+
+    // Assign and serialize RepeatedFieldsGenerator.
+    ByteString data = TestParsingMergeLite.RepeatedFieldsGenerator.newBuilder()
+        .addField1(msg1).addField1(msg2).addField1(msg3)
+        .addField2(msg1).addField2(msg2).addField2(msg3)
+        .addField3(msg1).addField3(msg2).addField3(msg3)
+        .addGroup1(optionalG1).addGroup1(optionalG2).addGroup1(optionalG3)
+        .addGroup2(repeatedG1).addGroup2(repeatedG2).addGroup2(repeatedG3)
+        .addExt1(msg1).addExt1(msg2).addExt1(msg3)
+        .addExt2(msg1).addExt2(msg2).addExt2(msg3)
+        .build().toByteString();
+
+    // Parse TestParsingMergeLite.
+    ExtensionRegistry registry = ExtensionRegistry.newInstance();
+    UnittestLite.registerAllExtensions(registry);
+    TestParsingMergeLite parsingMerge = TestParsingMergeLite.parser().parseFrom(data, registry);
+
+    // Required and optional fields should be merged.
+    assertMessageMerged(parsingMerge.getRequiredAllTypes());
+    assertMessageMerged(parsingMerge.getOptionalAllTypes());
+    assertMessageMerged(
+        parsingMerge.getOptionalGroup().getOptionalGroupAllTypes());
+    assertMessageMerged(parsingMerge.getExtension(
+        TestParsingMergeLite.optionalExt));
+
+    // Repeated fields should not be merged.
+    assertEquals(3, parsingMerge.getRepeatedAllTypesCount());
+    assertEquals(3, parsingMerge.getRepeatedGroupCount());
+    assertEquals(3, parsingMerge.getExtensionCount(
+        TestParsingMergeLite.repeatedExt));
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/ProtobufArrayListTest.java b/java/core/src/test/java/com/google/protobuf/ProtobufArrayListTest.java
new file mode 100644
index 00000000..245c3dee
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ProtobufArrayListTest.java
@@ -0,0 +1,303 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import static java.util.Arrays.asList;
+
+import junit.framework.TestCase;
+
+import java.util.Collections;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * Tests for {@link ProtobufArrayList}.
+ */
+public class ProtobufArrayListTest extends TestCase {
+  
+  private static final ProtobufArrayList<Integer> UNARY_LIST = newImmutableProtoArrayList(1);
+  private static final ProtobufArrayList<Integer> TERTIARY_LIST =
+      newImmutableProtoArrayList(1, 2, 3);
+  
+  private ProtobufArrayList<Integer> list;
+  
+  @Override
+  protected void setUp() throws Exception {
+    list = new ProtobufArrayList<Integer>();
+  }
+  
+  public void testEmptyListReturnsSameInstance() {
+    assertSame(ProtobufArrayList.emptyList(), ProtobufArrayList.emptyList());
+  }
+  
+  public void testEmptyListIsImmutable() {
+    assertImmutable(ProtobufArrayList.<Integer>emptyList());
+  }
+  
+  public void testCopyConstructor() {
+    ProtobufArrayList<Integer> copy = new ProtobufArrayList<Integer>(TERTIARY_LIST);
+    assertEquals(TERTIARY_LIST, copy);
+
+    copy = new ProtobufArrayList<Integer>(IntArrayList.emptyList());
+    assertEquals(ProtobufArrayList.emptyList(), copy);
+    
+    copy = new ProtobufArrayList<Integer>(asList(1, 2, 3));
+    assertEquals(asList(1, 2, 3), copy);
+
+    copy = new ProtobufArrayList<Integer>(Collections.<Integer>emptyList());
+    assertEquals(ProtobufArrayList.emptyList(), copy);
+  }
+  
+  public void testModificationWithIteration() {
+    list.addAll(asList(1, 2, 3, 4));
+    Iterator<Integer> iterator = list.iterator();
+    assertEquals(4, list.size());
+    assertEquals(1, (int) list.get(0));
+    assertEquals(1, (int) iterator.next());
+    
+    list.remove(0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+    
+    iterator = list.iterator();
+    list.set(0, 1);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+    
+    iterator = list.iterator();
+    list.add(0, 0);
+    try {
+      iterator.next();
+      fail();
+    } catch (ConcurrentModificationException e) {
+      // expected
+    }
+  }
+  
+  public void testMakeImmutable() {
+    list.add(2);
+    list.add(4);
+    list.add(6);
+    list.add(8);
+    list.makeImmutable();
+    assertImmutable(list);
+  }
+  
+  public void testRemove() {
+    list.add(2);
+    list.add(4);
+    list.add(6);
+
+    list.remove(1);
+    assertEquals(asList(2, 6), list);
+
+    list.remove(1);
+    assertEquals(asList(2), list);
+
+    list.remove(0);
+    assertEquals(asList(), list);
+  }
+  
+  public void testGet() {
+    list.add(2);
+    list.add(6);
+    
+    assertEquals(2, (int) list.get(0));
+    assertEquals(6, (int) list.get(1));
+  }
+  
+  public void testSet() {
+    list.add(2);
+    list.add(6);
+    
+    list.set(0, 1);
+    assertEquals(1, (int) list.get(0));
+    list.set(1, 2);
+    assertEquals(2, (int) list.get(1));
+  }
+
+  private void assertImmutable(List<Integer> list) {
+    if (list.contains(1)) {
+      throw new RuntimeException("Cannot test the immutability of lists that contain 1.");
+    }
+    
+    try {
+      list.add(1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.add(0, 1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.<Integer>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(Collections.singletonList(1));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(new ProtobufArrayList<Integer>());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.singleton(1));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.addAll(0, Collections.<Integer>emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    } 
+
+    try {
+      list.clear();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+
+    try {
+      list.remove(1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.remove(new Object());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(Collections.singleton(1));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.removeAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.emptyList());
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(Collections.singleton(1));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.retainAll(UNARY_LIST);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    
+    try {
+      list.set(0, 0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+  }
+  
+  private static ProtobufArrayList<Integer> newImmutableProtoArrayList(int... elements) {
+    ProtobufArrayList<Integer> list = new ProtobufArrayList<Integer>();
+    for (int element : elements) {
+      list.add(element);
+    }
+    list.makeImmutable();
+    return list;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java b/java/core/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java
new file mode 100644
index 00000000..49d52321
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java
@@ -0,0 +1,190 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestAllTypesOrBuilder;
+
+import junit.framework.TestCase;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Tests for {@link RepeatedFieldBuilder}. This tests basic functionality.
+ * More extensive testing is provided via other tests that exercise the
+ * builder.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ */
+public class RepeatedFieldBuilderTest extends TestCase {
+
+  public void testBasicUse() {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+    RepeatedFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder> builder = newRepeatedFieldBuilder(mockParent);
+    builder.addMessage(TestAllTypes.newBuilder().setOptionalInt32(0).build());
+    builder.addMessage(TestAllTypes.newBuilder().setOptionalInt32(1).build());
+    assertEquals(0, builder.getMessage(0).getOptionalInt32());
+    assertEquals(1, builder.getMessage(1).getOptionalInt32());
+
+    List<TestAllTypes> list = builder.build();
+    assertEquals(2, list.size());
+    assertEquals(0, list.get(0).getOptionalInt32());
+    assertEquals(1, list.get(1).getOptionalInt32());
+    assertIsUnmodifiable(list);
+
+    // Make sure it doesn't change.
+    List<TestAllTypes> list2 = builder.build();
+    assertSame(list, list2);
+    assertEquals(0, mockParent.getInvalidationCount());
+  }
+
+  public void testGoingBackAndForth() {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+    RepeatedFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder> builder = newRepeatedFieldBuilder(mockParent);
+    builder.addMessage(TestAllTypes.newBuilder().setOptionalInt32(0).build());
+    builder.addMessage(TestAllTypes.newBuilder().setOptionalInt32(1).build());
+    assertEquals(0, builder.getMessage(0).getOptionalInt32());
+    assertEquals(1, builder.getMessage(1).getOptionalInt32());
+
+    // Convert to list
+    List<TestAllTypes> list = builder.build();
+    assertEquals(2, list.size());
+    assertEquals(0, list.get(0).getOptionalInt32());
+    assertEquals(1, list.get(1).getOptionalInt32());
+    assertIsUnmodifiable(list);
+
+    // Update 0th item
+    assertEquals(0, mockParent.getInvalidationCount());
+    builder.getBuilder(0).setOptionalString("foo");
+    assertEquals(1, mockParent.getInvalidationCount());
+    list = builder.build();
+    assertEquals(2, list.size());
+    assertEquals(0, list.get(0).getOptionalInt32());
+      assertEquals("foo", list.get(0).getOptionalString());
+    assertEquals(1, list.get(1).getOptionalInt32());
+    assertIsUnmodifiable(list);
+    assertEquals(1, mockParent.getInvalidationCount());
+  }
+
+  public void testVariousMethods() {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+    RepeatedFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder> builder = newRepeatedFieldBuilder(mockParent);
+    builder.addMessage(TestAllTypes.newBuilder().setOptionalInt32(1).build());
+    builder.addMessage(TestAllTypes.newBuilder().setOptionalInt32(2).build());
+    builder.addBuilder(0, TestAllTypes.getDefaultInstance())
+        .setOptionalInt32(0);
+    builder.addBuilder(TestAllTypes.getDefaultInstance()).setOptionalInt32(3);
+
+    assertEquals(0, builder.getMessage(0).getOptionalInt32());
+    assertEquals(1, builder.getMessage(1).getOptionalInt32());
+    assertEquals(2, builder.getMessage(2).getOptionalInt32());
+    assertEquals(3, builder.getMessage(3).getOptionalInt32());
+
+    assertEquals(0, mockParent.getInvalidationCount());
+    List<TestAllTypes> messages = builder.build();
+    assertEquals(4, messages.size());
+    assertSame(messages, builder.build()); // expect same list
+
+    // Remove a message.
+    builder.remove(2);
+    assertEquals(1, mockParent.getInvalidationCount());
+    assertEquals(3, builder.getCount());
+    assertEquals(0, builder.getMessage(0).getOptionalInt32());
+    assertEquals(1, builder.getMessage(1).getOptionalInt32());
+    assertEquals(3, builder.getMessage(2).getOptionalInt32());
+
+    // Remove a builder.
+    builder.remove(0);
+    assertEquals(1, mockParent.getInvalidationCount());
+    assertEquals(2, builder.getCount());
+    assertEquals(1, builder.getMessage(0).getOptionalInt32());
+    assertEquals(3, builder.getMessage(1).getOptionalInt32());
+
+    // Test clear.
+    builder.clear();
+    assertEquals(1, mockParent.getInvalidationCount());
+    assertEquals(0, builder.getCount());
+    assertTrue(builder.isEmpty());
+  }
+
+  public void testLists() {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+    RepeatedFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder> builder = newRepeatedFieldBuilder(mockParent);
+    builder.addMessage(TestAllTypes.newBuilder().setOptionalInt32(1).build());
+    builder.addMessage(0,
+        TestAllTypes.newBuilder().setOptionalInt32(0).build());
+    assertEquals(0, builder.getMessage(0).getOptionalInt32());
+    assertEquals(1, builder.getMessage(1).getOptionalInt32());
+
+    // Use list of builders.
+    List<TestAllTypes.Builder> builders = builder.getBuilderList();
+    assertEquals(0, builders.get(0).getOptionalInt32());
+    assertEquals(1, builders.get(1).getOptionalInt32());
+    builders.get(0).setOptionalInt32(10);
+    builders.get(1).setOptionalInt32(11);
+
+    // Use list of protos
+    List<TestAllTypes> protos = builder.getMessageList();
+    assertEquals(10, protos.get(0).getOptionalInt32());
+    assertEquals(11, protos.get(1).getOptionalInt32());
+
+    // Add an item to the builders and verify it's updated in both
+    builder.addMessage(TestAllTypes.newBuilder().setOptionalInt32(12).build());
+    assertEquals(3, builders.size());
+    assertEquals(3, protos.size());
+  }
+
+  private void assertIsUnmodifiable(List<?> list) {
+    if (list == Collections.emptyList()) {
+      // OKAY -- Need to check this b/c EmptyList allows you to call clear.
+    } else {
+      try {
+        list.clear();
+        fail("List wasn't immutable");
+      } catch (UnsupportedOperationException e) {
+        // good
+      }
+    }
+  }
+
+  private RepeatedFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+      TestAllTypesOrBuilder>
+      newRepeatedFieldBuilder(GeneratedMessage.BuilderParent parent) {
+    return new RepeatedFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder>(Collections.<TestAllTypes>emptyList(), false,
+        parent, false);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java b/java/core/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java
new file mode 100644
index 00000000..dc56f2e9
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java
@@ -0,0 +1,127 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.io.UnsupportedEncodingException;
+import java.util.Iterator;
+
+/**
+ * This class tests {@link RopeByteString#substring(int, int)} by inheriting the tests from
+ * {@link LiteralByteStringTest}.  Only a couple of methods are overridden.
+ *
+ * @author carlanton@google.com (Carl Haverl)
+ */
+public class RopeByteStringSubstringTest extends LiteralByteStringTest {
+
+  @Override
+  protected void setUp() throws Exception {
+    classUnderTest = "RopeByteString";
+    byte[] sourceBytes = ByteStringTest.getTestBytes(22341, 22337766L);
+    Iterator<ByteString> iter = ByteStringTest.makeConcretePieces(sourceBytes).iterator();
+    ByteString sourceString = iter.next();
+    while (iter.hasNext()) {
+      sourceString = sourceString.concat(iter.next());
+    }
+
+    int from = 1130;
+    int to = sourceBytes.length - 5555;
+    stringUnderTest = sourceString.substring(from, to);
+    referenceBytes = new byte[to - from];
+    System.arraycopy(sourceBytes, from, referenceBytes, 0, to - from);
+    expectedHashCode = -1259260680;
+  }
+
+  @Override
+  public void testGetTreeDepth() {
+    assertEquals(classUnderTest + " must have the expected tree depth",
+        3, stringUnderTest.getTreeDepth());
+  }
+
+  @Override
+  public void testToString() throws UnsupportedEncodingException {
+    String sourceString = "I love unicode \u1234\u5678 characters";
+    ByteString sourceByteString = ByteString.copyFromUtf8(sourceString);
+    int copies = 250;
+
+    // By building the RopeByteString by concatenating, this is actually a fairly strenuous test.
+    StringBuilder builder = new StringBuilder(copies * sourceString.length());
+    ByteString unicode = ByteString.EMPTY;
+    for (int i = 0; i < copies; ++i) {
+      builder.append(sourceString);
+      unicode = RopeByteString.concatenate(unicode, sourceByteString);
+    }
+    String testString = builder.toString();
+
+    // Do the substring part
+    testString = testString.substring(2, testString.length() - 6);
+    unicode = unicode.substring(2, unicode.size() - 6);
+
+    assertEquals(classUnderTest + " from string must have the expected type",
+        classUnderTest, getActualClassName(unicode));
+    String roundTripString = unicode.toString(UTF_8);
+    assertEquals(classUnderTest + " unicode bytes must match",
+        testString, roundTripString);
+    ByteString flatString = ByteString.copyFromUtf8(testString);
+    assertEquals(classUnderTest + " string must equal the flat string", flatString, unicode);
+    assertEquals(classUnderTest + " string must must have same hashCode as the flat string",
+        flatString.hashCode(), unicode.hashCode());
+  }
+
+  @Override
+  public void testCharsetToString() {
+    String sourceString = "I love unicode \u1234\u5678 characters";
+    ByteString sourceByteString = ByteString.copyFromUtf8(sourceString);
+    int copies = 250;
+
+    // By building the RopeByteString by concatenating, this is actually a fairly strenuous test.
+    StringBuilder builder = new StringBuilder(copies * sourceString.length());
+    ByteString unicode = ByteString.EMPTY;
+    for (int i = 0; i < copies; ++i) {
+      builder.append(sourceString);
+      unicode = RopeByteString.concatenate(unicode, sourceByteString);
+    }
+    String testString = builder.toString();
+
+    // Do the substring part
+    testString = testString.substring(2, testString.length() - 6);
+    unicode = unicode.substring(2, unicode.size() - 6);
+
+    assertEquals(classUnderTest + " from string must have the expected type",
+        classUnderTest, getActualClassName(unicode));
+    String roundTripString = unicode.toString(Internal.UTF_8);
+    assertEquals(classUnderTest + " unicode bytes must match",
+        testString, roundTripString);
+    ByteString flatString = ByteString.copyFromUtf8(testString);
+    assertEquals(classUnderTest + " string must equal the flat string", flatString, unicode);
+    assertEquals(classUnderTest + " string must must have same hashCode as the flat string",
+        flatString.hashCode(), unicode.hashCode());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/RopeByteStringTest.java b/java/core/src/test/java/com/google/protobuf/RopeByteStringTest.java
new file mode 100644
index 00000000..4ec3a409
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/RopeByteStringTest.java
@@ -0,0 +1,189 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.UnsupportedEncodingException;
+import java.util.Arrays;
+import java.util.Iterator;
+
+/**
+ * This class tests {@link RopeByteString} by inheriting the tests from
+ * {@link LiteralByteStringTest}.  Only a couple of methods are overridden.
+ *
+ * <p>A full test of the result of {@link RopeByteString#substring(int, int)} is found in the
+ * separate class {@link RopeByteStringSubstringTest}.
+ *
+ * @author carlanton@google.com (Carl Haverl)
+ */
+public class RopeByteStringTest extends LiteralByteStringTest {
+
+  @Override
+  protected void setUp() throws Exception {
+    classUnderTest = "RopeByteString";
+    referenceBytes = ByteStringTest.getTestBytes(22341, 22337766L);
+    Iterator<ByteString> iter = ByteStringTest.makeConcretePieces(referenceBytes).iterator();
+    stringUnderTest = iter.next();
+    while (iter.hasNext()) {
+      stringUnderTest = stringUnderTest.concat(iter.next());
+    }
+    expectedHashCode = -1214197238;
+  }
+
+  @Override
+  public void testGetTreeDepth() {
+    assertEquals(classUnderTest + " must have the expected tree depth",
+        4, stringUnderTest.getTreeDepth());
+  }
+
+  public void testBalance() {
+    int numberOfPieces = 10000;
+    int pieceSize = 64;
+    byte[] testBytes = ByteStringTest.getTestBytes(numberOfPieces * pieceSize, 113377L);
+
+    // Build up a big ByteString from smaller pieces to force a rebalance
+    ByteString concatenated = ByteString.EMPTY;
+    for (int i = 0; i < numberOfPieces; ++i) {
+      concatenated = concatenated.concat(ByteString.copyFrom(testBytes, i * pieceSize, pieceSize));
+    }
+
+    assertEquals(classUnderTest + " from string must have the expected type",
+        classUnderTest, getActualClassName(concatenated));
+    assertTrue(classUnderTest + " underlying bytes must match after balancing",
+        Arrays.equals(testBytes, concatenated.toByteArray()));
+    ByteString testString = ByteString.copyFrom(testBytes);
+    assertTrue(classUnderTest + " balanced string must equal flat string",
+        concatenated.equals(testString));
+    assertTrue(classUnderTest + " flat string must equal balanced string",
+        testString.equals(concatenated));
+    assertEquals(classUnderTest + " balanced string must have same hash code as flat string",
+        testString.hashCode(), concatenated.hashCode());
+  }
+
+  @Override
+  public void testToString() throws UnsupportedEncodingException {
+    String sourceString = "I love unicode \u1234\u5678 characters";
+    ByteString sourceByteString = ByteString.copyFromUtf8(sourceString);
+    int copies = 250;
+
+    // By building the RopeByteString by concatenating, this is actually a fairly strenuous test.
+    StringBuilder builder = new StringBuilder(copies * sourceString.length());
+    ByteString unicode = ByteString.EMPTY;
+    for (int i = 0; i < copies; ++i) {
+      builder.append(sourceString);
+      unicode = RopeByteString.concatenate(unicode, sourceByteString);
+    }
+    String testString = builder.toString();
+
+    assertEquals(classUnderTest + " from string must have the expected type",
+        classUnderTest, getActualClassName(unicode));
+    String roundTripString = unicode.toString(UTF_8);
+    assertEquals(classUnderTest + " unicode bytes must match",
+        testString, roundTripString);
+    ByteString flatString = ByteString.copyFromUtf8(testString);
+    assertEquals(classUnderTest + " string must equal the flat string", flatString, unicode);
+    assertEquals(classUnderTest + " string must must have same hashCode as the flat string",
+        flatString.hashCode(), unicode.hashCode());
+  }
+
+  @Override
+  public void testCharsetToString() {
+    String sourceString = "I love unicode \u1234\u5678 characters";
+    ByteString sourceByteString = ByteString.copyFromUtf8(sourceString);
+    int copies = 250;
+
+    // By building the RopeByteString by concatenating, this is actually a fairly strenuous test.
+    StringBuilder builder = new StringBuilder(copies * sourceString.length());
+    ByteString unicode = ByteString.EMPTY;
+    for (int i = 0; i < copies; ++i) {
+      builder.append(sourceString);
+      unicode = RopeByteString.concatenate(unicode, sourceByteString);
+    }
+    String testString = builder.toString();
+
+    assertEquals(classUnderTest + " from string must have the expected type",
+        classUnderTest, getActualClassName(unicode));
+    String roundTripString = unicode.toString(Internal.UTF_8);
+    assertEquals(classUnderTest + " unicode bytes must match",
+        testString, roundTripString);
+    ByteString flatString = ByteString.copyFromUtf8(testString);
+    assertEquals(classUnderTest + " string must equal the flat string", flatString, unicode);
+    assertEquals(classUnderTest + " string must must have same hashCode as the flat string",
+        flatString.hashCode(), unicode.hashCode());
+  }
+
+  @Override
+  public void testToString_returnsCanonicalEmptyString() {
+    RopeByteString ropeByteString =
+        RopeByteString.newInstanceForTest(ByteString.EMPTY, ByteString.EMPTY);
+    assertSame(classUnderTest + " must be the same string references",
+        ByteString.EMPTY.toString(Internal.UTF_8), ropeByteString.toString(Internal.UTF_8));
+  }
+
+  @Override
+  public void testToString_raisesException() {
+    try {
+      ByteString byteString =
+          RopeByteString.newInstanceForTest(ByteString.EMPTY, ByteString.EMPTY);
+      byteString.toString("invalid");
+      fail("Should have thrown an exception.");
+    } catch (UnsupportedEncodingException expected) {
+      // This is success
+    }
+
+    try {
+      ByteString byteString = RopeByteString.concatenate(ByteString.copyFromUtf8("foo"),
+          ByteString.copyFromUtf8("bar"));
+      byteString.toString("invalid");
+      fail("Should have thrown an exception.");
+    } catch (UnsupportedEncodingException expected) {
+      // This is success
+    }
+  }
+
+  @Override
+  public void testJavaSerialization() throws Exception {
+    ByteArrayOutputStream out = new ByteArrayOutputStream();
+    ObjectOutputStream oos = new ObjectOutputStream(out);
+    oos.writeObject(stringUnderTest);
+    oos.close();
+    byte[] pickled = out.toByteArray();
+    InputStream in = new ByteArrayInputStream(pickled);
+    ObjectInputStream ois = new ObjectInputStream(in);
+    Object o = ois.readObject();
+    assertTrue("Didn't get a ByteString back", o instanceof ByteString);
+    assertEquals("Should get an equal ByteString back", stringUnderTest, o);
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/ServiceTest.java b/java/core/src/test/java/com/google/protobuf/ServiceTest.java
new file mode 100644
index 00000000..ff980d66
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ServiceTest.java
@@ -0,0 +1,320 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.Descriptors.MethodDescriptor;
+import google.protobuf.no_generic_services_test.UnittestNoGenericServices;
+import protobuf_unittest.MessageWithNoOuter;
+import protobuf_unittest.ServiceWithNoOuter;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestService;
+import protobuf_unittest.UnittestProto.FooRequest;
+import protobuf_unittest.UnittestProto.FooResponse;
+import protobuf_unittest.UnittestProto.BarRequest;
+import protobuf_unittest.UnittestProto.BarResponse;
+
+import org.easymock.classextension.EasyMock;
+import org.easymock.classextension.IMocksControl;
+import org.easymock.IArgumentMatcher;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import junit.framework.TestCase;
+
+/**
+ * Tests services and stubs.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class ServiceTest extends TestCase {
+  private IMocksControl control;
+  private RpcController mockController;
+
+  private final Descriptors.MethodDescriptor fooDescriptor =
+    TestService.getDescriptor().getMethods().get(0);
+  private final Descriptors.MethodDescriptor barDescriptor =
+    TestService.getDescriptor().getMethods().get(1);
+
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+    control = EasyMock.createStrictControl();
+    mockController = control.createMock(RpcController.class);
+  }
+
+  // =================================================================
+
+  /** Tests Service.callMethod(). */
+  public void testCallMethod() throws Exception {
+    FooRequest fooRequest = FooRequest.newBuilder().build();
+    BarRequest barRequest = BarRequest.newBuilder().build();
+    MockCallback<Message> fooCallback = new MockCallback<Message>();
+    MockCallback<Message> barCallback = new MockCallback<Message>();
+    TestService mockService = control.createMock(TestService.class);
+
+    mockService.foo(EasyMock.same(mockController), EasyMock.same(fooRequest),
+                    this.<FooResponse>wrapsCallback(fooCallback));
+    mockService.bar(EasyMock.same(mockController), EasyMock.same(barRequest),
+                    this.<BarResponse>wrapsCallback(barCallback));
+    control.replay();
+
+    mockService.callMethod(fooDescriptor, mockController,
+                           fooRequest, fooCallback);
+    mockService.callMethod(barDescriptor, mockController,
+                           barRequest, barCallback);
+    control.verify();
+  }
+
+  /** Tests Service.get{Request,Response}Prototype(). */
+  public void testGetPrototype() throws Exception {
+    TestService mockService = control.createMock(TestService.class);
+
+    assertSame(mockService.getRequestPrototype(fooDescriptor),
+               FooRequest.getDefaultInstance());
+    assertSame(mockService.getResponsePrototype(fooDescriptor),
+               FooResponse.getDefaultInstance());
+    assertSame(mockService.getRequestPrototype(barDescriptor),
+               BarRequest.getDefaultInstance());
+    assertSame(mockService.getResponsePrototype(barDescriptor),
+               BarResponse.getDefaultInstance());
+  }
+
+  /** Tests generated stubs. */
+  public void testStub() throws Exception {
+    FooRequest fooRequest = FooRequest.newBuilder().build();
+    BarRequest barRequest = BarRequest.newBuilder().build();
+    MockCallback<FooResponse> fooCallback = new MockCallback<FooResponse>();
+    MockCallback<BarResponse> barCallback = new MockCallback<BarResponse>();
+    RpcChannel mockChannel = control.createMock(RpcChannel.class);
+    TestService stub = TestService.newStub(mockChannel);
+
+    mockChannel.callMethod(
+      EasyMock.same(fooDescriptor),
+      EasyMock.same(mockController),
+      EasyMock.same(fooRequest),
+      EasyMock.same(FooResponse.getDefaultInstance()),
+      this.<Message>wrapsCallback(fooCallback));
+    mockChannel.callMethod(
+      EasyMock.same(barDescriptor),
+      EasyMock.same(mockController),
+      EasyMock.same(barRequest),
+      EasyMock.same(BarResponse.getDefaultInstance()),
+      this.<Message>wrapsCallback(barCallback));
+    control.replay();
+
+    stub.foo(mockController, fooRequest, fooCallback);
+    stub.bar(mockController, barRequest, barCallback);
+    control.verify();
+  }
+
+  /** Tests generated blocking stubs. */
+  public void testBlockingStub() throws Exception {
+    FooRequest fooRequest = FooRequest.newBuilder().build();
+    BarRequest barRequest = BarRequest.newBuilder().build();
+    BlockingRpcChannel mockChannel =
+        control.createMock(BlockingRpcChannel.class);
+    TestService.BlockingInterface stub =
+        TestService.newBlockingStub(mockChannel);
+
+    FooResponse fooResponse = FooResponse.newBuilder().build();
+    BarResponse barResponse = BarResponse.newBuilder().build();
+
+    EasyMock.expect(mockChannel.callBlockingMethod(
+      EasyMock.same(fooDescriptor),
+      EasyMock.same(mockController),
+      EasyMock.same(fooRequest),
+      EasyMock.same(FooResponse.getDefaultInstance()))).andReturn(fooResponse);
+    EasyMock.expect(mockChannel.callBlockingMethod(
+      EasyMock.same(barDescriptor),
+      EasyMock.same(mockController),
+      EasyMock.same(barRequest),
+      EasyMock.same(BarResponse.getDefaultInstance()))).andReturn(barResponse);
+    control.replay();
+
+    assertSame(fooResponse, stub.foo(mockController, fooRequest));
+    assertSame(barResponse, stub.bar(mockController, barRequest));
+    control.verify();
+  }
+
+  public void testNewReflectiveService() {
+    ServiceWithNoOuter.Interface impl =
+        control.createMock(ServiceWithNoOuter.Interface.class);
+    RpcController controller = control.createMock(RpcController.class);
+    Service service = ServiceWithNoOuter.newReflectiveService(impl);
+
+    MethodDescriptor fooMethod =
+        ServiceWithNoOuter.getDescriptor().findMethodByName("Foo");
+    MessageWithNoOuter request = MessageWithNoOuter.getDefaultInstance();
+    RpcCallback<Message> callback = new RpcCallback<Message>() {
+      public void run(Message parameter) {
+        // No reason this should be run.
+        fail();
+      }
+    };
+    RpcCallback<TestAllTypes> specializedCallback =
+        RpcUtil.specializeCallback(callback);
+
+    impl.foo(EasyMock.same(controller), EasyMock.same(request),
+        EasyMock.same(specializedCallback));
+    EasyMock.expectLastCall();
+
+    control.replay();
+
+    service.callMethod(fooMethod, controller, request, callback);
+
+    control.verify();
+  }
+
+  public void testNewReflectiveBlockingService() throws ServiceException {
+    ServiceWithNoOuter.BlockingInterface impl =
+        control.createMock(ServiceWithNoOuter.BlockingInterface.class);
+    RpcController controller = control.createMock(RpcController.class);
+    BlockingService service =
+        ServiceWithNoOuter.newReflectiveBlockingService(impl);
+
+    MethodDescriptor fooMethod =
+        ServiceWithNoOuter.getDescriptor().findMethodByName("Foo");
+    MessageWithNoOuter request = MessageWithNoOuter.getDefaultInstance();
+
+    TestAllTypes expectedResponse = TestAllTypes.getDefaultInstance();
+    EasyMock.expect(impl.foo(EasyMock.same(controller), EasyMock.same(request)))
+        .andReturn(expectedResponse);
+
+    control.replay();
+
+    Message response =
+        service.callBlockingMethod(fooMethod, controller, request);
+    assertEquals(expectedResponse, response);
+
+    control.verify();
+  }
+
+  public void testNoGenericServices() throws Exception {
+    // Non-services should be usable.
+    UnittestNoGenericServices.TestMessage message =
+      UnittestNoGenericServices.TestMessage.newBuilder()
+        .setA(123)
+        .setExtension(UnittestNoGenericServices.testExtension, 456)
+        .build();
+    assertEquals(123, message.getA());
+    assertEquals(1, UnittestNoGenericServices.TestEnum.FOO.getNumber());
+
+    // Build a list of the class names nested in UnittestNoGenericServices.
+    String outerName = "google.protobuf.no_generic_services_test." +
+                       "UnittestNoGenericServices";
+    Class<?> outerClass = Class.forName(outerName);
+
+    Set<String> innerClassNames = new HashSet<String>();
+    for (Class<?> innerClass : outerClass.getClasses()) {
+      String fullName = innerClass.getName();
+      // Figure out the unqualified name of the inner class.
+      // Note:  Surprisingly, the full name of an inner class will be separated
+      //   from the outer class name by a '$' rather than a '.'.  This is not
+      //   mentioned in the documentation for java.lang.Class.  I don't want to
+      //   make assumptions, so I'm just going to accept any character as the
+      //   separator.
+      assertTrue(fullName.startsWith(outerName));
+
+      if (!Service.class.isAssignableFrom(innerClass) &&
+          !Message.class.isAssignableFrom(innerClass) &&
+          !ProtocolMessageEnum.class.isAssignableFrom(innerClass)) {
+        // Ignore any classes not generated by the base code generator.
+        continue;
+      }
+
+      innerClassNames.add(fullName.substring(outerName.length() + 1));
+    }
+
+    // No service class should have been generated.
+    assertTrue(innerClassNames.contains("TestMessage"));
+    assertTrue(innerClassNames.contains("TestEnum"));
+    assertFalse(innerClassNames.contains("TestService"));
+
+    // But descriptors are there.
+    FileDescriptor file = UnittestNoGenericServices.getDescriptor();
+    assertEquals(1, file.getServices().size());
+    assertEquals("TestService", file.getServices().get(0).getName());
+    assertEquals(1, file.getServices().get(0).getMethods().size());
+    assertEquals("Foo",
+        file.getServices().get(0).getMethods().get(0).getName());
+  }
+
+  // =================================================================
+
+  /**
+   * wrapsCallback() is an EasyMock argument predicate.  wrapsCallback(c)
+   * matches a callback if calling that callback causes c to be called.
+   * In other words, c wraps the given callback.
+   */
+  private <Type extends Message> RpcCallback<Type> wrapsCallback(
+      MockCallback<?> callback) {
+    EasyMock.reportMatcher(new WrapsCallback(callback));
+    return null;
+  }
+
+  /** The parameter to wrapsCallback() must be a MockCallback. */
+  private static class MockCallback<Type extends Message>
+      implements RpcCallback<Type> {
+    private boolean called = false;
+
+    public boolean isCalled() { return called; }
+
+    public void reset() { called = false; }
+    public void run(Type message) { called = true; }
+  }
+
+  /** Implementation of the wrapsCallback() argument matcher. */
+  private static class WrapsCallback implements IArgumentMatcher {
+    private MockCallback<?> callback;
+
+    public WrapsCallback(MockCallback<?> callback) {
+      this.callback = callback;
+    }
+
+    @SuppressWarnings("unchecked")
+    public boolean matches(Object actual) {
+      if (!(actual instanceof RpcCallback)) {
+        return false;
+      }
+      RpcCallback actualCallback = (RpcCallback)actual;
+
+      callback.reset();
+      actualCallback.run(null);
+      return callback.isCalled();
+    }
+
+    public void appendTo(StringBuffer buffer) {
+      buffer.append("wrapsCallback(mockCallback)");
+    }
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java b/java/core/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java
new file mode 100644
index 00000000..58b80007
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java
@@ -0,0 +1,155 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestAllTypesOrBuilder;
+
+import junit.framework.TestCase;
+
+/**
+ * Tests for {@link SingleFieldBuilder}. This tests basic functionality.
+ * More extensive testing is provided via other tests that exercise the
+ * builder.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ */
+public class SingleFieldBuilderTest extends TestCase {
+
+  public void testBasicUseAndInvalidations() {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+    SingleFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder> builder =
+        new SingleFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+            TestAllTypesOrBuilder>(
+            TestAllTypes.getDefaultInstance(),
+            mockParent,
+            false);
+    assertSame(TestAllTypes.getDefaultInstance(), builder.getMessage());
+    assertEquals(TestAllTypes.getDefaultInstance(),
+        builder.getBuilder().buildPartial());
+    assertEquals(0, mockParent.getInvalidationCount());
+
+    builder.getBuilder().setOptionalInt32(10);
+    assertEquals(0, mockParent.getInvalidationCount());
+    TestAllTypes message = builder.build();
+    assertEquals(10, message.getOptionalInt32());
+
+    // Test that we receive invalidations now that build has been called.
+    assertEquals(0, mockParent.getInvalidationCount());
+    builder.getBuilder().setOptionalInt32(20);
+    assertEquals(1, mockParent.getInvalidationCount());
+
+    // Test that we don't keep getting invalidations on every change
+    builder.getBuilder().setOptionalInt32(30);
+    assertEquals(1, mockParent.getInvalidationCount());
+
+  }
+
+  public void testSetMessage() {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+    SingleFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder> builder =
+        new SingleFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+            TestAllTypesOrBuilder>(
+            TestAllTypes.getDefaultInstance(),
+            mockParent,
+            false);
+    builder.setMessage(TestAllTypes.newBuilder().setOptionalInt32(0).build());
+    assertEquals(0, builder.getMessage().getOptionalInt32());
+
+    // Update message using the builder
+    builder.getBuilder().setOptionalInt32(1);
+    assertEquals(0, mockParent.getInvalidationCount());
+    assertEquals(1, builder.getBuilder().getOptionalInt32());
+    assertEquals(1, builder.getMessage().getOptionalInt32());
+    builder.build();
+    builder.getBuilder().setOptionalInt32(2);
+    assertEquals(2, builder.getBuilder().getOptionalInt32());
+    assertEquals(2, builder.getMessage().getOptionalInt32());
+
+    // Make sure message stays cached
+    assertSame(builder.getMessage(), builder.getMessage());
+  }
+
+  public void testClear() {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+    SingleFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder> builder =
+        new SingleFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+            TestAllTypesOrBuilder>(
+            TestAllTypes.getDefaultInstance(),
+            mockParent,
+            false);
+    builder.setMessage(TestAllTypes.newBuilder().setOptionalInt32(0).build());
+    assertNotSame(TestAllTypes.getDefaultInstance(), builder.getMessage());
+    builder.clear();
+    assertSame(TestAllTypes.getDefaultInstance(), builder.getMessage());
+
+    builder.getBuilder().setOptionalInt32(1);
+    assertNotSame(TestAllTypes.getDefaultInstance(), builder.getMessage());
+    builder.clear();
+    assertSame(TestAllTypes.getDefaultInstance(), builder.getMessage());
+  }
+
+  public void testMerge() {
+    TestUtil.MockBuilderParent mockParent = new TestUtil.MockBuilderParent();
+    SingleFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+        TestAllTypesOrBuilder> builder =
+        new SingleFieldBuilder<TestAllTypes, TestAllTypes.Builder,
+            TestAllTypesOrBuilder>(
+            TestAllTypes.getDefaultInstance(),
+            mockParent,
+            false);
+
+    // Merge into default field.
+    builder.mergeFrom(TestAllTypes.getDefaultInstance());
+    assertSame(TestAllTypes.getDefaultInstance(), builder.getMessage());
+
+    // Merge into non-default field on existing builder.
+    builder.getBuilder().setOptionalInt32(2);
+    builder.mergeFrom(TestAllTypes.newBuilder()
+        .setOptionalDouble(4.0)
+        .buildPartial());
+    assertEquals(2, builder.getMessage().getOptionalInt32());
+    assertEquals(4.0, builder.getMessage().getOptionalDouble());
+
+    // Merge into non-default field on existing message
+    builder.setMessage(TestAllTypes.newBuilder()
+        .setOptionalInt32(10)
+        .buildPartial());
+    builder.mergeFrom(TestAllTypes.newBuilder()
+        .setOptionalDouble(5.0)
+        .buildPartial());
+    assertEquals(10, builder.getMessage().getOptionalInt32());
+    assertEquals(5.0, builder.getMessage().getOptionalDouble());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java b/java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java
new file mode 100644
index 00000000..366086d3
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java
@@ -0,0 +1,420 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * @author darick@google.com Darick Tong
+ */
+public class SmallSortedMapTest extends TestCase {
+  // java.util.AbstractMap.SimpleEntry is private in JDK 1.5. We re-implement it
+  // here for JDK 1.5 users.
+  private static class SimpleEntry<K, V> implements Map.Entry<K, V> {
+    private final K key;
+    private V value;
+
+    SimpleEntry(K key, V value) {
+      this.key = key;
+      this.value = value;
+    }
+
+    public K getKey() {
+      return key;
+    }
+
+    public V getValue() {
+      return value;
+    }
+
+    public V setValue(V value) {
+      V oldValue = this.value;
+      this.value = value;
+      return oldValue;
+    }
+
+    private static boolean eq(Object o1, Object o2) {
+      return o1 == null ? o2 == null : o1.equals(o2);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (!(o instanceof Map.Entry))
+        return false;
+      Map.Entry e = (Map.Entry) o;
+      return eq(key, e.getKey()) && eq(value, e.getValue());
+    }
+
+    @Override
+    public int hashCode() {
+      return ((key == null) ? 0 : key.hashCode()) ^
+          ((value == null) ? 0 : value.hashCode());
+    }
+  }
+
+  public void testPutAndGetArrayEntriesOnly() {
+    runPutAndGetTest(3);
+  }
+
+  public void testPutAndGetOverflowEntries() {
+    runPutAndGetTest(6);
+  }
+
+  private void runPutAndGetTest(int numElements) {
+    // Test with even and odd arraySize
+    SmallSortedMap<Integer, Integer> map1 =
+        SmallSortedMap.newInstanceForTest(3);
+    SmallSortedMap<Integer, Integer> map2 =
+        SmallSortedMap.newInstanceForTest(4);
+    SmallSortedMap<Integer, Integer> map3 =
+        SmallSortedMap.newInstanceForTest(3);
+    SmallSortedMap<Integer, Integer> map4 =
+        SmallSortedMap.newInstanceForTest(4);
+
+    // Test with puts in ascending order.
+    for (int i = 0; i < numElements; i++) {
+      assertNull(map1.put(i, i + 1));
+      assertNull(map2.put(i, i + 1));
+    }
+    // Test with puts in descending order.
+    for (int i = numElements - 1; i >= 0; i--) {
+      assertNull(map3.put(i, i + 1));
+      assertNull(map4.put(i, i + 1));
+    }
+
+    assertEquals(Math.min(3, numElements), map1.getNumArrayEntries());
+    assertEquals(Math.min(4, numElements), map2.getNumArrayEntries());
+    assertEquals(Math.min(3, numElements), map3.getNumArrayEntries());
+    assertEquals(Math.min(4, numElements), map4.getNumArrayEntries());
+
+    List<SmallSortedMap<Integer, Integer>> allMaps =
+        new ArrayList<SmallSortedMap<Integer, Integer>>();
+    allMaps.add(map1);
+    allMaps.add(map2);
+    allMaps.add(map3);
+    allMaps.add(map4);
+
+    for (SmallSortedMap<Integer, Integer> map : allMaps) {
+      assertEquals(numElements, map.size());
+      for (int i = 0; i < numElements; i++) {
+        assertEquals(new Integer(i + 1), map.get(i));
+      }
+    }
+
+    assertEquals(map1, map2);
+    assertEquals(map2, map3);
+    assertEquals(map3, map4);
+  }
+
+  public void testReplacingPut() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+      assertNull(map.remove(i + 1));
+    }
+    for (int i = 0; i < 6; i++) {
+      assertEquals(new Integer(i + 1), map.put(i, i + 2));
+    }
+  }
+
+  public void testRemove() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+      assertNull(map.remove(i + 1));
+    }
+
+    assertEquals(3, map.getNumArrayEntries());
+    assertEquals(3, map.getNumOverflowEntries());
+    assertEquals(6,  map.size());
+    assertEquals(makeSortedKeySet(0, 1, 2, 3, 4, 5), map.keySet());
+
+    assertEquals(new Integer(2), map.remove(1));
+    assertEquals(3, map.getNumArrayEntries());
+    assertEquals(2, map.getNumOverflowEntries());
+    assertEquals(5,  map.size());
+    assertEquals(makeSortedKeySet(0, 2, 3, 4, 5), map.keySet());
+
+    assertEquals(new Integer(5), map.remove(4));
+    assertEquals(3, map.getNumArrayEntries());
+    assertEquals(1, map.getNumOverflowEntries());
+    assertEquals(4,  map.size());
+    assertEquals(makeSortedKeySet(0, 2, 3, 5), map.keySet());
+
+    assertEquals(new Integer(4), map.remove(3));
+    assertEquals(3, map.getNumArrayEntries());
+    assertEquals(0, map.getNumOverflowEntries());
+    assertEquals(3, map.size());
+    assertEquals(makeSortedKeySet(0, 2, 5), map.keySet());
+
+    assertNull(map.remove(3));
+    assertEquals(3, map.getNumArrayEntries());
+    assertEquals(0, map.getNumOverflowEntries());
+    assertEquals(3, map.size());
+
+    assertEquals(new Integer(1), map.remove(0));
+    assertEquals(2, map.getNumArrayEntries());
+    assertEquals(0, map.getNumOverflowEntries());
+    assertEquals(2, map.size());
+  }
+
+  public void testClear() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    map.clear();
+    assertEquals(0, map.getNumArrayEntries());
+    assertEquals(0, map.getNumOverflowEntries());
+    assertEquals(0, map.size());
+  }
+
+  public void testGetArrayEntryAndOverflowEntries() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    assertEquals(3, map.getNumArrayEntries());
+    for (int i = 0; i < 3; i++) {
+      Map.Entry<Integer, Integer> entry = map.getArrayEntryAt(i);
+      assertEquals(new Integer(i), entry.getKey());
+      assertEquals(new Integer(i + 1), entry.getValue());
+    }
+    Iterator<Map.Entry<Integer, Integer>> it =
+        map.getOverflowEntries().iterator();
+    for (int i = 3; i < 6; i++) {
+      assertTrue(it.hasNext());
+      Map.Entry<Integer, Integer> entry = it.next();
+      assertEquals(new Integer(i), entry.getKey());
+      assertEquals(new Integer(i + 1), entry.getValue());
+    }
+    assertFalse(it.hasNext());
+  }
+
+  public void testEntrySetContains() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    Set<Map.Entry<Integer, Integer>> entrySet = map.entrySet();
+    for (int i = 0; i < 6; i++) {
+      assertTrue(
+          entrySet.contains(new SimpleEntry<Integer, Integer>(i, i + 1)));
+      assertFalse(
+          entrySet.contains(new SimpleEntry<Integer, Integer>(i, i)));
+    }
+  }
+
+  public void testEntrySetAdd() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    Set<Map.Entry<Integer, Integer>> entrySet = map.entrySet();
+    for (int i = 0; i < 6; i++) {
+      Map.Entry<Integer, Integer> entry =
+          new SimpleEntry<Integer, Integer>(i, i + 1);
+      assertTrue(entrySet.add(entry));
+      assertFalse(entrySet.add(entry));
+    }
+    for (int i = 0; i < 6; i++) {
+      assertEquals(new Integer(i + 1), map.get(i));
+    }
+    assertEquals(3, map.getNumArrayEntries());
+    assertEquals(3, map.getNumOverflowEntries());
+    assertEquals(6, map.size());
+  }
+
+  public void testEntrySetRemove() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    Set<Map.Entry<Integer, Integer>> entrySet = map.entrySet();
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    for (int i = 0; i < 6; i++) {
+      Map.Entry<Integer, Integer> entry =
+          new SimpleEntry<Integer, Integer>(i, i + 1);
+      assertTrue(entrySet.remove(entry));
+      assertFalse(entrySet.remove(entry));
+    }
+    assertTrue(map.isEmpty());
+    assertEquals(0, map.getNumArrayEntries());
+    assertEquals(0, map.getNumOverflowEntries());
+    assertEquals(0, map.size());
+  }
+
+  public void testEntrySetClear() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    map.entrySet().clear();
+    assertTrue(map.isEmpty());
+    assertEquals(0, map.getNumArrayEntries());
+    assertEquals(0, map.getNumOverflowEntries());
+    assertEquals(0, map.size());
+  }
+
+  public void testEntrySetIteratorNext() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    Iterator<Map.Entry<Integer, Integer>> it = map.entrySet().iterator();
+    for (int i = 0; i < 6; i++) {
+      assertTrue(it.hasNext());
+      Map.Entry<Integer, Integer> entry = it.next();
+      assertEquals(new Integer(i), entry.getKey());
+      assertEquals(new Integer(i + 1), entry.getValue());
+    }
+    assertFalse(it.hasNext());
+  }
+
+  public void testEntrySetIteratorRemove() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    Iterator<Map.Entry<Integer, Integer>> it = map.entrySet().iterator();
+    for (int i = 0; i < 6; i++) {
+      assertTrue(map.containsKey(i));
+      it.next();
+      it.remove();
+      assertFalse(map.containsKey(i));
+      assertEquals(6 - i - 1, map.size());
+    }
+  }
+
+  public void testMapEntryModification() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    Iterator<Map.Entry<Integer, Integer>> it = map.entrySet().iterator();
+    for (int i = 0; i < 6; i++) {
+      Map.Entry<Integer, Integer> entry = it.next();
+      entry.setValue(i + 23);
+    }
+    for (int i = 0; i < 6; i++) {
+      assertEquals(new Integer(i + 23), map.get(i));
+    }
+  }
+
+  public void testMakeImmutable() {
+    SmallSortedMap<Integer, Integer> map = SmallSortedMap.newInstanceForTest(3);
+    for (int i = 0; i < 6; i++) {
+      assertNull(map.put(i, i + 1));
+    }
+    map.makeImmutable();
+    assertEquals(new Integer(1), map.get(0));
+    assertEquals(6, map.size());
+
+    try {
+      map.put(23, 23);
+      fail("Expected UnsupportedOperationException");
+    } catch (UnsupportedOperationException expected) {
+    }
+
+    Map<Integer, Integer> other = new HashMap<Integer, Integer>();
+    other.put(23, 23);
+    try {
+      map.putAll(other);
+      fail("Expected UnsupportedOperationException");
+    } catch (UnsupportedOperationException expected) {
+    }
+
+    try {
+      map.remove(0);
+      fail("Expected UnsupportedOperationException");
+    } catch (UnsupportedOperationException expected) {
+    }
+
+    try {
+      map.clear();
+      fail("Expected UnsupportedOperationException");
+    } catch (UnsupportedOperationException expected) {
+    }
+
+    Set<Map.Entry<Integer, Integer>> entrySet = map.entrySet();
+    try {
+      entrySet.clear();
+      fail("Expected UnsupportedOperationException");
+    } catch (UnsupportedOperationException expected) {
+    }
+
+    Iterator<Map.Entry<Integer, Integer>> it = entrySet.iterator();
+    while (it.hasNext()) {
+      Map.Entry<Integer, Integer> entry = it.next();
+      try {
+        entry.setValue(0);
+        fail("Expected UnsupportedOperationException");
+      } catch (UnsupportedOperationException expected) {
+      }
+      try {
+        it.remove();
+        fail("Expected UnsupportedOperationException");
+      } catch (UnsupportedOperationException expected) {
+      }
+    }
+
+    Set<Integer> keySet = map.keySet();
+    try {
+      keySet.clear();
+      fail("Expected UnsupportedOperationException");
+    } catch (UnsupportedOperationException expected) {
+    }
+
+    Iterator<Integer> keys = keySet.iterator();
+    while (keys.hasNext()) {
+      Integer key = keys.next();
+      try {
+        keySet.remove(key);
+        fail("Expected UnsupportedOperationException");
+      } catch (UnsupportedOperationException expected) {
+      }
+      try {
+        keys.remove();
+        fail("Expected UnsupportedOperationException");
+      } catch (UnsupportedOperationException expected) {
+      }
+    }
+  }
+
+  private Set<Integer> makeSortedKeySet(Integer... keys) {
+    return new TreeSet<Integer>(Arrays.<Integer>asList(keys));
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java b/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java
new file mode 100644
index 00000000..2c60fe0e
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java
@@ -0,0 +1,96 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import junit.framework.TestCase;
+
+/**
+ * Tests that proto2 api generation doesn't cause compile errors when
+ * compiling protocol buffers that have names that would otherwise conflict
+ * if not fully qualified (like @Deprecated and @Override).
+ *
+ * @author jonp@google.com (Jon Perlow)
+ */
+public class TestBadIdentifiers extends TestCase {
+
+  public void testCompilation() {
+    // If this compiles, it means the generation was correct.
+    TestBadIdentifiersProto.Deprecated.newBuilder();
+    TestBadIdentifiersProto.Override.newBuilder();
+  }
+
+  public void testGetDescriptor() {
+    Descriptors.FileDescriptor fileDescriptor =
+        TestBadIdentifiersProto.getDescriptor();
+    String descriptorField = TestBadIdentifiersProto.Descriptor
+        .getDefaultInstance().getDescriptor();
+    Descriptors.Descriptor protoDescriptor = TestBadIdentifiersProto.Descriptor
+        .getDefaultInstance().getDescriptorForType();
+    String nestedDescriptorField = TestBadIdentifiersProto.Descriptor
+        .NestedDescriptor.getDefaultInstance().getDescriptor();
+    Descriptors.Descriptor nestedProtoDescriptor = TestBadIdentifiersProto
+        .Descriptor.NestedDescriptor.getDefaultInstance()
+        .getDescriptorForType();
+  }
+
+  public void testConflictingFieldNames() throws Exception {
+    TestBadIdentifiersProto.TestConflictingFieldNames message =
+        TestBadIdentifiersProto.TestConflictingFieldNames.getDefaultInstance();
+    // Make sure generated accessors are properly named.
+    assertEquals(0, message.getInt32Field1Count());
+    assertEquals(0, message.getEnumField2Count());
+    assertEquals(0, message.getStringField3Count());
+    assertEquals(0, message.getBytesField4Count());
+    assertEquals(0, message.getMessageField5Count());
+
+    assertEquals(0, message.getInt32FieldCount11());
+    assertEquals(0, message.getEnumFieldCount12().getNumber());
+    assertEquals("", message.getStringFieldCount13());
+    assertEquals(ByteString.EMPTY, message.getBytesFieldCount14());
+    assertEquals(0, message.getMessageFieldCount15().getSerializedSize());
+
+    assertEquals(0, message.getInt32Field21Count());
+    assertEquals(0, message.getEnumField22Count());
+    assertEquals(0, message.getStringField23Count());
+    assertEquals(0, message.getBytesField24Count());
+    assertEquals(0, message.getMessageField25Count());
+
+    assertEquals(0, message.getInt32Field1List().size());
+    assertEquals(0, message.getInt32FieldList31());
+
+    assertEquals(0, message.getInt64FieldCount());
+    assertEquals(0L, message.getExtension(
+        TestBadIdentifiersProto.TestConflictingFieldNames.int64FieldCount).longValue());
+    assertEquals(0L, message.getExtension(
+        TestBadIdentifiersProto.TestConflictingFieldNames.int64FieldList).longValue());
+
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/TestUtil.java b/java/core/src/test/java/com/google/protobuf/TestUtil.java
new file mode 100644
index 00000000..01acb884
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/TestUtil.java
@@ -0,0 +1,4275 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto;
+import com.google.protobuf.UnittestLite;
+
+// The static imports are to avoid 100+ char lines.  The following is roughly equivalent to
+// import static protobuf_unittest.UnittestProto.*;
+import static protobuf_unittest.UnittestProto.defaultInt32Extension;
+import static protobuf_unittest.UnittestProto.defaultInt64Extension;
+import static protobuf_unittest.UnittestProto.defaultUint32Extension;
+import static protobuf_unittest.UnittestProto.defaultUint64Extension;
+import static protobuf_unittest.UnittestProto.defaultSint32Extension;
+import static protobuf_unittest.UnittestProto.defaultSint64Extension;
+import static protobuf_unittest.UnittestProto.defaultFixed32Extension;
+import static protobuf_unittest.UnittestProto.defaultFixed64Extension;
+import static protobuf_unittest.UnittestProto.defaultSfixed32Extension;
+import static protobuf_unittest.UnittestProto.defaultSfixed64Extension;
+import static protobuf_unittest.UnittestProto.defaultFloatExtension;
+import static protobuf_unittest.UnittestProto.defaultDoubleExtension;
+import static protobuf_unittest.UnittestProto.defaultBoolExtension;
+import static protobuf_unittest.UnittestProto.defaultStringExtension;
+import static protobuf_unittest.UnittestProto.defaultBytesExtension;
+import static protobuf_unittest.UnittestProto.defaultNestedEnumExtension;
+import static protobuf_unittest.UnittestProto.defaultForeignEnumExtension;
+import static protobuf_unittest.UnittestProto.defaultImportEnumExtension;
+import static protobuf_unittest.UnittestProto.defaultStringPieceExtension;
+import static protobuf_unittest.UnittestProto.defaultCordExtension;
+
+import static protobuf_unittest.UnittestProto.oneofUint32Extension;
+import static protobuf_unittest.UnittestProto.oneofNestedMessageExtension;
+import static protobuf_unittest.UnittestProto.oneofStringExtension;
+import static protobuf_unittest.UnittestProto.oneofBytesExtension;
+
+import static protobuf_unittest.UnittestProto.optionalInt32Extension;
+import static protobuf_unittest.UnittestProto.optionalInt64Extension;
+import static protobuf_unittest.UnittestProto.optionalUint32Extension;
+import static protobuf_unittest.UnittestProto.optionalUint64Extension;
+import static protobuf_unittest.UnittestProto.optionalSint32Extension;
+import static protobuf_unittest.UnittestProto.optionalSint64Extension;
+import static protobuf_unittest.UnittestProto.optionalFixed32Extension;
+import static protobuf_unittest.UnittestProto.optionalFixed64Extension;
+import static protobuf_unittest.UnittestProto.optionalSfixed32Extension;
+import static protobuf_unittest.UnittestProto.optionalSfixed64Extension;
+import static protobuf_unittest.UnittestProto.optionalFloatExtension;
+import static protobuf_unittest.UnittestProto.optionalDoubleExtension;
+import static protobuf_unittest.UnittestProto.optionalBoolExtension;
+import static protobuf_unittest.UnittestProto.optionalStringExtension;
+import static protobuf_unittest.UnittestProto.optionalBytesExtension;
+import static protobuf_unittest.UnittestProto.optionalGroupExtension;
+import static protobuf_unittest.UnittestProto.optionalCordExtension;
+import static protobuf_unittest.UnittestProto.optionalForeignEnumExtension;
+import static protobuf_unittest.UnittestProto.optionalForeignMessageExtension;
+import static protobuf_unittest.UnittestProto.optionalImportEnumExtension;
+import static protobuf_unittest.UnittestProto.optionalImportMessageExtension;
+import static protobuf_unittest.UnittestProto.optionalNestedEnumExtension;
+import static protobuf_unittest.UnittestProto.optionalNestedMessageExtension;
+import static protobuf_unittest.UnittestProto.optionalPublicImportMessageExtension;
+import static protobuf_unittest.UnittestProto.optionalLazyMessageExtension;
+import static protobuf_unittest.UnittestProto.optionalStringPieceExtension;
+
+import static protobuf_unittest.UnittestProto.repeatedInt32Extension;
+import static protobuf_unittest.UnittestProto.repeatedInt64Extension;
+import static protobuf_unittest.UnittestProto.repeatedUint32Extension;
+import static protobuf_unittest.UnittestProto.repeatedUint64Extension;
+import static protobuf_unittest.UnittestProto.repeatedSint32Extension;
+import static protobuf_unittest.UnittestProto.repeatedSint64Extension;
+import static protobuf_unittest.UnittestProto.repeatedFixed32Extension;
+import static protobuf_unittest.UnittestProto.repeatedFixed64Extension;
+import static protobuf_unittest.UnittestProto.repeatedSfixed32Extension;
+import static protobuf_unittest.UnittestProto.repeatedSfixed64Extension;
+import static protobuf_unittest.UnittestProto.repeatedFloatExtension;
+import static protobuf_unittest.UnittestProto.repeatedDoubleExtension;
+import static protobuf_unittest.UnittestProto.repeatedBoolExtension;
+import static protobuf_unittest.UnittestProto.repeatedStringExtension;
+import static protobuf_unittest.UnittestProto.repeatedBytesExtension;
+import static protobuf_unittest.UnittestProto.repeatedGroupExtension;
+import static protobuf_unittest.UnittestProto.repeatedNestedMessageExtension;
+import static protobuf_unittest.UnittestProto.repeatedForeignMessageExtension;
+import static protobuf_unittest.UnittestProto.repeatedImportMessageExtension;
+import static protobuf_unittest.UnittestProto.repeatedLazyMessageExtension;
+import static protobuf_unittest.UnittestProto.repeatedNestedEnumExtension;
+import static protobuf_unittest.UnittestProto.repeatedForeignEnumExtension;
+import static protobuf_unittest.UnittestProto.repeatedImportEnumExtension;
+import static protobuf_unittest.UnittestProto.repeatedStringPieceExtension;
+import static protobuf_unittest.UnittestProto.repeatedCordExtension;
+
+import static protobuf_unittest.UnittestProto.OptionalGroup_extension;
+import static protobuf_unittest.UnittestProto.RepeatedGroup_extension;
+
+import static protobuf_unittest.UnittestProto.packedInt32Extension;
+import static protobuf_unittest.UnittestProto.packedInt64Extension;
+import static protobuf_unittest.UnittestProto.packedUint32Extension;
+import static protobuf_unittest.UnittestProto.packedUint64Extension;
+import static protobuf_unittest.UnittestProto.packedSint32Extension;
+import static protobuf_unittest.UnittestProto.packedSint64Extension;
+import static protobuf_unittest.UnittestProto.packedFixed32Extension;
+import static protobuf_unittest.UnittestProto.packedFixed64Extension;
+import static protobuf_unittest.UnittestProto.packedSfixed32Extension;
+import static protobuf_unittest.UnittestProto.packedSfixed64Extension;
+import static protobuf_unittest.UnittestProto.packedFloatExtension;
+import static protobuf_unittest.UnittestProto.packedDoubleExtension;
+import static protobuf_unittest.UnittestProto.packedBoolExtension;
+import static protobuf_unittest.UnittestProto.packedEnumExtension;
+
+import static com.google.protobuf.UnittestLite.defaultInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultStringExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.defaultCordExtensionLite;
+
+import static com.google.protobuf.UnittestLite.oneofUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofStringExtensionLite;
+import static com.google.protobuf.UnittestLite.oneofBytesExtensionLite;
+
+import static com.google.protobuf.UnittestLite.optionalInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalStringExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalGroupExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalForeignMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalPublicImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalLazyMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.optionalCordExtensionLite;
+
+import static com.google.protobuf.UnittestLite.repeatedInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedStringExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedBytesExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedGroupExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedNestedMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedForeignMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedImportMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedLazyMessageExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedNestedEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedForeignEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedImportEnumExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedStringPieceExtensionLite;
+import static com.google.protobuf.UnittestLite.repeatedCordExtensionLite;
+
+import static com.google.protobuf.UnittestLite.OptionalGroup_extension_lite;
+import static com.google.protobuf.UnittestLite.RepeatedGroup_extension_lite;
+
+import static com.google.protobuf.UnittestLite.packedInt32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedInt64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedUint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedUint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSint32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSint64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSfixed32ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedSfixed64ExtensionLite;
+import static com.google.protobuf.UnittestLite.packedFloatExtensionLite;
+import static com.google.protobuf.UnittestLite.packedDoubleExtensionLite;
+import static com.google.protobuf.UnittestLite.packedBoolExtensionLite;
+import static com.google.protobuf.UnittestLite.packedEnumExtensionLite;
+
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllExtensionsOrBuilder;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestAllTypesOrBuilder;
+import protobuf_unittest.UnittestProto.TestOneof2;
+import protobuf_unittest.UnittestProto.TestPackedExtensions;
+import protobuf_unittest.UnittestProto.TestPackedTypes;
+import protobuf_unittest.UnittestProto.TestUnpackedTypes;
+import protobuf_unittest.UnittestProto.ForeignMessage;
+import protobuf_unittest.UnittestProto.ForeignEnum;
+import com.google.protobuf.test.UnittestImport.ImportEnum;
+import com.google.protobuf.test.UnittestImport.ImportMessage;
+import com.google.protobuf.test.UnittestImportPublic.PublicImportMessage;
+
+import com.google.protobuf.UnittestLite.TestAllTypesLite;
+import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
+import com.google.protobuf.UnittestLite.TestAllExtensionsLiteOrBuilder;
+import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
+import com.google.protobuf.UnittestLite.ForeignMessageLite;
+import com.google.protobuf.UnittestLite.ForeignEnumLite;
+import com.google.protobuf.UnittestImportLite.ImportEnumLite;
+import com.google.protobuf.UnittestImportLite.ImportMessageLite;
+import com.google.protobuf.UnittestImportPublicLite.PublicImportMessageLite;
+
+import junit.framework.Assert;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+/**
+ * Contains methods for setting all fields of {@code TestAllTypes} to
+ * some values as well as checking that all the fields are set to those values.
+ * These are useful for testing various protocol message features, e.g.
+ * set all fields of a message, serialize it, parse it, and check that all
+ * fields are set.
+ *
+ * <p>This code is not to be used outside of {@code com.google.protobuf} and
+ * subpackages.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public final class TestUtil {
+  private TestUtil() {}
+
+  /** Helper to convert a String to ByteString. */
+  static ByteString toBytes(String str) {
+    return ByteString.copyFrom(str.getBytes(Internal.UTF_8));
+  }
+
+  /**
+   * Get a {@code TestAllTypes} with all fields set as they would be by
+   * {@link #setAllFields(TestAllTypes.Builder)}.
+   */
+  public static TestAllTypes getAllSet() {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    setAllFields(builder);
+    return builder.build();
+  }
+
+  /**
+   * Get a {@code TestAllTypes.Builder} with all fields set as they would be by
+   * {@link #setAllFields(TestAllTypes.Builder)}.
+   */
+  public static TestAllTypes.Builder getAllSetBuilder() {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    setAllFields(builder);
+    return builder;
+  }
+
+  /**
+   * Get a {@code TestAllTypesLite.Builder} with all fields set as they would be by
+   * {@link #setAllFields(TestAllTypesLite.Builder)}.
+   */
+  public static TestAllTypesLite.Builder getAllLiteSetBuilder() {
+    TestAllTypesLite.Builder builder = TestAllTypesLite.newBuilder();
+    setAllFields(builder);
+    return builder;
+  }
+
+  /**
+   * Get a {@code TestAllExtensions} with all fields set as they would be by
+   * {@link #setAllExtensions(TestAllExtensions.Builder)}.
+   */
+  public static TestAllExtensions getAllExtensionsSet() {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    setAllExtensions(builder);
+    return builder.build();
+  }
+
+  public static TestAllExtensionsLite getAllLiteExtensionsSet() {
+    TestAllExtensionsLite.Builder builder = TestAllExtensionsLite.newBuilder();
+    setAllExtensions(builder);
+    return builder.build();
+  }
+
+  public static TestPackedTypes getPackedSet() {
+    TestPackedTypes.Builder builder = TestPackedTypes.newBuilder();
+    setPackedFields(builder);
+    return builder.build();
+  }
+
+  public static TestUnpackedTypes getUnpackedSet() {
+    TestUnpackedTypes.Builder builder = TestUnpackedTypes.newBuilder();
+    setUnpackedFields(builder);
+    return builder.build();
+  }
+
+  public static TestPackedExtensions getPackedExtensionsSet() {
+    TestPackedExtensions.Builder builder = TestPackedExtensions.newBuilder();
+    setPackedExtensions(builder);
+    return builder.build();
+  }
+
+  public static TestPackedExtensionsLite getLitePackedExtensionsSet() {
+    TestPackedExtensionsLite.Builder builder =
+        TestPackedExtensionsLite.newBuilder();
+    setPackedExtensions(builder);
+    return builder.build();
+  }
+  
+  /**
+   * Set every field of {@code builder} to the values expected by
+   * {@code assertAllFieldsSet()}.
+   */
+  public static void setAllFields(TestAllTypesLite.Builder builder) {
+    builder.setOptionalInt32   (101);
+    builder.setOptionalInt64   (102);
+    builder.setOptionalUint32  (103);
+    builder.setOptionalUint64  (104);
+    builder.setOptionalSint32  (105);
+    builder.setOptionalSint64  (106);
+    builder.setOptionalFixed32 (107);
+    builder.setOptionalFixed64 (108);
+    builder.setOptionalSfixed32(109);
+    builder.setOptionalSfixed64(110);
+    builder.setOptionalFloat   (111);
+    builder.setOptionalDouble  (112);
+    builder.setOptionalBool    (true);
+    builder.setOptionalString  ("115");
+    builder.setOptionalBytes   (toBytes("116"));
+
+    builder.setOptionalGroup(
+        TestAllTypesLite.OptionalGroup.newBuilder().setA(117).build());
+    builder.setOptionalNestedMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(118).build());
+    builder.setOptionalForeignMessage(
+        ForeignMessageLite.newBuilder().setC(119).build());
+    builder.setOptionalImportMessage(
+        ImportMessageLite.newBuilder().setD(120).build());
+    builder.setOptionalPublicImportMessage(
+        PublicImportMessageLite.newBuilder().setE(126).build());
+    builder.setOptionalLazyMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(127).build());
+
+    builder.setOptionalNestedEnum (TestAllTypesLite.NestedEnum.BAZ);
+    builder.setOptionalForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAZ);
+    builder.setOptionalImportEnum (ImportEnumLite.IMPORT_LITE_BAZ);
+
+    builder.setOptionalStringPiece("124");
+    builder.setOptionalCord("125");
+
+    // -----------------------------------------------------------------
+
+    builder.addRepeatedInt32   (201);
+    builder.addRepeatedInt64   (202);
+    builder.addRepeatedUint32  (203);
+    builder.addRepeatedUint64  (204);
+    builder.addRepeatedSint32  (205);
+    builder.addRepeatedSint64  (206);
+    builder.addRepeatedFixed32 (207);
+    builder.addRepeatedFixed64 (208);
+    builder.addRepeatedSfixed32(209);
+    builder.addRepeatedSfixed64(210);
+    builder.addRepeatedFloat   (211);
+    builder.addRepeatedDouble  (212);
+    builder.addRepeatedBool    (true);
+    builder.addRepeatedString  ("215");
+    builder.addRepeatedBytes   (toBytes("216"));
+
+    builder.addRepeatedGroup(
+        TestAllTypesLite.RepeatedGroup.newBuilder().setA(217).build());
+    builder.addRepeatedNestedMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(218).build());
+    builder.addRepeatedForeignMessage(
+        ForeignMessageLite.newBuilder().setC(219).build());
+    builder.addRepeatedImportMessage(
+        ImportMessageLite.newBuilder().setD(220).build());
+    builder.addRepeatedLazyMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(227).build());
+
+    builder.addRepeatedNestedEnum (TestAllTypesLite.NestedEnum.BAR);
+    builder.addRepeatedForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAR);
+    builder.addRepeatedImportEnum (ImportEnumLite.IMPORT_LITE_BAR);
+
+    builder.addRepeatedStringPiece("224");
+    builder.addRepeatedCord("225");
+
+    // Add a second one of each field.
+    builder.addRepeatedInt32   (301);
+    builder.addRepeatedInt64   (302);
+    builder.addRepeatedUint32  (303);
+    builder.addRepeatedUint64  (304);
+    builder.addRepeatedSint32  (305);
+    builder.addRepeatedSint64  (306);
+    builder.addRepeatedFixed32 (307);
+    builder.addRepeatedFixed64 (308);
+    builder.addRepeatedSfixed32(309);
+    builder.addRepeatedSfixed64(310);
+    builder.addRepeatedFloat   (311);
+    builder.addRepeatedDouble  (312);
+    builder.addRepeatedBool    (false);
+    builder.addRepeatedString  ("315");
+    builder.addRepeatedBytes   (toBytes("316"));
+
+    builder.addRepeatedGroup(
+        TestAllTypesLite.RepeatedGroup.newBuilder().setA(317).build());
+    builder.addRepeatedNestedMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(318).build());
+    builder.addRepeatedForeignMessage(
+        ForeignMessageLite.newBuilder().setC(319).build());
+    builder.addRepeatedImportMessage(
+        ImportMessageLite.newBuilder().setD(320).build());
+    builder.addRepeatedLazyMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(327).build());
+
+    builder.addRepeatedNestedEnum (TestAllTypesLite.NestedEnum.BAZ);
+    builder.addRepeatedForeignEnum(ForeignEnumLite.FOREIGN_LITE_BAZ);
+    builder.addRepeatedImportEnum (ImportEnumLite.IMPORT_LITE_BAZ);
+
+    builder.addRepeatedStringPiece("324");
+    builder.addRepeatedCord("325");
+
+    // -----------------------------------------------------------------
+
+    builder.setDefaultInt32   (401);
+    builder.setDefaultInt64   (402);
+    builder.setDefaultUint32  (403);
+    builder.setDefaultUint64  (404);
+    builder.setDefaultSint32  (405);
+    builder.setDefaultSint64  (406);
+    builder.setDefaultFixed32 (407);
+    builder.setDefaultFixed64 (408);
+    builder.setDefaultSfixed32(409);
+    builder.setDefaultSfixed64(410);
+    builder.setDefaultFloat   (411);
+    builder.setDefaultDouble  (412);
+    builder.setDefaultBool    (false);
+    builder.setDefaultString  ("415");
+    builder.setDefaultBytes   (toBytes("416"));
+
+    builder.setDefaultNestedEnum (TestAllTypesLite.NestedEnum.FOO);
+    builder.setDefaultForeignEnum(ForeignEnumLite.FOREIGN_LITE_FOO);
+    builder.setDefaultImportEnum (ImportEnumLite.IMPORT_LITE_FOO);
+
+    builder.setDefaultStringPiece("424");
+    builder.setDefaultCord("425");
+
+    builder.setOneofUint32(601);
+    builder.setOneofNestedMessage(
+        TestAllTypesLite.NestedMessage.newBuilder().setBb(602).build());
+    builder.setOneofString("603");
+    builder.setOneofBytes(toBytes("604"));
+  }
+
+  /**
+   * Set every field of {@code message} to the values expected by
+   * {@code assertAllFieldsSet()}.
+   */
+  public static void setAllFields(TestAllTypes.Builder message) {
+    message.setOptionalInt32   (101);
+    message.setOptionalInt64   (102);
+    message.setOptionalUint32  (103);
+    message.setOptionalUint64  (104);
+    message.setOptionalSint32  (105);
+    message.setOptionalSint64  (106);
+    message.setOptionalFixed32 (107);
+    message.setOptionalFixed64 (108);
+    message.setOptionalSfixed32(109);
+    message.setOptionalSfixed64(110);
+    message.setOptionalFloat   (111);
+    message.setOptionalDouble  (112);
+    message.setOptionalBool    (true);
+    message.setOptionalString  ("115");
+    message.setOptionalBytes   (toBytes("116"));
+
+    message.setOptionalGroup(
+      TestAllTypes.OptionalGroup.newBuilder().setA(117).build());
+    message.setOptionalNestedMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(118).build());
+    message.setOptionalForeignMessage(
+      ForeignMessage.newBuilder().setC(119).build());
+    message.setOptionalImportMessage(
+      ImportMessage.newBuilder().setD(120).build());
+    message.setOptionalPublicImportMessage(
+      PublicImportMessage.newBuilder().setE(126).build());
+    message.setOptionalLazyMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(127).build());
+
+    message.setOptionalNestedEnum (TestAllTypes.NestedEnum.BAZ);
+    message.setOptionalForeignEnum(ForeignEnum.FOREIGN_BAZ);
+    message.setOptionalImportEnum (ImportEnum.IMPORT_BAZ);
+
+    message.setOptionalStringPiece("124");
+    message.setOptionalCord("125");
+
+    // -----------------------------------------------------------------
+
+    message.addRepeatedInt32   (201);
+    message.addRepeatedInt64   (202);
+    message.addRepeatedUint32  (203);
+    message.addRepeatedUint64  (204);
+    message.addRepeatedSint32  (205);
+    message.addRepeatedSint64  (206);
+    message.addRepeatedFixed32 (207);
+    message.addRepeatedFixed64 (208);
+    message.addRepeatedSfixed32(209);
+    message.addRepeatedSfixed64(210);
+    message.addRepeatedFloat   (211);
+    message.addRepeatedDouble  (212);
+    message.addRepeatedBool    (true);
+    message.addRepeatedString  ("215");
+    message.addRepeatedBytes   (toBytes("216"));
+
+    message.addRepeatedGroup(
+      TestAllTypes.RepeatedGroup.newBuilder().setA(217).build());
+    message.addRepeatedNestedMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(218).build());
+    message.addRepeatedForeignMessage(
+      ForeignMessage.newBuilder().setC(219).build());
+    message.addRepeatedImportMessage(
+      ImportMessage.newBuilder().setD(220).build());
+    message.addRepeatedLazyMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(227).build());
+
+    message.addRepeatedNestedEnum (TestAllTypes.NestedEnum.BAR);
+    message.addRepeatedForeignEnum(ForeignEnum.FOREIGN_BAR);
+    message.addRepeatedImportEnum (ImportEnum.IMPORT_BAR);
+
+    message.addRepeatedStringPiece("224");
+    message.addRepeatedCord("225");
+
+    // Add a second one of each field.
+    message.addRepeatedInt32   (301);
+    message.addRepeatedInt64   (302);
+    message.addRepeatedUint32  (303);
+    message.addRepeatedUint64  (304);
+    message.addRepeatedSint32  (305);
+    message.addRepeatedSint64  (306);
+    message.addRepeatedFixed32 (307);
+    message.addRepeatedFixed64 (308);
+    message.addRepeatedSfixed32(309);
+    message.addRepeatedSfixed64(310);
+    message.addRepeatedFloat   (311);
+    message.addRepeatedDouble  (312);
+    message.addRepeatedBool    (false);
+    message.addRepeatedString  ("315");
+    message.addRepeatedBytes   (toBytes("316"));
+
+    message.addRepeatedGroup(
+      TestAllTypes.RepeatedGroup.newBuilder().setA(317).build());
+    message.addRepeatedNestedMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(318).build());
+    message.addRepeatedForeignMessage(
+      ForeignMessage.newBuilder().setC(319).build());
+    message.addRepeatedImportMessage(
+      ImportMessage.newBuilder().setD(320).build());
+    message.addRepeatedLazyMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(327).build());
+
+    message.addRepeatedNestedEnum (TestAllTypes.NestedEnum.BAZ);
+    message.addRepeatedForeignEnum(ForeignEnum.FOREIGN_BAZ);
+    message.addRepeatedImportEnum (ImportEnum.IMPORT_BAZ);
+
+    message.addRepeatedStringPiece("324");
+    message.addRepeatedCord("325");
+
+    // -----------------------------------------------------------------
+
+    message.setDefaultInt32   (401);
+    message.setDefaultInt64   (402);
+    message.setDefaultUint32  (403);
+    message.setDefaultUint64  (404);
+    message.setDefaultSint32  (405);
+    message.setDefaultSint64  (406);
+    message.setDefaultFixed32 (407);
+    message.setDefaultFixed64 (408);
+    message.setDefaultSfixed32(409);
+    message.setDefaultSfixed64(410);
+    message.setDefaultFloat   (411);
+    message.setDefaultDouble  (412);
+    message.setDefaultBool    (false);
+    message.setDefaultString  ("415");
+    message.setDefaultBytes   (toBytes("416"));
+
+    message.setDefaultNestedEnum (TestAllTypes.NestedEnum.FOO);
+    message.setDefaultForeignEnum(ForeignEnum.FOREIGN_FOO);
+    message.setDefaultImportEnum (ImportEnum.IMPORT_FOO);
+
+    message.setDefaultStringPiece("424");
+    message.setDefaultCord("425");
+
+    message.setOneofUint32(601);
+    message.setOneofNestedMessage(
+      TestAllTypes.NestedMessage.newBuilder().setBb(602).build());
+    message.setOneofString("603");
+    message.setOneofBytes(toBytes("604"));
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Modify the repeated fields of {@code message} to contain the values
+   * expected by {@code assertRepeatedFieldsModified()}.
+   */
+  public static void modifyRepeatedFields(TestAllTypes.Builder message) {
+    message.setRepeatedInt32   (1, 501);
+    message.setRepeatedInt64   (1, 502);
+    message.setRepeatedUint32  (1, 503);
+    message.setRepeatedUint64  (1, 504);
+    message.setRepeatedSint32  (1, 505);
+    message.setRepeatedSint64  (1, 506);
+    message.setRepeatedFixed32 (1, 507);
+    message.setRepeatedFixed64 (1, 508);
+    message.setRepeatedSfixed32(1, 509);
+    message.setRepeatedSfixed64(1, 510);
+    message.setRepeatedFloat   (1, 511);
+    message.setRepeatedDouble  (1, 512);
+    message.setRepeatedBool    (1, true);
+    message.setRepeatedString  (1, "515");
+    message.setRepeatedBytes   (1, toBytes("516"));
+
+    message.setRepeatedGroup(1,
+      TestAllTypes.RepeatedGroup.newBuilder().setA(517).build());
+    message.setRepeatedNestedMessage(1,
+      TestAllTypes.NestedMessage.newBuilder().setBb(518).build());
+    message.setRepeatedForeignMessage(1,
+      ForeignMessage.newBuilder().setC(519).build());
+    message.setRepeatedImportMessage(1,
+      ImportMessage.newBuilder().setD(520).build());
+    message.setRepeatedLazyMessage(1,
+      TestAllTypes.NestedMessage.newBuilder().setBb(527).build());
+
+    message.setRepeatedNestedEnum (1, TestAllTypes.NestedEnum.FOO);
+    message.setRepeatedForeignEnum(1, ForeignEnum.FOREIGN_FOO);
+    message.setRepeatedImportEnum (1, ImportEnum.IMPORT_FOO);
+
+    message.setRepeatedStringPiece(1, "524");
+    message.setRepeatedCord(1, "525");
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all fields of
+   * {@code message} are set to the values assigned by {@code setAllFields}.
+   */
+  public static void assertAllFieldsSet(TestAllTypesOrBuilder message) {
+    Assert.assertTrue(message.hasOptionalInt32   ());
+    Assert.assertTrue(message.hasOptionalInt64   ());
+    Assert.assertTrue(message.hasOptionalUint32  ());
+    Assert.assertTrue(message.hasOptionalUint64  ());
+    Assert.assertTrue(message.hasOptionalSint32  ());
+    Assert.assertTrue(message.hasOptionalSint64  ());
+    Assert.assertTrue(message.hasOptionalFixed32 ());
+    Assert.assertTrue(message.hasOptionalFixed64 ());
+    Assert.assertTrue(message.hasOptionalSfixed32());
+    Assert.assertTrue(message.hasOptionalSfixed64());
+    Assert.assertTrue(message.hasOptionalFloat   ());
+    Assert.assertTrue(message.hasOptionalDouble  ());
+    Assert.assertTrue(message.hasOptionalBool    ());
+    Assert.assertTrue(message.hasOptionalString  ());
+    Assert.assertTrue(message.hasOptionalBytes   ());
+
+    Assert.assertTrue(message.hasOptionalGroup         ());
+    Assert.assertTrue(message.hasOptionalNestedMessage ());
+    Assert.assertTrue(message.hasOptionalForeignMessage());
+    Assert.assertTrue(message.hasOptionalImportMessage ());
+
+    Assert.assertTrue(message.getOptionalGroup         ().hasA());
+    Assert.assertTrue(message.getOptionalNestedMessage ().hasBb());
+    Assert.assertTrue(message.getOptionalForeignMessage().hasC());
+    Assert.assertTrue(message.getOptionalImportMessage ().hasD());
+
+    Assert.assertTrue(message.hasOptionalNestedEnum ());
+    Assert.assertTrue(message.hasOptionalForeignEnum());
+    Assert.assertTrue(message.hasOptionalImportEnum ());
+
+    Assert.assertTrue(message.hasOptionalStringPiece());
+    Assert.assertTrue(message.hasOptionalCord());
+
+    Assert.assertEquals(101  , message.getOptionalInt32   ());
+    Assert.assertEquals(102  , message.getOptionalInt64   ());
+    Assert.assertEquals(103  , message.getOptionalUint32  ());
+    Assert.assertEquals(104  , message.getOptionalUint64  ());
+    Assert.assertEquals(105  , message.getOptionalSint32  ());
+    Assert.assertEquals(106  , message.getOptionalSint64  ());
+    Assert.assertEquals(107  , message.getOptionalFixed32 ());
+    Assert.assertEquals(108  , message.getOptionalFixed64 ());
+    Assert.assertEquals(109  , message.getOptionalSfixed32());
+    Assert.assertEquals(110  , message.getOptionalSfixed64());
+    Assert.assertEquals(111  , message.getOptionalFloat   (), 0.0);
+    Assert.assertEquals(112  , message.getOptionalDouble  (), 0.0);
+    Assert.assertEquals(true , message.getOptionalBool    ());
+    Assert.assertEquals("115", message.getOptionalString  ());
+    Assert.assertEquals(toBytes("116"), message.getOptionalBytes());
+
+    Assert.assertEquals(117, message.getOptionalGroup              ().getA());
+    Assert.assertEquals(118, message.getOptionalNestedMessage      ().getBb());
+    Assert.assertEquals(119, message.getOptionalForeignMessage     ().getC());
+    Assert.assertEquals(120, message.getOptionalImportMessage      ().getD());
+    Assert.assertEquals(126, message.getOptionalPublicImportMessage().getE());
+    Assert.assertEquals(127, message.getOptionalLazyMessage        ().getBb());
+
+    Assert.assertEquals(TestAllTypes.NestedEnum.BAZ, message.getOptionalNestedEnum());
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAZ, message.getOptionalForeignEnum());
+    Assert.assertEquals(ImportEnum.IMPORT_BAZ, message.getOptionalImportEnum());
+
+    Assert.assertEquals("124", message.getOptionalStringPiece());
+    Assert.assertEquals("125", message.getOptionalCord());
+
+    // -----------------------------------------------------------------
+
+    Assert.assertEquals(2, message.getRepeatedInt32Count   ());
+    Assert.assertEquals(2, message.getRepeatedInt64Count   ());
+    Assert.assertEquals(2, message.getRepeatedUint32Count  ());
+    Assert.assertEquals(2, message.getRepeatedUint64Count  ());
+    Assert.assertEquals(2, message.getRepeatedSint32Count  ());
+    Assert.assertEquals(2, message.getRepeatedSint64Count  ());
+    Assert.assertEquals(2, message.getRepeatedFixed32Count ());
+    Assert.assertEquals(2, message.getRepeatedFixed64Count ());
+    Assert.assertEquals(2, message.getRepeatedSfixed32Count());
+    Assert.assertEquals(2, message.getRepeatedSfixed64Count());
+    Assert.assertEquals(2, message.getRepeatedFloatCount   ());
+    Assert.assertEquals(2, message.getRepeatedDoubleCount  ());
+    Assert.assertEquals(2, message.getRepeatedBoolCount    ());
+    Assert.assertEquals(2, message.getRepeatedStringCount  ());
+    Assert.assertEquals(2, message.getRepeatedBytesCount   ());
+
+    Assert.assertEquals(2, message.getRepeatedGroupCount         ());
+    Assert.assertEquals(2, message.getRepeatedNestedMessageCount ());
+    Assert.assertEquals(2, message.getRepeatedForeignMessageCount());
+    Assert.assertEquals(2, message.getRepeatedImportMessageCount ());
+    Assert.assertEquals(2, message.getRepeatedLazyMessageCount   ());
+    Assert.assertEquals(2, message.getRepeatedNestedEnumCount    ());
+    Assert.assertEquals(2, message.getRepeatedForeignEnumCount   ());
+    Assert.assertEquals(2, message.getRepeatedImportEnumCount    ());
+
+    Assert.assertEquals(2, message.getRepeatedStringPieceCount());
+    Assert.assertEquals(2, message.getRepeatedCordCount());
+
+    Assert.assertEquals(201  , message.getRepeatedInt32   (0));
+    Assert.assertEquals(202  , message.getRepeatedInt64   (0));
+    Assert.assertEquals(203  , message.getRepeatedUint32  (0));
+    Assert.assertEquals(204  , message.getRepeatedUint64  (0));
+    Assert.assertEquals(205  , message.getRepeatedSint32  (0));
+    Assert.assertEquals(206  , message.getRepeatedSint64  (0));
+    Assert.assertEquals(207  , message.getRepeatedFixed32 (0));
+    Assert.assertEquals(208  , message.getRepeatedFixed64 (0));
+    Assert.assertEquals(209  , message.getRepeatedSfixed32(0));
+    Assert.assertEquals(210  , message.getRepeatedSfixed64(0));
+    Assert.assertEquals(211  , message.getRepeatedFloat   (0), 0.0);
+    Assert.assertEquals(212  , message.getRepeatedDouble  (0), 0.0);
+    Assert.assertEquals(true , message.getRepeatedBool    (0));
+    Assert.assertEquals("215", message.getRepeatedString  (0));
+    Assert.assertEquals(toBytes("216"), message.getRepeatedBytes(0));
+
+    Assert.assertEquals(217, message.getRepeatedGroup         (0).getA());
+    Assert.assertEquals(218, message.getRepeatedNestedMessage (0).getBb());
+    Assert.assertEquals(219, message.getRepeatedForeignMessage(0).getC());
+    Assert.assertEquals(220, message.getRepeatedImportMessage (0).getD());
+    Assert.assertEquals(227, message.getRepeatedLazyMessage   (0).getBb());
+
+    Assert.assertEquals(TestAllTypes.NestedEnum.BAR, message.getRepeatedNestedEnum (0));
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAR, message.getRepeatedForeignEnum(0));
+    Assert.assertEquals(ImportEnum.IMPORT_BAR, message.getRepeatedImportEnum(0));
+
+    Assert.assertEquals("224", message.getRepeatedStringPiece(0));
+    Assert.assertEquals("225", message.getRepeatedCord(0));
+
+    Assert.assertEquals(301  , message.getRepeatedInt32   (1));
+    Assert.assertEquals(302  , message.getRepeatedInt64   (1));
+    Assert.assertEquals(303  , message.getRepeatedUint32  (1));
+    Assert.assertEquals(304  , message.getRepeatedUint64  (1));
+    Assert.assertEquals(305  , message.getRepeatedSint32  (1));
+    Assert.assertEquals(306  , message.getRepeatedSint64  (1));
+    Assert.assertEquals(307  , message.getRepeatedFixed32 (1));
+    Assert.assertEquals(308  , message.getRepeatedFixed64 (1));
+    Assert.assertEquals(309  , message.getRepeatedSfixed32(1));
+    Assert.assertEquals(310  , message.getRepeatedSfixed64(1));
+    Assert.assertEquals(311  , message.getRepeatedFloat   (1), 0.0);
+    Assert.assertEquals(312  , message.getRepeatedDouble  (1), 0.0);
+    Assert.assertEquals(false, message.getRepeatedBool    (1));
+    Assert.assertEquals("315", message.getRepeatedString  (1));
+    Assert.assertEquals(toBytes("316"), message.getRepeatedBytes(1));
+
+    Assert.assertEquals(317, message.getRepeatedGroup         (1).getA());
+    Assert.assertEquals(318, message.getRepeatedNestedMessage (1).getBb());
+    Assert.assertEquals(319, message.getRepeatedForeignMessage(1).getC());
+    Assert.assertEquals(320, message.getRepeatedImportMessage (1).getD());
+    Assert.assertEquals(327, message.getRepeatedLazyMessage   (1).getBb());
+
+    Assert.assertEquals(TestAllTypes.NestedEnum.BAZ, message.getRepeatedNestedEnum (1));
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAZ, message.getRepeatedForeignEnum(1));
+    Assert.assertEquals(ImportEnum.IMPORT_BAZ, message.getRepeatedImportEnum(1));
+
+    Assert.assertEquals("324", message.getRepeatedStringPiece(1));
+    Assert.assertEquals("325", message.getRepeatedCord(1));
+
+    // -----------------------------------------------------------------
+
+    Assert.assertTrue(message.hasDefaultInt32   ());
+    Assert.assertTrue(message.hasDefaultInt64   ());
+    Assert.assertTrue(message.hasDefaultUint32  ());
+    Assert.assertTrue(message.hasDefaultUint64  ());
+    Assert.assertTrue(message.hasDefaultSint32  ());
+    Assert.assertTrue(message.hasDefaultSint64  ());
+    Assert.assertTrue(message.hasDefaultFixed32 ());
+    Assert.assertTrue(message.hasDefaultFixed64 ());
+    Assert.assertTrue(message.hasDefaultSfixed32());
+    Assert.assertTrue(message.hasDefaultSfixed64());
+    Assert.assertTrue(message.hasDefaultFloat   ());
+    Assert.assertTrue(message.hasDefaultDouble  ());
+    Assert.assertTrue(message.hasDefaultBool    ());
+    Assert.assertTrue(message.hasDefaultString  ());
+    Assert.assertTrue(message.hasDefaultBytes   ());
+
+    Assert.assertTrue(message.hasDefaultNestedEnum ());
+    Assert.assertTrue(message.hasDefaultForeignEnum());
+    Assert.assertTrue(message.hasDefaultImportEnum ());
+
+    Assert.assertTrue(message.hasDefaultStringPiece());
+    Assert.assertTrue(message.hasDefaultCord());
+
+    Assert.assertEquals(401  , message.getDefaultInt32   ());
+    Assert.assertEquals(402  , message.getDefaultInt64   ());
+    Assert.assertEquals(403  , message.getDefaultUint32  ());
+    Assert.assertEquals(404  , message.getDefaultUint64  ());
+    Assert.assertEquals(405  , message.getDefaultSint32  ());
+    Assert.assertEquals(406  , message.getDefaultSint64  ());
+    Assert.assertEquals(407  , message.getDefaultFixed32 ());
+    Assert.assertEquals(408  , message.getDefaultFixed64 ());
+    Assert.assertEquals(409  , message.getDefaultSfixed32());
+    Assert.assertEquals(410  , message.getDefaultSfixed64());
+    Assert.assertEquals(411  , message.getDefaultFloat   (), 0.0);
+    Assert.assertEquals(412  , message.getDefaultDouble  (), 0.0);
+    Assert.assertEquals(false, message.getDefaultBool    ());
+    Assert.assertEquals("415", message.getDefaultString  ());
+    Assert.assertEquals(toBytes("416"), message.getDefaultBytes());
+
+    Assert.assertEquals(TestAllTypes.NestedEnum.FOO, message.getDefaultNestedEnum ());
+    Assert.assertEquals(ForeignEnum.FOREIGN_FOO, message.getDefaultForeignEnum());
+    Assert.assertEquals(ImportEnum.IMPORT_FOO, message.getDefaultImportEnum());
+
+    Assert.assertEquals("424", message.getDefaultStringPiece());
+    Assert.assertEquals("425", message.getDefaultCord());
+
+    Assert.assertEquals(TestAllTypes.OneofFieldCase.ONEOF_BYTES, message.getOneofFieldCase());
+    Assert.assertFalse(message.hasOneofUint32());
+    Assert.assertFalse(message.hasOneofNestedMessage());
+    Assert.assertFalse(message.hasOneofString());
+    Assert.assertTrue(message.hasOneofBytes());
+
+    Assert.assertEquals(toBytes("604"), message.getOneofBytes());
+  }
+
+  // -------------------------------------------------------------------
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all fields of
+   * {@code message} are cleared, and that getting the fields returns their
+   * default values.
+   */
+  public static void assertClear(TestAllTypesOrBuilder message) {
+    // hasBlah() should initially be false for all optional fields.
+    Assert.assertFalse(message.hasOptionalInt32   ());
+    Assert.assertFalse(message.hasOptionalInt64   ());
+    Assert.assertFalse(message.hasOptionalUint32  ());
+    Assert.assertFalse(message.hasOptionalUint64  ());
+    Assert.assertFalse(message.hasOptionalSint32  ());
+    Assert.assertFalse(message.hasOptionalSint64  ());
+    Assert.assertFalse(message.hasOptionalFixed32 ());
+    Assert.assertFalse(message.hasOptionalFixed64 ());
+    Assert.assertFalse(message.hasOptionalSfixed32());
+    Assert.assertFalse(message.hasOptionalSfixed64());
+    Assert.assertFalse(message.hasOptionalFloat   ());
+    Assert.assertFalse(message.hasOptionalDouble  ());
+    Assert.assertFalse(message.hasOptionalBool    ());
+    Assert.assertFalse(message.hasOptionalString  ());
+    Assert.assertFalse(message.hasOptionalBytes   ());
+
+    Assert.assertFalse(message.hasOptionalGroup         ());
+    Assert.assertFalse(message.hasOptionalNestedMessage ());
+    Assert.assertFalse(message.hasOptionalForeignMessage());
+    Assert.assertFalse(message.hasOptionalImportMessage ());
+
+    Assert.assertFalse(message.hasOptionalNestedEnum ());
+    Assert.assertFalse(message.hasOptionalForeignEnum());
+    Assert.assertFalse(message.hasOptionalImportEnum ());
+
+    Assert.assertFalse(message.hasOptionalStringPiece());
+    Assert.assertFalse(message.hasOptionalCord());
+
+    // Optional fields without defaults are set to zero or something like it.
+    Assert.assertEquals(0    , message.getOptionalInt32   ());
+    Assert.assertEquals(0    , message.getOptionalInt64   ());
+    Assert.assertEquals(0    , message.getOptionalUint32  ());
+    Assert.assertEquals(0    , message.getOptionalUint64  ());
+    Assert.assertEquals(0    , message.getOptionalSint32  ());
+    Assert.assertEquals(0    , message.getOptionalSint64  ());
+    Assert.assertEquals(0    , message.getOptionalFixed32 ());
+    Assert.assertEquals(0    , message.getOptionalFixed64 ());
+    Assert.assertEquals(0    , message.getOptionalSfixed32());
+    Assert.assertEquals(0    , message.getOptionalSfixed64());
+    Assert.assertEquals(0    , message.getOptionalFloat   (), 0.0);
+    Assert.assertEquals(0    , message.getOptionalDouble  (), 0.0);
+    Assert.assertEquals(false, message.getOptionalBool    ());
+    Assert.assertEquals(""   , message.getOptionalString  ());
+    Assert.assertEquals(ByteString.EMPTY, message.getOptionalBytes());
+
+    // Embedded messages should also be clear.
+    Assert.assertFalse(message.getOptionalGroup              ().hasA());
+    Assert.assertFalse(message.getOptionalNestedMessage      ().hasBb());
+    Assert.assertFalse(message.getOptionalForeignMessage     ().hasC());
+    Assert.assertFalse(message.getOptionalImportMessage      ().hasD());
+    Assert.assertFalse(message.getOptionalPublicImportMessage().hasE());
+    Assert.assertFalse(message.getOptionalLazyMessage        ().hasBb());
+
+    Assert.assertEquals(0, message.getOptionalGroup              ().getA());
+    Assert.assertEquals(0, message.getOptionalNestedMessage      ().getBb());
+    Assert.assertEquals(0, message.getOptionalForeignMessage     ().getC());
+    Assert.assertEquals(0, message.getOptionalImportMessage      ().getD());
+    Assert.assertEquals(0, message.getOptionalPublicImportMessage().getE());
+    Assert.assertEquals(0, message.getOptionalLazyMessage        ().getBb());
+
+    // Enums without defaults are set to the first value in the enum.
+    Assert.assertEquals(TestAllTypes.NestedEnum.FOO, message.getOptionalNestedEnum ());
+    Assert.assertEquals(ForeignEnum.FOREIGN_FOO, message.getOptionalForeignEnum());
+    Assert.assertEquals(ImportEnum.IMPORT_FOO, message.getOptionalImportEnum());
+
+    Assert.assertEquals("", message.getOptionalStringPiece());
+    Assert.assertEquals("", message.getOptionalCord());
+
+    // Repeated fields are empty.
+    Assert.assertEquals(0, message.getRepeatedInt32Count   ());
+    Assert.assertEquals(0, message.getRepeatedInt64Count   ());
+    Assert.assertEquals(0, message.getRepeatedUint32Count  ());
+    Assert.assertEquals(0, message.getRepeatedUint64Count  ());
+    Assert.assertEquals(0, message.getRepeatedSint32Count  ());
+    Assert.assertEquals(0, message.getRepeatedSint64Count  ());
+    Assert.assertEquals(0, message.getRepeatedFixed32Count ());
+    Assert.assertEquals(0, message.getRepeatedFixed64Count ());
+    Assert.assertEquals(0, message.getRepeatedSfixed32Count());
+    Assert.assertEquals(0, message.getRepeatedSfixed64Count());
+    Assert.assertEquals(0, message.getRepeatedFloatCount   ());
+    Assert.assertEquals(0, message.getRepeatedDoubleCount  ());
+    Assert.assertEquals(0, message.getRepeatedBoolCount    ());
+    Assert.assertEquals(0, message.getRepeatedStringCount  ());
+    Assert.assertEquals(0, message.getRepeatedBytesCount   ());
+
+    Assert.assertEquals(0, message.getRepeatedGroupCount         ());
+    Assert.assertEquals(0, message.getRepeatedNestedMessageCount ());
+    Assert.assertEquals(0, message.getRepeatedForeignMessageCount());
+    Assert.assertEquals(0, message.getRepeatedImportMessageCount ());
+    Assert.assertEquals(0, message.getRepeatedLazyMessageCount   ());
+    Assert.assertEquals(0, message.getRepeatedNestedEnumCount    ());
+    Assert.assertEquals(0, message.getRepeatedForeignEnumCount   ());
+    Assert.assertEquals(0, message.getRepeatedImportEnumCount    ());
+
+    Assert.assertEquals(0, message.getRepeatedStringPieceCount());
+    Assert.assertEquals(0, message.getRepeatedCordCount());
+
+    // hasBlah() should also be false for all default fields.
+    Assert.assertFalse(message.hasDefaultInt32   ());
+    Assert.assertFalse(message.hasDefaultInt64   ());
+    Assert.assertFalse(message.hasDefaultUint32  ());
+    Assert.assertFalse(message.hasDefaultUint64  ());
+    Assert.assertFalse(message.hasDefaultSint32  ());
+    Assert.assertFalse(message.hasDefaultSint64  ());
+    Assert.assertFalse(message.hasDefaultFixed32 ());
+    Assert.assertFalse(message.hasDefaultFixed64 ());
+    Assert.assertFalse(message.hasDefaultSfixed32());
+    Assert.assertFalse(message.hasDefaultSfixed64());
+    Assert.assertFalse(message.hasDefaultFloat   ());
+    Assert.assertFalse(message.hasDefaultDouble  ());
+    Assert.assertFalse(message.hasDefaultBool    ());
+    Assert.assertFalse(message.hasDefaultString  ());
+    Assert.assertFalse(message.hasDefaultBytes   ());
+
+    Assert.assertFalse(message.hasDefaultNestedEnum ());
+    Assert.assertFalse(message.hasDefaultForeignEnum());
+    Assert.assertFalse(message.hasDefaultImportEnum ());
+
+    Assert.assertFalse(message.hasDefaultStringPiece());
+    Assert.assertFalse(message.hasDefaultCord());
+
+    // Fields with defaults have their default values (duh).
+    Assert.assertEquals( 41    , message.getDefaultInt32   ());
+    Assert.assertEquals( 42    , message.getDefaultInt64   ());
+    Assert.assertEquals( 43    , message.getDefaultUint32  ());
+    Assert.assertEquals( 44    , message.getDefaultUint64  ());
+    Assert.assertEquals(-45    , message.getDefaultSint32  ());
+    Assert.assertEquals( 46    , message.getDefaultSint64  ());
+    Assert.assertEquals( 47    , message.getDefaultFixed32 ());
+    Assert.assertEquals( 48    , message.getDefaultFixed64 ());
+    Assert.assertEquals( 49    , message.getDefaultSfixed32());
+    Assert.assertEquals(-50    , message.getDefaultSfixed64());
+    Assert.assertEquals( 51.5  , message.getDefaultFloat   (), 0.0);
+    Assert.assertEquals( 52e3  , message.getDefaultDouble  (), 0.0);
+    Assert.assertEquals(true   , message.getDefaultBool    ());
+    Assert.assertEquals("hello", message.getDefaultString  ());
+    Assert.assertEquals(toBytes("world"), message.getDefaultBytes());
+
+    Assert.assertEquals(TestAllTypes.NestedEnum.BAR, message.getDefaultNestedEnum ());
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAR, message.getDefaultForeignEnum());
+    Assert.assertEquals(ImportEnum.IMPORT_BAR, message.getDefaultImportEnum());
+
+    Assert.assertEquals("abc", message.getDefaultStringPiece());
+    Assert.assertEquals("123", message.getDefaultCord());
+
+    Assert.assertFalse(message.hasOneofUint32());
+    Assert.assertFalse(message.hasOneofNestedMessage());
+    Assert.assertFalse(message.hasOneofString());
+    Assert.assertFalse(message.hasOneofBytes());
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all fields of
+   * {@code message} are set to the values assigned by {@code setAllFields}
+   * followed by {@code modifyRepeatedFields}.
+   */
+  public static void assertRepeatedFieldsModified(
+      TestAllTypesOrBuilder message) {
+    // ModifyRepeatedFields only sets the second repeated element of each
+    // field.  In addition to verifying this, we also verify that the first
+    // element and size were *not* modified.
+    Assert.assertEquals(2, message.getRepeatedInt32Count   ());
+    Assert.assertEquals(2, message.getRepeatedInt64Count   ());
+    Assert.assertEquals(2, message.getRepeatedUint32Count  ());
+    Assert.assertEquals(2, message.getRepeatedUint64Count  ());
+    Assert.assertEquals(2, message.getRepeatedSint32Count  ());
+    Assert.assertEquals(2, message.getRepeatedSint64Count  ());
+    Assert.assertEquals(2, message.getRepeatedFixed32Count ());
+    Assert.assertEquals(2, message.getRepeatedFixed64Count ());
+    Assert.assertEquals(2, message.getRepeatedSfixed32Count());
+    Assert.assertEquals(2, message.getRepeatedSfixed64Count());
+    Assert.assertEquals(2, message.getRepeatedFloatCount   ());
+    Assert.assertEquals(2, message.getRepeatedDoubleCount  ());
+    Assert.assertEquals(2, message.getRepeatedBoolCount    ());
+    Assert.assertEquals(2, message.getRepeatedStringCount  ());
+    Assert.assertEquals(2, message.getRepeatedBytesCount   ());
+
+    Assert.assertEquals(2, message.getRepeatedGroupCount         ());
+    Assert.assertEquals(2, message.getRepeatedNestedMessageCount ());
+    Assert.assertEquals(2, message.getRepeatedForeignMessageCount());
+    Assert.assertEquals(2, message.getRepeatedImportMessageCount ());
+    Assert.assertEquals(2, message.getRepeatedLazyMessageCount   ());
+    Assert.assertEquals(2, message.getRepeatedNestedEnumCount    ());
+    Assert.assertEquals(2, message.getRepeatedForeignEnumCount   ());
+    Assert.assertEquals(2, message.getRepeatedImportEnumCount    ());
+
+    Assert.assertEquals(2, message.getRepeatedStringPieceCount());
+    Assert.assertEquals(2, message.getRepeatedCordCount());
+
+    Assert.assertEquals(201  , message.getRepeatedInt32   (0));
+    Assert.assertEquals(202L , message.getRepeatedInt64   (0));
+    Assert.assertEquals(203  , message.getRepeatedUint32  (0));
+    Assert.assertEquals(204L , message.getRepeatedUint64  (0));
+    Assert.assertEquals(205  , message.getRepeatedSint32  (0));
+    Assert.assertEquals(206L , message.getRepeatedSint64  (0));
+    Assert.assertEquals(207  , message.getRepeatedFixed32 (0));
+    Assert.assertEquals(208L , message.getRepeatedFixed64 (0));
+    Assert.assertEquals(209  , message.getRepeatedSfixed32(0));
+    Assert.assertEquals(210L , message.getRepeatedSfixed64(0));
+    Assert.assertEquals(211F , message.getRepeatedFloat   (0));
+    Assert.assertEquals(212D , message.getRepeatedDouble  (0));
+    Assert.assertEquals(true , message.getRepeatedBool    (0));
+    Assert.assertEquals("215", message.getRepeatedString  (0));
+    Assert.assertEquals(toBytes("216"), message.getRepeatedBytes(0));
+
+    Assert.assertEquals(217, message.getRepeatedGroup         (0).getA());
+    Assert.assertEquals(218, message.getRepeatedNestedMessage (0).getBb());
+    Assert.assertEquals(219, message.getRepeatedForeignMessage(0).getC());
+    Assert.assertEquals(220, message.getRepeatedImportMessage (0).getD());
+    Assert.assertEquals(227, message.getRepeatedLazyMessage   (0).getBb());
+
+    Assert.assertEquals(TestAllTypes.NestedEnum.BAR, message.getRepeatedNestedEnum (0));
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAR, message.getRepeatedForeignEnum(0));
+    Assert.assertEquals(ImportEnum.IMPORT_BAR, message.getRepeatedImportEnum(0));
+
+    Assert.assertEquals("224", message.getRepeatedStringPiece(0));
+    Assert.assertEquals("225", message.getRepeatedCord(0));
+
+    // Actually verify the second (modified) elements now.
+    Assert.assertEquals(501  , message.getRepeatedInt32   (1));
+    Assert.assertEquals(502L , message.getRepeatedInt64   (1));
+    Assert.assertEquals(503  , message.getRepeatedUint32  (1));
+    Assert.assertEquals(504L , message.getRepeatedUint64  (1));
+    Assert.assertEquals(505  , message.getRepeatedSint32  (1));
+    Assert.assertEquals(506L , message.getRepeatedSint64  (1));
+    Assert.assertEquals(507  , message.getRepeatedFixed32 (1));
+    Assert.assertEquals(508L , message.getRepeatedFixed64 (1));
+    Assert.assertEquals(509  , message.getRepeatedSfixed32(1));
+    Assert.assertEquals(510L , message.getRepeatedSfixed64(1));
+    Assert.assertEquals(511F , message.getRepeatedFloat   (1));
+    Assert.assertEquals(512D , message.getRepeatedDouble  (1));
+    Assert.assertEquals(true , message.getRepeatedBool    (1));
+    Assert.assertEquals("515", message.getRepeatedString  (1));
+    Assert.assertEquals(toBytes("516"), message.getRepeatedBytes(1));
+
+    Assert.assertEquals(517, message.getRepeatedGroup         (1).getA());
+    Assert.assertEquals(518, message.getRepeatedNestedMessage (1).getBb());
+    Assert.assertEquals(519, message.getRepeatedForeignMessage(1).getC());
+    Assert.assertEquals(520, message.getRepeatedImportMessage (1).getD());
+    Assert.assertEquals(527, message.getRepeatedLazyMessage   (1).getBb());
+
+    Assert.assertEquals(TestAllTypes.NestedEnum.FOO, message.getRepeatedNestedEnum (1));
+    Assert.assertEquals(ForeignEnum.FOREIGN_FOO, message.getRepeatedForeignEnum(1));
+    Assert.assertEquals(ImportEnum.IMPORT_FOO, message.getRepeatedImportEnum(1));
+
+    Assert.assertEquals("524", message.getRepeatedStringPiece(1));
+    Assert.assertEquals("525", message.getRepeatedCord(1));
+  }
+
+  /**
+   * Set every field of {@code message} to a unique value.
+   */
+  public static void setPackedFields(TestPackedTypes.Builder message) {
+    message.addPackedInt32   (601);
+    message.addPackedInt64   (602);
+    message.addPackedUint32  (603);
+    message.addPackedUint64  (604);
+    message.addPackedSint32  (605);
+    message.addPackedSint64  (606);
+    message.addPackedFixed32 (607);
+    message.addPackedFixed64 (608);
+    message.addPackedSfixed32(609);
+    message.addPackedSfixed64(610);
+    message.addPackedFloat   (611);
+    message.addPackedDouble  (612);
+    message.addPackedBool    (true);
+    message.addPackedEnum    (ForeignEnum.FOREIGN_BAR);
+    // Add a second one of each field.
+    message.addPackedInt32   (701);
+    message.addPackedInt64   (702);
+    message.addPackedUint32  (703);
+    message.addPackedUint64  (704);
+    message.addPackedSint32  (705);
+    message.addPackedSint64  (706);
+    message.addPackedFixed32 (707);
+    message.addPackedFixed64 (708);
+    message.addPackedSfixed32(709);
+    message.addPackedSfixed64(710);
+    message.addPackedFloat   (711);
+    message.addPackedDouble  (712);
+    message.addPackedBool    (false);
+    message.addPackedEnum    (ForeignEnum.FOREIGN_BAZ);
+  }
+
+  /**
+   * Set every field of {@code message} to a unique value. Must correspond with
+   * the values applied by {@code setPackedFields}.
+   */
+  public static void setUnpackedFields(TestUnpackedTypes.Builder message) {
+    message.addUnpackedInt32   (601);
+    message.addUnpackedInt64   (602);
+    message.addUnpackedUint32  (603);
+    message.addUnpackedUint64  (604);
+    message.addUnpackedSint32  (605);
+    message.addUnpackedSint64  (606);
+    message.addUnpackedFixed32 (607);
+    message.addUnpackedFixed64 (608);
+    message.addUnpackedSfixed32(609);
+    message.addUnpackedSfixed64(610);
+    message.addUnpackedFloat   (611);
+    message.addUnpackedDouble  (612);
+    message.addUnpackedBool    (true);
+    message.addUnpackedEnum    (ForeignEnum.FOREIGN_BAR);
+    // Add a second one of each field.
+    message.addUnpackedInt32   (701);
+    message.addUnpackedInt64   (702);
+    message.addUnpackedUint32  (703);
+    message.addUnpackedUint64  (704);
+    message.addUnpackedSint32  (705);
+    message.addUnpackedSint64  (706);
+    message.addUnpackedFixed32 (707);
+    message.addUnpackedFixed64 (708);
+    message.addUnpackedSfixed32(709);
+    message.addUnpackedSfixed64(710);
+    message.addUnpackedFloat   (711);
+    message.addUnpackedDouble  (712);
+    message.addUnpackedBool    (false);
+    message.addUnpackedEnum    (ForeignEnum.FOREIGN_BAZ);
+  }
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all fields of
+   * {@code message} are set to the values assigned by {@code setPackedFields}.
+   */
+  public static void assertPackedFieldsSet(TestPackedTypes message) {
+    Assert.assertEquals(2, message.getPackedInt32Count   ());
+    Assert.assertEquals(2, message.getPackedInt64Count   ());
+    Assert.assertEquals(2, message.getPackedUint32Count  ());
+    Assert.assertEquals(2, message.getPackedUint64Count  ());
+    Assert.assertEquals(2, message.getPackedSint32Count  ());
+    Assert.assertEquals(2, message.getPackedSint64Count  ());
+    Assert.assertEquals(2, message.getPackedFixed32Count ());
+    Assert.assertEquals(2, message.getPackedFixed64Count ());
+    Assert.assertEquals(2, message.getPackedSfixed32Count());
+    Assert.assertEquals(2, message.getPackedSfixed64Count());
+    Assert.assertEquals(2, message.getPackedFloatCount   ());
+    Assert.assertEquals(2, message.getPackedDoubleCount  ());
+    Assert.assertEquals(2, message.getPackedBoolCount    ());
+    Assert.assertEquals(2, message.getPackedEnumCount   ());
+    Assert.assertEquals(601  , message.getPackedInt32   (0));
+    Assert.assertEquals(602  , message.getPackedInt64   (0));
+    Assert.assertEquals(603  , message.getPackedUint32  (0));
+    Assert.assertEquals(604  , message.getPackedUint64  (0));
+    Assert.assertEquals(605  , message.getPackedSint32  (0));
+    Assert.assertEquals(606  , message.getPackedSint64  (0));
+    Assert.assertEquals(607  , message.getPackedFixed32 (0));
+    Assert.assertEquals(608  , message.getPackedFixed64 (0));
+    Assert.assertEquals(609  , message.getPackedSfixed32(0));
+    Assert.assertEquals(610  , message.getPackedSfixed64(0));
+    Assert.assertEquals(611  , message.getPackedFloat   (0), 0.0);
+    Assert.assertEquals(612  , message.getPackedDouble  (0), 0.0);
+    Assert.assertEquals(true , message.getPackedBool    (0));
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAR, message.getPackedEnum(0));
+    Assert.assertEquals(701  , message.getPackedInt32   (1));
+    Assert.assertEquals(702  , message.getPackedInt64   (1));
+    Assert.assertEquals(703  , message.getPackedUint32  (1));
+    Assert.assertEquals(704  , message.getPackedUint64  (1));
+    Assert.assertEquals(705  , message.getPackedSint32  (1));
+    Assert.assertEquals(706  , message.getPackedSint64  (1));
+    Assert.assertEquals(707  , message.getPackedFixed32 (1));
+    Assert.assertEquals(708  , message.getPackedFixed64 (1));
+    Assert.assertEquals(709  , message.getPackedSfixed32(1));
+    Assert.assertEquals(710  , message.getPackedSfixed64(1));
+    Assert.assertEquals(711  , message.getPackedFloat   (1), 0.0);
+    Assert.assertEquals(712  , message.getPackedDouble  (1), 0.0);
+    Assert.assertEquals(false, message.getPackedBool    (1));
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAZ, message.getPackedEnum(1));
+  }
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all fields of
+   * {@code message} are set to the values assigned by {@code setUnpackedFields}.
+   */
+  public static void assertUnpackedFieldsSet(TestUnpackedTypes message) {
+    Assert.assertEquals(2, message.getUnpackedInt32Count   ());
+    Assert.assertEquals(2, message.getUnpackedInt64Count   ());
+    Assert.assertEquals(2, message.getUnpackedUint32Count  ());
+    Assert.assertEquals(2, message.getUnpackedUint64Count  ());
+    Assert.assertEquals(2, message.getUnpackedSint32Count  ());
+    Assert.assertEquals(2, message.getUnpackedSint64Count  ());
+    Assert.assertEquals(2, message.getUnpackedFixed32Count ());
+    Assert.assertEquals(2, message.getUnpackedFixed64Count ());
+    Assert.assertEquals(2, message.getUnpackedSfixed32Count());
+    Assert.assertEquals(2, message.getUnpackedSfixed64Count());
+    Assert.assertEquals(2, message.getUnpackedFloatCount   ());
+    Assert.assertEquals(2, message.getUnpackedDoubleCount  ());
+    Assert.assertEquals(2, message.getUnpackedBoolCount    ());
+    Assert.assertEquals(2, message.getUnpackedEnumCount   ());
+    Assert.assertEquals(601  , message.getUnpackedInt32   (0));
+    Assert.assertEquals(602  , message.getUnpackedInt64   (0));
+    Assert.assertEquals(603  , message.getUnpackedUint32  (0));
+    Assert.assertEquals(604  , message.getUnpackedUint64  (0));
+    Assert.assertEquals(605  , message.getUnpackedSint32  (0));
+    Assert.assertEquals(606  , message.getUnpackedSint64  (0));
+    Assert.assertEquals(607  , message.getUnpackedFixed32 (0));
+    Assert.assertEquals(608  , message.getUnpackedFixed64 (0));
+    Assert.assertEquals(609  , message.getUnpackedSfixed32(0));
+    Assert.assertEquals(610  , message.getUnpackedSfixed64(0));
+    Assert.assertEquals(611  , message.getUnpackedFloat   (0), 0.0);
+    Assert.assertEquals(612  , message.getUnpackedDouble  (0), 0.0);
+    Assert.assertEquals(true , message.getUnpackedBool    (0));
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAR, message.getUnpackedEnum(0));
+    Assert.assertEquals(701  , message.getUnpackedInt32   (1));
+    Assert.assertEquals(702  , message.getUnpackedInt64   (1));
+    Assert.assertEquals(703  , message.getUnpackedUint32  (1));
+    Assert.assertEquals(704  , message.getUnpackedUint64  (1));
+    Assert.assertEquals(705  , message.getUnpackedSint32  (1));
+    Assert.assertEquals(706  , message.getUnpackedSint64  (1));
+    Assert.assertEquals(707  , message.getUnpackedFixed32 (1));
+    Assert.assertEquals(708  , message.getUnpackedFixed64 (1));
+    Assert.assertEquals(709  , message.getUnpackedSfixed32(1));
+    Assert.assertEquals(710  , message.getUnpackedSfixed64(1));
+    Assert.assertEquals(711  , message.getUnpackedFloat   (1), 0.0);
+    Assert.assertEquals(712  , message.getUnpackedDouble  (1), 0.0);
+    Assert.assertEquals(false, message.getUnpackedBool    (1));
+    Assert.assertEquals(ForeignEnum.FOREIGN_BAZ, message.getUnpackedEnum(1));
+  }
+
+  // ===================================================================
+  // Like above, but for extensions
+
+  // Java gets confused with things like assertEquals(int, Integer):  it can't
+  // decide whether to call assertEquals(int, int) or assertEquals(Object,
+  // Object).  So we define these methods to help it.
+  private static void assertEqualsExactType(int a, int b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(long a, long b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(float a, float b) {
+    Assert.assertEquals(a, b, 0.0);
+  }
+  private static void assertEqualsExactType(double a, double b) {
+    Assert.assertEquals(a, b, 0.0);
+  }
+  private static void assertEqualsExactType(boolean a, boolean b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(String a, String b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(ByteString a, ByteString b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(TestAllTypes.NestedEnum a,
+                                            TestAllTypes.NestedEnum b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(ForeignEnum a, ForeignEnum b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(ImportEnum a, ImportEnum b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(TestAllTypesLite.NestedEnum a,
+                                            TestAllTypesLite.NestedEnum b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(ForeignEnumLite a,
+                                            ForeignEnumLite b) {
+    Assert.assertEquals(a, b);
+  }
+  private static void assertEqualsExactType(ImportEnumLite a,
+                                            ImportEnumLite b) {
+    Assert.assertEquals(a, b);
+  }
+
+  /**
+   * Get an unmodifiable {@link ExtensionRegistry} containing all the
+   * extensions of {@code TestAllExtensions}.
+   */
+  public static ExtensionRegistry getExtensionRegistry() {
+    ExtensionRegistry registry = ExtensionRegistry.newInstance();
+    registerAllExtensions(registry);
+    return registry.getUnmodifiable();
+  }
+
+  public static ExtensionRegistryLite getExtensionRegistryLite() {
+    ExtensionRegistryLite registry = ExtensionRegistryLite.newInstance();
+    registerAllExtensionsLite(registry);
+    return registry.getUnmodifiable();
+  }
+
+  /**
+   * Register all of {@code TestAllExtensions}'s extensions with the
+   * given {@link ExtensionRegistry}.
+   */
+  public static void registerAllExtensions(ExtensionRegistry registry) {
+    UnittestProto.registerAllExtensions(registry);
+    registerAllExtensionsLite(registry);
+  }
+
+  public static void registerAllExtensionsLite(ExtensionRegistryLite registry) {
+    UnittestLite.registerAllExtensions(registry);
+  }
+
+  /**
+   * Set every field of {@code message} to the values expected by
+   * {@code assertAllExtensionsSet()}.
+   */
+  public static void setAllExtensions(TestAllExtensions.Builder message) {
+    message.setExtension(optionalInt32Extension   , 101);
+    message.setExtension(optionalInt64Extension   , 102L);
+    message.setExtension(optionalUint32Extension  , 103);
+    message.setExtension(optionalUint64Extension  , 104L);
+    message.setExtension(optionalSint32Extension  , 105);
+    message.setExtension(optionalSint64Extension  , 106L);
+    message.setExtension(optionalFixed32Extension , 107);
+    message.setExtension(optionalFixed64Extension , 108L);
+    message.setExtension(optionalSfixed32Extension, 109);
+    message.setExtension(optionalSfixed64Extension, 110L);
+    message.setExtension(optionalFloatExtension   , 111F);
+    message.setExtension(optionalDoubleExtension  , 112D);
+    message.setExtension(optionalBoolExtension    , true);
+    message.setExtension(optionalStringExtension  , "115");
+    message.setExtension(optionalBytesExtension   , toBytes("116"));
+
+    message.setExtension(optionalGroupExtension,
+      OptionalGroup_extension.newBuilder().setA(117).build());
+    message.setExtension(optionalNestedMessageExtension,
+      TestAllTypes.NestedMessage.newBuilder().setBb(118).build());
+    message.setExtension(optionalForeignMessageExtension,
+      ForeignMessage.newBuilder().setC(119).build());
+    message.setExtension(optionalImportMessageExtension,
+      ImportMessage.newBuilder().setD(120).build());
+    message.setExtension(optionalPublicImportMessageExtension,
+      PublicImportMessage.newBuilder().setE(126).build());
+    message.setExtension(optionalLazyMessageExtension,
+      TestAllTypes.NestedMessage.newBuilder().setBb(127).build());
+
+    message.setExtension(optionalNestedEnumExtension, TestAllTypes.NestedEnum.BAZ);
+    message.setExtension(optionalForeignEnumExtension, ForeignEnum.FOREIGN_BAZ);
+    message.setExtension(optionalImportEnumExtension, ImportEnum.IMPORT_BAZ);
+
+    message.setExtension(optionalStringPieceExtension, "124");
+    message.setExtension(optionalCordExtension, "125");
+
+    // -----------------------------------------------------------------
+
+    message.addExtension(repeatedInt32Extension   , 201);
+    message.addExtension(repeatedInt64Extension   , 202L);
+    message.addExtension(repeatedUint32Extension  , 203);
+    message.addExtension(repeatedUint64Extension  , 204L);
+    message.addExtension(repeatedSint32Extension  , 205);
+    message.addExtension(repeatedSint64Extension  , 206L);
+    message.addExtension(repeatedFixed32Extension , 207);
+    message.addExtension(repeatedFixed64Extension , 208L);
+    message.addExtension(repeatedSfixed32Extension, 209);
+    message.addExtension(repeatedSfixed64Extension, 210L);
+    message.addExtension(repeatedFloatExtension   , 211F);
+    message.addExtension(repeatedDoubleExtension  , 212D);
+    message.addExtension(repeatedBoolExtension    , true);
+    message.addExtension(repeatedStringExtension  , "215");
+    message.addExtension(repeatedBytesExtension   , toBytes("216"));
+
+    message.addExtension(repeatedGroupExtension,
+      RepeatedGroup_extension.newBuilder().setA(217).build());
+    message.addExtension(repeatedNestedMessageExtension,
+      TestAllTypes.NestedMessage.newBuilder().setBb(218).build());
+    message.addExtension(repeatedForeignMessageExtension,
+      ForeignMessage.newBuilder().setC(219).build());
+    message.addExtension(repeatedImportMessageExtension,
+      ImportMessage.newBuilder().setD(220).build());
+    message.addExtension(repeatedLazyMessageExtension,
+      TestAllTypes.NestedMessage.newBuilder().setBb(227).build());
+
+    message.addExtension(repeatedNestedEnumExtension, TestAllTypes.NestedEnum.BAR);
+    message.addExtension(repeatedForeignEnumExtension, ForeignEnum.FOREIGN_BAR);
+    message.addExtension(repeatedImportEnumExtension, ImportEnum.IMPORT_BAR);
+
+    message.addExtension(repeatedStringPieceExtension, "224");
+    message.addExtension(repeatedCordExtension, "225");
+
+    // Add a second one of each field.
+    message.addExtension(repeatedInt32Extension   , 301);
+    message.addExtension(repeatedInt64Extension   , 302L);
+    message.addExtension(repeatedUint32Extension  , 303);
+    message.addExtension(repeatedUint64Extension  , 304L);
+    message.addExtension(repeatedSint32Extension  , 305);
+    message.addExtension(repeatedSint64Extension  , 306L);
+    message.addExtension(repeatedFixed32Extension , 307);
+    message.addExtension(repeatedFixed64Extension , 308L);
+    message.addExtension(repeatedSfixed32Extension, 309);
+    message.addExtension(repeatedSfixed64Extension, 310L);
+    message.addExtension(repeatedFloatExtension   , 311F);
+    message.addExtension(repeatedDoubleExtension  , 312D);
+    message.addExtension(repeatedBoolExtension    , false);
+    message.addExtension(repeatedStringExtension  , "315");
+    message.addExtension(repeatedBytesExtension   , toBytes("316"));
+
+    message.addExtension(repeatedGroupExtension,
+      RepeatedGroup_extension.newBuilder().setA(317).build());
+    message.addExtension(repeatedNestedMessageExtension,
+      TestAllTypes.NestedMessage.newBuilder().setBb(318).build());
+    message.addExtension(repeatedForeignMessageExtension,
+      ForeignMessage.newBuilder().setC(319).build());
+    message.addExtension(repeatedImportMessageExtension,
+      ImportMessage.newBuilder().setD(320).build());
+    message.addExtension(repeatedLazyMessageExtension,
+      TestAllTypes.NestedMessage.newBuilder().setBb(327).build());
+
+    message.addExtension(repeatedNestedEnumExtension, TestAllTypes.NestedEnum.BAZ);
+    message.addExtension(repeatedForeignEnumExtension, ForeignEnum.FOREIGN_BAZ);
+    message.addExtension(repeatedImportEnumExtension, ImportEnum.IMPORT_BAZ);
+
+    message.addExtension(repeatedStringPieceExtension, "324");
+    message.addExtension(repeatedCordExtension, "325");
+
+    // -----------------------------------------------------------------
+
+    message.setExtension(defaultInt32Extension   , 401);
+    message.setExtension(defaultInt64Extension   , 402L);
+    message.setExtension(defaultUint32Extension  , 403);
+    message.setExtension(defaultUint64Extension  , 404L);
+    message.setExtension(defaultSint32Extension  , 405);
+    message.setExtension(defaultSint64Extension  , 406L);
+    message.setExtension(defaultFixed32Extension , 407);
+    message.setExtension(defaultFixed64Extension , 408L);
+    message.setExtension(defaultSfixed32Extension, 409);
+    message.setExtension(defaultSfixed64Extension, 410L);
+    message.setExtension(defaultFloatExtension   , 411F);
+    message.setExtension(defaultDoubleExtension  , 412D);
+    message.setExtension(defaultBoolExtension    , false);
+    message.setExtension(defaultStringExtension  , "415");
+    message.setExtension(defaultBytesExtension   , toBytes("416"));
+
+    message.setExtension(defaultNestedEnumExtension, TestAllTypes.NestedEnum.FOO);
+    message.setExtension(defaultForeignEnumExtension, ForeignEnum.FOREIGN_FOO);
+    message.setExtension(defaultImportEnumExtension, ImportEnum.IMPORT_FOO);
+
+    message.setExtension(defaultStringPieceExtension, "424");
+    message.setExtension(defaultCordExtension, "425");
+
+    message.setExtension(oneofUint32Extension, 601);
+    message.setExtension(oneofNestedMessageExtension,
+      TestAllTypes.NestedMessage.newBuilder().setBb(602).build());
+    message.setExtension(oneofStringExtension, "603");
+    message.setExtension(oneofBytesExtension, toBytes("604"));
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Modify the repeated extensions of {@code message} to contain the values
+   * expected by {@code assertRepeatedExtensionsModified()}.
+   */
+  public static void modifyRepeatedExtensions(
+      TestAllExtensions.Builder message) {
+    message.setExtension(repeatedInt32Extension   , 1, 501);
+    message.setExtension(repeatedInt64Extension   , 1, 502L);
+    message.setExtension(repeatedUint32Extension  , 1, 503);
+    message.setExtension(repeatedUint64Extension  , 1, 504L);
+    message.setExtension(repeatedSint32Extension  , 1, 505);
+    message.setExtension(repeatedSint64Extension  , 1, 506L);
+    message.setExtension(repeatedFixed32Extension , 1, 507);
+    message.setExtension(repeatedFixed64Extension , 1, 508L);
+    message.setExtension(repeatedSfixed32Extension, 1, 509);
+    message.setExtension(repeatedSfixed64Extension, 1, 510L);
+    message.setExtension(repeatedFloatExtension   , 1, 511F);
+    message.setExtension(repeatedDoubleExtension  , 1, 512D);
+    message.setExtension(repeatedBoolExtension    , 1, true);
+    message.setExtension(repeatedStringExtension  , 1, "515");
+    message.setExtension(repeatedBytesExtension   , 1, toBytes("516"));
+
+    message.setExtension(repeatedGroupExtension, 1,
+      RepeatedGroup_extension.newBuilder().setA(517).build());
+    message.setExtension(repeatedNestedMessageExtension, 1,
+      TestAllTypes.NestedMessage.newBuilder().setBb(518).build());
+    message.setExtension(repeatedForeignMessageExtension, 1,
+      ForeignMessage.newBuilder().setC(519).build());
+    message.setExtension(repeatedImportMessageExtension, 1,
+      ImportMessage.newBuilder().setD(520).build());
+    message.setExtension(repeatedLazyMessageExtension, 1,
+      TestAllTypes.NestedMessage.newBuilder().setBb(527).build());
+
+    message.setExtension(repeatedNestedEnumExtension , 1, TestAllTypes.NestedEnum.FOO);
+    message.setExtension(repeatedForeignEnumExtension, 1, ForeignEnum.FOREIGN_FOO);
+    message.setExtension(repeatedImportEnumExtension , 1, ImportEnum.IMPORT_FOO);
+
+    message.setExtension(repeatedStringPieceExtension, 1, "524");
+    message.setExtension(repeatedCordExtension, 1, "525");
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all extensions of
+   * {@code message} are set to the values assigned by {@code setAllExtensions}.
+   */
+  public static void assertAllExtensionsSet(
+      TestAllExtensionsOrBuilder message) {
+    Assert.assertTrue(message.hasExtension(optionalInt32Extension   ));
+    Assert.assertTrue(message.hasExtension(optionalInt64Extension   ));
+    Assert.assertTrue(message.hasExtension(optionalUint32Extension  ));
+    Assert.assertTrue(message.hasExtension(optionalUint64Extension  ));
+    Assert.assertTrue(message.hasExtension(optionalSint32Extension  ));
+    Assert.assertTrue(message.hasExtension(optionalSint64Extension  ));
+    Assert.assertTrue(message.hasExtension(optionalFixed32Extension ));
+    Assert.assertTrue(message.hasExtension(optionalFixed64Extension ));
+    Assert.assertTrue(message.hasExtension(optionalSfixed32Extension));
+    Assert.assertTrue(message.hasExtension(optionalSfixed64Extension));
+    Assert.assertTrue(message.hasExtension(optionalFloatExtension   ));
+    Assert.assertTrue(message.hasExtension(optionalDoubleExtension  ));
+    Assert.assertTrue(message.hasExtension(optionalBoolExtension    ));
+    Assert.assertTrue(message.hasExtension(optionalStringExtension  ));
+    Assert.assertTrue(message.hasExtension(optionalBytesExtension   ));
+
+    Assert.assertTrue(message.hasExtension(optionalGroupExtension         ));
+    Assert.assertTrue(message.hasExtension(optionalNestedMessageExtension ));
+    Assert.assertTrue(message.hasExtension(optionalForeignMessageExtension));
+    Assert.assertTrue(message.hasExtension(optionalImportMessageExtension ));
+
+    Assert.assertTrue(message.getExtension(optionalGroupExtension         ).hasA());
+    Assert.assertTrue(message.getExtension(optionalNestedMessageExtension ).hasBb());
+    Assert.assertTrue(message.getExtension(optionalForeignMessageExtension).hasC());
+    Assert.assertTrue(message.getExtension(optionalImportMessageExtension ).hasD());
+
+    Assert.assertTrue(message.hasExtension(optionalNestedEnumExtension ));
+    Assert.assertTrue(message.hasExtension(optionalForeignEnumExtension));
+    Assert.assertTrue(message.hasExtension(optionalImportEnumExtension ));
+
+    Assert.assertTrue(message.hasExtension(optionalStringPieceExtension));
+    Assert.assertTrue(message.hasExtension(optionalCordExtension));
+
+    assertEqualsExactType(101  , message.getExtension(optionalInt32Extension   ));
+    assertEqualsExactType(102L , message.getExtension(optionalInt64Extension   ));
+    assertEqualsExactType(103  , message.getExtension(optionalUint32Extension  ));
+    assertEqualsExactType(104L , message.getExtension(optionalUint64Extension  ));
+    assertEqualsExactType(105  , message.getExtension(optionalSint32Extension  ));
+    assertEqualsExactType(106L , message.getExtension(optionalSint64Extension  ));
+    assertEqualsExactType(107  , message.getExtension(optionalFixed32Extension ));
+    assertEqualsExactType(108L , message.getExtension(optionalFixed64Extension ));
+    assertEqualsExactType(109  , message.getExtension(optionalSfixed32Extension));
+    assertEqualsExactType(110L , message.getExtension(optionalSfixed64Extension));
+    assertEqualsExactType(111F , message.getExtension(optionalFloatExtension   ));
+    assertEqualsExactType(112D , message.getExtension(optionalDoubleExtension  ));
+    assertEqualsExactType(true , message.getExtension(optionalBoolExtension    ));
+    assertEqualsExactType("115", message.getExtension(optionalStringExtension  ));
+    assertEqualsExactType(toBytes("116"), message.getExtension(optionalBytesExtension));
+
+    assertEqualsExactType(117, message.getExtension(optionalGroupExtension              ).getA());
+    assertEqualsExactType(118, message.getExtension(optionalNestedMessageExtension      ).getBb());
+    assertEqualsExactType(119, message.getExtension(optionalForeignMessageExtension     ).getC());
+    assertEqualsExactType(120, message.getExtension(optionalImportMessageExtension      ).getD());
+    assertEqualsExactType(126, message.getExtension(optionalPublicImportMessageExtension).getE());
+    assertEqualsExactType(127, message.getExtension(optionalLazyMessageExtension        ).getBb());
+
+    assertEqualsExactType(TestAllTypes.NestedEnum.BAZ,
+      message.getExtension(optionalNestedEnumExtension));
+    assertEqualsExactType(ForeignEnum.FOREIGN_BAZ,
+      message.getExtension(optionalForeignEnumExtension));
+    assertEqualsExactType(ImportEnum.IMPORT_BAZ,
+      message.getExtension(optionalImportEnumExtension));
+
+    assertEqualsExactType("124", message.getExtension(optionalStringPieceExtension));
+    assertEqualsExactType("125", message.getExtension(optionalCordExtension));
+
+    // -----------------------------------------------------------------
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedInt32Extension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedInt64Extension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedUint32Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedUint64Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSint32Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSint64Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFixed32Extension ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFixed64Extension ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSfixed32Extension));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSfixed64Extension));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFloatExtension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedDoubleExtension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedBoolExtension    ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedStringExtension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedBytesExtension   ));
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedGroupExtension         ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedNestedMessageExtension ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedForeignMessageExtension));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedImportMessageExtension ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedLazyMessageExtension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedNestedEnumExtension    ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedForeignEnumExtension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedImportEnumExtension    ));
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedStringPieceExtension));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedCordExtension));
+
+    assertEqualsExactType(201  , message.getExtension(repeatedInt32Extension   , 0));
+    assertEqualsExactType(202L , message.getExtension(repeatedInt64Extension   , 0));
+    assertEqualsExactType(203  , message.getExtension(repeatedUint32Extension  , 0));
+    assertEqualsExactType(204L , message.getExtension(repeatedUint64Extension  , 0));
+    assertEqualsExactType(205  , message.getExtension(repeatedSint32Extension  , 0));
+    assertEqualsExactType(206L , message.getExtension(repeatedSint64Extension  , 0));
+    assertEqualsExactType(207  , message.getExtension(repeatedFixed32Extension , 0));
+    assertEqualsExactType(208L , message.getExtension(repeatedFixed64Extension , 0));
+    assertEqualsExactType(209  , message.getExtension(repeatedSfixed32Extension, 0));
+    assertEqualsExactType(210L , message.getExtension(repeatedSfixed64Extension, 0));
+    assertEqualsExactType(211F , message.getExtension(repeatedFloatExtension   , 0));
+    assertEqualsExactType(212D , message.getExtension(repeatedDoubleExtension  , 0));
+    assertEqualsExactType(true , message.getExtension(repeatedBoolExtension    , 0));
+    assertEqualsExactType("215", message.getExtension(repeatedStringExtension  , 0));
+    assertEqualsExactType(toBytes("216"), message.getExtension(repeatedBytesExtension, 0));
+
+    assertEqualsExactType(217, message.getExtension(repeatedGroupExtension         , 0).getA());
+    assertEqualsExactType(218, message.getExtension(repeatedNestedMessageExtension , 0).getBb());
+    assertEqualsExactType(219, message.getExtension(repeatedForeignMessageExtension, 0).getC());
+    assertEqualsExactType(220, message.getExtension(repeatedImportMessageExtension , 0).getD());
+    assertEqualsExactType(227, message.getExtension(repeatedLazyMessageExtension   , 0).getBb());
+
+    assertEqualsExactType(TestAllTypes.NestedEnum.BAR,
+      message.getExtension(repeatedNestedEnumExtension, 0));
+    assertEqualsExactType(ForeignEnum.FOREIGN_BAR,
+      message.getExtension(repeatedForeignEnumExtension, 0));
+    assertEqualsExactType(ImportEnum.IMPORT_BAR,
+      message.getExtension(repeatedImportEnumExtension, 0));
+
+    assertEqualsExactType("224", message.getExtension(repeatedStringPieceExtension, 0));
+    assertEqualsExactType("225", message.getExtension(repeatedCordExtension, 0));
+
+    assertEqualsExactType(301  , message.getExtension(repeatedInt32Extension   , 1));
+    assertEqualsExactType(302L , message.getExtension(repeatedInt64Extension   , 1));
+    assertEqualsExactType(303  , message.getExtension(repeatedUint32Extension  , 1));
+    assertEqualsExactType(304L , message.getExtension(repeatedUint64Extension  , 1));
+    assertEqualsExactType(305  , message.getExtension(repeatedSint32Extension  , 1));
+    assertEqualsExactType(306L , message.getExtension(repeatedSint64Extension  , 1));
+    assertEqualsExactType(307  , message.getExtension(repeatedFixed32Extension , 1));
+    assertEqualsExactType(308L , message.getExtension(repeatedFixed64Extension , 1));
+    assertEqualsExactType(309  , message.getExtension(repeatedSfixed32Extension, 1));
+    assertEqualsExactType(310L , message.getExtension(repeatedSfixed64Extension, 1));
+    assertEqualsExactType(311F , message.getExtension(repeatedFloatExtension   , 1));
+    assertEqualsExactType(312D , message.getExtension(repeatedDoubleExtension  , 1));
+    assertEqualsExactType(false, message.getExtension(repeatedBoolExtension    , 1));
+    assertEqualsExactType("315", message.getExtension(repeatedStringExtension  , 1));
+    assertEqualsExactType(toBytes("316"), message.getExtension(repeatedBytesExtension, 1));
+
+    assertEqualsExactType(317, message.getExtension(repeatedGroupExtension         , 1).getA());
+    assertEqualsExactType(318, message.getExtension(repeatedNestedMessageExtension , 1).getBb());
+    assertEqualsExactType(319, message.getExtension(repeatedForeignMessageExtension, 1).getC());
+    assertEqualsExactType(320, message.getExtension(repeatedImportMessageExtension , 1).getD());
+    assertEqualsExactType(327, message.getExtension(repeatedLazyMessageExtension   , 1).getBb());
+
+    assertEqualsExactType(TestAllTypes.NestedEnum.BAZ,
+      message.getExtension(repeatedNestedEnumExtension, 1));
+    assertEqualsExactType(ForeignEnum.FOREIGN_BAZ,
+      message.getExtension(repeatedForeignEnumExtension, 1));
+    assertEqualsExactType(ImportEnum.IMPORT_BAZ,
+      message.getExtension(repeatedImportEnumExtension, 1));
+
+    assertEqualsExactType("324", message.getExtension(repeatedStringPieceExtension, 1));
+    assertEqualsExactType("325", message.getExtension(repeatedCordExtension, 1));
+
+    // -----------------------------------------------------------------
+
+    Assert.assertTrue(message.hasExtension(defaultInt32Extension   ));
+    Assert.assertTrue(message.hasExtension(defaultInt64Extension   ));
+    Assert.assertTrue(message.hasExtension(defaultUint32Extension  ));
+    Assert.assertTrue(message.hasExtension(defaultUint64Extension  ));
+    Assert.assertTrue(message.hasExtension(defaultSint32Extension  ));
+    Assert.assertTrue(message.hasExtension(defaultSint64Extension  ));
+    Assert.assertTrue(message.hasExtension(defaultFixed32Extension ));
+    Assert.assertTrue(message.hasExtension(defaultFixed64Extension ));
+    Assert.assertTrue(message.hasExtension(defaultSfixed32Extension));
+    Assert.assertTrue(message.hasExtension(defaultSfixed64Extension));
+    Assert.assertTrue(message.hasExtension(defaultFloatExtension   ));
+    Assert.assertTrue(message.hasExtension(defaultDoubleExtension  ));
+    Assert.assertTrue(message.hasExtension(defaultBoolExtension    ));
+    Assert.assertTrue(message.hasExtension(defaultStringExtension  ));
+    Assert.assertTrue(message.hasExtension(defaultBytesExtension   ));
+
+    Assert.assertTrue(message.hasExtension(defaultNestedEnumExtension ));
+    Assert.assertTrue(message.hasExtension(defaultForeignEnumExtension));
+    Assert.assertTrue(message.hasExtension(defaultImportEnumExtension ));
+
+    Assert.assertTrue(message.hasExtension(defaultStringPieceExtension));
+    Assert.assertTrue(message.hasExtension(defaultCordExtension));
+
+    assertEqualsExactType(401  , message.getExtension(defaultInt32Extension   ));
+    assertEqualsExactType(402L , message.getExtension(defaultInt64Extension   ));
+    assertEqualsExactType(403  , message.getExtension(defaultUint32Extension  ));
+    assertEqualsExactType(404L , message.getExtension(defaultUint64Extension  ));
+    assertEqualsExactType(405  , message.getExtension(defaultSint32Extension  ));
+    assertEqualsExactType(406L , message.getExtension(defaultSint64Extension  ));
+    assertEqualsExactType(407  , message.getExtension(defaultFixed32Extension ));
+    assertEqualsExactType(408L , message.getExtension(defaultFixed64Extension ));
+    assertEqualsExactType(409  , message.getExtension(defaultSfixed32Extension));
+    assertEqualsExactType(410L , message.getExtension(defaultSfixed64Extension));
+    assertEqualsExactType(411F , message.getExtension(defaultFloatExtension   ));
+    assertEqualsExactType(412D , message.getExtension(defaultDoubleExtension  ));
+    assertEqualsExactType(false, message.getExtension(defaultBoolExtension    ));
+    assertEqualsExactType("415", message.getExtension(defaultStringExtension  ));
+    assertEqualsExactType(toBytes("416"), message.getExtension(defaultBytesExtension));
+
+    assertEqualsExactType(TestAllTypes.NestedEnum.FOO,
+      message.getExtension(defaultNestedEnumExtension ));
+    assertEqualsExactType(ForeignEnum.FOREIGN_FOO,
+      message.getExtension(defaultForeignEnumExtension));
+    assertEqualsExactType(ImportEnum.IMPORT_FOO,
+      message.getExtension(defaultImportEnumExtension));
+
+    assertEqualsExactType("424", message.getExtension(defaultStringPieceExtension));
+    assertEqualsExactType("425", message.getExtension(defaultCordExtension));
+
+    Assert.assertTrue(message.hasExtension(oneofBytesExtension));
+
+    assertEqualsExactType(toBytes("604"), message.getExtension(oneofBytesExtension));
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all extensions of
+   * {@code message} are cleared, and that getting the extensions returns their
+   * default values.
+   */
+  public static void assertExtensionsClear(TestAllExtensionsOrBuilder message) {
+    // hasBlah() should initially be false for all optional fields.
+    Assert.assertFalse(message.hasExtension(optionalInt32Extension   ));
+    Assert.assertFalse(message.hasExtension(optionalInt64Extension   ));
+    Assert.assertFalse(message.hasExtension(optionalUint32Extension  ));
+    Assert.assertFalse(message.hasExtension(optionalUint64Extension  ));
+    Assert.assertFalse(message.hasExtension(optionalSint32Extension  ));
+    Assert.assertFalse(message.hasExtension(optionalSint64Extension  ));
+    Assert.assertFalse(message.hasExtension(optionalFixed32Extension ));
+    Assert.assertFalse(message.hasExtension(optionalFixed64Extension ));
+    Assert.assertFalse(message.hasExtension(optionalSfixed32Extension));
+    Assert.assertFalse(message.hasExtension(optionalSfixed64Extension));
+    Assert.assertFalse(message.hasExtension(optionalFloatExtension   ));
+    Assert.assertFalse(message.hasExtension(optionalDoubleExtension  ));
+    Assert.assertFalse(message.hasExtension(optionalBoolExtension    ));
+    Assert.assertFalse(message.hasExtension(optionalStringExtension  ));
+    Assert.assertFalse(message.hasExtension(optionalBytesExtension   ));
+
+    Assert.assertFalse(message.hasExtension(optionalGroupExtension         ));
+    Assert.assertFalse(message.hasExtension(optionalNestedMessageExtension ));
+    Assert.assertFalse(message.hasExtension(optionalForeignMessageExtension));
+    Assert.assertFalse(message.hasExtension(optionalImportMessageExtension ));
+
+    Assert.assertFalse(message.hasExtension(optionalNestedEnumExtension ));
+    Assert.assertFalse(message.hasExtension(optionalForeignEnumExtension));
+    Assert.assertFalse(message.hasExtension(optionalImportEnumExtension ));
+
+    Assert.assertFalse(message.hasExtension(optionalStringPieceExtension));
+    Assert.assertFalse(message.hasExtension(optionalCordExtension));
+
+    // Optional fields without defaults are set to zero or something like it.
+    assertEqualsExactType(0    , message.getExtension(optionalInt32Extension   ));
+    assertEqualsExactType(0L   , message.getExtension(optionalInt64Extension   ));
+    assertEqualsExactType(0    , message.getExtension(optionalUint32Extension  ));
+    assertEqualsExactType(0L   , message.getExtension(optionalUint64Extension  ));
+    assertEqualsExactType(0    , message.getExtension(optionalSint32Extension  ));
+    assertEqualsExactType(0L   , message.getExtension(optionalSint64Extension  ));
+    assertEqualsExactType(0    , message.getExtension(optionalFixed32Extension ));
+    assertEqualsExactType(0L   , message.getExtension(optionalFixed64Extension ));
+    assertEqualsExactType(0    , message.getExtension(optionalSfixed32Extension));
+    assertEqualsExactType(0L   , message.getExtension(optionalSfixed64Extension));
+    assertEqualsExactType(0F   , message.getExtension(optionalFloatExtension   ));
+    assertEqualsExactType(0D   , message.getExtension(optionalDoubleExtension  ));
+    assertEqualsExactType(false, message.getExtension(optionalBoolExtension    ));
+    assertEqualsExactType(""   , message.getExtension(optionalStringExtension  ));
+    assertEqualsExactType(ByteString.EMPTY, message.getExtension(optionalBytesExtension));
+
+    // Embedded messages should also be clear.
+    Assert.assertFalse(message.getExtension(optionalGroupExtension         ).hasA());
+    Assert.assertFalse(message.getExtension(optionalNestedMessageExtension ).hasBb());
+    Assert.assertFalse(message.getExtension(optionalForeignMessageExtension).hasC());
+    Assert.assertFalse(message.getExtension(optionalImportMessageExtension ).hasD());
+
+    assertEqualsExactType(0, message.getExtension(optionalGroupExtension         ).getA());
+    assertEqualsExactType(0, message.getExtension(optionalNestedMessageExtension ).getBb());
+    assertEqualsExactType(0, message.getExtension(optionalForeignMessageExtension).getC());
+    assertEqualsExactType(0, message.getExtension(optionalImportMessageExtension ).getD());
+
+    // Enums without defaults are set to the first value in the enum.
+    assertEqualsExactType(TestAllTypes.NestedEnum.FOO,
+      message.getExtension(optionalNestedEnumExtension ));
+    assertEqualsExactType(ForeignEnum.FOREIGN_FOO,
+      message.getExtension(optionalForeignEnumExtension));
+    assertEqualsExactType(ImportEnum.IMPORT_FOO,
+      message.getExtension(optionalImportEnumExtension));
+
+    assertEqualsExactType("", message.getExtension(optionalStringPieceExtension));
+    assertEqualsExactType("", message.getExtension(optionalCordExtension));
+
+    // Repeated fields are empty.
+    Assert.assertEquals(0, message.getExtensionCount(repeatedInt32Extension   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedInt64Extension   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedUint32Extension  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedUint64Extension  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedSint32Extension  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedSint64Extension  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedFixed32Extension ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedFixed64Extension ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedSfixed32Extension));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedSfixed64Extension));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedFloatExtension   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedDoubleExtension  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedBoolExtension    ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedStringExtension  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedBytesExtension   ));
+
+    Assert.assertEquals(0, message.getExtensionCount(repeatedGroupExtension         ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedNestedMessageExtension ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedForeignMessageExtension));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedImportMessageExtension ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedLazyMessageExtension   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedNestedEnumExtension    ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedForeignEnumExtension   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedImportEnumExtension    ));
+
+    Assert.assertEquals(0, message.getExtensionCount(repeatedStringPieceExtension));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedCordExtension));
+
+    // Repeated fields are empty via getExtension().size().
+    Assert.assertEquals(0, message.getExtension(repeatedInt32Extension   ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedInt64Extension   ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedUint32Extension  ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedUint64Extension  ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedSint32Extension  ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedSint64Extension  ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedFixed32Extension ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedFixed64Extension ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedSfixed32Extension).size());
+    Assert.assertEquals(0, message.getExtension(repeatedSfixed64Extension).size());
+    Assert.assertEquals(0, message.getExtension(repeatedFloatExtension   ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedDoubleExtension  ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedBoolExtension    ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedStringExtension  ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedBytesExtension   ).size());
+
+    Assert.assertEquals(0, message.getExtension(repeatedGroupExtension         ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedNestedMessageExtension ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedForeignMessageExtension).size());
+    Assert.assertEquals(0, message.getExtension(repeatedImportMessageExtension ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedLazyMessageExtension   ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedNestedEnumExtension    ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedForeignEnumExtension   ).size());
+    Assert.assertEquals(0, message.getExtension(repeatedImportEnumExtension    ).size());
+
+    Assert.assertEquals(0, message.getExtension(repeatedStringPieceExtension).size());
+    Assert.assertEquals(0, message.getExtension(repeatedCordExtension).size());
+
+    // hasBlah() should also be false for all default fields.
+    Assert.assertFalse(message.hasExtension(defaultInt32Extension   ));
+    Assert.assertFalse(message.hasExtension(defaultInt64Extension   ));
+    Assert.assertFalse(message.hasExtension(defaultUint32Extension  ));
+    Assert.assertFalse(message.hasExtension(defaultUint64Extension  ));
+    Assert.assertFalse(message.hasExtension(defaultSint32Extension  ));
+    Assert.assertFalse(message.hasExtension(defaultSint64Extension  ));
+    Assert.assertFalse(message.hasExtension(defaultFixed32Extension ));
+    Assert.assertFalse(message.hasExtension(defaultFixed64Extension ));
+    Assert.assertFalse(message.hasExtension(defaultSfixed32Extension));
+    Assert.assertFalse(message.hasExtension(defaultSfixed64Extension));
+    Assert.assertFalse(message.hasExtension(defaultFloatExtension   ));
+    Assert.assertFalse(message.hasExtension(defaultDoubleExtension  ));
+    Assert.assertFalse(message.hasExtension(defaultBoolExtension    ));
+    Assert.assertFalse(message.hasExtension(defaultStringExtension  ));
+    Assert.assertFalse(message.hasExtension(defaultBytesExtension   ));
+
+    Assert.assertFalse(message.hasExtension(defaultNestedEnumExtension ));
+    Assert.assertFalse(message.hasExtension(defaultForeignEnumExtension));
+    Assert.assertFalse(message.hasExtension(defaultImportEnumExtension ));
+
+    Assert.assertFalse(message.hasExtension(defaultStringPieceExtension));
+    Assert.assertFalse(message.hasExtension(defaultCordExtension));
+
+    // Fields with defaults have their default values (duh).
+    assertEqualsExactType( 41    , message.getExtension(defaultInt32Extension   ));
+    assertEqualsExactType( 42L   , message.getExtension(defaultInt64Extension   ));
+    assertEqualsExactType( 43    , message.getExtension(defaultUint32Extension  ));
+    assertEqualsExactType( 44L   , message.getExtension(defaultUint64Extension  ));
+    assertEqualsExactType(-45    , message.getExtension(defaultSint32Extension  ));
+    assertEqualsExactType( 46L   , message.getExtension(defaultSint64Extension  ));
+    assertEqualsExactType( 47    , message.getExtension(defaultFixed32Extension ));
+    assertEqualsExactType( 48L   , message.getExtension(defaultFixed64Extension ));
+    assertEqualsExactType( 49    , message.getExtension(defaultSfixed32Extension));
+    assertEqualsExactType(-50L   , message.getExtension(defaultSfixed64Extension));
+    assertEqualsExactType( 51.5F , message.getExtension(defaultFloatExtension   ));
+    assertEqualsExactType( 52e3D , message.getExtension(defaultDoubleExtension  ));
+    assertEqualsExactType(true   , message.getExtension(defaultBoolExtension    ));
+    assertEqualsExactType("hello", message.getExtension(defaultStringExtension  ));
+    assertEqualsExactType(toBytes("world"), message.getExtension(defaultBytesExtension));
+
+    assertEqualsExactType(TestAllTypes.NestedEnum.BAR,
+      message.getExtension(defaultNestedEnumExtension ));
+    assertEqualsExactType(ForeignEnum.FOREIGN_BAR,
+      message.getExtension(defaultForeignEnumExtension));
+    assertEqualsExactType(ImportEnum.IMPORT_BAR,
+      message.getExtension(defaultImportEnumExtension));
+
+    assertEqualsExactType("abc", message.getExtension(defaultStringPieceExtension));
+    assertEqualsExactType("123", message.getExtension(defaultCordExtension));
+
+    Assert.assertFalse(message.hasExtension(oneofUint32Extension));
+    Assert.assertFalse(message.hasExtension(oneofNestedMessageExtension));
+    Assert.assertFalse(message.hasExtension(oneofStringExtension));
+    Assert.assertFalse(message.hasExtension(oneofBytesExtension));
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all extensions of
+   * {@code message} are set to the values assigned by {@code setAllExtensions}
+   * followed by {@code modifyRepeatedExtensions}.
+   */
+  public static void assertRepeatedExtensionsModified(
+      TestAllExtensionsOrBuilder message) {
+    // ModifyRepeatedFields only sets the second repeated element of each
+    // field.  In addition to verifying this, we also verify that the first
+    // element and size were *not* modified.
+    Assert.assertEquals(2, message.getExtensionCount(repeatedInt32Extension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedInt64Extension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedUint32Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedUint64Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSint32Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSint64Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFixed32Extension ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFixed64Extension ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSfixed32Extension));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSfixed64Extension));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFloatExtension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedDoubleExtension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedBoolExtension    ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedStringExtension  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedBytesExtension   ));
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedGroupExtension         ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedNestedMessageExtension ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedForeignMessageExtension));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedImportMessageExtension ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedLazyMessageExtension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedNestedEnumExtension    ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedForeignEnumExtension   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedImportEnumExtension    ));
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedStringPieceExtension));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedCordExtension));
+
+    assertEqualsExactType(201  , message.getExtension(repeatedInt32Extension   , 0));
+    assertEqualsExactType(202L , message.getExtension(repeatedInt64Extension   , 0));
+    assertEqualsExactType(203  , message.getExtension(repeatedUint32Extension  , 0));
+    assertEqualsExactType(204L , message.getExtension(repeatedUint64Extension  , 0));
+    assertEqualsExactType(205  , message.getExtension(repeatedSint32Extension  , 0));
+    assertEqualsExactType(206L , message.getExtension(repeatedSint64Extension  , 0));
+    assertEqualsExactType(207  , message.getExtension(repeatedFixed32Extension , 0));
+    assertEqualsExactType(208L , message.getExtension(repeatedFixed64Extension , 0));
+    assertEqualsExactType(209  , message.getExtension(repeatedSfixed32Extension, 0));
+    assertEqualsExactType(210L , message.getExtension(repeatedSfixed64Extension, 0));
+    assertEqualsExactType(211F , message.getExtension(repeatedFloatExtension   , 0));
+    assertEqualsExactType(212D , message.getExtension(repeatedDoubleExtension  , 0));
+    assertEqualsExactType(true , message.getExtension(repeatedBoolExtension    , 0));
+    assertEqualsExactType("215", message.getExtension(repeatedStringExtension  , 0));
+    assertEqualsExactType(toBytes("216"), message.getExtension(repeatedBytesExtension, 0));
+
+    assertEqualsExactType(217, message.getExtension(repeatedGroupExtension         , 0).getA());
+    assertEqualsExactType(218, message.getExtension(repeatedNestedMessageExtension , 0).getBb());
+    assertEqualsExactType(219, message.getExtension(repeatedForeignMessageExtension, 0).getC());
+    assertEqualsExactType(220, message.getExtension(repeatedImportMessageExtension , 0).getD());
+    assertEqualsExactType(227, message.getExtension(repeatedLazyMessageExtension   , 0).getBb());
+
+    assertEqualsExactType(TestAllTypes.NestedEnum.BAR,
+      message.getExtension(repeatedNestedEnumExtension, 0));
+    assertEqualsExactType(ForeignEnum.FOREIGN_BAR,
+      message.getExtension(repeatedForeignEnumExtension, 0));
+    assertEqualsExactType(ImportEnum.IMPORT_BAR,
+      message.getExtension(repeatedImportEnumExtension, 0));
+
+    assertEqualsExactType("224", message.getExtension(repeatedStringPieceExtension, 0));
+    assertEqualsExactType("225", message.getExtension(repeatedCordExtension, 0));
+
+    // Actually verify the second (modified) elements now.
+    assertEqualsExactType(501  , message.getExtension(repeatedInt32Extension   , 1));
+    assertEqualsExactType(502L , message.getExtension(repeatedInt64Extension   , 1));
+    assertEqualsExactType(503  , message.getExtension(repeatedUint32Extension  , 1));
+    assertEqualsExactType(504L , message.getExtension(repeatedUint64Extension  , 1));
+    assertEqualsExactType(505  , message.getExtension(repeatedSint32Extension  , 1));
+    assertEqualsExactType(506L , message.getExtension(repeatedSint64Extension  , 1));
+    assertEqualsExactType(507  , message.getExtension(repeatedFixed32Extension , 1));
+    assertEqualsExactType(508L , message.getExtension(repeatedFixed64Extension , 1));
+    assertEqualsExactType(509  , message.getExtension(repeatedSfixed32Extension, 1));
+    assertEqualsExactType(510L , message.getExtension(repeatedSfixed64Extension, 1));
+    assertEqualsExactType(511F , message.getExtension(repeatedFloatExtension   , 1));
+    assertEqualsExactType(512D , message.getExtension(repeatedDoubleExtension  , 1));
+    assertEqualsExactType(true , message.getExtension(repeatedBoolExtension    , 1));
+    assertEqualsExactType("515", message.getExtension(repeatedStringExtension  , 1));
+    assertEqualsExactType(toBytes("516"), message.getExtension(repeatedBytesExtension, 1));
+
+    assertEqualsExactType(517, message.getExtension(repeatedGroupExtension         , 1).getA());
+    assertEqualsExactType(518, message.getExtension(repeatedNestedMessageExtension , 1).getBb());
+    assertEqualsExactType(519, message.getExtension(repeatedForeignMessageExtension, 1).getC());
+    assertEqualsExactType(520, message.getExtension(repeatedImportMessageExtension , 1).getD());
+    assertEqualsExactType(527, message.getExtension(repeatedLazyMessageExtension   , 1).getBb());
+
+    assertEqualsExactType(TestAllTypes.NestedEnum.FOO,
+      message.getExtension(repeatedNestedEnumExtension, 1));
+    assertEqualsExactType(ForeignEnum.FOREIGN_FOO,
+      message.getExtension(repeatedForeignEnumExtension, 1));
+    assertEqualsExactType(ImportEnum.IMPORT_FOO,
+      message.getExtension(repeatedImportEnumExtension, 1));
+
+    assertEqualsExactType("524", message.getExtension(repeatedStringPieceExtension, 1));
+    assertEqualsExactType("525", message.getExtension(repeatedCordExtension, 1));
+  }
+
+  public static void setPackedExtensions(TestPackedExtensions.Builder message) {
+    message.addExtension(packedInt32Extension   , 601);
+    message.addExtension(packedInt64Extension   , 602L);
+    message.addExtension(packedUint32Extension  , 603);
+    message.addExtension(packedUint64Extension  , 604L);
+    message.addExtension(packedSint32Extension  , 605);
+    message.addExtension(packedSint64Extension  , 606L);
+    message.addExtension(packedFixed32Extension , 607);
+    message.addExtension(packedFixed64Extension , 608L);
+    message.addExtension(packedSfixed32Extension, 609);
+    message.addExtension(packedSfixed64Extension, 610L);
+    message.addExtension(packedFloatExtension   , 611F);
+    message.addExtension(packedDoubleExtension  , 612D);
+    message.addExtension(packedBoolExtension    , true);
+    message.addExtension(packedEnumExtension, ForeignEnum.FOREIGN_BAR);
+    // Add a second one of each field.
+    message.addExtension(packedInt32Extension   , 701);
+    message.addExtension(packedInt64Extension   , 702L);
+    message.addExtension(packedUint32Extension  , 703);
+    message.addExtension(packedUint64Extension  , 704L);
+    message.addExtension(packedSint32Extension  , 705);
+    message.addExtension(packedSint64Extension  , 706L);
+    message.addExtension(packedFixed32Extension , 707);
+    message.addExtension(packedFixed64Extension , 708L);
+    message.addExtension(packedSfixed32Extension, 709);
+    message.addExtension(packedSfixed64Extension, 710L);
+    message.addExtension(packedFloatExtension   , 711F);
+    message.addExtension(packedDoubleExtension  , 712D);
+    message.addExtension(packedBoolExtension    , false);
+    message.addExtension(packedEnumExtension, ForeignEnum.FOREIGN_BAZ);
+  }
+
+  public static void assertPackedExtensionsSet(TestPackedExtensions message) {
+    Assert.assertEquals(2, message.getExtensionCount(packedInt32Extension   ));
+    Assert.assertEquals(2, message.getExtensionCount(packedInt64Extension   ));
+    Assert.assertEquals(2, message.getExtensionCount(packedUint32Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedUint64Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedSint32Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedSint64Extension  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedFixed32Extension ));
+    Assert.assertEquals(2, message.getExtensionCount(packedFixed64Extension ));
+    Assert.assertEquals(2, message.getExtensionCount(packedSfixed32Extension));
+    Assert.assertEquals(2, message.getExtensionCount(packedSfixed64Extension));
+    Assert.assertEquals(2, message.getExtensionCount(packedFloatExtension   ));
+    Assert.assertEquals(2, message.getExtensionCount(packedDoubleExtension  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedBoolExtension    ));
+    Assert.assertEquals(2, message.getExtensionCount(packedEnumExtension));
+    assertEqualsExactType(601  , message.getExtension(packedInt32Extension   , 0));
+    assertEqualsExactType(602L , message.getExtension(packedInt64Extension   , 0));
+    assertEqualsExactType(603  , message.getExtension(packedUint32Extension  , 0));
+    assertEqualsExactType(604L , message.getExtension(packedUint64Extension  , 0));
+    assertEqualsExactType(605  , message.getExtension(packedSint32Extension  , 0));
+    assertEqualsExactType(606L , message.getExtension(packedSint64Extension  , 0));
+    assertEqualsExactType(607  , message.getExtension(packedFixed32Extension , 0));
+    assertEqualsExactType(608L , message.getExtension(packedFixed64Extension , 0));
+    assertEqualsExactType(609  , message.getExtension(packedSfixed32Extension, 0));
+    assertEqualsExactType(610L , message.getExtension(packedSfixed64Extension, 0));
+    assertEqualsExactType(611F , message.getExtension(packedFloatExtension   , 0));
+    assertEqualsExactType(612D , message.getExtension(packedDoubleExtension  , 0));
+    assertEqualsExactType(true , message.getExtension(packedBoolExtension    , 0));
+    assertEqualsExactType(ForeignEnum.FOREIGN_BAR,
+                          message.getExtension(packedEnumExtension, 0));
+    assertEqualsExactType(701  , message.getExtension(packedInt32Extension   , 1));
+    assertEqualsExactType(702L , message.getExtension(packedInt64Extension   , 1));
+    assertEqualsExactType(703  , message.getExtension(packedUint32Extension  , 1));
+    assertEqualsExactType(704L , message.getExtension(packedUint64Extension  , 1));
+    assertEqualsExactType(705  , message.getExtension(packedSint32Extension  , 1));
+    assertEqualsExactType(706L , message.getExtension(packedSint64Extension  , 1));
+    assertEqualsExactType(707  , message.getExtension(packedFixed32Extension , 1));
+    assertEqualsExactType(708L , message.getExtension(packedFixed64Extension , 1));
+    assertEqualsExactType(709  , message.getExtension(packedSfixed32Extension, 1));
+    assertEqualsExactType(710L , message.getExtension(packedSfixed64Extension, 1));
+    assertEqualsExactType(711F , message.getExtension(packedFloatExtension   , 1));
+    assertEqualsExactType(712D , message.getExtension(packedDoubleExtension  , 1));
+    assertEqualsExactType(false, message.getExtension(packedBoolExtension    , 1));
+    assertEqualsExactType(ForeignEnum.FOREIGN_BAZ,
+                          message.getExtension(packedEnumExtension, 1));
+  }
+
+  // ===================================================================
+  // Lite extensions
+
+  /**
+   * Set every field of {@code message} to the values expected by
+   * {@code assertAllExtensionsSet()}.
+   */
+  public static void setAllExtensions(TestAllExtensionsLite.Builder message) {
+    message.setExtension(optionalInt32ExtensionLite   , 101);
+    message.setExtension(optionalInt64ExtensionLite   , 102L);
+    message.setExtension(optionalUint32ExtensionLite  , 103);
+    message.setExtension(optionalUint64ExtensionLite  , 104L);
+    message.setExtension(optionalSint32ExtensionLite  , 105);
+    message.setExtension(optionalSint64ExtensionLite  , 106L);
+    message.setExtension(optionalFixed32ExtensionLite , 107);
+    message.setExtension(optionalFixed64ExtensionLite , 108L);
+    message.setExtension(optionalSfixed32ExtensionLite, 109);
+    message.setExtension(optionalSfixed64ExtensionLite, 110L);
+    message.setExtension(optionalFloatExtensionLite   , 111F);
+    message.setExtension(optionalDoubleExtensionLite  , 112D);
+    message.setExtension(optionalBoolExtensionLite    , true);
+    message.setExtension(optionalStringExtensionLite  , "115");
+    message.setExtension(optionalBytesExtensionLite   , toBytes("116"));
+
+    message.setExtension(optionalGroupExtensionLite,
+      OptionalGroup_extension_lite.newBuilder().setA(117).build());
+    message.setExtension(optionalNestedMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(118).build());
+    message.setExtension(optionalForeignMessageExtensionLite,
+      ForeignMessageLite.newBuilder().setC(119).build());
+    message.setExtension(optionalImportMessageExtensionLite,
+      ImportMessageLite.newBuilder().setD(120).build());
+    message.setExtension(optionalPublicImportMessageExtensionLite,
+      PublicImportMessageLite.newBuilder().setE(126).build());
+    message.setExtension(optionalLazyMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(127).build());
+
+    message.setExtension(optionalNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAZ);
+    message.setExtension(optionalForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
+    message.setExtension(optionalImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ);
+
+    message.setExtension(optionalStringPieceExtensionLite, "124");
+    message.setExtension(optionalCordExtensionLite, "125");
+
+    // -----------------------------------------------------------------
+
+    message.addExtension(repeatedInt32ExtensionLite   , 201);
+    message.addExtension(repeatedInt64ExtensionLite   , 202L);
+    message.addExtension(repeatedUint32ExtensionLite  , 203);
+    message.addExtension(repeatedUint64ExtensionLite  , 204L);
+    message.addExtension(repeatedSint32ExtensionLite  , 205);
+    message.addExtension(repeatedSint64ExtensionLite  , 206L);
+    message.addExtension(repeatedFixed32ExtensionLite , 207);
+    message.addExtension(repeatedFixed64ExtensionLite , 208L);
+    message.addExtension(repeatedSfixed32ExtensionLite, 209);
+    message.addExtension(repeatedSfixed64ExtensionLite, 210L);
+    message.addExtension(repeatedFloatExtensionLite   , 211F);
+    message.addExtension(repeatedDoubleExtensionLite  , 212D);
+    message.addExtension(repeatedBoolExtensionLite    , true);
+    message.addExtension(repeatedStringExtensionLite  , "215");
+    message.addExtension(repeatedBytesExtensionLite   , toBytes("216"));
+
+    message.addExtension(repeatedGroupExtensionLite,
+      RepeatedGroup_extension_lite.newBuilder().setA(217).build());
+    message.addExtension(repeatedNestedMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(218).build());
+    message.addExtension(repeatedForeignMessageExtensionLite,
+      ForeignMessageLite.newBuilder().setC(219).build());
+    message.addExtension(repeatedImportMessageExtensionLite,
+      ImportMessageLite.newBuilder().setD(220).build());
+    message.addExtension(repeatedLazyMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(227).build());
+
+    message.addExtension(repeatedNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAR);
+    message.addExtension(repeatedForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAR);
+    message.addExtension(repeatedImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAR);
+
+    message.addExtension(repeatedStringPieceExtensionLite, "224");
+    message.addExtension(repeatedCordExtensionLite, "225");
+
+    // Add a second one of each field.
+    message.addExtension(repeatedInt32ExtensionLite   , 301);
+    message.addExtension(repeatedInt64ExtensionLite   , 302L);
+    message.addExtension(repeatedUint32ExtensionLite  , 303);
+    message.addExtension(repeatedUint64ExtensionLite  , 304L);
+    message.addExtension(repeatedSint32ExtensionLite  , 305);
+    message.addExtension(repeatedSint64ExtensionLite  , 306L);
+    message.addExtension(repeatedFixed32ExtensionLite , 307);
+    message.addExtension(repeatedFixed64ExtensionLite , 308L);
+    message.addExtension(repeatedSfixed32ExtensionLite, 309);
+    message.addExtension(repeatedSfixed64ExtensionLite, 310L);
+    message.addExtension(repeatedFloatExtensionLite   , 311F);
+    message.addExtension(repeatedDoubleExtensionLite  , 312D);
+    message.addExtension(repeatedBoolExtensionLite    , false);
+    message.addExtension(repeatedStringExtensionLite  , "315");
+    message.addExtension(repeatedBytesExtensionLite   , toBytes("316"));
+
+    message.addExtension(repeatedGroupExtensionLite,
+      RepeatedGroup_extension_lite.newBuilder().setA(317).build());
+    message.addExtension(repeatedNestedMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(318).build());
+    message.addExtension(repeatedForeignMessageExtensionLite,
+      ForeignMessageLite.newBuilder().setC(319).build());
+    message.addExtension(repeatedImportMessageExtensionLite,
+      ImportMessageLite.newBuilder().setD(320).build());
+    message.addExtension(repeatedLazyMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(327).build());
+
+    message.addExtension(repeatedNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.BAZ);
+    message.addExtension(repeatedForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
+    message.addExtension(repeatedImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_BAZ);
+
+    message.addExtension(repeatedStringPieceExtensionLite, "324");
+    message.addExtension(repeatedCordExtensionLite, "325");
+
+    // -----------------------------------------------------------------
+
+    message.setExtension(defaultInt32ExtensionLite   , 401);
+    message.setExtension(defaultInt64ExtensionLite   , 402L);
+    message.setExtension(defaultUint32ExtensionLite  , 403);
+    message.setExtension(defaultUint64ExtensionLite  , 404L);
+    message.setExtension(defaultSint32ExtensionLite  , 405);
+    message.setExtension(defaultSint64ExtensionLite  , 406L);
+    message.setExtension(defaultFixed32ExtensionLite , 407);
+    message.setExtension(defaultFixed64ExtensionLite , 408L);
+    message.setExtension(defaultSfixed32ExtensionLite, 409);
+    message.setExtension(defaultSfixed64ExtensionLite, 410L);
+    message.setExtension(defaultFloatExtensionLite   , 411F);
+    message.setExtension(defaultDoubleExtensionLite  , 412D);
+    message.setExtension(defaultBoolExtensionLite    , false);
+    message.setExtension(defaultStringExtensionLite  , "415");
+    message.setExtension(defaultBytesExtensionLite   , toBytes("416"));
+
+    message.setExtension(defaultNestedEnumExtensionLite, TestAllTypesLite.NestedEnum.FOO);
+    message.setExtension(defaultForeignEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_FOO);
+    message.setExtension(defaultImportEnumExtensionLite, ImportEnumLite.IMPORT_LITE_FOO);
+
+    message.setExtension(defaultStringPieceExtensionLite, "424");
+    message.setExtension(defaultCordExtensionLite, "425");
+
+    message.setExtension(oneofUint32ExtensionLite, 601);
+    message.setExtension(oneofNestedMessageExtensionLite,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(602).build());
+    message.setExtension(oneofStringExtensionLite, "603");
+    message.setExtension(oneofBytesExtensionLite, toBytes("604"));
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Modify the repeated extensions of {@code message} to contain the values
+   * expected by {@code assertRepeatedExtensionsModified()}.
+   */
+  public static void modifyRepeatedExtensions(
+      TestAllExtensionsLite.Builder message) {
+    message.setExtension(repeatedInt32ExtensionLite   , 1, 501);
+    message.setExtension(repeatedInt64ExtensionLite   , 1, 502L);
+    message.setExtension(repeatedUint32ExtensionLite  , 1, 503);
+    message.setExtension(repeatedUint64ExtensionLite  , 1, 504L);
+    message.setExtension(repeatedSint32ExtensionLite  , 1, 505);
+    message.setExtension(repeatedSint64ExtensionLite  , 1, 506L);
+    message.setExtension(repeatedFixed32ExtensionLite , 1, 507);
+    message.setExtension(repeatedFixed64ExtensionLite , 1, 508L);
+    message.setExtension(repeatedSfixed32ExtensionLite, 1, 509);
+    message.setExtension(repeatedSfixed64ExtensionLite, 1, 510L);
+    message.setExtension(repeatedFloatExtensionLite   , 1, 511F);
+    message.setExtension(repeatedDoubleExtensionLite  , 1, 512D);
+    message.setExtension(repeatedBoolExtensionLite    , 1, true);
+    message.setExtension(repeatedStringExtensionLite  , 1, "515");
+    message.setExtension(repeatedBytesExtensionLite   , 1, toBytes("516"));
+
+    message.setExtension(repeatedGroupExtensionLite, 1,
+      RepeatedGroup_extension_lite.newBuilder().setA(517).build());
+    message.setExtension(repeatedNestedMessageExtensionLite, 1,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(518).build());
+    message.setExtension(repeatedForeignMessageExtensionLite, 1,
+      ForeignMessageLite.newBuilder().setC(519).build());
+    message.setExtension(repeatedImportMessageExtensionLite, 1,
+      ImportMessageLite.newBuilder().setD(520).build());
+    message.setExtension(repeatedLazyMessageExtensionLite, 1,
+      TestAllTypesLite.NestedMessage.newBuilder().setBb(527).build());
+
+    message.setExtension(repeatedNestedEnumExtensionLite , 1, TestAllTypesLite.NestedEnum.FOO);
+    message.setExtension(repeatedForeignEnumExtensionLite, 1, ForeignEnumLite.FOREIGN_LITE_FOO);
+    message.setExtension(repeatedImportEnumExtensionLite , 1, ImportEnumLite.IMPORT_LITE_FOO);
+
+    message.setExtension(repeatedStringPieceExtensionLite, 1, "524");
+    message.setExtension(repeatedCordExtensionLite, 1, "525");
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all extensions of
+   * {@code message} are set to the values assigned by {@code setAllExtensions}.
+   */
+  public static void assertAllExtensionsSet(
+      TestAllExtensionsLiteOrBuilder message) {
+    Assert.assertTrue(message.hasExtension(optionalInt32ExtensionLite   ));
+    Assert.assertTrue(message.hasExtension(optionalInt64ExtensionLite   ));
+    Assert.assertTrue(message.hasExtension(optionalUint32ExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(optionalUint64ExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(optionalSint32ExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(optionalSint64ExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(optionalFixed32ExtensionLite ));
+    Assert.assertTrue(message.hasExtension(optionalFixed64ExtensionLite ));
+    Assert.assertTrue(message.hasExtension(optionalSfixed32ExtensionLite));
+    Assert.assertTrue(message.hasExtension(optionalSfixed64ExtensionLite));
+    Assert.assertTrue(message.hasExtension(optionalFloatExtensionLite   ));
+    Assert.assertTrue(message.hasExtension(optionalDoubleExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(optionalBoolExtensionLite    ));
+    Assert.assertTrue(message.hasExtension(optionalStringExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(optionalBytesExtensionLite   ));
+
+    Assert.assertTrue(message.hasExtension(optionalGroupExtensionLite         ));
+    Assert.assertTrue(message.hasExtension(optionalNestedMessageExtensionLite ));
+    Assert.assertTrue(message.hasExtension(optionalForeignMessageExtensionLite));
+    Assert.assertTrue(message.hasExtension(optionalImportMessageExtensionLite ));
+
+    Assert.assertTrue(message.getExtension(optionalGroupExtensionLite         ).hasA());
+    Assert.assertTrue(message.getExtension(optionalNestedMessageExtensionLite ).hasBb());
+    Assert.assertTrue(message.getExtension(optionalForeignMessageExtensionLite).hasC());
+    Assert.assertTrue(message.getExtension(optionalImportMessageExtensionLite ).hasD());
+
+    Assert.assertTrue(message.hasExtension(optionalNestedEnumExtensionLite ));
+    Assert.assertTrue(message.hasExtension(optionalForeignEnumExtensionLite));
+    Assert.assertTrue(message.hasExtension(optionalImportEnumExtensionLite ));
+
+    Assert.assertTrue(message.hasExtension(optionalStringPieceExtensionLite));
+    Assert.assertTrue(message.hasExtension(optionalCordExtensionLite));
+
+    assertEqualsExactType(101  , message.getExtension(optionalInt32ExtensionLite   ));
+    assertEqualsExactType(102L , message.getExtension(optionalInt64ExtensionLite   ));
+    assertEqualsExactType(103  , message.getExtension(optionalUint32ExtensionLite  ));
+    assertEqualsExactType(104L , message.getExtension(optionalUint64ExtensionLite  ));
+    assertEqualsExactType(105  , message.getExtension(optionalSint32ExtensionLite  ));
+    assertEqualsExactType(106L , message.getExtension(optionalSint64ExtensionLite  ));
+    assertEqualsExactType(107  , message.getExtension(optionalFixed32ExtensionLite ));
+    assertEqualsExactType(108L , message.getExtension(optionalFixed64ExtensionLite ));
+    assertEqualsExactType(109  , message.getExtension(optionalSfixed32ExtensionLite));
+    assertEqualsExactType(110L , message.getExtension(optionalSfixed64ExtensionLite));
+    assertEqualsExactType(111F , message.getExtension(optionalFloatExtensionLite   ));
+    assertEqualsExactType(112D , message.getExtension(optionalDoubleExtensionLite  ));
+    assertEqualsExactType(true , message.getExtension(optionalBoolExtensionLite    ));
+    assertEqualsExactType("115", message.getExtension(optionalStringExtensionLite  ));
+    assertEqualsExactType(toBytes("116"), message.getExtension(optionalBytesExtensionLite));
+
+    assertEqualsExactType(117, message.getExtension(optionalGroupExtensionLite         ).getA());
+    assertEqualsExactType(118, message.getExtension(optionalNestedMessageExtensionLite ).getBb());
+    assertEqualsExactType(119, message.getExtension(optionalForeignMessageExtensionLite).getC());
+    assertEqualsExactType(120, message.getExtension(optionalImportMessageExtensionLite ).getD());
+    assertEqualsExactType(126, message.getExtension(
+        optionalPublicImportMessageExtensionLite).getE());
+    assertEqualsExactType(127, message.getExtension(optionalLazyMessageExtensionLite).getBb());
+
+    assertEqualsExactType(TestAllTypesLite.NestedEnum.BAZ,
+      message.getExtension(optionalNestedEnumExtensionLite));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_BAZ,
+      message.getExtension(optionalForeignEnumExtensionLite));
+    assertEqualsExactType(ImportEnumLite.IMPORT_LITE_BAZ,
+      message.getExtension(optionalImportEnumExtensionLite));
+
+    assertEqualsExactType("124", message.getExtension(optionalStringPieceExtensionLite));
+    assertEqualsExactType("125", message.getExtension(optionalCordExtensionLite));
+
+    // -----------------------------------------------------------------
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedInt32ExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedInt64ExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedUint32ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedUint64ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSint32ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSint64ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFixed32ExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFixed64ExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSfixed32ExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSfixed64ExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFloatExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedDoubleExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedBoolExtensionLite    ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedStringExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedBytesExtensionLite   ));
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedGroupExtensionLite         ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedNestedMessageExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedForeignMessageExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedImportMessageExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedLazyMessageExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedNestedEnumExtensionLite    ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedForeignEnumExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedImportEnumExtensionLite    ));
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedStringPieceExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedCordExtensionLite));
+
+    assertEqualsExactType(201  , message.getExtension(repeatedInt32ExtensionLite   , 0));
+    assertEqualsExactType(202L , message.getExtension(repeatedInt64ExtensionLite   , 0));
+    assertEqualsExactType(203  , message.getExtension(repeatedUint32ExtensionLite  , 0));
+    assertEqualsExactType(204L , message.getExtension(repeatedUint64ExtensionLite  , 0));
+    assertEqualsExactType(205  , message.getExtension(repeatedSint32ExtensionLite  , 0));
+    assertEqualsExactType(206L , message.getExtension(repeatedSint64ExtensionLite  , 0));
+    assertEqualsExactType(207  , message.getExtension(repeatedFixed32ExtensionLite , 0));
+    assertEqualsExactType(208L , message.getExtension(repeatedFixed64ExtensionLite , 0));
+    assertEqualsExactType(209  , message.getExtension(repeatedSfixed32ExtensionLite, 0));
+    assertEqualsExactType(210L , message.getExtension(repeatedSfixed64ExtensionLite, 0));
+    assertEqualsExactType(211F , message.getExtension(repeatedFloatExtensionLite   , 0));
+    assertEqualsExactType(212D , message.getExtension(repeatedDoubleExtensionLite  , 0));
+    assertEqualsExactType(true , message.getExtension(repeatedBoolExtensionLite    , 0));
+    assertEqualsExactType("215", message.getExtension(repeatedStringExtensionLite  , 0));
+    assertEqualsExactType(toBytes("216"), message.getExtension(repeatedBytesExtensionLite, 0));
+
+    assertEqualsExactType(217, message.getExtension(repeatedGroupExtensionLite         ,0).getA());
+    assertEqualsExactType(218, message.getExtension(repeatedNestedMessageExtensionLite ,0).getBb());
+    assertEqualsExactType(219, message.getExtension(repeatedForeignMessageExtensionLite,0).getC());
+    assertEqualsExactType(220, message.getExtension(repeatedImportMessageExtensionLite ,0).getD());
+    assertEqualsExactType(227, message.getExtension(repeatedLazyMessageExtensionLite   ,0).getBb());
+
+    assertEqualsExactType(TestAllTypesLite.NestedEnum.BAR,
+      message.getExtension(repeatedNestedEnumExtensionLite, 0));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_BAR,
+      message.getExtension(repeatedForeignEnumExtensionLite, 0));
+    assertEqualsExactType(ImportEnumLite.IMPORT_LITE_BAR,
+      message.getExtension(repeatedImportEnumExtensionLite, 0));
+
+    assertEqualsExactType("224", message.getExtension(repeatedStringPieceExtensionLite, 0));
+    assertEqualsExactType("225", message.getExtension(repeatedCordExtensionLite, 0));
+
+    assertEqualsExactType(301  , message.getExtension(repeatedInt32ExtensionLite   , 1));
+    assertEqualsExactType(302L , message.getExtension(repeatedInt64ExtensionLite   , 1));
+    assertEqualsExactType(303  , message.getExtension(repeatedUint32ExtensionLite  , 1));
+    assertEqualsExactType(304L , message.getExtension(repeatedUint64ExtensionLite  , 1));
+    assertEqualsExactType(305  , message.getExtension(repeatedSint32ExtensionLite  , 1));
+    assertEqualsExactType(306L , message.getExtension(repeatedSint64ExtensionLite  , 1));
+    assertEqualsExactType(307  , message.getExtension(repeatedFixed32ExtensionLite , 1));
+    assertEqualsExactType(308L , message.getExtension(repeatedFixed64ExtensionLite , 1));
+    assertEqualsExactType(309  , message.getExtension(repeatedSfixed32ExtensionLite, 1));
+    assertEqualsExactType(310L , message.getExtension(repeatedSfixed64ExtensionLite, 1));
+    assertEqualsExactType(311F , message.getExtension(repeatedFloatExtensionLite   , 1));
+    assertEqualsExactType(312D , message.getExtension(repeatedDoubleExtensionLite  , 1));
+    assertEqualsExactType(false, message.getExtension(repeatedBoolExtensionLite    , 1));
+    assertEqualsExactType("315", message.getExtension(repeatedStringExtensionLite  , 1));
+    assertEqualsExactType(toBytes("316"), message.getExtension(repeatedBytesExtensionLite, 1));
+
+    assertEqualsExactType(317, message.getExtension(repeatedGroupExtensionLite         ,1).getA());
+    assertEqualsExactType(318, message.getExtension(repeatedNestedMessageExtensionLite ,1).getBb());
+    assertEqualsExactType(319, message.getExtension(repeatedForeignMessageExtensionLite,1).getC());
+    assertEqualsExactType(320, message.getExtension(repeatedImportMessageExtensionLite ,1).getD());
+    assertEqualsExactType(327, message.getExtension(repeatedLazyMessageExtensionLite   ,1).getBb());
+
+    assertEqualsExactType(TestAllTypesLite.NestedEnum.BAZ,
+      message.getExtension(repeatedNestedEnumExtensionLite, 1));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_BAZ,
+      message.getExtension(repeatedForeignEnumExtensionLite, 1));
+    assertEqualsExactType(ImportEnumLite.IMPORT_LITE_BAZ,
+      message.getExtension(repeatedImportEnumExtensionLite, 1));
+
+    assertEqualsExactType("324", message.getExtension(repeatedStringPieceExtensionLite, 1));
+    assertEqualsExactType("325", message.getExtension(repeatedCordExtensionLite, 1));
+
+    // -----------------------------------------------------------------
+
+    Assert.assertTrue(message.hasExtension(defaultInt32ExtensionLite   ));
+    Assert.assertTrue(message.hasExtension(defaultInt64ExtensionLite   ));
+    Assert.assertTrue(message.hasExtension(defaultUint32ExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(defaultUint64ExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(defaultSint32ExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(defaultSint64ExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(defaultFixed32ExtensionLite ));
+    Assert.assertTrue(message.hasExtension(defaultFixed64ExtensionLite ));
+    Assert.assertTrue(message.hasExtension(defaultSfixed32ExtensionLite));
+    Assert.assertTrue(message.hasExtension(defaultSfixed64ExtensionLite));
+    Assert.assertTrue(message.hasExtension(defaultFloatExtensionLite   ));
+    Assert.assertTrue(message.hasExtension(defaultDoubleExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(defaultBoolExtensionLite    ));
+    Assert.assertTrue(message.hasExtension(defaultStringExtensionLite  ));
+    Assert.assertTrue(message.hasExtension(defaultBytesExtensionLite   ));
+
+    Assert.assertTrue(message.hasExtension(defaultNestedEnumExtensionLite ));
+    Assert.assertTrue(message.hasExtension(defaultForeignEnumExtensionLite));
+    Assert.assertTrue(message.hasExtension(defaultImportEnumExtensionLite ));
+
+    Assert.assertTrue(message.hasExtension(defaultStringPieceExtensionLite));
+    Assert.assertTrue(message.hasExtension(defaultCordExtensionLite));
+
+    assertEqualsExactType(401  , message.getExtension(defaultInt32ExtensionLite   ));
+    assertEqualsExactType(402L , message.getExtension(defaultInt64ExtensionLite   ));
+    assertEqualsExactType(403  , message.getExtension(defaultUint32ExtensionLite  ));
+    assertEqualsExactType(404L , message.getExtension(defaultUint64ExtensionLite  ));
+    assertEqualsExactType(405  , message.getExtension(defaultSint32ExtensionLite  ));
+    assertEqualsExactType(406L , message.getExtension(defaultSint64ExtensionLite  ));
+    assertEqualsExactType(407  , message.getExtension(defaultFixed32ExtensionLite ));
+    assertEqualsExactType(408L , message.getExtension(defaultFixed64ExtensionLite ));
+    assertEqualsExactType(409  , message.getExtension(defaultSfixed32ExtensionLite));
+    assertEqualsExactType(410L , message.getExtension(defaultSfixed64ExtensionLite));
+    assertEqualsExactType(411F , message.getExtension(defaultFloatExtensionLite   ));
+    assertEqualsExactType(412D , message.getExtension(defaultDoubleExtensionLite  ));
+    assertEqualsExactType(false, message.getExtension(defaultBoolExtensionLite    ));
+    assertEqualsExactType("415", message.getExtension(defaultStringExtensionLite  ));
+    assertEqualsExactType(toBytes("416"), message.getExtension(defaultBytesExtensionLite));
+
+    assertEqualsExactType(TestAllTypesLite.NestedEnum.FOO,
+      message.getExtension(defaultNestedEnumExtensionLite ));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_FOO,
+      message.getExtension(defaultForeignEnumExtensionLite));
+    assertEqualsExactType(ImportEnumLite.IMPORT_LITE_FOO,
+      message.getExtension(defaultImportEnumExtensionLite));
+
+    assertEqualsExactType("424", message.getExtension(defaultStringPieceExtensionLite));
+    assertEqualsExactType("425", message.getExtension(defaultCordExtensionLite));
+
+    Assert.assertTrue(message.hasExtension(oneofBytesExtensionLite));
+
+    assertEqualsExactType(toBytes("604"), message.getExtension(oneofBytesExtensionLite));
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all extensions of
+   * {@code message} are cleared, and that getting the extensions returns their
+   * default values.
+   */
+  public static void assertExtensionsClear(
+      TestAllExtensionsLiteOrBuilder message) {
+    // hasBlah() should initially be false for all optional fields.
+    Assert.assertFalse(message.hasExtension(optionalInt32ExtensionLite   ));
+    Assert.assertFalse(message.hasExtension(optionalInt64ExtensionLite   ));
+    Assert.assertFalse(message.hasExtension(optionalUint32ExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(optionalUint64ExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(optionalSint32ExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(optionalSint64ExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(optionalFixed32ExtensionLite ));
+    Assert.assertFalse(message.hasExtension(optionalFixed64ExtensionLite ));
+    Assert.assertFalse(message.hasExtension(optionalSfixed32ExtensionLite));
+    Assert.assertFalse(message.hasExtension(optionalSfixed64ExtensionLite));
+    Assert.assertFalse(message.hasExtension(optionalFloatExtensionLite   ));
+    Assert.assertFalse(message.hasExtension(optionalDoubleExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(optionalBoolExtensionLite    ));
+    Assert.assertFalse(message.hasExtension(optionalStringExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(optionalBytesExtensionLite   ));
+
+    Assert.assertFalse(message.hasExtension(optionalGroupExtensionLite              ));
+    Assert.assertFalse(message.hasExtension(optionalNestedMessageExtensionLite      ));
+    Assert.assertFalse(message.hasExtension(optionalForeignMessageExtensionLite     ));
+    Assert.assertFalse(message.hasExtension(optionalImportMessageExtensionLite      ));
+    Assert.assertFalse(message.hasExtension(optionalPublicImportMessageExtensionLite));
+    Assert.assertFalse(message.hasExtension(optionalLazyMessageExtensionLite        ));
+
+    Assert.assertFalse(message.hasExtension(optionalNestedEnumExtensionLite ));
+    Assert.assertFalse(message.hasExtension(optionalForeignEnumExtensionLite));
+    Assert.assertFalse(message.hasExtension(optionalImportEnumExtensionLite ));
+
+    Assert.assertFalse(message.hasExtension(optionalStringPieceExtensionLite));
+    Assert.assertFalse(message.hasExtension(optionalCordExtensionLite));
+
+    // Optional fields without defaults are set to zero or something like it.
+    assertEqualsExactType(0    , message.getExtension(optionalInt32ExtensionLite   ));
+    assertEqualsExactType(0L   , message.getExtension(optionalInt64ExtensionLite   ));
+    assertEqualsExactType(0    , message.getExtension(optionalUint32ExtensionLite  ));
+    assertEqualsExactType(0L   , message.getExtension(optionalUint64ExtensionLite  ));
+    assertEqualsExactType(0    , message.getExtension(optionalSint32ExtensionLite  ));
+    assertEqualsExactType(0L   , message.getExtension(optionalSint64ExtensionLite  ));
+    assertEqualsExactType(0    , message.getExtension(optionalFixed32ExtensionLite ));
+    assertEqualsExactType(0L   , message.getExtension(optionalFixed64ExtensionLite ));
+    assertEqualsExactType(0    , message.getExtension(optionalSfixed32ExtensionLite));
+    assertEqualsExactType(0L   , message.getExtension(optionalSfixed64ExtensionLite));
+    assertEqualsExactType(0F   , message.getExtension(optionalFloatExtensionLite   ));
+    assertEqualsExactType(0D   , message.getExtension(optionalDoubleExtensionLite  ));
+    assertEqualsExactType(false, message.getExtension(optionalBoolExtensionLite    ));
+    assertEqualsExactType(""   , message.getExtension(optionalStringExtensionLite  ));
+    assertEqualsExactType(ByteString.EMPTY, message.getExtension(optionalBytesExtensionLite));
+
+    // Embedded messages should also be clear.
+    Assert.assertFalse(message.getExtension(optionalGroupExtensionLite              ).hasA());
+    Assert.assertFalse(message.getExtension(optionalNestedMessageExtensionLite      ).hasBb());
+    Assert.assertFalse(message.getExtension(optionalForeignMessageExtensionLite     ).hasC());
+    Assert.assertFalse(message.getExtension(optionalImportMessageExtensionLite      ).hasD());
+    Assert.assertFalse(message.getExtension(optionalPublicImportMessageExtensionLite).hasE());
+    Assert.assertFalse(message.getExtension(optionalLazyMessageExtensionLite        ).hasBb());
+
+    assertEqualsExactType(0, message.getExtension(optionalGroupExtensionLite         ).getA());
+    assertEqualsExactType(0, message.getExtension(optionalNestedMessageExtensionLite ).getBb());
+    assertEqualsExactType(0, message.getExtension(optionalForeignMessageExtensionLite).getC());
+    assertEqualsExactType(0, message.getExtension(optionalImportMessageExtensionLite ).getD());
+    assertEqualsExactType(0, message.getExtension(
+        optionalPublicImportMessageExtensionLite).getE());
+    assertEqualsExactType(0, message.getExtension(optionalLazyMessageExtensionLite   ).getBb());
+
+    // Enums without defaults are set to the first value in the enum.
+    assertEqualsExactType(TestAllTypesLite.NestedEnum.FOO,
+      message.getExtension(optionalNestedEnumExtensionLite ));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_FOO,
+      message.getExtension(optionalForeignEnumExtensionLite));
+    assertEqualsExactType(ImportEnumLite.IMPORT_LITE_FOO,
+      message.getExtension(optionalImportEnumExtensionLite));
+
+    assertEqualsExactType("", message.getExtension(optionalStringPieceExtensionLite));
+    assertEqualsExactType("", message.getExtension(optionalCordExtensionLite));
+
+    // Repeated fields are empty.
+    Assert.assertEquals(0, message.getExtensionCount(repeatedInt32ExtensionLite   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedInt64ExtensionLite   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedUint32ExtensionLite  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedUint64ExtensionLite  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedSint32ExtensionLite  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedSint64ExtensionLite  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedFixed32ExtensionLite ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedFixed64ExtensionLite ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedSfixed32ExtensionLite));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedSfixed64ExtensionLite));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedFloatExtensionLite   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedDoubleExtensionLite  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedBoolExtensionLite    ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedStringExtensionLite  ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedBytesExtensionLite   ));
+
+    Assert.assertEquals(0, message.getExtensionCount(repeatedGroupExtensionLite         ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedNestedMessageExtensionLite ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedForeignMessageExtensionLite));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedImportMessageExtensionLite ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedLazyMessageExtensionLite   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedNestedEnumExtensionLite    ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedForeignEnumExtensionLite   ));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedImportEnumExtensionLite    ));
+
+    Assert.assertEquals(0, message.getExtensionCount(repeatedStringPieceExtensionLite));
+    Assert.assertEquals(0, message.getExtensionCount(repeatedCordExtensionLite));
+
+    // hasBlah() should also be false for all default fields.
+    Assert.assertFalse(message.hasExtension(defaultInt32ExtensionLite   ));
+    Assert.assertFalse(message.hasExtension(defaultInt64ExtensionLite   ));
+    Assert.assertFalse(message.hasExtension(defaultUint32ExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(defaultUint64ExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(defaultSint32ExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(defaultSint64ExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(defaultFixed32ExtensionLite ));
+    Assert.assertFalse(message.hasExtension(defaultFixed64ExtensionLite ));
+    Assert.assertFalse(message.hasExtension(defaultSfixed32ExtensionLite));
+    Assert.assertFalse(message.hasExtension(defaultSfixed64ExtensionLite));
+    Assert.assertFalse(message.hasExtension(defaultFloatExtensionLite   ));
+    Assert.assertFalse(message.hasExtension(defaultDoubleExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(defaultBoolExtensionLite    ));
+    Assert.assertFalse(message.hasExtension(defaultStringExtensionLite  ));
+    Assert.assertFalse(message.hasExtension(defaultBytesExtensionLite   ));
+
+    Assert.assertFalse(message.hasExtension(defaultNestedEnumExtensionLite ));
+    Assert.assertFalse(message.hasExtension(defaultForeignEnumExtensionLite));
+    Assert.assertFalse(message.hasExtension(defaultImportEnumExtensionLite ));
+
+    Assert.assertFalse(message.hasExtension(defaultStringPieceExtensionLite));
+    Assert.assertFalse(message.hasExtension(defaultCordExtensionLite));
+
+    // Fields with defaults have their default values (duh).
+    assertEqualsExactType( 41    , message.getExtension(defaultInt32ExtensionLite   ));
+    assertEqualsExactType( 42L   , message.getExtension(defaultInt64ExtensionLite   ));
+    assertEqualsExactType( 43    , message.getExtension(defaultUint32ExtensionLite  ));
+    assertEqualsExactType( 44L   , message.getExtension(defaultUint64ExtensionLite  ));
+    assertEqualsExactType(-45    , message.getExtension(defaultSint32ExtensionLite  ));
+    assertEqualsExactType( 46L   , message.getExtension(defaultSint64ExtensionLite  ));
+    assertEqualsExactType( 47    , message.getExtension(defaultFixed32ExtensionLite ));
+    assertEqualsExactType( 48L   , message.getExtension(defaultFixed64ExtensionLite ));
+    assertEqualsExactType( 49    , message.getExtension(defaultSfixed32ExtensionLite));
+    assertEqualsExactType(-50L   , message.getExtension(defaultSfixed64ExtensionLite));
+    assertEqualsExactType( 51.5F , message.getExtension(defaultFloatExtensionLite   ));
+    assertEqualsExactType( 52e3D , message.getExtension(defaultDoubleExtensionLite  ));
+    assertEqualsExactType(true   , message.getExtension(defaultBoolExtensionLite    ));
+    assertEqualsExactType("hello", message.getExtension(defaultStringExtensionLite  ));
+    assertEqualsExactType(toBytes("world"), message.getExtension(defaultBytesExtensionLite));
+
+    assertEqualsExactType(TestAllTypesLite.NestedEnum.BAR,
+      message.getExtension(defaultNestedEnumExtensionLite ));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_BAR,
+      message.getExtension(defaultForeignEnumExtensionLite));
+    assertEqualsExactType(ImportEnumLite.IMPORT_LITE_BAR,
+      message.getExtension(defaultImportEnumExtensionLite));
+
+    assertEqualsExactType("abc", message.getExtension(defaultStringPieceExtensionLite));
+    assertEqualsExactType("123", message.getExtension(defaultCordExtensionLite));
+
+    Assert.assertFalse(message.hasExtension(oneofUint32ExtensionLite));
+    Assert.assertFalse(message.hasExtension(oneofNestedMessageExtensionLite));
+    Assert.assertFalse(message.hasExtension(oneofStringExtensionLite));
+    Assert.assertFalse(message.hasExtension(oneofBytesExtensionLite));
+  }
+
+  // -------------------------------------------------------------------
+
+  /**
+   * Assert (using {@code junit.framework.Assert}} that all extensions of
+   * {@code message} are set to the values assigned by {@code setAllExtensions}
+   * followed by {@code modifyRepeatedExtensions}.
+   */
+  public static void assertRepeatedExtensionsModified(
+      TestAllExtensionsLiteOrBuilder message) {
+    // ModifyRepeatedFields only sets the second repeated element of each
+    // field.  In addition to verifying this, we also verify that the first
+    // element and size were *not* modified.
+    Assert.assertEquals(2, message.getExtensionCount(repeatedInt32ExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedInt64ExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedUint32ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedUint64ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSint32ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSint64ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFixed32ExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFixed64ExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSfixed32ExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedSfixed64ExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedFloatExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedDoubleExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedBoolExtensionLite    ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedStringExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedBytesExtensionLite   ));
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedGroupExtensionLite         ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedNestedMessageExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedForeignMessageExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedImportMessageExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedLazyMessageExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedNestedEnumExtensionLite    ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedForeignEnumExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedImportEnumExtensionLite    ));
+
+    Assert.assertEquals(2, message.getExtensionCount(repeatedStringPieceExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(repeatedCordExtensionLite));
+
+    assertEqualsExactType(201  , message.getExtension(repeatedInt32ExtensionLite   , 0));
+    assertEqualsExactType(202L , message.getExtension(repeatedInt64ExtensionLite   , 0));
+    assertEqualsExactType(203  , message.getExtension(repeatedUint32ExtensionLite  , 0));
+    assertEqualsExactType(204L , message.getExtension(repeatedUint64ExtensionLite  , 0));
+    assertEqualsExactType(205  , message.getExtension(repeatedSint32ExtensionLite  , 0));
+    assertEqualsExactType(206L , message.getExtension(repeatedSint64ExtensionLite  , 0));
+    assertEqualsExactType(207  , message.getExtension(repeatedFixed32ExtensionLite , 0));
+    assertEqualsExactType(208L , message.getExtension(repeatedFixed64ExtensionLite , 0));
+    assertEqualsExactType(209  , message.getExtension(repeatedSfixed32ExtensionLite, 0));
+    assertEqualsExactType(210L , message.getExtension(repeatedSfixed64ExtensionLite, 0));
+    assertEqualsExactType(211F , message.getExtension(repeatedFloatExtensionLite   , 0));
+    assertEqualsExactType(212D , message.getExtension(repeatedDoubleExtensionLite  , 0));
+    assertEqualsExactType(true , message.getExtension(repeatedBoolExtensionLite    , 0));
+    assertEqualsExactType("215", message.getExtension(repeatedStringExtensionLite  , 0));
+    assertEqualsExactType(toBytes("216"), message.getExtension(repeatedBytesExtensionLite, 0));
+
+    assertEqualsExactType(217, message.getExtension(repeatedGroupExtensionLite         ,0).getA());
+    assertEqualsExactType(218, message.getExtension(repeatedNestedMessageExtensionLite ,0).getBb());
+    assertEqualsExactType(219, message.getExtension(repeatedForeignMessageExtensionLite,0).getC());
+    assertEqualsExactType(220, message.getExtension(repeatedImportMessageExtensionLite ,0).getD());
+    assertEqualsExactType(227, message.getExtension(repeatedLazyMessageExtensionLite   ,0).getBb());
+
+    assertEqualsExactType(TestAllTypesLite.NestedEnum.BAR,
+      message.getExtension(repeatedNestedEnumExtensionLite, 0));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_BAR,
+      message.getExtension(repeatedForeignEnumExtensionLite, 0));
+    assertEqualsExactType(ImportEnumLite.IMPORT_LITE_BAR,
+      message.getExtension(repeatedImportEnumExtensionLite, 0));
+
+    assertEqualsExactType("224", message.getExtension(repeatedStringPieceExtensionLite, 0));
+    assertEqualsExactType("225", message.getExtension(repeatedCordExtensionLite, 0));
+
+    // Actually verify the second (modified) elements now.
+    assertEqualsExactType(501  , message.getExtension(repeatedInt32ExtensionLite   , 1));
+    assertEqualsExactType(502L , message.getExtension(repeatedInt64ExtensionLite   , 1));
+    assertEqualsExactType(503  , message.getExtension(repeatedUint32ExtensionLite  , 1));
+    assertEqualsExactType(504L , message.getExtension(repeatedUint64ExtensionLite  , 1));
+    assertEqualsExactType(505  , message.getExtension(repeatedSint32ExtensionLite  , 1));
+    assertEqualsExactType(506L , message.getExtension(repeatedSint64ExtensionLite  , 1));
+    assertEqualsExactType(507  , message.getExtension(repeatedFixed32ExtensionLite , 1));
+    assertEqualsExactType(508L , message.getExtension(repeatedFixed64ExtensionLite , 1));
+    assertEqualsExactType(509  , message.getExtension(repeatedSfixed32ExtensionLite, 1));
+    assertEqualsExactType(510L , message.getExtension(repeatedSfixed64ExtensionLite, 1));
+    assertEqualsExactType(511F , message.getExtension(repeatedFloatExtensionLite   , 1));
+    assertEqualsExactType(512D , message.getExtension(repeatedDoubleExtensionLite  , 1));
+    assertEqualsExactType(true , message.getExtension(repeatedBoolExtensionLite    , 1));
+    assertEqualsExactType("515", message.getExtension(repeatedStringExtensionLite  , 1));
+    assertEqualsExactType(toBytes("516"), message.getExtension(repeatedBytesExtensionLite, 1));
+
+    assertEqualsExactType(517, message.getExtension(repeatedGroupExtensionLite         ,1).getA());
+    assertEqualsExactType(518, message.getExtension(repeatedNestedMessageExtensionLite ,1).getBb());
+    assertEqualsExactType(519, message.getExtension(repeatedForeignMessageExtensionLite,1).getC());
+    assertEqualsExactType(520, message.getExtension(repeatedImportMessageExtensionLite ,1).getD());
+    assertEqualsExactType(527, message.getExtension(repeatedLazyMessageExtensionLite   ,1).getBb());
+
+    assertEqualsExactType(TestAllTypesLite.NestedEnum.FOO,
+      message.getExtension(repeatedNestedEnumExtensionLite, 1));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_FOO,
+      message.getExtension(repeatedForeignEnumExtensionLite, 1));
+    assertEqualsExactType(ImportEnumLite.IMPORT_LITE_FOO,
+      message.getExtension(repeatedImportEnumExtensionLite, 1));
+
+    assertEqualsExactType("524", message.getExtension(repeatedStringPieceExtensionLite, 1));
+    assertEqualsExactType("525", message.getExtension(repeatedCordExtensionLite, 1));
+  }
+
+  public static void setPackedExtensions(TestPackedExtensionsLite.Builder message) {
+    message.addExtension(packedInt32ExtensionLite   , 601);
+    message.addExtension(packedInt64ExtensionLite   , 602L);
+    message.addExtension(packedUint32ExtensionLite  , 603);
+    message.addExtension(packedUint64ExtensionLite  , 604L);
+    message.addExtension(packedSint32ExtensionLite  , 605);
+    message.addExtension(packedSint64ExtensionLite  , 606L);
+    message.addExtension(packedFixed32ExtensionLite , 607);
+    message.addExtension(packedFixed64ExtensionLite , 608L);
+    message.addExtension(packedSfixed32ExtensionLite, 609);
+    message.addExtension(packedSfixed64ExtensionLite, 610L);
+    message.addExtension(packedFloatExtensionLite   , 611F);
+    message.addExtension(packedDoubleExtensionLite  , 612D);
+    message.addExtension(packedBoolExtensionLite    , true);
+    message.addExtension(packedEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAR);
+    // Add a second one of each field.
+    message.addExtension(packedInt32ExtensionLite   , 701);
+    message.addExtension(packedInt64ExtensionLite   , 702L);
+    message.addExtension(packedUint32ExtensionLite  , 703);
+    message.addExtension(packedUint64ExtensionLite  , 704L);
+    message.addExtension(packedSint32ExtensionLite  , 705);
+    message.addExtension(packedSint64ExtensionLite  , 706L);
+    message.addExtension(packedFixed32ExtensionLite , 707);
+    message.addExtension(packedFixed64ExtensionLite , 708L);
+    message.addExtension(packedSfixed32ExtensionLite, 709);
+    message.addExtension(packedSfixed64ExtensionLite, 710L);
+    message.addExtension(packedFloatExtensionLite   , 711F);
+    message.addExtension(packedDoubleExtensionLite  , 712D);
+    message.addExtension(packedBoolExtensionLite    , false);
+    message.addExtension(packedEnumExtensionLite, ForeignEnumLite.FOREIGN_LITE_BAZ);
+  }
+
+  public static void assertPackedExtensionsSet(TestPackedExtensionsLite message) {
+    Assert.assertEquals(2, message.getExtensionCount(packedInt32ExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(packedInt64ExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(packedUint32ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedUint64ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedSint32ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedSint64ExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedFixed32ExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(packedFixed64ExtensionLite ));
+    Assert.assertEquals(2, message.getExtensionCount(packedSfixed32ExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(packedSfixed64ExtensionLite));
+    Assert.assertEquals(2, message.getExtensionCount(packedFloatExtensionLite   ));
+    Assert.assertEquals(2, message.getExtensionCount(packedDoubleExtensionLite  ));
+    Assert.assertEquals(2, message.getExtensionCount(packedBoolExtensionLite    ));
+    Assert.assertEquals(2, message.getExtensionCount(packedEnumExtensionLite));
+    assertEqualsExactType(601  , message.getExtension(packedInt32ExtensionLite   , 0));
+    assertEqualsExactType(602L , message.getExtension(packedInt64ExtensionLite   , 0));
+    assertEqualsExactType(603  , message.getExtension(packedUint32ExtensionLite  , 0));
+    assertEqualsExactType(604L , message.getExtension(packedUint64ExtensionLite  , 0));
+    assertEqualsExactType(605  , message.getExtension(packedSint32ExtensionLite  , 0));
+    assertEqualsExactType(606L , message.getExtension(packedSint64ExtensionLite  , 0));
+    assertEqualsExactType(607  , message.getExtension(packedFixed32ExtensionLite , 0));
+    assertEqualsExactType(608L , message.getExtension(packedFixed64ExtensionLite , 0));
+    assertEqualsExactType(609  , message.getExtension(packedSfixed32ExtensionLite, 0));
+    assertEqualsExactType(610L , message.getExtension(packedSfixed64ExtensionLite, 0));
+    assertEqualsExactType(611F , message.getExtension(packedFloatExtensionLite   , 0));
+    assertEqualsExactType(612D , message.getExtension(packedDoubleExtensionLite  , 0));
+    assertEqualsExactType(true , message.getExtension(packedBoolExtensionLite    , 0));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_BAR,
+                          message.getExtension(packedEnumExtensionLite, 0));
+    assertEqualsExactType(701  , message.getExtension(packedInt32ExtensionLite   , 1));
+    assertEqualsExactType(702L , message.getExtension(packedInt64ExtensionLite   , 1));
+    assertEqualsExactType(703  , message.getExtension(packedUint32ExtensionLite  , 1));
+    assertEqualsExactType(704L , message.getExtension(packedUint64ExtensionLite  , 1));
+    assertEqualsExactType(705  , message.getExtension(packedSint32ExtensionLite  , 1));
+    assertEqualsExactType(706L , message.getExtension(packedSint64ExtensionLite  , 1));
+    assertEqualsExactType(707  , message.getExtension(packedFixed32ExtensionLite , 1));
+    assertEqualsExactType(708L , message.getExtension(packedFixed64ExtensionLite , 1));
+    assertEqualsExactType(709  , message.getExtension(packedSfixed32ExtensionLite, 1));
+    assertEqualsExactType(710L , message.getExtension(packedSfixed64ExtensionLite, 1));
+    assertEqualsExactType(711F , message.getExtension(packedFloatExtensionLite   , 1));
+    assertEqualsExactType(712D , message.getExtension(packedDoubleExtensionLite  , 1));
+    assertEqualsExactType(false, message.getExtension(packedBoolExtensionLite    , 1));
+    assertEqualsExactType(ForeignEnumLite.FOREIGN_LITE_BAZ,
+                          message.getExtension(packedEnumExtensionLite, 1));
+  }
+
+  // ===================================================================
+  // oneof
+  public static void setOneof(TestOneof2.Builder message) {
+    message.setFooLazyMessage(
+        TestOneof2.NestedMessage.newBuilder().setQuxInt(100).build());
+    message.setBarString("101");
+    message.setBazInt(102);
+    message.setBazString("103");
+  }
+
+  public static void assertOneofSet(TestOneof2 message) {
+    Assert.assertTrue(message.hasFooLazyMessage            ());
+    Assert.assertTrue(message.getFooLazyMessage().hasQuxInt());
+
+    Assert.assertTrue(message.hasBarString());
+    Assert.assertTrue(message.hasBazInt   ());
+    Assert.assertTrue(message.hasBazString());
+
+    Assert.assertEquals(100  , message.getFooLazyMessage().getQuxInt());
+    Assert.assertEquals("101", message.getBarString                 ());
+    Assert.assertEquals(102  , message.getBazInt                    ());
+    Assert.assertEquals("103", message.getBazString                 ());
+  }
+
+  public static void assertAtMostOneFieldSetOneof(TestOneof2 message) {
+    int count = 0;
+    if (message.hasFooInt()) { ++count; }
+    if (message.hasFooString()) { ++count; }
+    if (message.hasFooCord()) { ++count; }
+    if (message.hasFooStringPiece()) { ++count; }
+    if (message.hasFooBytes()) { ++count; }
+    if (message.hasFooEnum()) { ++count; }
+    if (message.hasFooMessage()) { ++count; }
+    if (message.hasFooGroup()) { ++count; }
+    if (message.hasFooLazyMessage()) { ++count; }
+    Assert.assertTrue(count <= 1);
+
+    count = 0;
+    if (message.hasBarInt()) { ++count; }
+    if (message.hasBarString()) { ++count; }
+    if (message.hasBarCord()) { ++count; }
+    if (message.hasBarStringPiece()) { ++count; }
+    if (message.hasBarBytes()) { ++count; }
+    if (message.hasBarEnum()) { ++count; }
+    Assert.assertTrue(count <= 1);
+
+    switch (message.getFooCase()) {
+      case FOO_INT:
+        Assert.assertTrue(message.hasFooInt());
+        break;
+      case FOO_STRING:
+        Assert.assertTrue(message.hasFooString());
+        break;
+      case FOO_CORD:
+        Assert.assertTrue(message.hasFooCord());
+        break;
+      case FOO_BYTES:
+        Assert.assertTrue(message.hasFooBytes());
+        break;
+      case FOO_ENUM:
+        Assert.assertTrue(message.hasFooEnum());
+        break;
+      case FOO_MESSAGE:
+        Assert.assertTrue(message.hasFooMessage());
+        break;
+      case FOOGROUP:
+        Assert.assertTrue(message.hasFooGroup());
+        break;
+      case FOO_LAZY_MESSAGE:
+        Assert.assertTrue(message.hasFooLazyMessage());
+        break;
+      case FOO_NOT_SET:
+        break;
+    }
+  }
+
+  // =================================================================
+
+  /**
+   * Performs the same things that the methods of {@code TestUtil} do, but
+   * via the reflection interface.  This is its own class because it needs
+   * to know what descriptor to use.
+   */
+  public static class ReflectionTester {
+    private final Descriptors.Descriptor baseDescriptor;
+    private final ExtensionRegistry extensionRegistry;
+
+    private final Descriptors.FileDescriptor file;
+    private final Descriptors.FileDescriptor importFile;
+    private final Descriptors.FileDescriptor publicImportFile;
+
+    private final Descriptors.Descriptor optionalGroup;
+    private final Descriptors.Descriptor repeatedGroup;
+    private final Descriptors.Descriptor nestedMessage;
+    private final Descriptors.Descriptor foreignMessage;
+    private final Descriptors.Descriptor importMessage;
+    private final Descriptors.Descriptor publicImportMessage;
+
+    private final Descriptors.FieldDescriptor groupA;
+    private final Descriptors.FieldDescriptor repeatedGroupA;
+    private final Descriptors.FieldDescriptor nestedB;
+    private final Descriptors.FieldDescriptor foreignC;
+    private final Descriptors.FieldDescriptor importD;
+    private final Descriptors.FieldDescriptor importE;
+
+    private final Descriptors.EnumDescriptor nestedEnum;
+    private final Descriptors.EnumDescriptor foreignEnum;
+    private final Descriptors.EnumDescriptor importEnum;
+
+    private final Descriptors.EnumValueDescriptor nestedFoo;
+    private final Descriptors.EnumValueDescriptor nestedBar;
+    private final Descriptors.EnumValueDescriptor nestedBaz;
+    private final Descriptors.EnumValueDescriptor foreignFoo;
+    private final Descriptors.EnumValueDescriptor foreignBar;
+    private final Descriptors.EnumValueDescriptor foreignBaz;
+    private final Descriptors.EnumValueDescriptor importFoo;
+    private final Descriptors.EnumValueDescriptor importBar;
+    private final Descriptors.EnumValueDescriptor importBaz;
+
+    /**
+     * Construct a {@code ReflectionTester} that will expect messages using
+     * the given descriptor.
+     *
+     * Normally {@code baseDescriptor} should be a descriptor for the type
+     * {@code TestAllTypes}, defined in
+     * {@code google/protobuf/unittest.proto}.  However, if
+     * {@code extensionRegistry} is non-null, then {@code baseDescriptor} should
+     * be for {@code TestAllExtensions} instead, and instead of reading and
+     * writing normal fields, the tester will read and write extensions.
+     * All of {@code TestAllExtensions}' extensions must be registered in the
+     * registry.
+     */
+    public ReflectionTester(Descriptors.Descriptor baseDescriptor,
+                            ExtensionRegistry extensionRegistry) {
+      this.baseDescriptor = baseDescriptor;
+      this.extensionRegistry = extensionRegistry;
+
+      this.file = baseDescriptor.getFile();
+      Assert.assertEquals(1, file.getDependencies().size());
+      this.importFile = file.getDependencies().get(0);
+      this.publicImportFile = importFile.getDependencies().get(0);
+
+      Descriptors.Descriptor testAllTypes;
+      if (baseDescriptor.getName() == "TestAllTypes") {
+        testAllTypes = baseDescriptor;
+      } else {
+        testAllTypes = file.findMessageTypeByName("TestAllTypes");
+        Assert.assertNotNull(testAllTypes);
+      }
+
+      if (extensionRegistry == null) {
+        // Use testAllTypes, rather than baseDescriptor, to allow
+        // initialization using TestPackedTypes descriptors. These objects
+        // won't be used by the methods for packed fields.
+        this.optionalGroup =
+          testAllTypes.findNestedTypeByName("OptionalGroup");
+        this.repeatedGroup =
+          testAllTypes.findNestedTypeByName("RepeatedGroup");
+      } else {
+        this.optionalGroup =
+          file.findMessageTypeByName("OptionalGroup_extension");
+        this.repeatedGroup =
+          file.findMessageTypeByName("RepeatedGroup_extension");
+      }
+      this.nestedMessage = testAllTypes.findNestedTypeByName("NestedMessage");
+      this.foreignMessage = file.findMessageTypeByName("ForeignMessage");
+      this.importMessage = importFile.findMessageTypeByName("ImportMessage");
+      this.publicImportMessage = publicImportFile.findMessageTypeByName(
+          "PublicImportMessage");
+
+      this.nestedEnum = testAllTypes.findEnumTypeByName("NestedEnum");
+      this.foreignEnum = file.findEnumTypeByName("ForeignEnum");
+      this.importEnum = importFile.findEnumTypeByName("ImportEnum");
+
+      Assert.assertNotNull(optionalGroup );
+      Assert.assertNotNull(repeatedGroup );
+      Assert.assertNotNull(nestedMessage );
+      Assert.assertNotNull(foreignMessage);
+      Assert.assertNotNull(importMessage );
+      Assert.assertNotNull(nestedEnum    );
+      Assert.assertNotNull(foreignEnum   );
+      Assert.assertNotNull(importEnum    );
+
+      this.nestedB  = nestedMessage .findFieldByName("bb");
+      this.foreignC = foreignMessage.findFieldByName("c");
+      this.importD  = importMessage .findFieldByName("d");
+      this.importE  = publicImportMessage.findFieldByName("e");
+      this.nestedFoo = nestedEnum.findValueByName("FOO");
+      this.nestedBar = nestedEnum.findValueByName("BAR");
+      this.nestedBaz = nestedEnum.findValueByName("BAZ");
+      this.foreignFoo = foreignEnum.findValueByName("FOREIGN_FOO");
+      this.foreignBar = foreignEnum.findValueByName("FOREIGN_BAR");
+      this.foreignBaz = foreignEnum.findValueByName("FOREIGN_BAZ");
+      this.importFoo = importEnum.findValueByName("IMPORT_FOO");
+      this.importBar = importEnum.findValueByName("IMPORT_BAR");
+      this.importBaz = importEnum.findValueByName("IMPORT_BAZ");
+
+      this.groupA = optionalGroup.findFieldByName("a");
+      this.repeatedGroupA = repeatedGroup.findFieldByName("a");
+
+      Assert.assertNotNull(groupA        );
+      Assert.assertNotNull(repeatedGroupA);
+      Assert.assertNotNull(nestedB       );
+      Assert.assertNotNull(foreignC      );
+      Assert.assertNotNull(importD       );
+      Assert.assertNotNull(importE       );
+      Assert.assertNotNull(nestedFoo     );
+      Assert.assertNotNull(nestedBar     );
+      Assert.assertNotNull(nestedBaz     );
+      Assert.assertNotNull(foreignFoo    );
+      Assert.assertNotNull(foreignBar    );
+      Assert.assertNotNull(foreignBaz    );
+      Assert.assertNotNull(importFoo     );
+      Assert.assertNotNull(importBar     );
+      Assert.assertNotNull(importBaz     );
+    }
+
+    /**
+     * Shorthand to get a FieldDescriptor for a field of unittest::TestAllTypes.
+     */
+    private Descriptors.FieldDescriptor f(String name) {
+      Descriptors.FieldDescriptor result;
+      if (extensionRegistry == null) {
+        result = baseDescriptor.findFieldByName(name);
+      } else {
+        result = file.findExtensionByName(name + "_extension");
+      }
+      Assert.assertNotNull(result);
+      return result;
+    }
+
+    /**
+     * Calls {@code parent.newBuilderForField()} or uses the
+     * {@code ExtensionRegistry} to find an appropriate builder, depending
+     * on what type is being tested.
+     */
+    private Message.Builder newBuilderForField(
+        Message.Builder parent, Descriptors.FieldDescriptor field) {
+      if (extensionRegistry == null) {
+        return parent.newBuilderForField(field);
+      } else {
+        ExtensionRegistry.ExtensionInfo extension =
+          extensionRegistry.findImmutableExtensionByNumber(
+              field.getContainingType(), field.getNumber());
+        Assert.assertNotNull(extension);
+        Assert.assertNotNull(extension.defaultInstance);
+        return extension.defaultInstance.newBuilderForType();
+      }
+    }
+
+    // -------------------------------------------------------------------
+
+    /**
+     * Set every field of {@code message} to the values expected by
+     * {@code assertAllFieldsSet()}, using the {@link Message.Builder}
+     * reflection interface.
+     */
+    void setAllFieldsViaReflection(Message.Builder message) {
+      message.setField(f("optional_int32"   ), 101 );
+      message.setField(f("optional_int64"   ), 102L);
+      message.setField(f("optional_uint32"  ), 103 );
+      message.setField(f("optional_uint64"  ), 104L);
+      message.setField(f("optional_sint32"  ), 105 );
+      message.setField(f("optional_sint64"  ), 106L);
+      message.setField(f("optional_fixed32" ), 107 );
+      message.setField(f("optional_fixed64" ), 108L);
+      message.setField(f("optional_sfixed32"), 109 );
+      message.setField(f("optional_sfixed64"), 110L);
+      message.setField(f("optional_float"   ), 111F);
+      message.setField(f("optional_double"  ), 112D);
+      message.setField(f("optional_bool"    ), true);
+      message.setField(f("optional_string"  ), "115");
+      message.setField(f("optional_bytes"   ), toBytes("116"));
+
+      message.setField(f("optionalgroup"),
+        newBuilderForField(message, f("optionalgroup"))
+               .setField(groupA, 117).build());
+      message.setField(f("optional_nested_message"),
+        newBuilderForField(message, f("optional_nested_message"))
+               .setField(nestedB, 118).build());
+      message.setField(f("optional_foreign_message"),
+        newBuilderForField(message, f("optional_foreign_message"))
+               .setField(foreignC, 119).build());
+      message.setField(f("optional_import_message"),
+        newBuilderForField(message, f("optional_import_message"))
+               .setField(importD, 120).build());
+      message.setField(f("optional_public_import_message"),
+        newBuilderForField(message, f("optional_public_import_message"))
+               .setField(importE, 126).build());
+      message.setField(f("optional_lazy_message"),
+        newBuilderForField(message, f("optional_lazy_message"))
+               .setField(nestedB, 127).build());
+
+      message.setField(f("optional_nested_enum" ),  nestedBaz);
+      message.setField(f("optional_foreign_enum"), foreignBaz);
+      message.setField(f("optional_import_enum" ),  importBaz);
+
+      message.setField(f("optional_string_piece" ), "124");
+      message.setField(f("optional_cord" ), "125");
+
+      // -----------------------------------------------------------------
+
+      message.addRepeatedField(f("repeated_int32"   ), 201 );
+      message.addRepeatedField(f("repeated_int64"   ), 202L);
+      message.addRepeatedField(f("repeated_uint32"  ), 203 );
+      message.addRepeatedField(f("repeated_uint64"  ), 204L);
+      message.addRepeatedField(f("repeated_sint32"  ), 205 );
+      message.addRepeatedField(f("repeated_sint64"  ), 206L);
+      message.addRepeatedField(f("repeated_fixed32" ), 207 );
+      message.addRepeatedField(f("repeated_fixed64" ), 208L);
+      message.addRepeatedField(f("repeated_sfixed32"), 209 );
+      message.addRepeatedField(f("repeated_sfixed64"), 210L);
+      message.addRepeatedField(f("repeated_float"   ), 211F);
+      message.addRepeatedField(f("repeated_double"  ), 212D);
+      message.addRepeatedField(f("repeated_bool"    ), true);
+      message.addRepeatedField(f("repeated_string"  ), "215");
+      message.addRepeatedField(f("repeated_bytes"   ), toBytes("216"));
+
+      message.addRepeatedField(f("repeatedgroup"),
+        newBuilderForField(message, f("repeatedgroup"))
+               .setField(repeatedGroupA, 217).build());
+      message.addRepeatedField(f("repeated_nested_message"),
+        newBuilderForField(message, f("repeated_nested_message"))
+               .setField(nestedB, 218).build());
+      message.addRepeatedField(f("repeated_foreign_message"),
+        newBuilderForField(message, f("repeated_foreign_message"))
+               .setField(foreignC, 219).build());
+      message.addRepeatedField(f("repeated_import_message"),
+        newBuilderForField(message, f("repeated_import_message"))
+               .setField(importD, 220).build());
+      message.addRepeatedField(f("repeated_lazy_message"),
+        newBuilderForField(message, f("repeated_lazy_message"))
+               .setField(nestedB, 227).build());
+
+      message.addRepeatedField(f("repeated_nested_enum" ),  nestedBar);
+      message.addRepeatedField(f("repeated_foreign_enum"), foreignBar);
+      message.addRepeatedField(f("repeated_import_enum" ),  importBar);
+
+      message.addRepeatedField(f("repeated_string_piece" ), "224");
+      message.addRepeatedField(f("repeated_cord" ), "225");
+
+      // Add a second one of each field.
+      message.addRepeatedField(f("repeated_int32"   ), 301 );
+      message.addRepeatedField(f("repeated_int64"   ), 302L);
+      message.addRepeatedField(f("repeated_uint32"  ), 303 );
+      message.addRepeatedField(f("repeated_uint64"  ), 304L);
+      message.addRepeatedField(f("repeated_sint32"  ), 305 );
+      message.addRepeatedField(f("repeated_sint64"  ), 306L);
+      message.addRepeatedField(f("repeated_fixed32" ), 307 );
+      message.addRepeatedField(f("repeated_fixed64" ), 308L);
+      message.addRepeatedField(f("repeated_sfixed32"), 309 );
+      message.addRepeatedField(f("repeated_sfixed64"), 310L);
+      message.addRepeatedField(f("repeated_float"   ), 311F);
+      message.addRepeatedField(f("repeated_double"  ), 312D);
+      message.addRepeatedField(f("repeated_bool"    ), false);
+      message.addRepeatedField(f("repeated_string"  ), "315");
+      message.addRepeatedField(f("repeated_bytes"   ), toBytes("316"));
+
+      message.addRepeatedField(f("repeatedgroup"),
+        newBuilderForField(message, f("repeatedgroup"))
+               .setField(repeatedGroupA, 317).build());
+      message.addRepeatedField(f("repeated_nested_message"),
+        newBuilderForField(message, f("repeated_nested_message"))
+               .setField(nestedB, 318).build());
+      message.addRepeatedField(f("repeated_foreign_message"),
+        newBuilderForField(message, f("repeated_foreign_message"))
+               .setField(foreignC, 319).build());
+      message.addRepeatedField(f("repeated_import_message"),
+        newBuilderForField(message, f("repeated_import_message"))
+               .setField(importD, 320).build());
+      message.addRepeatedField(f("repeated_lazy_message"),
+        newBuilderForField(message, f("repeated_lazy_message"))
+               .setField(nestedB, 327).build());
+
+      message.addRepeatedField(f("repeated_nested_enum" ),  nestedBaz);
+      message.addRepeatedField(f("repeated_foreign_enum"), foreignBaz);
+      message.addRepeatedField(f("repeated_import_enum" ),  importBaz);
+
+      message.addRepeatedField(f("repeated_string_piece" ), "324");
+      message.addRepeatedField(f("repeated_cord" ), "325");
+
+      // -----------------------------------------------------------------
+
+      message.setField(f("default_int32"   ), 401 );
+      message.setField(f("default_int64"   ), 402L);
+      message.setField(f("default_uint32"  ), 403 );
+      message.setField(f("default_uint64"  ), 404L);
+      message.setField(f("default_sint32"  ), 405 );
+      message.setField(f("default_sint64"  ), 406L);
+      message.setField(f("default_fixed32" ), 407 );
+      message.setField(f("default_fixed64" ), 408L);
+      message.setField(f("default_sfixed32"), 409 );
+      message.setField(f("default_sfixed64"), 410L);
+      message.setField(f("default_float"   ), 411F);
+      message.setField(f("default_double"  ), 412D);
+      message.setField(f("default_bool"    ), false);
+      message.setField(f("default_string"  ), "415");
+      message.setField(f("default_bytes"   ), toBytes("416"));
+
+      message.setField(f("default_nested_enum" ),  nestedFoo);
+      message.setField(f("default_foreign_enum"), foreignFoo);
+      message.setField(f("default_import_enum" ),  importFoo);
+
+      message.setField(f("default_string_piece" ), "424");
+      message.setField(f("default_cord" ), "425");
+
+      message.setField(f("oneof_uint32" ), 601);
+      message.setField(f("oneof_nested_message"),
+        newBuilderForField(message, f("oneof_nested_message"))
+          .setField(nestedB, 602).build());
+      message.setField(f("oneof_string" ), "603");
+      message.setField(f("oneof_bytes" ), toBytes("604"));
+    }
+
+    // -------------------------------------------------------------------
+
+    /**
+     * Modify the repeated fields of {@code message} to contain the values
+     * expected by {@code assertRepeatedFieldsModified()}, using the
+     * {@link Message.Builder} reflection interface.
+     */
+    void modifyRepeatedFieldsViaReflection(Message.Builder message) {
+      message.setRepeatedField(f("repeated_int32"   ), 1, 501 );
+      message.setRepeatedField(f("repeated_int64"   ), 1, 502L);
+      message.setRepeatedField(f("repeated_uint32"  ), 1, 503 );
+      message.setRepeatedField(f("repeated_uint64"  ), 1, 504L);
+      message.setRepeatedField(f("repeated_sint32"  ), 1, 505 );
+      message.setRepeatedField(f("repeated_sint64"  ), 1, 506L);
+      message.setRepeatedField(f("repeated_fixed32" ), 1, 507 );
+      message.setRepeatedField(f("repeated_fixed64" ), 1, 508L);
+      message.setRepeatedField(f("repeated_sfixed32"), 1, 509 );
+      message.setRepeatedField(f("repeated_sfixed64"), 1, 510L);
+      message.setRepeatedField(f("repeated_float"   ), 1, 511F);
+      message.setRepeatedField(f("repeated_double"  ), 1, 512D);
+      message.setRepeatedField(f("repeated_bool"    ), 1, true);
+      message.setRepeatedField(f("repeated_string"  ), 1, "515");
+      message.setRepeatedField(f("repeated_bytes"   ), 1, toBytes("516"));
+
+      message.setRepeatedField(f("repeatedgroup"), 1,
+        newBuilderForField(message, f("repeatedgroup"))
+               .setField(repeatedGroupA, 517).build());
+      message.setRepeatedField(f("repeated_nested_message"), 1,
+        newBuilderForField(message, f("repeated_nested_message"))
+               .setField(nestedB, 518).build());
+      message.setRepeatedField(f("repeated_foreign_message"), 1,
+        newBuilderForField(message, f("repeated_foreign_message"))
+               .setField(foreignC, 519).build());
+      message.setRepeatedField(f("repeated_import_message"), 1,
+        newBuilderForField(message, f("repeated_import_message"))
+               .setField(importD, 520).build());
+      message.setRepeatedField(f("repeated_lazy_message"), 1,
+        newBuilderForField(message, f("repeated_lazy_message"))
+               .setField(nestedB, 527).build());
+
+      message.setRepeatedField(f("repeated_nested_enum" ), 1,  nestedFoo);
+      message.setRepeatedField(f("repeated_foreign_enum"), 1, foreignFoo);
+      message.setRepeatedField(f("repeated_import_enum" ), 1,  importFoo);
+
+      message.setRepeatedField(f("repeated_string_piece"), 1, "524");
+      message.setRepeatedField(f("repeated_cord"), 1, "525");
+    }
+
+    // -------------------------------------------------------------------
+
+    /**
+     * Assert (using {@code junit.framework.Assert}} that all fields of
+     * {@code message} are set to the values assigned by {@code setAllFields},
+     * using the {@link Message} reflection interface.
+     */
+    public void assertAllFieldsSetViaReflection(MessageOrBuilder message) {
+      Assert.assertTrue(message.hasField(f("optional_int32"   )));
+      Assert.assertTrue(message.hasField(f("optional_int64"   )));
+      Assert.assertTrue(message.hasField(f("optional_uint32"  )));
+      Assert.assertTrue(message.hasField(f("optional_uint64"  )));
+      Assert.assertTrue(message.hasField(f("optional_sint32"  )));
+      Assert.assertTrue(message.hasField(f("optional_sint64"  )));
+      Assert.assertTrue(message.hasField(f("optional_fixed32" )));
+      Assert.assertTrue(message.hasField(f("optional_fixed64" )));
+      Assert.assertTrue(message.hasField(f("optional_sfixed32")));
+      Assert.assertTrue(message.hasField(f("optional_sfixed64")));
+      Assert.assertTrue(message.hasField(f("optional_float"   )));
+      Assert.assertTrue(message.hasField(f("optional_double"  )));
+      Assert.assertTrue(message.hasField(f("optional_bool"    )));
+      Assert.assertTrue(message.hasField(f("optional_string"  )));
+      Assert.assertTrue(message.hasField(f("optional_bytes"   )));
+
+      Assert.assertTrue(message.hasField(f("optionalgroup"           )));
+      Assert.assertTrue(message.hasField(f("optional_nested_message" )));
+      Assert.assertTrue(message.hasField(f("optional_foreign_message")));
+      Assert.assertTrue(message.hasField(f("optional_import_message" )));
+
+      Assert.assertTrue(
+        ((Message)message.getField(f("optionalgroup"))).hasField(groupA));
+      Assert.assertTrue(
+        ((Message)message.getField(f("optional_nested_message")))
+                         .hasField(nestedB));
+      Assert.assertTrue(
+        ((Message)message.getField(f("optional_foreign_message")))
+                         .hasField(foreignC));
+      Assert.assertTrue(
+        ((Message)message.getField(f("optional_import_message")))
+                         .hasField(importD));
+
+      Assert.assertTrue(message.hasField(f("optional_nested_enum" )));
+      Assert.assertTrue(message.hasField(f("optional_foreign_enum")));
+      Assert.assertTrue(message.hasField(f("optional_import_enum" )));
+
+      Assert.assertTrue(message.hasField(f("optional_string_piece")));
+      Assert.assertTrue(message.hasField(f("optional_cord")));
+
+      Assert.assertEquals(101  , message.getField(f("optional_int32"   )));
+      Assert.assertEquals(102L , message.getField(f("optional_int64"   )));
+      Assert.assertEquals(103  , message.getField(f("optional_uint32"  )));
+      Assert.assertEquals(104L , message.getField(f("optional_uint64"  )));
+      Assert.assertEquals(105  , message.getField(f("optional_sint32"  )));
+      Assert.assertEquals(106L , message.getField(f("optional_sint64"  )));
+      Assert.assertEquals(107  , message.getField(f("optional_fixed32" )));
+      Assert.assertEquals(108L , message.getField(f("optional_fixed64" )));
+      Assert.assertEquals(109  , message.getField(f("optional_sfixed32")));
+      Assert.assertEquals(110L , message.getField(f("optional_sfixed64")));
+      Assert.assertEquals(111F , message.getField(f("optional_float"   )));
+      Assert.assertEquals(112D , message.getField(f("optional_double"  )));
+      Assert.assertEquals(true , message.getField(f("optional_bool"    )));
+      Assert.assertEquals("115", message.getField(f("optional_string"  )));
+      Assert.assertEquals(toBytes("116"), message.getField(f("optional_bytes")));
+
+      Assert.assertEquals(117,
+        ((Message)message.getField(f("optionalgroup"))).getField(groupA));
+      Assert.assertEquals(118,
+        ((Message)message.getField(f("optional_nested_message")))
+                         .getField(nestedB));
+      Assert.assertEquals(119,
+        ((Message)message.getField(f("optional_foreign_message")))
+                         .getField(foreignC));
+      Assert.assertEquals(120,
+        ((Message)message.getField(f("optional_import_message")))
+                         .getField(importD));
+      Assert.assertEquals(126,
+        ((Message)message.getField(f("optional_public_import_message")))
+                         .getField(importE));
+      Assert.assertEquals(127,
+        ((Message)message.getField(f("optional_lazy_message")))
+                         .getField(nestedB));
+
+      Assert.assertEquals( nestedBaz, message.getField(f("optional_nested_enum" )));
+      Assert.assertEquals(foreignBaz, message.getField(f("optional_foreign_enum")));
+      Assert.assertEquals( importBaz, message.getField(f("optional_import_enum" )));
+
+      Assert.assertEquals("124", message.getField(f("optional_string_piece")));
+      Assert.assertEquals("125", message.getField(f("optional_cord")));
+
+      // -----------------------------------------------------------------
+
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_int32"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_int64"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_uint32"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_uint64"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_sint32"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_sint64"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_fixed32" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_fixed64" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_sfixed32")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_sfixed64")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_float"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_double"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_bool"    )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_string"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_bytes"   )));
+
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeatedgroup"           )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_nested_message" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_foreign_message")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_import_message" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_lazy_message" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_nested_enum"    )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_foreign_enum"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_import_enum"    )));
+
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_string_piece")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_cord")));
+
+      Assert.assertEquals(201  , message.getRepeatedField(f("repeated_int32"   ), 0));
+      Assert.assertEquals(202L , message.getRepeatedField(f("repeated_int64"   ), 0));
+      Assert.assertEquals(203  , message.getRepeatedField(f("repeated_uint32"  ), 0));
+      Assert.assertEquals(204L , message.getRepeatedField(f("repeated_uint64"  ), 0));
+      Assert.assertEquals(205  , message.getRepeatedField(f("repeated_sint32"  ), 0));
+      Assert.assertEquals(206L , message.getRepeatedField(f("repeated_sint64"  ), 0));
+      Assert.assertEquals(207  , message.getRepeatedField(f("repeated_fixed32" ), 0));
+      Assert.assertEquals(208L , message.getRepeatedField(f("repeated_fixed64" ), 0));
+      Assert.assertEquals(209  , message.getRepeatedField(f("repeated_sfixed32"), 0));
+      Assert.assertEquals(210L , message.getRepeatedField(f("repeated_sfixed64"), 0));
+      Assert.assertEquals(211F , message.getRepeatedField(f("repeated_float"   ), 0));
+      Assert.assertEquals(212D , message.getRepeatedField(f("repeated_double"  ), 0));
+      Assert.assertEquals(true , message.getRepeatedField(f("repeated_bool"    ), 0));
+      Assert.assertEquals("215", message.getRepeatedField(f("repeated_string"  ), 0));
+      Assert.assertEquals(toBytes("216"), message.getRepeatedField(f("repeated_bytes"), 0));
+
+      Assert.assertEquals(217,
+        ((Message)message.getRepeatedField(f("repeatedgroup"), 0))
+                         .getField(repeatedGroupA));
+      Assert.assertEquals(218,
+        ((Message)message.getRepeatedField(f("repeated_nested_message"), 0))
+                         .getField(nestedB));
+      Assert.assertEquals(219,
+        ((Message)message.getRepeatedField(f("repeated_foreign_message"), 0))
+                         .getField(foreignC));
+      Assert.assertEquals(220,
+        ((Message)message.getRepeatedField(f("repeated_import_message"), 0))
+                         .getField(importD));
+      Assert.assertEquals(227,
+        ((Message)message.getRepeatedField(f("repeated_lazy_message"), 0))
+                         .getField(nestedB));
+
+      Assert.assertEquals( nestedBar, message.getRepeatedField(f("repeated_nested_enum" ),0));
+      Assert.assertEquals(foreignBar, message.getRepeatedField(f("repeated_foreign_enum"),0));
+      Assert.assertEquals( importBar, message.getRepeatedField(f("repeated_import_enum" ),0));
+
+      Assert.assertEquals("224", message.getRepeatedField(f("repeated_string_piece"), 0));
+      Assert.assertEquals("225", message.getRepeatedField(f("repeated_cord"), 0));
+
+      Assert.assertEquals(301  , message.getRepeatedField(f("repeated_int32"   ), 1));
+      Assert.assertEquals(302L , message.getRepeatedField(f("repeated_int64"   ), 1));
+      Assert.assertEquals(303  , message.getRepeatedField(f("repeated_uint32"  ), 1));
+      Assert.assertEquals(304L , message.getRepeatedField(f("repeated_uint64"  ), 1));
+      Assert.assertEquals(305  , message.getRepeatedField(f("repeated_sint32"  ), 1));
+      Assert.assertEquals(306L , message.getRepeatedField(f("repeated_sint64"  ), 1));
+      Assert.assertEquals(307  , message.getRepeatedField(f("repeated_fixed32" ), 1));
+      Assert.assertEquals(308L , message.getRepeatedField(f("repeated_fixed64" ), 1));
+      Assert.assertEquals(309  , message.getRepeatedField(f("repeated_sfixed32"), 1));
+      Assert.assertEquals(310L , message.getRepeatedField(f("repeated_sfixed64"), 1));
+      Assert.assertEquals(311F , message.getRepeatedField(f("repeated_float"   ), 1));
+      Assert.assertEquals(312D , message.getRepeatedField(f("repeated_double"  ), 1));
+      Assert.assertEquals(false, message.getRepeatedField(f("repeated_bool"    ), 1));
+      Assert.assertEquals("315", message.getRepeatedField(f("repeated_string"  ), 1));
+      Assert.assertEquals(toBytes("316"), message.getRepeatedField(f("repeated_bytes"), 1));
+
+      Assert.assertEquals(317,
+        ((Message)message.getRepeatedField(f("repeatedgroup"), 1))
+                         .getField(repeatedGroupA));
+      Assert.assertEquals(318,
+        ((Message)message.getRepeatedField(f("repeated_nested_message"), 1))
+                         .getField(nestedB));
+      Assert.assertEquals(319,
+        ((Message)message.getRepeatedField(f("repeated_foreign_message"), 1))
+                         .getField(foreignC));
+      Assert.assertEquals(320,
+        ((Message)message.getRepeatedField(f("repeated_import_message"), 1))
+                         .getField(importD));
+      Assert.assertEquals(327,
+        ((Message)message.getRepeatedField(f("repeated_lazy_message"), 1))
+                         .getField(nestedB));
+
+      Assert.assertEquals( nestedBaz, message.getRepeatedField(f("repeated_nested_enum" ),1));
+      Assert.assertEquals(foreignBaz, message.getRepeatedField(f("repeated_foreign_enum"),1));
+      Assert.assertEquals( importBaz, message.getRepeatedField(f("repeated_import_enum" ),1));
+
+      Assert.assertEquals("324", message.getRepeatedField(f("repeated_string_piece"), 1));
+      Assert.assertEquals("325", message.getRepeatedField(f("repeated_cord"), 1));
+
+      // -----------------------------------------------------------------
+
+      Assert.assertTrue(message.hasField(f("default_int32"   )));
+      Assert.assertTrue(message.hasField(f("default_int64"   )));
+      Assert.assertTrue(message.hasField(f("default_uint32"  )));
+      Assert.assertTrue(message.hasField(f("default_uint64"  )));
+      Assert.assertTrue(message.hasField(f("default_sint32"  )));
+      Assert.assertTrue(message.hasField(f("default_sint64"  )));
+      Assert.assertTrue(message.hasField(f("default_fixed32" )));
+      Assert.assertTrue(message.hasField(f("default_fixed64" )));
+      Assert.assertTrue(message.hasField(f("default_sfixed32")));
+      Assert.assertTrue(message.hasField(f("default_sfixed64")));
+      Assert.assertTrue(message.hasField(f("default_float"   )));
+      Assert.assertTrue(message.hasField(f("default_double"  )));
+      Assert.assertTrue(message.hasField(f("default_bool"    )));
+      Assert.assertTrue(message.hasField(f("default_string"  )));
+      Assert.assertTrue(message.hasField(f("default_bytes"   )));
+
+      Assert.assertTrue(message.hasField(f("default_nested_enum" )));
+      Assert.assertTrue(message.hasField(f("default_foreign_enum")));
+      Assert.assertTrue(message.hasField(f("default_import_enum" )));
+
+      Assert.assertTrue(message.hasField(f("default_string_piece")));
+      Assert.assertTrue(message.hasField(f("default_cord")));
+
+      Assert.assertEquals(401  , message.getField(f("default_int32"   )));
+      Assert.assertEquals(402L , message.getField(f("default_int64"   )));
+      Assert.assertEquals(403  , message.getField(f("default_uint32"  )));
+      Assert.assertEquals(404L , message.getField(f("default_uint64"  )));
+      Assert.assertEquals(405  , message.getField(f("default_sint32"  )));
+      Assert.assertEquals(406L , message.getField(f("default_sint64"  )));
+      Assert.assertEquals(407  , message.getField(f("default_fixed32" )));
+      Assert.assertEquals(408L , message.getField(f("default_fixed64" )));
+      Assert.assertEquals(409  , message.getField(f("default_sfixed32")));
+      Assert.assertEquals(410L , message.getField(f("default_sfixed64")));
+      Assert.assertEquals(411F , message.getField(f("default_float"   )));
+      Assert.assertEquals(412D , message.getField(f("default_double"  )));
+      Assert.assertEquals(false, message.getField(f("default_bool"    )));
+      Assert.assertEquals("415", message.getField(f("default_string"  )));
+      Assert.assertEquals(toBytes("416"), message.getField(f("default_bytes")));
+
+      Assert.assertEquals( nestedFoo, message.getField(f("default_nested_enum" )));
+      Assert.assertEquals(foreignFoo, message.getField(f("default_foreign_enum")));
+      Assert.assertEquals( importFoo, message.getField(f("default_import_enum" )));
+
+      Assert.assertEquals("424", message.getField(f("default_string_piece")));
+      Assert.assertEquals("425", message.getField(f("default_cord")));
+
+      Assert.assertTrue(message.hasField(f("oneof_bytes")));
+      Assert.assertEquals(toBytes("604"), message.getField(f("oneof_bytes")));
+
+      if (extensionRegistry == null) {
+        Assert.assertFalse(message.hasField(f("oneof_uint32")));
+        Assert.assertFalse(message.hasField(f("oneof_nested_message")));
+        Assert.assertFalse(message.hasField(f("oneof_string")));
+      } else {
+        Assert.assertTrue(message.hasField(f("oneof_uint32")));
+        Assert.assertTrue(message.hasField(f("oneof_nested_message")));
+        Assert.assertTrue(message.hasField(f("oneof_string")));
+        Assert.assertEquals(601, message.getField(f("oneof_uint32")));
+        Assert.assertEquals(602,
+            ((MessageOrBuilder) message.getField(f("oneof_nested_message")))
+            .getField(nestedB));
+        Assert.assertEquals("603", message.getField(f("oneof_string")));
+      }
+    }
+
+    // -------------------------------------------------------------------
+
+    /**
+     * Assert (using {@code junit.framework.Assert}} that all fields of
+     * {@code message} are cleared, and that getting the fields returns their
+     * default values, using the {@link Message} reflection interface.
+     */
+    public void assertClearViaReflection(MessageOrBuilder message) {
+      // has_blah() should initially be false for all optional fields.
+      Assert.assertFalse(message.hasField(f("optional_int32"   )));
+      Assert.assertFalse(message.hasField(f("optional_int64"   )));
+      Assert.assertFalse(message.hasField(f("optional_uint32"  )));
+      Assert.assertFalse(message.hasField(f("optional_uint64"  )));
+      Assert.assertFalse(message.hasField(f("optional_sint32"  )));
+      Assert.assertFalse(message.hasField(f("optional_sint64"  )));
+      Assert.assertFalse(message.hasField(f("optional_fixed32" )));
+      Assert.assertFalse(message.hasField(f("optional_fixed64" )));
+      Assert.assertFalse(message.hasField(f("optional_sfixed32")));
+      Assert.assertFalse(message.hasField(f("optional_sfixed64")));
+      Assert.assertFalse(message.hasField(f("optional_float"   )));
+      Assert.assertFalse(message.hasField(f("optional_double"  )));
+      Assert.assertFalse(message.hasField(f("optional_bool"    )));
+      Assert.assertFalse(message.hasField(f("optional_string"  )));
+      Assert.assertFalse(message.hasField(f("optional_bytes"   )));
+
+      Assert.assertFalse(message.hasField(f("optionalgroup"           )));
+      Assert.assertFalse(message.hasField(f("optional_nested_message" )));
+      Assert.assertFalse(message.hasField(f("optional_foreign_message")));
+      Assert.assertFalse(message.hasField(f("optional_import_message" )));
+
+      Assert.assertFalse(message.hasField(f("optional_nested_enum" )));
+      Assert.assertFalse(message.hasField(f("optional_foreign_enum")));
+      Assert.assertFalse(message.hasField(f("optional_import_enum" )));
+
+      Assert.assertFalse(message.hasField(f("optional_string_piece")));
+      Assert.assertFalse(message.hasField(f("optional_cord")));
+
+      // Optional fields without defaults are set to zero or something like it.
+      Assert.assertEquals(0    , message.getField(f("optional_int32"   )));
+      Assert.assertEquals(0L   , message.getField(f("optional_int64"   )));
+      Assert.assertEquals(0    , message.getField(f("optional_uint32"  )));
+      Assert.assertEquals(0L   , message.getField(f("optional_uint64"  )));
+      Assert.assertEquals(0    , message.getField(f("optional_sint32"  )));
+      Assert.assertEquals(0L   , message.getField(f("optional_sint64"  )));
+      Assert.assertEquals(0    , message.getField(f("optional_fixed32" )));
+      Assert.assertEquals(0L   , message.getField(f("optional_fixed64" )));
+      Assert.assertEquals(0    , message.getField(f("optional_sfixed32")));
+      Assert.assertEquals(0L   , message.getField(f("optional_sfixed64")));
+      Assert.assertEquals(0F   , message.getField(f("optional_float"   )));
+      Assert.assertEquals(0D   , message.getField(f("optional_double"  )));
+      Assert.assertEquals(false, message.getField(f("optional_bool"    )));
+      Assert.assertEquals(""   , message.getField(f("optional_string"  )));
+      Assert.assertEquals(ByteString.EMPTY, message.getField(f("optional_bytes")));
+
+      // Embedded messages should also be clear.
+      Assert.assertFalse(
+        ((Message)message.getField(f("optionalgroup"))).hasField(groupA));
+      Assert.assertFalse(
+        ((Message)message.getField(f("optional_nested_message")))
+                         .hasField(nestedB));
+      Assert.assertFalse(
+        ((Message)message.getField(f("optional_foreign_message")))
+                         .hasField(foreignC));
+      Assert.assertFalse(
+        ((Message)message.getField(f("optional_import_message")))
+                         .hasField(importD));
+      Assert.assertFalse(
+        ((Message)message.getField(f("optional_public_import_message")))
+                         .hasField(importE));
+      Assert.assertFalse(
+        ((Message)message.getField(f("optional_lazy_message")))
+                         .hasField(nestedB));
+
+      Assert.assertEquals(0,
+        ((Message)message.getField(f("optionalgroup"))).getField(groupA));
+      Assert.assertEquals(0,
+        ((Message)message.getField(f("optional_nested_message")))
+                         .getField(nestedB));
+      Assert.assertEquals(0,
+        ((Message)message.getField(f("optional_foreign_message")))
+                         .getField(foreignC));
+      Assert.assertEquals(0,
+        ((Message)message.getField(f("optional_import_message")))
+                         .getField(importD));
+      Assert.assertEquals(0,
+        ((Message)message.getField(f("optional_public_import_message")))
+                         .getField(importE));
+      Assert.assertEquals(0,
+        ((Message)message.getField(f("optional_lazy_message")))
+                         .getField(nestedB));
+
+      // Enums without defaults are set to the first value in the enum.
+      Assert.assertEquals( nestedFoo, message.getField(f("optional_nested_enum" )));
+      Assert.assertEquals(foreignFoo, message.getField(f("optional_foreign_enum")));
+      Assert.assertEquals( importFoo, message.getField(f("optional_import_enum" )));
+
+      Assert.assertEquals("", message.getField(f("optional_string_piece")));
+      Assert.assertEquals("", message.getField(f("optional_cord")));
+
+      // Repeated fields are empty.
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_int32"   )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_int64"   )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_uint32"  )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_uint64"  )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_sint32"  )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_sint64"  )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_fixed32" )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_fixed64" )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_sfixed32")));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_sfixed64")));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_float"   )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_double"  )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_bool"    )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_string"  )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_bytes"   )));
+
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeatedgroup"           )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_nested_message" )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_foreign_message")));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_import_message" )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_lazy_message"   )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_nested_enum"    )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_foreign_enum"   )));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_import_enum"    )));
+
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_string_piece")));
+      Assert.assertEquals(0, message.getRepeatedFieldCount(f("repeated_cord")));
+
+      // has_blah() should also be false for all default fields.
+      Assert.assertFalse(message.hasField(f("default_int32"   )));
+      Assert.assertFalse(message.hasField(f("default_int64"   )));
+      Assert.assertFalse(message.hasField(f("default_uint32"  )));
+      Assert.assertFalse(message.hasField(f("default_uint64"  )));
+      Assert.assertFalse(message.hasField(f("default_sint32"  )));
+      Assert.assertFalse(message.hasField(f("default_sint64"  )));
+      Assert.assertFalse(message.hasField(f("default_fixed32" )));
+      Assert.assertFalse(message.hasField(f("default_fixed64" )));
+      Assert.assertFalse(message.hasField(f("default_sfixed32")));
+      Assert.assertFalse(message.hasField(f("default_sfixed64")));
+      Assert.assertFalse(message.hasField(f("default_float"   )));
+      Assert.assertFalse(message.hasField(f("default_double"  )));
+      Assert.assertFalse(message.hasField(f("default_bool"    )));
+      Assert.assertFalse(message.hasField(f("default_string"  )));
+      Assert.assertFalse(message.hasField(f("default_bytes"   )));
+
+      Assert.assertFalse(message.hasField(f("default_nested_enum" )));
+      Assert.assertFalse(message.hasField(f("default_foreign_enum")));
+      Assert.assertFalse(message.hasField(f("default_import_enum" )));
+
+      Assert.assertFalse(message.hasField(f("default_string_piece" )));
+      Assert.assertFalse(message.hasField(f("default_cord" )));
+
+      // Fields with defaults have their default values (duh).
+      Assert.assertEquals( 41    , message.getField(f("default_int32"   )));
+      Assert.assertEquals( 42L   , message.getField(f("default_int64"   )));
+      Assert.assertEquals( 43    , message.getField(f("default_uint32"  )));
+      Assert.assertEquals( 44L   , message.getField(f("default_uint64"  )));
+      Assert.assertEquals(-45    , message.getField(f("default_sint32"  )));
+      Assert.assertEquals( 46L   , message.getField(f("default_sint64"  )));
+      Assert.assertEquals( 47    , message.getField(f("default_fixed32" )));
+      Assert.assertEquals( 48L   , message.getField(f("default_fixed64" )));
+      Assert.assertEquals( 49    , message.getField(f("default_sfixed32")));
+      Assert.assertEquals(-50L   , message.getField(f("default_sfixed64")));
+      Assert.assertEquals( 51.5F , message.getField(f("default_float"   )));
+      Assert.assertEquals( 52e3D , message.getField(f("default_double"  )));
+      Assert.assertEquals(true   , message.getField(f("default_bool"    )));
+      Assert.assertEquals("hello", message.getField(f("default_string"  )));
+      Assert.assertEquals(toBytes("world"), message.getField(f("default_bytes")));
+
+      Assert.assertEquals( nestedBar, message.getField(f("default_nested_enum" )));
+      Assert.assertEquals(foreignBar, message.getField(f("default_foreign_enum")));
+      Assert.assertEquals( importBar, message.getField(f("default_import_enum" )));
+
+      Assert.assertEquals("abc", message.getField(f("default_string_piece")));
+      Assert.assertEquals("123", message.getField(f("default_cord")));
+
+      Assert.assertFalse(message.hasField(f("oneof_uint32")));
+      Assert.assertFalse(message.hasField(f("oneof_nested_message")));
+      Assert.assertFalse(message.hasField(f("oneof_string")));
+      Assert.assertFalse(message.hasField(f("oneof_bytes")));
+
+      Assert.assertEquals(0, message.getField(f("oneof_uint32")));
+      Assert.assertEquals("", message.getField(f("oneof_string")));
+      Assert.assertEquals(toBytes(""), message.getField(f("oneof_bytes")));
+    }
+
+
+    // ---------------------------------------------------------------
+
+    public void assertRepeatedFieldsModifiedViaReflection(
+        MessageOrBuilder message) {
+      // ModifyRepeatedFields only sets the second repeated element of each
+      // field.  In addition to verifying this, we also verify that the first
+      // element and size were *not* modified.
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_int32"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_int64"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_uint32"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_uint64"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_sint32"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_sint64"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_fixed32" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_fixed64" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_sfixed32")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_sfixed64")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_float"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_double"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_bool"    )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_string"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_bytes"   )));
+
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeatedgroup"           )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_nested_message" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_foreign_message")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_import_message" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_lazy_message"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_nested_enum"    )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_foreign_enum"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_import_enum"    )));
+
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_string_piece")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("repeated_cord")));
+
+      Assert.assertEquals(201  , message.getRepeatedField(f("repeated_int32"   ), 0));
+      Assert.assertEquals(202L , message.getRepeatedField(f("repeated_int64"   ), 0));
+      Assert.assertEquals(203  , message.getRepeatedField(f("repeated_uint32"  ), 0));
+      Assert.assertEquals(204L , message.getRepeatedField(f("repeated_uint64"  ), 0));
+      Assert.assertEquals(205  , message.getRepeatedField(f("repeated_sint32"  ), 0));
+      Assert.assertEquals(206L , message.getRepeatedField(f("repeated_sint64"  ), 0));
+      Assert.assertEquals(207  , message.getRepeatedField(f("repeated_fixed32" ), 0));
+      Assert.assertEquals(208L , message.getRepeatedField(f("repeated_fixed64" ), 0));
+      Assert.assertEquals(209  , message.getRepeatedField(f("repeated_sfixed32"), 0));
+      Assert.assertEquals(210L , message.getRepeatedField(f("repeated_sfixed64"), 0));
+      Assert.assertEquals(211F , message.getRepeatedField(f("repeated_float"   ), 0));
+      Assert.assertEquals(212D , message.getRepeatedField(f("repeated_double"  ), 0));
+      Assert.assertEquals(true , message.getRepeatedField(f("repeated_bool"    ), 0));
+      Assert.assertEquals("215", message.getRepeatedField(f("repeated_string"  ), 0));
+      Assert.assertEquals(toBytes("216"), message.getRepeatedField(f("repeated_bytes"), 0));
+
+      Assert.assertEquals(217,
+        ((Message)message.getRepeatedField(f("repeatedgroup"), 0))
+                         .getField(repeatedGroupA));
+      Assert.assertEquals(218,
+        ((Message)message.getRepeatedField(f("repeated_nested_message"), 0))
+                         .getField(nestedB));
+      Assert.assertEquals(219,
+        ((Message)message.getRepeatedField(f("repeated_foreign_message"), 0))
+                         .getField(foreignC));
+      Assert.assertEquals(220,
+        ((Message)message.getRepeatedField(f("repeated_import_message"), 0))
+                         .getField(importD));
+      Assert.assertEquals(227,
+        ((Message)message.getRepeatedField(f("repeated_lazy_message"), 0))
+                         .getField(nestedB));
+
+      Assert.assertEquals( nestedBar, message.getRepeatedField(f("repeated_nested_enum" ),0));
+      Assert.assertEquals(foreignBar, message.getRepeatedField(f("repeated_foreign_enum"),0));
+      Assert.assertEquals( importBar, message.getRepeatedField(f("repeated_import_enum" ),0));
+
+      Assert.assertEquals("224", message.getRepeatedField(f("repeated_string_piece"), 0));
+      Assert.assertEquals("225", message.getRepeatedField(f("repeated_cord"), 0));
+
+      Assert.assertEquals(501  , message.getRepeatedField(f("repeated_int32"   ), 1));
+      Assert.assertEquals(502L , message.getRepeatedField(f("repeated_int64"   ), 1));
+      Assert.assertEquals(503  , message.getRepeatedField(f("repeated_uint32"  ), 1));
+      Assert.assertEquals(504L , message.getRepeatedField(f("repeated_uint64"  ), 1));
+      Assert.assertEquals(505  , message.getRepeatedField(f("repeated_sint32"  ), 1));
+      Assert.assertEquals(506L , message.getRepeatedField(f("repeated_sint64"  ), 1));
+      Assert.assertEquals(507  , message.getRepeatedField(f("repeated_fixed32" ), 1));
+      Assert.assertEquals(508L , message.getRepeatedField(f("repeated_fixed64" ), 1));
+      Assert.assertEquals(509  , message.getRepeatedField(f("repeated_sfixed32"), 1));
+      Assert.assertEquals(510L , message.getRepeatedField(f("repeated_sfixed64"), 1));
+      Assert.assertEquals(511F , message.getRepeatedField(f("repeated_float"   ), 1));
+      Assert.assertEquals(512D , message.getRepeatedField(f("repeated_double"  ), 1));
+      Assert.assertEquals(true , message.getRepeatedField(f("repeated_bool"    ), 1));
+      Assert.assertEquals("515", message.getRepeatedField(f("repeated_string"  ), 1));
+      Assert.assertEquals(toBytes("516"), message.getRepeatedField(f("repeated_bytes"), 1));
+
+      Assert.assertEquals(517,
+        ((Message)message.getRepeatedField(f("repeatedgroup"), 1))
+                         .getField(repeatedGroupA));
+      Assert.assertEquals(518,
+        ((Message)message.getRepeatedField(f("repeated_nested_message"), 1))
+                         .getField(nestedB));
+      Assert.assertEquals(519,
+        ((Message)message.getRepeatedField(f("repeated_foreign_message"), 1))
+                         .getField(foreignC));
+      Assert.assertEquals(520,
+        ((Message)message.getRepeatedField(f("repeated_import_message"), 1))
+                         .getField(importD));
+      Assert.assertEquals(527,
+        ((Message)message.getRepeatedField(f("repeated_lazy_message"), 1))
+                         .getField(nestedB));
+
+      Assert.assertEquals( nestedFoo, message.getRepeatedField(f("repeated_nested_enum" ),1));
+      Assert.assertEquals(foreignFoo, message.getRepeatedField(f("repeated_foreign_enum"),1));
+      Assert.assertEquals( importFoo, message.getRepeatedField(f("repeated_import_enum" ),1));
+
+      Assert.assertEquals("524", message.getRepeatedField(f("repeated_string_piece"), 1));
+      Assert.assertEquals("525", message.getRepeatedField(f("repeated_cord"), 1));
+    }
+
+    public void setPackedFieldsViaReflection(Message.Builder message) {
+      message.addRepeatedField(f("packed_int32"   ), 601 );
+      message.addRepeatedField(f("packed_int64"   ), 602L);
+      message.addRepeatedField(f("packed_uint32"  ), 603 );
+      message.addRepeatedField(f("packed_uint64"  ), 604L);
+      message.addRepeatedField(f("packed_sint32"  ), 605 );
+      message.addRepeatedField(f("packed_sint64"  ), 606L);
+      message.addRepeatedField(f("packed_fixed32" ), 607 );
+      message.addRepeatedField(f("packed_fixed64" ), 608L);
+      message.addRepeatedField(f("packed_sfixed32"), 609 );
+      message.addRepeatedField(f("packed_sfixed64"), 610L);
+      message.addRepeatedField(f("packed_float"   ), 611F);
+      message.addRepeatedField(f("packed_double"  ), 612D);
+      message.addRepeatedField(f("packed_bool"    ), true);
+      message.addRepeatedField(f("packed_enum" ),  foreignBar);
+      // Add a second one of each field.
+      message.addRepeatedField(f("packed_int32"   ), 701 );
+      message.addRepeatedField(f("packed_int64"   ), 702L);
+      message.addRepeatedField(f("packed_uint32"  ), 703 );
+      message.addRepeatedField(f("packed_uint64"  ), 704L);
+      message.addRepeatedField(f("packed_sint32"  ), 705 );
+      message.addRepeatedField(f("packed_sint64"  ), 706L);
+      message.addRepeatedField(f("packed_fixed32" ), 707 );
+      message.addRepeatedField(f("packed_fixed64" ), 708L);
+      message.addRepeatedField(f("packed_sfixed32"), 709 );
+      message.addRepeatedField(f("packed_sfixed64"), 710L);
+      message.addRepeatedField(f("packed_float"   ), 711F);
+      message.addRepeatedField(f("packed_double"  ), 712D);
+      message.addRepeatedField(f("packed_bool"    ), false);
+      message.addRepeatedField(f("packed_enum" ),  foreignBaz);
+    }
+
+    public void assertPackedFieldsSetViaReflection(MessageOrBuilder message) {
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_int32"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_int64"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_uint32"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_uint64"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_sint32"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_sint64"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_fixed32" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_fixed64" )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_sfixed32")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_sfixed64")));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_float"   )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_double"  )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_bool"    )));
+      Assert.assertEquals(2, message.getRepeatedFieldCount(f("packed_enum"   )));
+      Assert.assertEquals(601  , message.getRepeatedField(f("packed_int32"   ), 0));
+      Assert.assertEquals(602L , message.getRepeatedField(f("packed_int64"   ), 0));
+      Assert.assertEquals(603  , message.getRepeatedField(f("packed_uint32"  ), 0));
+      Assert.assertEquals(604L , message.getRepeatedField(f("packed_uint64"  ), 0));
+      Assert.assertEquals(605  , message.getRepeatedField(f("packed_sint32"  ), 0));
+      Assert.assertEquals(606L , message.getRepeatedField(f("packed_sint64"  ), 0));
+      Assert.assertEquals(607  , message.getRepeatedField(f("packed_fixed32" ), 0));
+      Assert.assertEquals(608L , message.getRepeatedField(f("packed_fixed64" ), 0));
+      Assert.assertEquals(609  , message.getRepeatedField(f("packed_sfixed32"), 0));
+      Assert.assertEquals(610L , message.getRepeatedField(f("packed_sfixed64"), 0));
+      Assert.assertEquals(611F , message.getRepeatedField(f("packed_float"   ), 0));
+      Assert.assertEquals(612D , message.getRepeatedField(f("packed_double"  ), 0));
+      Assert.assertEquals(true , message.getRepeatedField(f("packed_bool"    ), 0));
+      Assert.assertEquals(foreignBar, message.getRepeatedField(f("packed_enum" ),0));
+      Assert.assertEquals(701  , message.getRepeatedField(f("packed_int32"   ), 1));
+      Assert.assertEquals(702L , message.getRepeatedField(f("packed_int64"   ), 1));
+      Assert.assertEquals(703  , message.getRepeatedField(f("packed_uint32"  ), 1));
+      Assert.assertEquals(704L , message.getRepeatedField(f("packed_uint64"  ), 1));
+      Assert.assertEquals(705  , message.getRepeatedField(f("packed_sint32"  ), 1));
+      Assert.assertEquals(706L , message.getRepeatedField(f("packed_sint64"  ), 1));
+      Assert.assertEquals(707  , message.getRepeatedField(f("packed_fixed32" ), 1));
+      Assert.assertEquals(708L , message.getRepeatedField(f("packed_fixed64" ), 1));
+      Assert.assertEquals(709  , message.getRepeatedField(f("packed_sfixed32"), 1));
+      Assert.assertEquals(710L , message.getRepeatedField(f("packed_sfixed64"), 1));
+      Assert.assertEquals(711F , message.getRepeatedField(f("packed_float"   ), 1));
+      Assert.assertEquals(712D , message.getRepeatedField(f("packed_double"  ), 1));
+      Assert.assertEquals(false, message.getRepeatedField(f("packed_bool"    ), 1));
+      Assert.assertEquals(foreignBaz, message.getRepeatedField(f("packed_enum" ),1));
+    }
+
+    /**
+     * Verifies that the reflection setters for the given.Builder object throw a
+     * NullPointerException if they are passed a null value.  Uses Assert to throw an
+     * appropriate assertion failure, if the condition is not verified.
+     */
+    public void assertReflectionSettersRejectNull(Message.Builder builder)
+        throws Exception {
+      try {
+        builder.setField(f("optional_string"), null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+      try {
+        builder.setField(f("optional_bytes"), null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+      try {
+        builder.setField(f("optional_nested_enum"), null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+      try {
+        builder.setField(f("optional_nested_message"),
+                         (TestAllTypes.NestedMessage) null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+      try {
+        builder.setField(f("optional_nested_message"),
+                         (TestAllTypes.NestedMessage.Builder) null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+
+      try {
+        builder.addRepeatedField(f("repeated_string"), null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+      try {
+        builder.addRepeatedField(f("repeated_bytes"), null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+      try {
+        builder.addRepeatedField(f("repeated_nested_enum"), null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+      try {
+        builder.addRepeatedField(f("repeated_nested_message"), null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+    }
+
+    /**
+     * Verifies that the reflection repeated setters for the given Builder object throw a
+     * NullPointerException if they are passed a null value.  Uses Assert to throw an appropriate
+     * assertion failure, if the condition is not verified.
+     */
+    public void assertReflectionRepeatedSettersRejectNull(Message.Builder builder)
+        throws Exception {
+      builder.addRepeatedField(f("repeated_string"), "one");
+      try {
+        builder.setRepeatedField(f("repeated_string"), 0, null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+
+      builder.addRepeatedField(f("repeated_bytes"), toBytes("one"));
+      try {
+        builder.setRepeatedField(f("repeated_bytes"), 0, null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+
+      builder.addRepeatedField(f("repeated_nested_enum"), nestedBaz);
+      try {
+        builder.setRepeatedField(f("repeated_nested_enum"), 0, null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+
+      builder.addRepeatedField(
+          f("repeated_nested_message"),
+          TestAllTypes.NestedMessage.newBuilder().setBb(218).build());
+      try {
+        builder.setRepeatedField(f("repeated_nested_message"), 0, null);
+        Assert.fail("Exception was not thrown");
+      } catch (NullPointerException e) {
+        // We expect this exception.
+      }
+    }
+  }
+
+  /**
+   * @param filePath The path relative to
+   * {@link #getTestDataDir}.
+   */
+  public static String readTextFromFile(String filePath) {
+    return readBytesFromFile(filePath).toStringUtf8();
+  }
+
+  private static File getTestDataDir() {
+    // Search each parent directory looking for "src/google/protobuf".
+    File ancestor = new File(".");
+    try {
+      ancestor = ancestor.getCanonicalFile();
+    } catch (IOException e) {
+      throw new RuntimeException(
+        "Couldn't get canonical name of working directory.", e);
+    }
+    while (ancestor != null && ancestor.exists()) {
+      if (new File(ancestor, "src/google/protobuf").exists()) {
+        return new File(ancestor, "src/google/protobuf/testdata");
+      }
+      ancestor = ancestor.getParentFile();
+    }
+
+    throw new RuntimeException(
+      "Could not find golden files.  This test must be run from within the " +
+      "protobuf source package so that it can read test data files from the " +
+      "C++ source tree.");
+  }
+
+  /**
+   * @param filename The path relative to
+   * {@link #getTestDataDir}.
+   */
+  public static ByteString readBytesFromFile(String filename) {
+    File fullPath = new File(getTestDataDir(), filename);
+    try {
+      RandomAccessFile file = new RandomAccessFile(fullPath, "r");
+      byte[] content = new byte[(int) file.length()];
+      file.readFully(content);
+      return ByteString.copyFrom(content);
+    } catch (IOException e) {
+      // Throw a RuntimeException here so that we can call this function from
+      // static initializers.
+      throw new IllegalArgumentException(
+        "Couldn't read file: " + fullPath.getPath(), e);
+    }
+  }
+
+  /**
+   * Get the bytes of the "golden message".  This is a serialized TestAllTypes
+   * with all fields set as they would be by
+   * {@link #setAllFields(TestAllTypes.Builder)}, but it is loaded from a file
+   * on disk rather than generated dynamically.  The file is actually generated
+   * by C++ code, so testing against it verifies compatibility with C++.
+   */
+  public static ByteString getGoldenMessage() {
+    if (goldenMessage == null) {
+      goldenMessage = readBytesFromFile("golden_message_oneof_implemented");
+    }
+    return goldenMessage;
+  }
+  private static ByteString goldenMessage = null;
+
+  /**
+   * Get the bytes of the "golden packed fields message".  This is a serialized
+   * TestPackedTypes with all fields set as they would be by
+   * {@link #setPackedFields(TestPackedTypes.Builder)}, but it is loaded from a
+   * file on disk rather than generated dynamically.  The file is actually
+   * generated by C++ code, so testing against it verifies compatibility with
+   * C++.
+   */
+  public static ByteString getGoldenPackedFieldsMessage() {
+    if (goldenPackedFieldsMessage == null) {
+      goldenPackedFieldsMessage =
+          readBytesFromFile("golden_packed_fields_message");
+    }
+    return goldenPackedFieldsMessage;
+  }
+  private static ByteString goldenPackedFieldsMessage = null;
+
+  /**
+   * Mock implementation of {@link GeneratedMessage.BuilderParent} for testing.
+   *
+   * @author jonp@google.com (Jon Perlow)
+   */
+  public static class MockBuilderParent
+      implements GeneratedMessage.BuilderParent {
+
+    private int invalidations;
+
+    //@Override (Java 1.6 override semantics, but we must support 1.5)
+    public void markDirty() {
+      invalidations++;
+    }
+
+    public int getInvalidationCount() {
+      return invalidations;
+    }
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/TextFormatTest.java b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
new file mode 100644
index 00000000..1df4fad7
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
@@ -0,0 +1,1021 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.TextFormat.Parser.SingularOverwritePolicy;
+import protobuf_unittest.UnittestMset.TestMessageSetExtension1;
+import protobuf_unittest.UnittestMset.TestMessageSetExtension2;
+import protobuf_unittest.UnittestProto.OneString;
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestAllTypes.NestedMessage;
+import protobuf_unittest.UnittestProto.TestEmptyMessage;
+import protobuf_unittest.UnittestProto.TestOneof2;
+import proto2_wireformat_unittest.UnittestMsetWireFormat.TestMessageSet;
+
+import junit.framework.TestCase;
+
+import java.io.StringReader;
+
+/**
+ * Test case for {@link TextFormat}.
+ *
+ * TODO(wenboz): ExtensionTest and rest of text_format_unittest.cc.
+ *
+ * @author wenboz@google.com (Wenbo Zhu)
+ */
+public class TextFormatTest extends TestCase {
+
+  // A basic string with different escapable characters for testing.
+  private final static String kEscapeTestString =
+      "\"A string with ' characters \n and \r newlines and \t tabs and \001 "
+          + "slashes \\";
+
+  // A representation of the above string with all the characters escaped.
+  private final static String kEscapeTestStringEscaped =
+      "\\\"A string with \\' characters \\n and \\r newlines "
+          + "and \\t tabs and \\001 slashes \\\\";
+
+  private static String allFieldsSetText = TestUtil.readTextFromFile(
+    "text_format_unittest_data_oneof_implemented.txt");
+  private static String allExtensionsSetText = TestUtil.readTextFromFile(
+    "text_format_unittest_extensions_data.txt");
+
+  private static String exoticText =
+    "repeated_int32: -1\n" +
+    "repeated_int32: -2147483648\n" +
+    "repeated_int64: -1,\n" +
+    "repeated_int64: -9223372036854775808\n" +
+    "repeated_uint32: 4294967295\n" +
+    "repeated_uint32: 2147483648\n" +
+    "repeated_uint64: 18446744073709551615\n" +
+    "repeated_uint64: 9223372036854775808\n" +
+    "repeated_double: 123.0\n" +
+    "repeated_double: 123.5\n" +
+    "repeated_double: 0.125\n" +
+    "repeated_double: .125\n" +
+    "repeated_double: -.125\n" +
+    "repeated_double: 1.23E17\n" +
+    "repeated_double: 1.23E+17\n" +
+    "repeated_double: -1.23e-17\n" +
+    "repeated_double: .23e+17\n" +
+    "repeated_double: -.23E17\n" +
+    "repeated_double: 1.235E22\n" +
+    "repeated_double: 1.235E-18\n" +
+    "repeated_double: 123.456789\n" +
+    "repeated_double: Infinity\n" +
+    "repeated_double: -Infinity\n" +
+    "repeated_double: NaN\n" +
+    "repeated_string: \"\\000\\001\\a\\b\\f\\n\\r\\t\\v\\\\\\'\\\"" +
+      "\\341\\210\\264\"\n" +
+    "repeated_bytes: \"\\000\\001\\a\\b\\f\\n\\r\\t\\v\\\\\\'\\\"\\376\"\n";
+
+  private static String canonicalExoticText =
+      exoticText.replace(": .", ": 0.").replace(": -.", ": -0.")   // short-form double
+      .replace("23e", "23E").replace("E+", "E").replace("0.23E17", "2.3E16").replace(",", "");
+
+  private String messageSetText =
+    "[protobuf_unittest.TestMessageSetExtension1] {\n" +
+    "  i: 123\n" +
+    "}\n" +
+    "[protobuf_unittest.TestMessageSetExtension2] {\n" +
+    "  str: \"foo\"\n" +
+    "}\n";
+
+  private String messageSetTextWithRepeatedExtension =
+      "[protobuf_unittest.TestMessageSetExtension1] {\n" +
+      "  i: 123\n" +
+      "}\n" +
+      "[protobuf_unittest.TestMessageSetExtension1] {\n" +
+      "  i: 456\n" +
+      "}\n";
+
+
+  private final TextFormat.Parser parserWithOverwriteForbidden =
+      TextFormat.Parser.newBuilder()
+          .setSingularOverwritePolicy(
+              SingularOverwritePolicy.FORBID_SINGULAR_OVERWRITES)
+          .build();
+
+  private final TextFormat.Parser defaultParser =
+      TextFormat.Parser.newBuilder().build();
+
+  /** Print TestAllTypes and compare with golden file. */
+  public void testPrintMessage() throws Exception {
+    String javaText = TextFormat.printToString(TestUtil.getAllSet());
+
+    // Java likes to add a trailing ".0" to floats and doubles.  C printf
+    // (with %g format) does not.  Our golden files are used for both
+    // C++ and Java TextFormat classes, so we need to conform.
+    javaText = javaText.replace(".0\n", "\n");
+
+    assertEquals(allFieldsSetText, javaText);
+  }
+
+  /** Print TestAllTypes as Builder and compare with golden file. */
+  public void testPrintMessageBuilder() throws Exception {
+    String javaText = TextFormat.printToString(TestUtil.getAllSetBuilder());
+
+    // Java likes to add a trailing ".0" to floats and doubles.  C printf
+    // (with %g format) does not.  Our golden files are used for both
+    // C++ and Java TextFormat classes, so we need to conform.
+    javaText = javaText.replace(".0\n", "\n");
+
+    assertEquals(allFieldsSetText, javaText);
+  }
+
+  /** Print TestAllExtensions and compare with golden file. */
+  public void testPrintExtensions() throws Exception {
+    String javaText = TextFormat.printToString(TestUtil.getAllExtensionsSet());
+
+    // Java likes to add a trailing ".0" to floats and doubles.  C printf
+    // (with %g format) does not.  Our golden files are used for both
+    // C++ and Java TextFormat classes, so we need to conform.
+    javaText = javaText.replace(".0\n", "\n");
+
+    assertEquals(allExtensionsSetText, javaText);
+  }
+
+  // Creates an example unknown field set.
+  private UnknownFieldSet makeUnknownFieldSet() {
+    return UnknownFieldSet.newBuilder()
+        .addField(5,
+            UnknownFieldSet.Field.newBuilder()
+            .addVarint(1)
+            .addFixed32(2)
+            .addFixed64(3)
+            .addLengthDelimited(ByteString.copyFromUtf8("4"))
+            .addGroup(
+                UnknownFieldSet.newBuilder()
+                .addField(10,
+                    UnknownFieldSet.Field.newBuilder()
+                    .addVarint(5)
+                    .build())
+                .build())
+            .build())
+        .addField(8,
+            UnknownFieldSet.Field.newBuilder()
+            .addVarint(1)
+            .addVarint(2)
+            .addVarint(3)
+            .build())
+        .addField(15,
+            UnknownFieldSet.Field.newBuilder()
+            .addVarint(0xABCDEF1234567890L)
+            .addFixed32(0xABCD1234)
+            .addFixed64(0xABCDEF1234567890L)
+            .build())
+        .build();
+  }
+
+  public void testPrintUnknownFields() throws Exception {
+    // Test printing of unknown fields in a message.
+
+    TestEmptyMessage message =
+      TestEmptyMessage.newBuilder()
+        .setUnknownFields(makeUnknownFieldSet())
+        .build();
+
+    assertEquals(
+      "5: 1\n" +
+      "5: 0x00000002\n" +
+      "5: 0x0000000000000003\n" +
+      "5: \"4\"\n" +
+      "5 {\n" +
+      "  10: 5\n" +
+      "}\n" +
+      "8: 1\n" +
+      "8: 2\n" +
+      "8: 3\n" +
+      "15: 12379813812177893520\n" +
+      "15: 0xabcd1234\n" +
+      "15: 0xabcdef1234567890\n",
+      TextFormat.printToString(message));
+  }
+
+  public void testPrintField() throws Exception {
+    final FieldDescriptor dataField =
+      OneString.getDescriptor().findFieldByName("data");
+    assertEquals(
+      "data: \"test data\"\n",
+      TextFormat.printFieldToString(dataField, "test data"));
+
+    final FieldDescriptor optionalField =
+      TestAllTypes.getDescriptor().findFieldByName("optional_nested_message");
+    final Object value = NestedMessage.newBuilder().setBb(42).build();
+
+    assertEquals(
+      "optional_nested_message {\n  bb: 42\n}\n",
+      TextFormat.printFieldToString(optionalField, value));
+  }
+
+  /**
+   * Helper to construct a ByteString from a String containing only 8-bit
+   * characters.  The characters are converted directly to bytes, *not*
+   * encoded using UTF-8.
+   */
+  private ByteString bytes(String str) {
+    return ByteString.copyFrom(str.getBytes(Internal.ISO_8859_1));
+  }
+
+  /**
+   * Helper to construct a ByteString from a bunch of bytes.  The inputs are
+   * actually ints so that I can use hex notation and not get stupid errors
+   * about precision.
+   */
+  private ByteString bytes(int... bytesAsInts) {
+    byte[] bytes = new byte[bytesAsInts.length];
+    for (int i = 0; i < bytesAsInts.length; i++) {
+      bytes[i] = (byte) bytesAsInts[i];
+    }
+    return ByteString.copyFrom(bytes);
+  }
+
+  public void testPrintExotic() throws Exception {
+    Message message = TestAllTypes.newBuilder()
+      // Signed vs. unsigned numbers.
+      .addRepeatedInt32 (-1)
+      .addRepeatedUint32(-1)
+      .addRepeatedInt64 (-1)
+      .addRepeatedUint64(-1)
+
+      .addRepeatedInt32 (1  << 31)
+      .addRepeatedUint32(1  << 31)
+      .addRepeatedInt64 (1L << 63)
+      .addRepeatedUint64(1L << 63)
+
+      // Floats of various precisions and exponents.
+      .addRepeatedDouble(123)
+      .addRepeatedDouble(123.5)
+      .addRepeatedDouble(0.125)
+      .addRepeatedDouble(.125)
+      .addRepeatedDouble(-.125)
+      .addRepeatedDouble(123e15)
+      .addRepeatedDouble(123e15)
+      .addRepeatedDouble(-1.23e-17)
+      .addRepeatedDouble(.23e17)
+      .addRepeatedDouble(-23e15)
+      .addRepeatedDouble(123.5e20)
+      .addRepeatedDouble(123.5e-20)
+      .addRepeatedDouble(123.456789)
+      .addRepeatedDouble(Double.POSITIVE_INFINITY)
+      .addRepeatedDouble(Double.NEGATIVE_INFINITY)
+      .addRepeatedDouble(Double.NaN)
+
+      // Strings and bytes that needing escaping.
+      .addRepeatedString("\0\001\007\b\f\n\r\t\013\\\'\"\u1234")
+      .addRepeatedBytes(bytes("\0\001\007\b\f\n\r\t\013\\\'\"\u00fe"))
+      .build();
+
+    assertEquals(canonicalExoticText, message.toString());
+  }
+
+  public void testPrintMessageSet() throws Exception {
+    TestMessageSet messageSet =
+      TestMessageSet.newBuilder()
+        .setExtension(
+          TestMessageSetExtension1.messageSetExtension,
+          TestMessageSetExtension1.newBuilder().setI(123).build())
+        .setExtension(
+          TestMessageSetExtension2.messageSetExtension,
+          TestMessageSetExtension2.newBuilder().setStr("foo").build())
+        .build();
+
+    assertEquals(messageSetText, messageSet.toString());
+  }
+
+  // =================================================================
+
+  public void testParse() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge(allFieldsSetText, builder);
+    TestUtil.assertAllFieldsSet(builder.build());
+  }
+
+  public void testParseReader() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge(new StringReader(allFieldsSetText), builder);
+    TestUtil.assertAllFieldsSet(builder.build());
+  }
+
+  public void testParseExtensions() throws Exception {
+    TestAllExtensions.Builder builder = TestAllExtensions.newBuilder();
+    TextFormat.merge(allExtensionsSetText,
+                     TestUtil.getExtensionRegistry(),
+                     builder);
+    TestUtil.assertAllExtensionsSet(builder.build());
+  }
+
+  public void testParseCompatibility() throws Exception {
+    String original = "repeated_float: inf\n" +
+                      "repeated_float: -inf\n" +
+                      "repeated_float: nan\n" +
+                      "repeated_float: inff\n" +
+                      "repeated_float: -inff\n" +
+                      "repeated_float: nanf\n" +
+                      "repeated_float: 1.0f\n" +
+                      "repeated_float: infinityf\n" +
+                      "repeated_float: -Infinityf\n" +
+                      "repeated_double: infinity\n" +
+                      "repeated_double: -infinity\n" +
+                      "repeated_double: nan\n";
+    String canonical =  "repeated_float: Infinity\n" +
+                        "repeated_float: -Infinity\n" +
+                        "repeated_float: NaN\n" +
+                        "repeated_float: Infinity\n" +
+                        "repeated_float: -Infinity\n" +
+                        "repeated_float: NaN\n" +
+                        "repeated_float: 1.0\n" +
+                        "repeated_float: Infinity\n" +
+                        "repeated_float: -Infinity\n" +
+                        "repeated_double: Infinity\n" +
+                        "repeated_double: -Infinity\n" +
+                        "repeated_double: NaN\n";
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge(original, builder);
+    assertEquals(canonical, builder.build().toString());
+  }
+
+  public void testParseExotic() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge(exoticText, builder);
+
+    // Too lazy to check things individually.  Don't try to debug this
+    // if testPrintExotic() is failing.
+    assertEquals(canonicalExoticText, builder.build().toString());
+  }
+
+  public void testParseMessageSet() throws Exception {
+    ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
+    extensionRegistry.add(TestMessageSetExtension1.messageSetExtension);
+    extensionRegistry.add(TestMessageSetExtension2.messageSetExtension);
+
+    TestMessageSet.Builder builder = TestMessageSet.newBuilder();
+    TextFormat.merge(messageSetText, extensionRegistry, builder);
+    TestMessageSet messageSet = builder.build();
+
+    assertTrue(messageSet.hasExtension(
+      TestMessageSetExtension1.messageSetExtension));
+    assertEquals(123, messageSet.getExtension(
+      TestMessageSetExtension1.messageSetExtension).getI());
+    assertTrue(messageSet.hasExtension(
+      TestMessageSetExtension2.messageSetExtension));
+    assertEquals("foo", messageSet.getExtension(
+      TestMessageSetExtension2.messageSetExtension).getStr());
+
+    builder = TestMessageSet.newBuilder();
+    TextFormat.merge(messageSetTextWithRepeatedExtension, extensionRegistry,
+        builder);
+    messageSet = builder.build();
+    assertEquals(456, messageSet.getExtension(
+      TestMessageSetExtension1.messageSetExtension).getI());
+  }
+
+  public void testParseMessageSetWithOverwriteForbidden() throws Exception {
+    ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
+    extensionRegistry.add(TestMessageSetExtension1.messageSetExtension);
+    extensionRegistry.add(TestMessageSetExtension2.messageSetExtension);
+
+    TestMessageSet.Builder builder = TestMessageSet.newBuilder();
+    parserWithOverwriteForbidden.merge(
+        messageSetText, extensionRegistry, builder);
+    TestMessageSet messageSet = builder.build();
+    assertEquals(123, messageSet.getExtension(
+        TestMessageSetExtension1.messageSetExtension).getI());
+    assertEquals("foo", messageSet.getExtension(
+      TestMessageSetExtension2.messageSetExtension).getStr());
+
+    builder = TestMessageSet.newBuilder();
+    try {
+      parserWithOverwriteForbidden.merge(
+          messageSetTextWithRepeatedExtension, extensionRegistry, builder);
+      fail("expected parse exception");
+    } catch (TextFormat.ParseException e) {
+      assertEquals("6:1: Non-repeated field "
+          + "\"protobuf_unittest.TestMessageSetExtension1.message_set_extension\""
+          + " cannot be overwritten.",
+          e.getMessage());
+    }
+  }
+
+  public void testParseNumericEnum() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge("optional_nested_enum: 2", builder);
+    assertEquals(TestAllTypes.NestedEnum.BAR, builder.getOptionalNestedEnum());
+  }
+
+  public void testParseAngleBrackets() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge("OptionalGroup: < a: 1 >", builder);
+    assertTrue(builder.hasOptionalGroup());
+    assertEquals(1, builder.getOptionalGroup().getA());
+  }
+
+  public void testParseComment() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge(
+      "# this is a comment\n" +
+      "optional_int32: 1  # another comment\n" +
+      "optional_int64: 2\n" +
+      "# EOF comment", builder);
+    assertEquals(1, builder.getOptionalInt32());
+    assertEquals(2, builder.getOptionalInt64());
+  }
+
+  private void assertParseError(String error, String text) {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    try {
+      TextFormat.merge(text, TestUtil.getExtensionRegistry(), builder);
+      fail("Expected parse exception.");
+    } catch (TextFormat.ParseException e) {
+      assertEquals(error, e.getMessage());
+    }
+  }
+
+
+  private void assertParseErrorWithOverwriteForbidden(String error,
+      String text) {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    try {
+      parserWithOverwriteForbidden.merge(
+          text, TestUtil.getExtensionRegistry(), builder);
+      fail("Expected parse exception.");
+    } catch (TextFormat.ParseException e) {
+      assertEquals(error, e.getMessage());
+    }
+  }
+
+  private TestAllTypes assertParseSuccessWithOverwriteForbidden(
+      String text) throws TextFormat.ParseException {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    parserWithOverwriteForbidden.merge(
+        text, TestUtil.getExtensionRegistry(), builder);
+    return builder.build();
+  }
+
+  public void testParseErrors() throws Exception {
+    assertParseError(
+      "1:16: Expected \":\".",
+      "optional_int32 123");
+    assertParseError(
+      "1:23: Expected identifier. Found '?'",
+      "optional_nested_enum: ?");
+    assertParseError(
+      "1:18: Couldn't parse integer: Number must be positive: -1",
+      "optional_uint32: -1");
+    assertParseError(
+      "1:17: Couldn't parse integer: Number out of range for 32-bit signed " +
+        "integer: 82301481290849012385230157",
+      "optional_int32: 82301481290849012385230157");
+    assertParseError(
+      "1:16: Expected \"true\" or \"false\".",
+      "optional_bool: maybe");
+    assertParseError(
+      "1:16: Expected \"true\" or \"false\".",
+      "optional_bool: 2");
+    assertParseError(
+      "1:18: Expected string.",
+      "optional_string: 123");
+    assertParseError(
+      "1:18: String missing ending quote.",
+      "optional_string: \"ueoauaoe");
+    assertParseError(
+      "1:18: String missing ending quote.",
+      "optional_string: \"ueoauaoe\n" +
+      "optional_int32: 123");
+    assertParseError(
+      "1:18: Invalid escape sequence: '\\z'",
+      "optional_string: \"\\z\"");
+    assertParseError(
+      "1:18: String missing ending quote.",
+      "optional_string: \"ueoauaoe\n" +
+      "optional_int32: 123");
+    assertParseError(
+      "1:2: Extension \"nosuchext\" not found in the ExtensionRegistry.",
+      "[nosuchext]: 123");
+    assertParseError(
+      "1:20: Extension \"protobuf_unittest.optional_int32_extension\" does " +
+        "not extend message type \"protobuf_unittest.TestAllTypes\".",
+      "[protobuf_unittest.optional_int32_extension]: 123");
+    assertParseError(
+      "1:1: Message type \"protobuf_unittest.TestAllTypes\" has no field " +
+        "named \"nosuchfield\".",
+      "nosuchfield: 123");
+    assertParseError(
+      "1:21: Expected \">\".",
+      "OptionalGroup < a: 1");
+    assertParseError(
+      "1:23: Enum type \"protobuf_unittest.TestAllTypes.NestedEnum\" has no " +
+        "value named \"NO_SUCH_VALUE\".",
+      "optional_nested_enum: NO_SUCH_VALUE");
+    assertParseError(
+      "1:23: Enum type \"protobuf_unittest.TestAllTypes.NestedEnum\" has no " +
+        "value with number 123.",
+      "optional_nested_enum: 123");
+
+    // Delimiters must match.
+    assertParseError(
+      "1:22: Expected identifier. Found '}'",
+      "OptionalGroup < a: 1 }");
+    assertParseError(
+      "1:22: Expected identifier. Found '>'",
+      "OptionalGroup { a: 1 >");
+  }
+
+  // =================================================================
+
+  public void testEscape() throws Exception {
+    // Escape sequences.
+    assertEquals("\\000\\001\\a\\b\\f\\n\\r\\t\\v\\\\\\'\\\"\\177",
+      TextFormat.escapeBytes(bytes("\0\001\007\b\f\n\r\t\013\\\'\"\177")));
+    assertEquals("\\000\\001\\a\\b\\f\\n\\r\\t\\v\\\\\\'\\\"\\177",
+      TextFormat.escapeText("\0\001\007\b\f\n\r\t\013\\\'\"\177"));
+    assertEquals(bytes("\0\001\007\b\f\n\r\t\013\\\'\""),
+      TextFormat.unescapeBytes("\\000\\001\\a\\b\\f\\n\\r\\t\\v\\\\\\'\\\""));
+    assertEquals("\0\001\007\b\f\n\r\t\013\\\'\"",
+      TextFormat.unescapeText("\\000\\001\\a\\b\\f\\n\\r\\t\\v\\\\\\'\\\""));
+    assertEquals(kEscapeTestStringEscaped,
+      TextFormat.escapeText(kEscapeTestString));
+    assertEquals(kEscapeTestString,
+      TextFormat.unescapeText(kEscapeTestStringEscaped));
+
+    // Unicode handling.
+    assertEquals("\\341\\210\\264", TextFormat.escapeText("\u1234"));
+    assertEquals("\\341\\210\\264",
+                 TextFormat.escapeBytes(bytes(0xe1, 0x88, 0xb4)));
+    assertEquals("\u1234", TextFormat.unescapeText("\\341\\210\\264"));
+    assertEquals(bytes(0xe1, 0x88, 0xb4),
+                 TextFormat.unescapeBytes("\\341\\210\\264"));
+    assertEquals("\u1234", TextFormat.unescapeText("\\xe1\\x88\\xb4"));
+    assertEquals(bytes(0xe1, 0x88, 0xb4),
+                 TextFormat.unescapeBytes("\\xe1\\x88\\xb4"));
+
+    // Handling of strings with unescaped Unicode characters > 255.
+    final String zh = "\u9999\u6e2f\u4e0a\u6d77\ud84f\udf80\u8c50\u9280\u884c";
+    ByteString zhByteString = ByteString.copyFromUtf8(zh);
+    assertEquals(zhByteString, TextFormat.unescapeBytes(zh));
+
+    // Errors.
+    try {
+      TextFormat.unescapeText("\\x");
+      fail("Should have thrown an exception.");
+    } catch (TextFormat.InvalidEscapeSequenceException e) {
+      // success
+    }
+
+    try {
+      TextFormat.unescapeText("\\z");
+      fail("Should have thrown an exception.");
+    } catch (TextFormat.InvalidEscapeSequenceException e) {
+      // success
+    }
+
+    try {
+      TextFormat.unescapeText("\\");
+      fail("Should have thrown an exception.");
+    } catch (TextFormat.InvalidEscapeSequenceException e) {
+      // success
+    }
+  }
+
+  public void testParseInteger() throws Exception {
+    assertEquals(          0, TextFormat.parseInt32(          "0"));
+    assertEquals(          1, TextFormat.parseInt32(          "1"));
+    assertEquals(         -1, TextFormat.parseInt32(         "-1"));
+    assertEquals(      12345, TextFormat.parseInt32(      "12345"));
+    assertEquals(     -12345, TextFormat.parseInt32(     "-12345"));
+    assertEquals( 2147483647, TextFormat.parseInt32( "2147483647"));
+    assertEquals(-2147483648, TextFormat.parseInt32("-2147483648"));
+
+    assertEquals(                0, TextFormat.parseUInt32(         "0"));
+    assertEquals(                1, TextFormat.parseUInt32(         "1"));
+    assertEquals(            12345, TextFormat.parseUInt32(     "12345"));
+    assertEquals(       2147483647, TextFormat.parseUInt32("2147483647"));
+    assertEquals((int) 2147483648L, TextFormat.parseUInt32("2147483648"));
+    assertEquals((int) 4294967295L, TextFormat.parseUInt32("4294967295"));
+
+    assertEquals(          0L, TextFormat.parseInt64(          "0"));
+    assertEquals(          1L, TextFormat.parseInt64(          "1"));
+    assertEquals(         -1L, TextFormat.parseInt64(         "-1"));
+    assertEquals(      12345L, TextFormat.parseInt64(      "12345"));
+    assertEquals(     -12345L, TextFormat.parseInt64(     "-12345"));
+    assertEquals( 2147483647L, TextFormat.parseInt64( "2147483647"));
+    assertEquals(-2147483648L, TextFormat.parseInt64("-2147483648"));
+    assertEquals( 4294967295L, TextFormat.parseInt64( "4294967295"));
+    assertEquals( 4294967296L, TextFormat.parseInt64( "4294967296"));
+    assertEquals(9223372036854775807L,
+                 TextFormat.parseInt64("9223372036854775807"));
+    assertEquals(-9223372036854775808L,
+                 TextFormat.parseInt64("-9223372036854775808"));
+
+    assertEquals(          0L, TextFormat.parseUInt64(          "0"));
+    assertEquals(          1L, TextFormat.parseUInt64(          "1"));
+    assertEquals(      12345L, TextFormat.parseUInt64(      "12345"));
+    assertEquals( 2147483647L, TextFormat.parseUInt64( "2147483647"));
+    assertEquals( 4294967295L, TextFormat.parseUInt64( "4294967295"));
+    assertEquals( 4294967296L, TextFormat.parseUInt64( "4294967296"));
+    assertEquals(9223372036854775807L,
+                 TextFormat.parseUInt64("9223372036854775807"));
+    assertEquals(-9223372036854775808L,
+                 TextFormat.parseUInt64("9223372036854775808"));
+    assertEquals(-1L, TextFormat.parseUInt64("18446744073709551615"));
+
+    // Hex
+    assertEquals(0x1234abcd, TextFormat.parseInt32("0x1234abcd"));
+    assertEquals(-0x1234abcd, TextFormat.parseInt32("-0x1234abcd"));
+    assertEquals(-1, TextFormat.parseUInt64("0xffffffffffffffff"));
+    assertEquals(0x7fffffffffffffffL,
+                 TextFormat.parseInt64("0x7fffffffffffffff"));
+
+    // Octal
+    assertEquals(01234567, TextFormat.parseInt32("01234567"));
+
+    // Out-of-range
+    try {
+      TextFormat.parseInt32("2147483648");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+
+    try {
+      TextFormat.parseInt32("-2147483649");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+
+    try {
+      TextFormat.parseUInt32("4294967296");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+
+    try {
+      TextFormat.parseUInt32("-1");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+
+    try {
+      TextFormat.parseInt64("9223372036854775808");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+
+    try {
+      TextFormat.parseInt64("-9223372036854775809");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+
+    try {
+      TextFormat.parseUInt64("18446744073709551616");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+
+    try {
+      TextFormat.parseUInt64("-1");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+
+    // Not a number.
+    try {
+      TextFormat.parseInt32("abcd");
+      fail("Should have thrown an exception.");
+    } catch (NumberFormatException e) {
+      // success
+    }
+  }
+
+  public void testParseString() throws Exception {
+    final String zh = "\u9999\u6e2f\u4e0a\u6d77\ud84f\udf80\u8c50\u9280\u884c";
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge("optional_string: \"" + zh + "\"", builder);
+    assertEquals(zh, builder.getOptionalString());
+  }
+
+  public void testParseLongString() throws Exception {
+    String longText =
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890" +
+      "123456789012345678901234567890123456789012345678901234567890";
+
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge("optional_string: \"" + longText + "\"", builder);
+    assertEquals(longText, builder.getOptionalString());
+  }
+
+  public void testParseBoolean() throws Exception {
+    String goodText =
+        "repeated_bool: t  repeated_bool : 0\n" +
+        "repeated_bool :f repeated_bool:1";
+    String goodTextCanonical =
+        "repeated_bool: true\n" +
+        "repeated_bool: false\n" +
+        "repeated_bool: false\n" +
+        "repeated_bool: true\n";
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge(goodText, builder);
+    assertEquals(goodTextCanonical, builder.build().toString());
+
+    try {
+      TestAllTypes.Builder badBuilder = TestAllTypes.newBuilder();
+      TextFormat.merge("optional_bool:2", badBuilder);
+      fail("Should have thrown an exception.");
+    } catch (TextFormat.ParseException e) {
+      // success
+    }
+    try {
+      TestAllTypes.Builder badBuilder = TestAllTypes.newBuilder();
+      TextFormat.merge("optional_bool: foo", badBuilder);
+      fail("Should have thrown an exception.");
+    } catch (TextFormat.ParseException e) {
+      // success
+    }
+  }
+
+  public void testParseAdjacentStringLiterals() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge("optional_string: \"foo\" 'corge' \"grault\"", builder);
+    assertEquals("foocorgegrault", builder.getOptionalString());
+  }
+
+  public void testPrintFieldValue() throws Exception {
+    assertPrintFieldValue("\"Hello\"", "Hello", "repeated_string");
+    assertPrintFieldValue("123.0",  123f, "repeated_float");
+    assertPrintFieldValue("123.0",  123d, "repeated_double");
+    assertPrintFieldValue("123",  123, "repeated_int32");
+    assertPrintFieldValue("123",  123L, "repeated_int64");
+    assertPrintFieldValue("true",  true, "repeated_bool");
+    assertPrintFieldValue("4294967295", 0xFFFFFFFF, "repeated_uint32");
+    assertPrintFieldValue("18446744073709551615",  0xFFFFFFFFFFFFFFFFL,
+        "repeated_uint64");
+    assertPrintFieldValue("\"\\001\\002\\003\"",
+        ByteString.copyFrom(new byte[] {1, 2, 3}), "repeated_bytes");
+  }
+
+  private void assertPrintFieldValue(String expect, Object value,
+      String fieldName) throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    StringBuilder sb = new StringBuilder();
+    TextFormat.printFieldValue(
+        TestAllTypes.getDescriptor().findFieldByName(fieldName),
+        value, sb);
+    assertEquals(expect, sb.toString());
+  }
+
+  public void testShortDebugString() {
+    assertEquals("optional_nested_message { bb: 42 } repeated_int32: 1"
+        + " repeated_uint32: 2",
+        TextFormat.shortDebugString(TestAllTypes.newBuilder()
+            .addRepeatedInt32(1)
+            .addRepeatedUint32(2)
+            .setOptionalNestedMessage(
+                NestedMessage.newBuilder().setBb(42).build())
+            .build()));
+  }
+
+  public void testShortDebugString_field() {
+    final FieldDescriptor dataField =
+      OneString.getDescriptor().findFieldByName("data");
+    assertEquals(
+      "data: \"test data\"",
+      TextFormat.shortDebugString(dataField, "test data"));
+
+    final FieldDescriptor optionalField =
+      TestAllTypes.getDescriptor().findFieldByName("optional_nested_message");
+    final Object value = NestedMessage.newBuilder().setBb(42).build();
+
+    assertEquals(
+      "optional_nested_message { bb: 42 }",
+      TextFormat.shortDebugString(optionalField, value));
+  }
+
+  public void testShortDebugString_unknown() {
+    assertEquals("5: 1 5: 0x00000002 5: 0x0000000000000003 5: \"4\" 5 { 10: 5 }"
+        + " 8: 1 8: 2 8: 3 15: 12379813812177893520 15: 0xabcd1234 15:"
+        + " 0xabcdef1234567890",
+        TextFormat.shortDebugString(makeUnknownFieldSet()));
+  }
+
+  public void testPrintToUnicodeString() throws Exception {
+    assertEquals(
+        "optional_string: \"abc\u3042efg\"\n" +
+        "optional_bytes: \"\\343\\201\\202\"\n" +
+        "repeated_string: \"\u3093XYZ\"\n",
+        TextFormat.printToUnicodeString(TestAllTypes.newBuilder()
+            .setOptionalString("abc\u3042efg")
+            .setOptionalBytes(bytes(0xe3, 0x81, 0x82))
+            .addRepeatedString("\u3093XYZ")
+            .build()));
+
+    // Double quotes and backslashes should be escaped
+    assertEquals(
+        "optional_string: \"a\\\\bc\\\"ef\\\"g\"\n",
+        TextFormat.printToUnicodeString(TestAllTypes.newBuilder()
+            .setOptionalString("a\\bc\"ef\"g")
+            .build()));
+
+    // Test escaping roundtrip
+    TestAllTypes message = TestAllTypes.newBuilder()
+        .setOptionalString("a\\bc\\\"ef\"g")
+        .build();
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge(TextFormat.printToUnicodeString(message), builder);
+    assertEquals(message.getOptionalString(), builder.getOptionalString());
+  }
+
+  public void testPrintToUnicodeStringWithNewlines() throws Exception {
+    // No newlines at start and end
+    assertEquals("optional_string: \"test newlines\\n\\nin\\nstring\"\n",
+        TextFormat.printToUnicodeString(TestAllTypes.newBuilder()
+            .setOptionalString("test newlines\n\nin\nstring")
+            .build()));
+
+    // Newlines at start and end
+    assertEquals("optional_string: \"\\ntest\\nnewlines\\n\\nin\\nstring\\n\"\n",
+        TextFormat.printToUnicodeString(TestAllTypes.newBuilder()
+            .setOptionalString("\ntest\nnewlines\n\nin\nstring\n")
+            .build()));
+
+    // Strings with 0, 1 and 2 newlines.
+    assertEquals("optional_string: \"\"\n",
+        TextFormat.printToUnicodeString(TestAllTypes.newBuilder()
+            .setOptionalString("")
+            .build()));
+    assertEquals("optional_string: \"\\n\"\n",
+        TextFormat.printToUnicodeString(TestAllTypes.newBuilder()
+            .setOptionalString("\n")
+            .build()));
+    assertEquals("optional_string: \"\\n\\n\"\n",
+        TextFormat.printToUnicodeString(TestAllTypes.newBuilder()
+            .setOptionalString("\n\n")
+            .build()));
+
+    // Test escaping roundtrip
+    TestAllTypes message = TestAllTypes.newBuilder()
+        .setOptionalString("\ntest\nnewlines\n\nin\nstring\n")
+        .build();
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    TextFormat.merge(TextFormat.printToUnicodeString(message), builder);
+    assertEquals(message.getOptionalString(), builder.getOptionalString());
+  }
+
+  public void testPrintToUnicodeString_unknown() {
+    assertEquals(
+        "1: \"\\343\\201\\202\"\n",
+        TextFormat.printToUnicodeString(UnknownFieldSet.newBuilder()
+            .addField(1,
+                UnknownFieldSet.Field.newBuilder()
+                .addLengthDelimited(bytes(0xe3, 0x81, 0x82)).build())
+            .build()));
+  }
+
+
+  public void testParseNonRepeatedFields() throws Exception {
+    assertParseSuccessWithOverwriteForbidden(
+        "repeated_int32: 1\n" +
+        "repeated_int32: 2\n");
+    assertParseSuccessWithOverwriteForbidden(
+        "RepeatedGroup { a: 1 }\n" +
+        "RepeatedGroup { a: 2 }\n");
+    assertParseSuccessWithOverwriteForbidden(
+        "repeated_nested_message { bb: 1 }\n" +
+        "repeated_nested_message { bb: 2 }\n");
+    assertParseErrorWithOverwriteForbidden(
+        "3:17: Non-repeated field " +
+        "\"protobuf_unittest.TestAllTypes.optional_int32\" " +
+        "cannot be overwritten.",
+        "optional_int32: 1\n" +
+        "optional_bool: true\n" +
+        "optional_int32: 1\n");
+    assertParseErrorWithOverwriteForbidden(
+        "2:17: Non-repeated field " +
+        "\"protobuf_unittest.TestAllTypes.optionalgroup\" " +
+        "cannot be overwritten.",
+        "OptionalGroup { a: 1 }\n" +
+        "OptionalGroup { }\n");
+    assertParseErrorWithOverwriteForbidden(
+        "2:33: Non-repeated field " +
+        "\"protobuf_unittest.TestAllTypes.optional_nested_message\" " +
+        "cannot be overwritten.",
+        "optional_nested_message { }\n" +
+        "optional_nested_message { bb: 3 }\n");
+    assertParseErrorWithOverwriteForbidden(
+        "2:16: Non-repeated field " +
+        "\"protobuf_unittest.TestAllTypes.default_int32\" " +
+        "cannot be overwritten.",
+        "default_int32: 41\n" +  // the default value
+        "default_int32: 41\n");
+    assertParseErrorWithOverwriteForbidden(
+        "2:17: Non-repeated field " +
+        "\"protobuf_unittest.TestAllTypes.default_string\" " +
+        "cannot be overwritten.",
+        "default_string: \"zxcv\"\n" +
+        "default_string: \"asdf\"\n");
+  }
+
+  public void testParseShortRepeatedFormOfRepeatedFields() throws Exception {
+    assertParseSuccessWithOverwriteForbidden("repeated_foreign_enum: [FOREIGN_FOO, FOREIGN_BAR]");
+    assertParseSuccessWithOverwriteForbidden("repeated_int32: [ 1, 2 ]\n");
+    assertParseSuccessWithOverwriteForbidden("RepeatedGroup [{ a: 1 },{ a: 2 }]\n");
+    assertParseSuccessWithOverwriteForbidden("repeated_nested_message [{ bb: 1 }, { bb: 2 }]\n");
+  }
+
+  public void testParseShortRepeatedFormOfNonRepeatedFields() throws Exception {
+    assertParseErrorWithOverwriteForbidden(
+        "1:17: Couldn't parse integer: For input string: \"[\"",
+        "optional_int32: [1]\n");
+  }
+
+  // =======================================================================
+  // test oneof
+
+  public void testOneofTextFormat() throws Exception {
+    TestOneof2.Builder builder = TestOneof2.newBuilder();
+    TestUtil.setOneof(builder);
+    TestOneof2 message = builder.build();
+    TestOneof2.Builder dest = TestOneof2.newBuilder();
+    TextFormat.merge(TextFormat.printToUnicodeString(message), dest);
+    TestUtil.assertOneofSet(dest.build());
+  }
+
+  public void testOneofOverwriteForbidden() throws Exception {
+    String input = "foo_string: \"stringvalue\" foo_int: 123";
+    TestOneof2.Builder builder = TestOneof2.newBuilder();
+    try {
+      parserWithOverwriteForbidden.merge(
+          input, TestUtil.getExtensionRegistry(), builder);
+      fail("Expected parse exception.");
+    } catch (TextFormat.ParseException e) {
+      assertEquals("1:36: Field \"protobuf_unittest.TestOneof2.foo_int\""
+                   + " is specified along with field \"protobuf_unittest.TestOneof2.foo_string\","
+                   + " another member of oneof \"foo\".", e.getMessage());
+    }
+  }
+
+  public void testOneofOverwriteAllowed() throws Exception {
+    String input = "foo_string: \"stringvalue\" foo_int: 123";
+    TestOneof2.Builder builder = TestOneof2.newBuilder();
+    defaultParser.merge(input, TestUtil.getExtensionRegistry(), builder);
+    // Only the last value sticks.
+    TestOneof2 oneof = builder.build();
+    assertFalse(oneof.hasFooString());
+    assertTrue(oneof.hasFooInt());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java b/java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java
new file mode 100644
index 00000000..8f45976f
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java
@@ -0,0 +1,255 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.Descriptor;
+import com.google.protobuf.Descriptors.EnumDescriptor;
+import com.google.protobuf.Descriptors.EnumValueDescriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.FieldPresenceTestProto.TestAllTypes;
+import com.google.protobuf.TextFormat.ParseException;
+
+import junit.framework.TestCase;
+
+/**
+ * Unit tests for protos that keep unknown enum values rather than discard
+ * them as unknown fields.
+ */
+public class UnknownEnumValueTest extends TestCase {
+  public void testUnknownEnumValues() throws Exception {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.setOptionalNestedEnumValue(4321);
+    builder.addRepeatedNestedEnumValue(5432);
+    builder.addPackedNestedEnumValue(6543);
+    TestAllTypes message = builder.build();
+    assertEquals(4321, message.getOptionalNestedEnumValue());
+    assertEquals(5432, message.getRepeatedNestedEnumValue(0));
+    assertEquals(5432, message.getRepeatedNestedEnumValueList().get(0).intValue());
+    assertEquals(6543, message.getPackedNestedEnumValue(0));
+    // Returns UNRECOGNIZED if an enum type is requested.
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, message.getOptionalNestedEnum());
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, message.getRepeatedNestedEnum(0));
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, message.getRepeatedNestedEnumList().get(0));
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, message.getPackedNestedEnum(0));
+    
+    // Test serialization and parsing.
+    ByteString data = message.toByteString();
+    message = TestAllTypes.parseFrom(data);
+    assertEquals(4321, message.getOptionalNestedEnumValue());
+    assertEquals(5432, message.getRepeatedNestedEnumValue(0));
+    assertEquals(5432, message.getRepeatedNestedEnumValueList().get(0).intValue());
+    assertEquals(6543, message.getPackedNestedEnumValue(0));
+    // Returns UNRECOGNIZED if an enum type is requested.
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, message.getOptionalNestedEnum());
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, message.getRepeatedNestedEnum(0));
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, message.getRepeatedNestedEnumList().get(0));
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, message.getPackedNestedEnum(0));
+    
+    // Test toBuilder().
+    builder = message.toBuilder();
+    assertEquals(4321, builder.getOptionalNestedEnumValue());
+    assertEquals(5432, builder.getRepeatedNestedEnumValue(0));
+    assertEquals(5432, builder.getRepeatedNestedEnumValueList().get(0).intValue());
+    assertEquals(6543, builder.getPackedNestedEnumValue(0));    
+    // Returns UNRECOGNIZED if an enum type is requested.
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, builder.getOptionalNestedEnum());
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, builder.getRepeatedNestedEnum(0));
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, builder.getRepeatedNestedEnumList().get(0));
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, builder.getPackedNestedEnum(0));
+    
+    // Test mergeFrom().
+    builder = TestAllTypes.newBuilder().mergeFrom(message);
+    assertEquals(4321, builder.getOptionalNestedEnumValue());
+    assertEquals(5432, builder.getRepeatedNestedEnumValue(0));
+    assertEquals(5432, builder.getRepeatedNestedEnumValueList().get(0).intValue());
+    assertEquals(6543, builder.getPackedNestedEnumValue(0));
+    // Returns UNRECOGNIZED if an enum type is requested.
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, builder.getOptionalNestedEnum());
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, builder.getRepeatedNestedEnum(0));
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, builder.getRepeatedNestedEnumList().get(0));
+    assertEquals(TestAllTypes.NestedEnum.UNRECOGNIZED, builder.getPackedNestedEnum(0));
+    
+    // Test equals() and hashCode()
+    TestAllTypes sameMessage = builder.build();
+    assertEquals(message, sameMessage);
+    assertEquals(message.hashCode(), sameMessage.hashCode());
+
+    // Getting the numeric value of UNRECOGNIZED will throw an exception.
+    try {
+      TestAllTypes.NestedEnum.UNRECOGNIZED.getNumber();
+      fail("Exception is expected.");
+    } catch (IllegalArgumentException e) {
+      // Expected.
+    }
+
+    // Setting an enum field to an UNRECOGNIZED value will throw an exception.
+    try {
+      builder.setOptionalNestedEnum(builder.getOptionalNestedEnum());
+      fail("Exception is expected.");
+    } catch (IllegalArgumentException e) {
+      // Expected.
+    }
+    try {
+      builder.addRepeatedNestedEnum(builder.getOptionalNestedEnum());
+      fail("Exception is expected.");
+    } catch (IllegalArgumentException e) {
+      // Expected.
+    }
+  }
+  
+  public void testUnknownEnumValueInReflectionApi() throws Exception {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+    FieldDescriptor optionalNestedEnumField = descriptor.findFieldByName("optional_nested_enum");
+    FieldDescriptor repeatedNestedEnumField = descriptor.findFieldByName("repeated_nested_enum");
+    FieldDescriptor packedNestedEnumField = descriptor.findFieldByName("packed_nested_enum");
+    EnumDescriptor enumType = TestAllTypes.NestedEnum.getDescriptor();
+
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.setField(optionalNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(4321));
+    builder.addRepeatedField(repeatedNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(5432));
+    builder.addRepeatedField(packedNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(6543));
+    TestAllTypes message = builder.build();
+    
+    // Getters will return unknown enum values as EnumValueDescriptor.
+    EnumValueDescriptor unknown4321 =
+        (EnumValueDescriptor) message.getField(optionalNestedEnumField);
+    EnumValueDescriptor unknown5432 =
+        (EnumValueDescriptor) message.getRepeatedField(repeatedNestedEnumField, 0);
+    EnumValueDescriptor unknown6543 =
+        (EnumValueDescriptor) message.getRepeatedField(packedNestedEnumField, 0);
+    assertEquals(4321, unknown4321.getNumber());
+    assertEquals(5432, unknown5432.getNumber());
+    assertEquals(6543, unknown6543.getNumber());
+    
+    // Unknown EnumValueDescriptor will map to UNRECOGNIZED.
+    assertEquals(
+        TestAllTypes.NestedEnum.valueOf(unknown4321),
+        TestAllTypes.NestedEnum.UNRECOGNIZED);
+    assertEquals(
+        TestAllTypes.NestedEnum.valueOf(unknown5432),
+        TestAllTypes.NestedEnum.UNRECOGNIZED);
+    assertEquals(
+        TestAllTypes.NestedEnum.valueOf(unknown6543),
+        TestAllTypes.NestedEnum.UNRECOGNIZED);
+    
+    // Setters also accept unknown EnumValueDescriptor.
+    builder.setField(optionalNestedEnumField, unknown6543);
+    builder.setRepeatedField(repeatedNestedEnumField, 0, unknown4321);
+    builder.setRepeatedField(packedNestedEnumField, 0, unknown5432);
+    message = builder.build();
+    // Like other descriptors, unknown EnumValueDescriptor can be compared by
+    // object identity.
+    assertTrue(unknown6543 == message.getField(optionalNestedEnumField));
+    assertTrue(unknown4321 == message.getRepeatedField(repeatedNestedEnumField, 0));
+    assertTrue(unknown5432 == message.getRepeatedField(packedNestedEnumField, 0));
+  }
+  
+  public void testUnknownEnumValueWithDynamicMessage() throws Exception {
+    Descriptor descriptor = TestAllTypes.getDescriptor();
+    FieldDescriptor optionalNestedEnumField = descriptor.findFieldByName("optional_nested_enum");
+    FieldDescriptor repeatedNestedEnumField = descriptor.findFieldByName("repeated_nested_enum");
+    FieldDescriptor packedNestedEnumField = descriptor.findFieldByName("packed_nested_enum");
+    EnumDescriptor enumType = TestAllTypes.NestedEnum.getDescriptor();
+    
+    Message dynamicMessageDefaultInstance = DynamicMessage.getDefaultInstance(descriptor);
+
+    Message.Builder builder = dynamicMessageDefaultInstance.newBuilderForType();
+    builder.setField(optionalNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(4321));
+    builder.addRepeatedField(repeatedNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(5432));
+    builder.addRepeatedField(packedNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(6543));
+    Message message = builder.build();
+    assertEquals(4321,
+        ((EnumValueDescriptor) message.getField(optionalNestedEnumField)).getNumber());
+    assertEquals(5432,
+        ((EnumValueDescriptor) message.getRepeatedField(repeatedNestedEnumField, 0)).getNumber());
+    assertEquals(6543,
+        ((EnumValueDescriptor) message.getRepeatedField(packedNestedEnumField, 0)).getNumber());
+    
+    // Test reflection based serialization/parsing implementation.
+    ByteString data = message.toByteString();
+    message = dynamicMessageDefaultInstance
+        .newBuilderForType()
+        .mergeFrom(data)
+        .build();
+    assertEquals(4321,
+        ((EnumValueDescriptor) message.getField(optionalNestedEnumField)).getNumber());
+    assertEquals(5432,
+        ((EnumValueDescriptor) message.getRepeatedField(repeatedNestedEnumField, 0)).getNumber());
+    assertEquals(6543,
+        ((EnumValueDescriptor) message.getRepeatedField(packedNestedEnumField, 0)).getNumber());
+    
+    // Test reflection based equals()/hashCode().
+    builder = dynamicMessageDefaultInstance.newBuilderForType();
+    builder.setField(optionalNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(4321));
+    builder.addRepeatedField(repeatedNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(5432));
+    builder.addRepeatedField(packedNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(6543));
+    Message sameMessage = builder.build();
+    assertEquals(message, sameMessage);
+    assertEquals(message.hashCode(), sameMessage.hashCode());
+    builder.setField(optionalNestedEnumField,
+        enumType.findValueByNumberCreatingIfUnknown(0));
+    Message differentMessage = builder.build();
+    assertFalse(message.equals(differentMessage));
+  }
+  
+  public void testUnknownEnumValuesInTextFormat() {
+    TestAllTypes.Builder builder = TestAllTypes.newBuilder();
+    builder.setOptionalNestedEnumValue(4321);
+    builder.addRepeatedNestedEnumValue(5432);
+    builder.addPackedNestedEnumValue(6543);
+    TestAllTypes message = builder.build();
+    
+    // We can print a message with unknown enum values.
+    String textData = TextFormat.printToString(message);
+    assertEquals(
+        "optional_nested_enum: UNKNOWN_ENUM_VALUE_NestedEnum_4321\n"
+        + "repeated_nested_enum: UNKNOWN_ENUM_VALUE_NestedEnum_5432\n"
+        + "packed_nested_enum: UNKNOWN_ENUM_VALUE_NestedEnum_6543\n", textData);
+    
+    // Parsing unknown enum values will fail just like parsing other kinds of
+    // unknown fields.
+    try {
+      TextFormat.merge(textData, builder);
+      fail();
+    } catch (ParseException e) {
+      // expected.
+    }
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java
new file mode 100644
index 00000000..dc987379
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java
@@ -0,0 +1,368 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
+import com.google.protobuf.UnittestLite.TestAllTypesLite;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Bar;
+import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Foo;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+/**
+ * Tests for {@link UnknownFieldSetLite}.
+ *
+ * @author dweis@google.com (Daniel Weis)
+ */
+public class UnknownFieldSetLiteTest extends TestCase {
+
+  public void testNoDataIsDefaultInstance() {
+    assertSame(
+        UnknownFieldSetLite.getDefaultInstance(),
+        UnknownFieldSetLite.newBuilder()
+            .build());
+  }
+  
+  public void testBuilderReuse() throws IOException {
+    UnknownFieldSetLite.Builder builder = UnknownFieldSetLite.newBuilder();
+    builder.mergeVarintField(10, 2);
+    builder.build();
+
+    try {
+      builder.build();
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // Expected.
+    }
+
+    try {
+      builder.mergeFieldFrom(0, CodedInputStream.newInstance(new byte[0]));
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // Expected.
+    }
+
+    try {
+      builder.mergeVarintField(5, 1);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // Expected.
+    }
+  }
+
+  public void testBuilderReuse_empty() {
+    UnknownFieldSetLite.Builder builder = UnknownFieldSetLite.newBuilder();
+    builder.build();
+    builder.build();
+  }
+  
+  public void testDefaultInstance() {
+    UnknownFieldSetLite unknownFields = UnknownFieldSetLite.getDefaultInstance();
+
+    assertEquals(0, unknownFields.getSerializedSize());
+    assertEquals(ByteString.EMPTY, toByteString(unknownFields));
+  }
+
+  public void testMergeFieldFrom() throws IOException {
+    Foo foo = Foo.newBuilder()
+      .setValue(2)
+      .build();
+
+    CodedInputStream input = CodedInputStream.newInstance(foo.toByteArray());
+
+    UnknownFieldSetLite instance = UnknownFieldSetLite.newInstance();
+    instance.mergeFieldFrom(input.readTag(), input);
+
+    assertEquals(foo.toByteString(), toByteString(instance));
+  }
+
+  public void testSerializedSize() throws IOException {
+    Foo foo = Foo.newBuilder()
+      .setValue(2)
+      .build();
+
+    CodedInputStream input = CodedInputStream.newInstance(foo.toByteArray());
+
+    UnknownFieldSetLite instance = UnknownFieldSetLite.newInstance();
+    instance.mergeFieldFrom(input.readTag(), input);
+
+    assertEquals(foo.toByteString().size(), instance.getSerializedSize());
+  }
+
+  public void testMergeVarintField() throws IOException {
+    UnknownFieldSetLite unknownFields = UnknownFieldSetLite.newInstance();
+    unknownFields.mergeVarintField(10, 2);
+
+    CodedInputStream input =
+        CodedInputStream.newInstance(toByteString(unknownFields).toByteArray());
+
+    int tag = input.readTag();
+    assertEquals(10, WireFormat.getTagFieldNumber(tag));
+    assertEquals(WireFormat.WIRETYPE_VARINT, WireFormat.getTagWireType(tag));
+    assertEquals(2, input.readUInt64());
+    assertTrue(input.isAtEnd());
+  }
+
+  public void testMergeVarintField_negative() throws IOException {
+    UnknownFieldSetLite builder = UnknownFieldSetLite.newInstance();
+    builder.mergeVarintField(10, -6);
+
+    CodedInputStream input =
+        CodedInputStream.newInstance(toByteString(builder).toByteArray());
+
+    int tag = input.readTag();
+    assertEquals(10, WireFormat.getTagFieldNumber(tag));
+    assertEquals(WireFormat.WIRETYPE_VARINT, WireFormat.getTagWireType(tag));
+    assertEquals(-6, input.readUInt64());
+    assertTrue(input.isAtEnd());
+  }
+
+  public void testEqualsAndHashCode() {
+    UnknownFieldSetLite unknownFields1 = UnknownFieldSetLite.newInstance();
+    unknownFields1.mergeVarintField(10, 2);
+
+    UnknownFieldSetLite unknownFields2 = UnknownFieldSetLite.newInstance();
+    unknownFields2.mergeVarintField(10, 2);
+
+    assertEquals(unknownFields1, unknownFields2);
+    assertEquals(unknownFields1.hashCode(), unknownFields2.hashCode());
+    assertFalse(unknownFields1.equals(UnknownFieldSetLite.getDefaultInstance()));
+    assertFalse(unknownFields1.hashCode() == UnknownFieldSetLite.getDefaultInstance().hashCode());
+  }
+
+  public void testMutableCopyOf() throws IOException {
+    UnknownFieldSetLite unknownFields = UnknownFieldSetLite.newInstance();
+    unknownFields.mergeVarintField(10, 2);
+    unknownFields = UnknownFieldSetLite.mutableCopyOf(unknownFields, unknownFields);
+    unknownFields.checkMutable();
+
+    CodedInputStream input =
+        CodedInputStream.newInstance(toByteString(unknownFields).toByteArray());
+
+    int tag = input.readTag();
+    assertEquals(10, WireFormat.getTagFieldNumber(tag));
+    assertEquals(WireFormat.WIRETYPE_VARINT, WireFormat.getTagWireType(tag));
+    assertEquals(2, input.readUInt64());
+    assertFalse(input.isAtEnd());
+    input.readTag();
+    assertEquals(10, WireFormat.getTagFieldNumber(tag));
+    assertEquals(WireFormat.WIRETYPE_VARINT, WireFormat.getTagWireType(tag));
+    assertEquals(2, input.readUInt64());
+    assertTrue(input.isAtEnd());
+  }
+
+  public void testMutableCopyOf_empty() {
+    UnknownFieldSetLite unknownFields = UnknownFieldSetLite.mutableCopyOf(
+        UnknownFieldSetLite.getDefaultInstance(), UnknownFieldSetLite.getDefaultInstance());
+    unknownFields.checkMutable();
+
+    assertEquals(0, unknownFields.getSerializedSize());
+    assertEquals(ByteString.EMPTY, toByteString(unknownFields));
+  }
+
+  public void testRoundTrips() throws InvalidProtocolBufferException {
+    Foo foo = Foo.newBuilder()
+        .setValue(1)
+        .setExtension(Bar.fooExt, Bar.newBuilder()
+            .setName("name")
+            .build())
+        .setExtension(LiteEqualsAndHash.varint, 22)
+        .setExtension(LiteEqualsAndHash.fixed32, 44)
+        .setExtension(LiteEqualsAndHash.fixed64, 66L)
+        .setExtension(LiteEqualsAndHash.myGroup, LiteEqualsAndHash.MyGroup.newBuilder()
+            .setGroupValue("value")
+            .build())
+        .build();
+
+    Foo copy = Foo.parseFrom(foo.toByteArray());
+
+    assertEquals(foo.getSerializedSize(), copy.getSerializedSize());
+    assertFalse(foo.equals(copy));
+
+    Foo secondCopy = Foo.parseFrom(foo.toByteArray());
+    assertEquals(copy, secondCopy);
+
+    ExtensionRegistryLite extensionRegistry = ExtensionRegistryLite.newInstance();
+    LiteEqualsAndHash.registerAllExtensions(extensionRegistry);
+    Foo copyOfCopy = Foo.parseFrom(copy.toByteArray(), extensionRegistry);
+
+    assertEquals(foo, copyOfCopy);
+  }
+
+  public void testMalformedBytes() throws Exception {
+    try {
+      Foo.parseFrom("this is a malformed protocol buffer".getBytes(Internal.UTF_8));
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Expected.
+    }
+  }
+
+  public void testMissingStartGroupTag() throws IOException {
+    ByteString.Output byteStringOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(byteStringOutput);
+    output.writeGroupNoTag(Foo.newBuilder().setValue(11).build());
+    output.writeTag(100, WireFormat.WIRETYPE_END_GROUP);
+    output.flush();
+
+    try {
+      Foo.parseFrom(byteStringOutput.toByteString());
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Expected.
+    }
+  }
+
+  public void testMissingEndGroupTag() throws IOException {
+    ByteString.Output byteStringOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(byteStringOutput);
+    output.writeTag(100, WireFormat.WIRETYPE_START_GROUP);
+    output.writeGroupNoTag(Foo.newBuilder().setValue(11).build());
+    output.flush();
+
+    try {
+      Foo.parseFrom(byteStringOutput.toByteString());
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Expected.
+    }
+  }
+
+  public void testMismatchingGroupTags() throws IOException {
+    ByteString.Output byteStringOutput = ByteString.newOutput();
+    CodedOutputStream output = CodedOutputStream.newInstance(byteStringOutput);
+    output.writeTag(100, WireFormat.WIRETYPE_START_GROUP);
+    output.writeGroupNoTag(Foo.newBuilder().setValue(11).build());
+    output.writeTag(101, WireFormat.WIRETYPE_END_GROUP);
+    output.flush();
+
+    try {
+      Foo.parseFrom(byteStringOutput.toByteString());
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Expected.
+    }
+  }
+
+  public void testTruncatedInput() {
+    Foo foo = Foo.newBuilder()
+        .setValue(1)
+        .setExtension(Bar.fooExt, Bar.newBuilder()
+            .setName("name")
+            .build())
+        .setExtension(LiteEqualsAndHash.varint, 22)
+        .setExtension(LiteEqualsAndHash.myGroup, LiteEqualsAndHash.MyGroup.newBuilder()
+            .setGroupValue("value")
+            .build())
+        .build();
+
+    try {
+      Foo.parseFrom(foo.toByteString().substring(0, foo.toByteString().size() - 10));
+      fail();
+    } catch (InvalidProtocolBufferException e) {
+      // Expected.
+    }
+  }
+  
+  public void testMakeImmutable() throws Exception {
+    UnknownFieldSetLite unknownFields = UnknownFieldSetLite.newInstance();
+    unknownFields.makeImmutable();
+    
+    try {
+      unknownFields.mergeVarintField(1, 1);
+      fail();
+    } catch (UnsupportedOperationException expected) {}
+    
+    try {
+      unknownFields.mergeLengthDelimitedField(2, ByteString.copyFromUtf8("hello"));
+      fail();
+    } catch (UnsupportedOperationException expected) {}
+    
+    try {
+      unknownFields.mergeFieldFrom(1, CodedInputStream.newInstance(new byte[0]));
+      fail();
+    } catch (UnsupportedOperationException expected) {}
+  }
+  
+  public void testEndToEnd() throws Exception {
+    TestAllTypesLite testAllTypes = TestAllTypesLite.getDefaultInstance();
+    try {
+      testAllTypes.unknownFields.checkMutable();
+      fail();
+    } catch (UnsupportedOperationException expected) {}
+    
+    testAllTypes = TestAllTypesLite.parseFrom(new byte[0]);
+    try {
+      testAllTypes.unknownFields.checkMutable();
+      fail();
+    } catch (UnsupportedOperationException expected) {}
+    
+    testAllTypes = TestAllTypesLite.newBuilder().build();
+    try {
+      testAllTypes.unknownFields.checkMutable();
+      fail();
+    } catch (UnsupportedOperationException expected) {}
+    
+    testAllTypes = TestAllTypesLite.newBuilder()
+        .setDefaultBool(true)
+        .build();
+    try {
+      testAllTypes.unknownFields.checkMutable();
+      fail();
+    } catch (UnsupportedOperationException expected) {}
+    
+    TestAllExtensionsLite testAllExtensions = TestAllExtensionsLite.newBuilder()
+        .mergeFrom(TestAllExtensionsLite.newBuilder()
+            .setExtension(UnittestLite.optionalInt32ExtensionLite, 2)
+            .build().toByteArray())
+        .build();
+    try {
+      testAllExtensions.unknownFields.checkMutable();
+      fail();
+    } catch (UnsupportedOperationException expected) {}
+  }
+
+  private ByteString toByteString(UnknownFieldSetLite unknownFields) {
+    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+    CodedOutputStream output = CodedOutputStream.newInstance(byteArrayOutputStream);
+    try {
+      unknownFields.writeTo(output);
+      output.flush();
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+    return ByteString.copyFrom(byteArrayOutputStream.toByteArray());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/UnknownFieldSetTest.java b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetTest.java
new file mode 100644
index 00000000..8c9dcafe
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetTest.java
@@ -0,0 +1,653 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import protobuf_unittest.UnittestProto;
+import protobuf_unittest.UnittestProto.ForeignEnum;
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestEmptyMessage;
+import protobuf_unittest.UnittestProto.TestEmptyMessageWithExtensions;
+import protobuf_unittest.UnittestProto.TestPackedExtensions;
+import protobuf_unittest.UnittestProto.TestPackedTypes;
+
+import junit.framework.TestCase;
+
+import java.util.Arrays;
+import java.util.Map;
+
+/**
+ * Tests related to unknown field handling.
+ *
+ * @author kenton@google.com (Kenton Varda)
+ */
+public class UnknownFieldSetTest extends TestCase {
+  public void setUp() throws Exception {
+    descriptor = TestAllTypes.getDescriptor();
+    allFields = TestUtil.getAllSet();
+    allFieldsData = allFields.toByteString();
+    emptyMessage = TestEmptyMessage.parseFrom(allFieldsData);
+    unknownFields = emptyMessage.getUnknownFields();
+  }
+
+  UnknownFieldSet.Field getField(String name) {
+    Descriptors.FieldDescriptor field = descriptor.findFieldByName(name);
+    assertNotNull(field);
+    return unknownFields.getField(field.getNumber());
+  }
+
+  // Constructs a protocol buffer which contains fields with all the same
+  // numbers as allFieldsData except that each field is some other wire
+  // type.
+  ByteString getBizarroData() throws Exception {
+    UnknownFieldSet.Builder bizarroFields = UnknownFieldSet.newBuilder();
+
+    UnknownFieldSet.Field varintField =
+      UnknownFieldSet.Field.newBuilder().addVarint(1).build();
+    UnknownFieldSet.Field fixed32Field =
+      UnknownFieldSet.Field.newBuilder().addFixed32(1).build();
+
+    for (Map.Entry<Integer, UnknownFieldSet.Field> entry :
+         unknownFields.asMap().entrySet()) {
+      if (entry.getValue().getVarintList().isEmpty()) {
+        // Original field is not a varint, so use a varint.
+        bizarroFields.addField(entry.getKey(), varintField);
+      } else {
+        // Original field *is* a varint, so use something else.
+        bizarroFields.addField(entry.getKey(), fixed32Field);
+      }
+    }
+
+    return bizarroFields.build().toByteString();
+  }
+
+  Descriptors.Descriptor descriptor;
+  TestAllTypes allFields;
+  ByteString allFieldsData;
+
+  // An empty message that has been parsed from allFieldsData.  So, it has
+  // unknown fields of every type.
+  TestEmptyMessage emptyMessage;
+  UnknownFieldSet unknownFields;
+
+  // =================================================================
+
+  public void testVarint() throws Exception {
+    UnknownFieldSet.Field field = getField("optional_int32");
+    assertEquals(1, field.getVarintList().size());
+    assertEquals(allFields.getOptionalInt32(),
+                 (long) field.getVarintList().get(0));
+  }
+
+  public void testFixed32() throws Exception {
+    UnknownFieldSet.Field field = getField("optional_fixed32");
+    assertEquals(1, field.getFixed32List().size());
+    assertEquals(allFields.getOptionalFixed32(),
+                 (int) field.getFixed32List().get(0));
+  }
+
+  public void testFixed64() throws Exception {
+    UnknownFieldSet.Field field = getField("optional_fixed64");
+    assertEquals(1, field.getFixed64List().size());
+    assertEquals(allFields.getOptionalFixed64(),
+                 (long) field.getFixed64List().get(0));
+  }
+
+  public void testLengthDelimited() throws Exception {
+    UnknownFieldSet.Field field = getField("optional_bytes");
+    assertEquals(1, field.getLengthDelimitedList().size());
+    assertEquals(allFields.getOptionalBytes(),
+                 field.getLengthDelimitedList().get(0));
+  }
+
+  public void testGroup() throws Exception {
+    Descriptors.FieldDescriptor nestedFieldDescriptor =
+      TestAllTypes.OptionalGroup.getDescriptor().findFieldByName("a");
+    assertNotNull(nestedFieldDescriptor);
+
+    UnknownFieldSet.Field field = getField("optionalgroup");
+    assertEquals(1, field.getGroupList().size());
+
+    UnknownFieldSet group = field.getGroupList().get(0);
+    assertEquals(1, group.asMap().size());
+    assertTrue(group.hasField(nestedFieldDescriptor.getNumber()));
+
+    UnknownFieldSet.Field nestedField =
+      group.getField(nestedFieldDescriptor.getNumber());
+    assertEquals(1, nestedField.getVarintList().size());
+    assertEquals(allFields.getOptionalGroup().getA(),
+                 (long) nestedField.getVarintList().get(0));
+  }
+
+  public void testSerialize() throws Exception {
+    // Check that serializing the UnknownFieldSet produces the original data
+    // again.
+    ByteString data = emptyMessage.toByteString();
+    assertEquals(allFieldsData, data);
+  }
+
+  public void testCopyFrom() throws Exception {
+    TestEmptyMessage message =
+      TestEmptyMessage.newBuilder().mergeFrom(emptyMessage).build();
+
+    assertEquals(emptyMessage.toString(), message.toString());
+  }
+
+  public void testMergeFrom() throws Exception {
+    TestEmptyMessage source =
+      TestEmptyMessage.newBuilder()
+        .setUnknownFields(
+          UnknownFieldSet.newBuilder()
+            .addField(2,
+              UnknownFieldSet.Field.newBuilder()
+                .addVarint(2).build())
+            .addField(3,
+              UnknownFieldSet.Field.newBuilder()
+                .addVarint(4).build())
+            .build())
+        .build();
+    TestEmptyMessage destination =
+      TestEmptyMessage.newBuilder()
+        .setUnknownFields(
+          UnknownFieldSet.newBuilder()
+            .addField(1,
+              UnknownFieldSet.Field.newBuilder()
+                .addVarint(1).build())
+            .addField(3,
+              UnknownFieldSet.Field.newBuilder()
+                .addVarint(3).build())
+            .build())
+        .mergeFrom(source)
+        .build();
+
+    assertEquals(
+      "1: 1\n" +
+      "2: 2\n" +
+      "3: 3\n" +
+      "3: 4\n",
+      destination.toString());
+  }
+
+  public void testClear() throws Exception {
+    UnknownFieldSet fields =
+      UnknownFieldSet.newBuilder().mergeFrom(unknownFields).clear().build();
+    assertTrue(fields.asMap().isEmpty());
+  }
+
+  public void testClearMessage() throws Exception {
+    TestEmptyMessage message =
+      TestEmptyMessage.newBuilder().mergeFrom(emptyMessage).clear().build();
+    assertEquals(0, message.getSerializedSize());
+  }
+  
+  public void testClearField() throws Exception {
+    int fieldNumber = unknownFields.asMap().keySet().iterator().next();
+    UnknownFieldSet fields =
+        UnknownFieldSet.newBuilder().mergeFrom(unknownFields).clearField(fieldNumber).build();
+    assertFalse(fields.hasField(fieldNumber));
+  }
+
+  public void testParseKnownAndUnknown() throws Exception {
+    // Test mixing known and unknown fields when parsing.
+
+    UnknownFieldSet fields =
+      UnknownFieldSet.newBuilder(unknownFields)
+        .addField(123456,
+          UnknownFieldSet.Field.newBuilder().addVarint(654321).build())
+        .build();
+
+    ByteString data = fields.toByteString();
+    TestAllTypes destination = TestAllTypes.parseFrom(data);
+
+    TestUtil.assertAllFieldsSet(destination);
+    assertEquals(1, destination.getUnknownFields().asMap().size());
+
+    UnknownFieldSet.Field field =
+      destination.getUnknownFields().getField(123456);
+    assertEquals(1, field.getVarintList().size());
+    assertEquals(654321, (long) field.getVarintList().get(0));
+  }
+
+  public void testWrongTypeTreatedAsUnknown() throws Exception {
+    // Test that fields of the wrong wire type are treated like unknown fields
+    // when parsing.
+
+    ByteString bizarroData = getBizarroData();
+    TestAllTypes allTypesMessage = TestAllTypes.parseFrom(bizarroData);
+    TestEmptyMessage emptyMessage = TestEmptyMessage.parseFrom(bizarroData);
+
+    // All fields should have been interpreted as unknown, so the debug strings
+    // should be the same.
+    assertEquals(emptyMessage.toString(), allTypesMessage.toString());
+  }
+
+  public void testUnknownExtensions() throws Exception {
+    // Make sure fields are properly parsed to the UnknownFieldSet even when
+    // they are declared as extension numbers.
+
+    TestEmptyMessageWithExtensions message =
+      TestEmptyMessageWithExtensions.parseFrom(allFieldsData);
+
+    assertEquals(unknownFields.asMap().size(),
+                 message.getUnknownFields().asMap().size());
+    assertEquals(allFieldsData, message.toByteString());
+  }
+
+  public void testWrongExtensionTypeTreatedAsUnknown() throws Exception {
+    // Test that fields of the wrong wire type are treated like unknown fields
+    // when parsing extensions.
+
+    ByteString bizarroData = getBizarroData();
+    TestAllExtensions allExtensionsMessage =
+      TestAllExtensions.parseFrom(bizarroData);
+    TestEmptyMessage emptyMessage = TestEmptyMessage.parseFrom(bizarroData);
+
+    // All fields should have been interpreted as unknown, so the debug strings
+    // should be the same.
+    assertEquals(emptyMessage.toString(),
+                 allExtensionsMessage.toString());
+  }
+
+  public void testParseUnknownEnumValue() throws Exception {
+    Descriptors.FieldDescriptor singularField =
+      TestAllTypes.getDescriptor().findFieldByName("optional_nested_enum");
+    Descriptors.FieldDescriptor repeatedField =
+      TestAllTypes.getDescriptor().findFieldByName("repeated_nested_enum");
+    assertNotNull(singularField);
+    assertNotNull(repeatedField);
+
+    ByteString data =
+      UnknownFieldSet.newBuilder()
+        .addField(singularField.getNumber(),
+          UnknownFieldSet.Field.newBuilder()
+            .addVarint(TestAllTypes.NestedEnum.BAR.getNumber())
+            .addVarint(5)   // not valid
+            .build())
+        .addField(repeatedField.getNumber(),
+          UnknownFieldSet.Field.newBuilder()
+            .addVarint(TestAllTypes.NestedEnum.FOO.getNumber())
+            .addVarint(4)   // not valid
+            .addVarint(TestAllTypes.NestedEnum.BAZ.getNumber())
+            .addVarint(6)   // not valid
+            .build())
+        .build()
+        .toByteString();
+
+    {
+      TestAllTypes message = TestAllTypes.parseFrom(data);
+      assertEquals(TestAllTypes.NestedEnum.BAR,
+                   message.getOptionalNestedEnum());
+      assertEquals(
+        Arrays.asList(TestAllTypes.NestedEnum.FOO, TestAllTypes.NestedEnum.BAZ),
+        message.getRepeatedNestedEnumList());
+      assertEquals(Arrays.asList(5L),
+                   message.getUnknownFields()
+                          .getField(singularField.getNumber())
+                          .getVarintList());
+      assertEquals(Arrays.asList(4L, 6L),
+                   message.getUnknownFields()
+                          .getField(repeatedField.getNumber())
+                          .getVarintList());
+    }
+
+    {
+      TestAllExtensions message =
+        TestAllExtensions.parseFrom(data, TestUtil.getExtensionRegistry());
+      assertEquals(TestAllTypes.NestedEnum.BAR,
+        message.getExtension(UnittestProto.optionalNestedEnumExtension));
+      assertEquals(
+        Arrays.asList(TestAllTypes.NestedEnum.FOO, TestAllTypes.NestedEnum.BAZ),
+        message.getExtension(UnittestProto.repeatedNestedEnumExtension));
+      assertEquals(Arrays.asList(5L),
+                   message.getUnknownFields()
+                          .getField(singularField.getNumber())
+                          .getVarintList());
+      assertEquals(Arrays.asList(4L, 6L),
+                   message.getUnknownFields()
+                          .getField(repeatedField.getNumber())
+                          .getVarintList());
+    }
+  }
+
+  public void testLargeVarint() throws Exception {
+    ByteString data =
+      UnknownFieldSet.newBuilder()
+        .addField(1,
+          UnknownFieldSet.Field.newBuilder()
+            .addVarint(0x7FFFFFFFFFFFFFFFL)
+            .build())
+        .build()
+        .toByteString();
+    UnknownFieldSet parsed = UnknownFieldSet.parseFrom(data);
+    UnknownFieldSet.Field field = parsed.getField(1);
+    assertEquals(1, field.getVarintList().size());
+    assertEquals(0x7FFFFFFFFFFFFFFFL, (long)field.getVarintList().get(0));
+  }
+
+  public void testEqualsAndHashCode() {
+    UnknownFieldSet.Field fixed32Field =
+        UnknownFieldSet.Field.newBuilder()
+            .addFixed32(1)
+            .build();
+    UnknownFieldSet.Field fixed64Field =
+        UnknownFieldSet.Field.newBuilder()
+            .addFixed64(1)
+            .build();
+    UnknownFieldSet.Field varIntField =
+        UnknownFieldSet.Field.newBuilder()
+            .addVarint(1)
+            .build();
+    UnknownFieldSet.Field lengthDelimitedField =
+        UnknownFieldSet.Field.newBuilder()
+            .addLengthDelimited(ByteString.EMPTY)
+            .build();
+    UnknownFieldSet.Field groupField =
+        UnknownFieldSet.Field.newBuilder()
+            .addGroup(unknownFields)
+            .build();
+
+    UnknownFieldSet a =
+        UnknownFieldSet.newBuilder()
+            .addField(1, fixed32Field)
+            .build();
+    UnknownFieldSet b =
+        UnknownFieldSet.newBuilder()
+            .addField(1, fixed64Field)
+            .build();
+    UnknownFieldSet c =
+        UnknownFieldSet.newBuilder()
+            .addField(1, varIntField)
+            .build();
+    UnknownFieldSet d =
+        UnknownFieldSet.newBuilder()
+            .addField(1, lengthDelimitedField)
+            .build();
+    UnknownFieldSet e =
+        UnknownFieldSet.newBuilder()
+            .addField(1, groupField)
+            .build();
+
+    checkEqualsIsConsistent(a);
+    checkEqualsIsConsistent(b);
+    checkEqualsIsConsistent(c);
+    checkEqualsIsConsistent(d);
+    checkEqualsIsConsistent(e);
+
+    checkNotEqual(a, b);
+    checkNotEqual(a, c);
+    checkNotEqual(a, d);
+    checkNotEqual(a, e);
+    checkNotEqual(b, c);
+    checkNotEqual(b, d);
+    checkNotEqual(b, e);
+    checkNotEqual(c, d);
+    checkNotEqual(c, e);
+    checkNotEqual(d, e);
+  }
+
+  /**
+   * Asserts that the given field sets are not equal and have different
+   * hash codes.
+   *
+   * @warning It's valid for non-equal objects to have the same hash code, so
+   *   this test is stricter than it needs to be. However, this should happen
+   *   relatively rarely.
+   */
+  private void checkNotEqual(UnknownFieldSet s1, UnknownFieldSet s2) {
+    String equalsError = String.format("%s should not be equal to %s", s1, s2);
+    assertFalse(equalsError, s1.equals(s2));
+    assertFalse(equalsError, s2.equals(s1));
+
+    assertFalse(
+        String.format("%s should have a different hash code from %s", s1, s2),
+        s1.hashCode() == s2.hashCode());
+  }
+
+  /**
+   * Asserts that the given field sets are equal and have identical hash codes.
+   */
+  private void checkEqualsIsConsistent(UnknownFieldSet set) {
+    // Object should be equal to itself.
+    assertEquals(set, set);
+
+    // Object should be equal to a copy of itself.
+    UnknownFieldSet copy = UnknownFieldSet.newBuilder(set).build();
+    assertEquals(set, copy);
+    assertEquals(copy, set);
+    assertEquals(set.hashCode(), copy.hashCode());
+  }
+
+  // =================================================================
+
+  public void testSerializeLite() throws Exception {
+    UnittestLite.TestEmptyMessageLite emptyMessageLite =
+        UnittestLite.TestEmptyMessageLite.parseFrom(allFieldsData);
+    assertEquals(allFieldsData.size(), emptyMessageLite.getSerializedSize());
+    ByteString data = emptyMessageLite.toByteString();
+    TestAllTypes message = TestAllTypes.parseFrom(data);
+    TestUtil.assertAllFieldsSet(message);
+    assertEquals(allFieldsData, data);
+  }
+
+  public void testAllExtensionsLite() throws Exception {
+    TestAllExtensions allExtensions = TestUtil.getAllExtensionsSet();
+    ByteString allExtensionsData = allExtensions.toByteString();
+    UnittestLite.TestEmptyMessageLite emptyMessageLite =
+        UnittestLite.TestEmptyMessageLite.parser().parseFrom(allExtensionsData);
+    ByteString data = emptyMessageLite.toByteString();
+    TestAllExtensions message =
+        TestAllExtensions.parseFrom(data, TestUtil.getExtensionRegistry());
+    TestUtil.assertAllExtensionsSet(message);
+    assertEquals(allExtensionsData, data);
+  }
+
+  public void testAllPackedFieldsLite() throws Exception {
+    TestPackedTypes allPackedFields = TestUtil.getPackedSet();
+    ByteString allPackedData = allPackedFields.toByteString();
+    UnittestLite.TestEmptyMessageLite emptyMessageLite =
+        UnittestLite.TestEmptyMessageLite.parseFrom(allPackedData);
+    ByteString data = emptyMessageLite.toByteString();
+    TestPackedTypes message =
+        TestPackedTypes.parseFrom(data, TestUtil.getExtensionRegistry());
+    TestUtil.assertPackedFieldsSet(message);
+    assertEquals(allPackedData, data);
+  }
+
+  public void testAllPackedExtensionsLite() throws Exception {
+    TestPackedExtensions allPackedExtensions = TestUtil.getPackedExtensionsSet();
+    ByteString allPackedExtensionsData = allPackedExtensions.toByteString();
+    UnittestLite.TestEmptyMessageLite emptyMessageLite =
+        UnittestLite.TestEmptyMessageLite.parseFrom(allPackedExtensionsData);
+    ByteString data = emptyMessageLite.toByteString();
+    TestPackedExtensions message =
+        TestPackedExtensions.parseFrom(data, TestUtil.getExtensionRegistry());
+    TestUtil.assertPackedExtensionsSet(message);
+    assertEquals(allPackedExtensionsData, data);
+  }
+
+  public void testCopyFromLite() throws Exception {
+    UnittestLite.TestEmptyMessageLite emptyMessageLite =
+        UnittestLite.TestEmptyMessageLite.parseFrom(allFieldsData);
+    UnittestLite.TestEmptyMessageLite emptyMessageLite2 =
+        UnittestLite.TestEmptyMessageLite.newBuilder()
+        .mergeFrom(emptyMessageLite).build();
+    assertEquals(emptyMessageLite.toByteString(), emptyMessageLite2.toByteString());
+  }
+
+  public void testMergeFromLite() throws Exception {
+    TestAllTypes message1 = TestAllTypes.newBuilder()
+        .setOptionalInt32(1)
+        .setOptionalString("foo")
+        .addRepeatedString("bar")
+        .setOptionalNestedEnum(TestAllTypes.NestedEnum.BAZ)
+        .build();
+
+    TestAllTypes message2 = TestAllTypes.newBuilder()
+        .setOptionalInt64(2)
+        .setOptionalString("baz")
+        .addRepeatedString("qux")
+        .setOptionalForeignEnum(ForeignEnum.FOREIGN_BAZ)
+        .build();
+
+    ByteString data1 = message1.toByteString();
+    UnittestLite.TestEmptyMessageLite emptyMessageLite1 =
+        UnittestLite.TestEmptyMessageLite.parseFrom(data1);
+    ByteString data2 = message2.toByteString();
+    UnittestLite.TestEmptyMessageLite emptyMessageLite2 =
+        UnittestLite.TestEmptyMessageLite.parseFrom(data2);
+
+    message1 = TestAllTypes.newBuilder(message1).mergeFrom(message2).build();
+    emptyMessageLite1 = UnittestLite.TestEmptyMessageLite.newBuilder(emptyMessageLite1)
+                        .mergeFrom(emptyMessageLite2).build();
+
+    data1 = emptyMessageLite1.toByteString();
+    message2 = TestAllTypes.parseFrom(data1);
+
+    assertEquals(message1, message2);
+  }
+
+  public void testWrongTypeTreatedAsUnknownLite() throws Exception {
+    // Test that fields of the wrong wire type are treated like unknown fields
+    // when parsing.
+
+    ByteString bizarroData = getBizarroData();
+    TestAllTypes allTypesMessage = TestAllTypes.parseFrom(bizarroData);
+    UnittestLite.TestEmptyMessageLite emptyMessageLite =
+        UnittestLite.TestEmptyMessageLite.parseFrom(bizarroData);
+    ByteString data = emptyMessageLite.toByteString();
+    TestAllTypes allTypesMessage2 = TestAllTypes.parseFrom(data);
+
+    assertEquals(allTypesMessage.toString(), allTypesMessage2.toString());
+  }
+
+  public void testUnknownExtensionsLite() throws Exception {
+    // Make sure fields are properly parsed to the UnknownFieldSet even when
+    // they are declared as extension numbers.
+
+    UnittestLite.TestEmptyMessageWithExtensionsLite message =
+      UnittestLite.TestEmptyMessageWithExtensionsLite.parseFrom(allFieldsData);
+
+    assertEquals(allFieldsData, message.toByteString());
+  }
+
+  public void testWrongExtensionTypeTreatedAsUnknownLite() throws Exception {
+    // Test that fields of the wrong wire type are treated like unknown fields
+    // when parsing extensions.
+
+    ByteString bizarroData = getBizarroData();
+    TestAllExtensions allExtensionsMessage =
+      TestAllExtensions.parseFrom(bizarroData);
+    UnittestLite.TestEmptyMessageLite emptyMessageLite =
+        UnittestLite.TestEmptyMessageLite.parseFrom(bizarroData);
+
+    // All fields should have been interpreted as unknown, so the byte strings
+    // should be the same.
+    assertEquals(emptyMessageLite.toByteString(),
+                 allExtensionsMessage.toByteString());
+  }
+
+  public void testParseUnknownEnumValueLite() throws Exception {
+    Descriptors.FieldDescriptor singularField =
+      TestAllTypes.getDescriptor().findFieldByName("optional_nested_enum");
+    Descriptors.FieldDescriptor repeatedField =
+      TestAllTypes.getDescriptor().findFieldByName("repeated_nested_enum");
+    assertNotNull(singularField);
+    assertNotNull(repeatedField);
+
+    ByteString data =
+      UnknownFieldSet.newBuilder()
+        .addField(singularField.getNumber(),
+          UnknownFieldSet.Field.newBuilder()
+            .addVarint(TestAllTypes.NestedEnum.BAR.getNumber())
+            .addVarint(5)   // not valid
+            .build())
+        .addField(repeatedField.getNumber(),
+          UnknownFieldSet.Field.newBuilder()
+            .addVarint(TestAllTypes.NestedEnum.FOO.getNumber())
+            .addVarint(4)   // not valid
+            .addVarint(TestAllTypes.NestedEnum.BAZ.getNumber())
+            .addVarint(6)   // not valid
+            .build())
+        .build()
+        .toByteString();
+
+    UnittestLite.TestEmptyMessageLite emptyMessageLite =
+        UnittestLite.TestEmptyMessageLite.parseFrom(data);
+    data = emptyMessageLite.toByteString();
+
+    {
+      TestAllTypes message = TestAllTypes.parseFrom(data);
+      assertEquals(TestAllTypes.NestedEnum.BAR,
+                   message.getOptionalNestedEnum());
+      assertEquals(
+        Arrays.asList(TestAllTypes.NestedEnum.FOO, TestAllTypes.NestedEnum.BAZ),
+        message.getRepeatedNestedEnumList());
+      assertEquals(Arrays.asList(5L),
+                   message.getUnknownFields()
+                          .getField(singularField.getNumber())
+                          .getVarintList());
+      assertEquals(Arrays.asList(4L, 6L),
+                   message.getUnknownFields()
+                          .getField(repeatedField.getNumber())
+                          .getVarintList());
+    }
+
+    {
+      TestAllExtensions message =
+        TestAllExtensions.parseFrom(data, TestUtil.getExtensionRegistry());
+      assertEquals(TestAllTypes.NestedEnum.BAR,
+        message.getExtension(UnittestProto.optionalNestedEnumExtension));
+      assertEquals(
+        Arrays.asList(TestAllTypes.NestedEnum.FOO, TestAllTypes.NestedEnum.BAZ),
+        message.getExtension(UnittestProto.repeatedNestedEnumExtension));
+      assertEquals(Arrays.asList(5L),
+                   message.getUnknownFields()
+                          .getField(singularField.getNumber())
+                          .getVarintList());
+      assertEquals(Arrays.asList(4L, 6L),
+                   message.getUnknownFields()
+                          .getField(repeatedField.getNumber())
+                          .getVarintList());
+    }
+  }
+
+  public void testClearLite() throws Exception {
+    UnittestLite.TestEmptyMessageLite emptyMessageLite1 =
+        UnittestLite.TestEmptyMessageLite.parseFrom(allFieldsData);
+    UnittestLite.TestEmptyMessageLite emptyMessageLite2 =
+        UnittestLite.TestEmptyMessageLite.newBuilder()
+        .mergeFrom(emptyMessageLite1).clear().build();
+    assertEquals(0, emptyMessageLite2.getSerializedSize());
+    ByteString data = emptyMessageLite2.toByteString();
+    assertEquals(0, data.size());
+  }
+
+}
diff --git a/java/core/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java b/java/core/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java
new file mode 100644
index 00000000..b1c75fc3
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java
@@ -0,0 +1,227 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import junit.framework.TestCase;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+
+/**
+ * Tests for {@link UnmodifiableLazyStringList}.
+ *
+ * @author jonp@google.com (Jon Perlow)
+ */
+public class UnmodifiableLazyStringListTest extends TestCase {
+
+  private static String STRING_A = "A";
+  private static String STRING_B = "B";
+  private static String STRING_C = "C";
+
+  private static ByteString BYTE_STRING_A = ByteString.copyFromUtf8("A");
+  private static ByteString BYTE_STRING_B = ByteString.copyFromUtf8("B");
+  private static ByteString BYTE_STRING_C = ByteString.copyFromUtf8("C");
+
+  public void testReadOnlyMethods() {
+    LazyStringArrayList rawList = createSampleList();
+    UnmodifiableLazyStringList list = new UnmodifiableLazyStringList(rawList);
+    assertEquals(3, list.size());
+    assertSame(STRING_A, list.get(0));
+    assertSame(STRING_B, list.get(1));
+    assertSame(STRING_C, list.get(2));
+    assertEquals(BYTE_STRING_A, list.getByteString(0));
+    assertEquals(BYTE_STRING_B, list.getByteString(1));
+    assertEquals(BYTE_STRING_C, list.getByteString(2));
+
+    List<ByteString> byteStringList = list.asByteStringList();
+    assertSame(list.getByteString(0), byteStringList.get(0));
+    assertSame(list.getByteString(1), byteStringList.get(1));
+    assertSame(list.getByteString(2), byteStringList.get(2));
+  }
+
+  public void testModifyMethods() {
+    LazyStringArrayList rawList = createSampleList();
+    UnmodifiableLazyStringList list = new UnmodifiableLazyStringList(rawList);
+
+    try {
+      list.remove(0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(3, list.size());
+
+    try {
+      list.add(STRING_B);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(3, list.size());
+
+    try {
+      list.set(1, STRING_B);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(3, list.size());
+
+    List<ByteString> byteStringList = list.asByteStringList();
+    try {
+      byteStringList.remove(0);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(3, list.size());
+    assertEquals(3, byteStringList.size());
+
+    try {
+      byteStringList.add(BYTE_STRING_B);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(3, list.size());
+    assertEquals(3, byteStringList.size());
+
+    try {
+      byteStringList.set(1, BYTE_STRING_B);
+      fail();
+    } catch (UnsupportedOperationException e) {
+      // expected
+    }
+    assertEquals(3, list.size());
+    assertEquals(3, byteStringList.size());
+  }
+
+  public void testIterator() {
+    LazyStringArrayList rawList = createSampleList();
+    UnmodifiableLazyStringList list = new UnmodifiableLazyStringList(rawList);
+
+    Iterator<String> iter = list.iterator();
+    int count = 0;
+    while (iter.hasNext()) {
+      iter.next();
+      count++;
+      try {
+        iter.remove();
+        fail();
+      } catch (UnsupportedOperationException e) {
+        // expected
+      }
+    }
+    assertEquals(3, count);
+
+    List<ByteString> byteStringList = list.asByteStringList();
+    Iterator<ByteString> byteIter = byteStringList.iterator();
+    count = 0;
+    while (byteIter.hasNext()) {
+      byteIter.next();
+      count++;
+      try {
+        byteIter.remove();
+        fail();
+      } catch (UnsupportedOperationException e) {
+        // expected
+      }
+    }
+    assertEquals(3, count);
+  }
+
+  public void testListIterator() {
+    LazyStringArrayList rawList = createSampleList();
+    UnmodifiableLazyStringList list = new UnmodifiableLazyStringList(rawList);
+
+    ListIterator<String> iter = list.listIterator();
+    int count = 0;
+    while (iter.hasNext()) {
+      iter.next();
+      count++;
+      try {
+        iter.remove();
+        fail();
+      } catch (UnsupportedOperationException e) {
+        // expected
+      }
+      try {
+        iter.set("bar");
+        fail();
+      } catch (UnsupportedOperationException e) {
+        // expected
+      }
+      try {
+        iter.add("bar");
+        fail();
+      } catch (UnsupportedOperationException e) {
+        // expected
+      }
+    }
+    assertEquals(3, count);
+
+    List<ByteString> byteStringList = list.asByteStringList();
+    ListIterator<ByteString> byteIter = byteStringList.listIterator();
+    count = 0;
+    while (byteIter.hasNext()) {
+      byteIter.next();
+      count++;
+      try {
+        byteIter.remove();
+        fail();
+      } catch (UnsupportedOperationException e) {
+        // expected
+      }
+      try {
+        byteIter.set(BYTE_STRING_A);
+        fail();
+      } catch (UnsupportedOperationException e) {
+        // expected
+      }
+      try {
+        byteIter.add(BYTE_STRING_A);
+        fail();
+      } catch (UnsupportedOperationException e) {
+        // expected
+      }
+    }
+    assertEquals(3, count);
+  }
+
+  private LazyStringArrayList createSampleList() {
+    LazyStringArrayList rawList = new LazyStringArrayList();
+    rawList.add(STRING_A);
+    rawList.add(STRING_B);
+    rawList.add(STRING_C);
+    return rawList;
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/WellKnownTypesTest.java b/java/core/src/test/java/com/google/protobuf/WellKnownTypesTest.java
new file mode 100644
index 00000000..982e200f
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/WellKnownTypesTest.java
@@ -0,0 +1,65 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import com.google.protobuf.Descriptors.Descriptor;
+import com.google.protobuf.Descriptors.EnumDescriptor;
+import com.google.protobuf.Descriptors.EnumValueDescriptor;
+import com.google.protobuf.Descriptors.FieldDescriptor;
+import com.google.protobuf.test.TestWellKnownTypes;
+
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * This test ensures that well-known types are included in protobuf Java
+ * runtime library.
+ */
+public class WellKnownTypesTest extends TestCase {
+  public void testWellKnownTypes() {
+    // The test passes if it compiles.
+    TestWellKnownTypes message = TestWellKnownTypes.newBuilder().build();
+    assertEquals(0, message.getAnyField().getSerializedSize());
+    assertEquals(0, message.getApiField().getSerializedSize());
+    assertEquals(0, message.getDurationField().getSerializedSize());
+    assertEquals(0, message.getEmptyField().getSerializedSize());
+    assertEquals(0, message.getFieldMaskField().getSerializedSize());
+    assertEquals(0, message.getSourceContextField().getSerializedSize());
+    assertEquals(0, message.getStructField().getSerializedSize());
+    assertEquals(0, message.getTimestampField().getSerializedSize());
+    assertEquals(0, message.getTypeField().getSerializedSize());
+    assertEquals(0, message.getInt32Field().getSerializedSize());
+  }
+}
diff --git a/java/core/src/test/java/com/google/protobuf/WireFormatTest.java b/java/core/src/test/java/com/google/protobuf/WireFormatTest.java
new file mode 100644
index 00000000..0175005d
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/WireFormatTest.java
@@ -0,0 +1,606 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf;
+
+import junit.framework.TestCase;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.util.List;
+
+import protobuf_unittest.UnittestProto;
+import protobuf_unittest.UnittestProto.TestAllExtensions;
+import protobuf_unittest.UnittestProto.TestAllTypes;
+import protobuf_unittest.UnittestProto.TestFieldOrderings;
+import protobuf_unittest.UnittestProto.TestOneof2;
+import protobuf_unittest.UnittestProto.TestOneofBackwardsCompatible;
+import protobuf_unittest.UnittestProto.TestPackedExtensions;
+import protobuf_unittest.UnittestProto.TestPackedTypes;
+import protobuf_unittest.UnittestMset.RawMessageSet;
+import protobuf_unittest.UnittestMset.TestMessageSetExtension1;
+import protobuf_unittest.UnittestMset.TestMessageSetExtension2;
+import proto2_wireformat_unittest.UnittestMsetWireFormat.TestMessageSet;
+import com.google.protobuf.UnittestLite.TestAllExtensionsLite;
+import com.google.protobuf.UnittestLite.TestPackedExtensionsLite;
+
+/**
+ * Tests related to parsing and serialization.
+ *
+ * @author kenton@google.com (Kenton Varda)
+ */
+public class WireFormatTest extends TestCase {
+  public void testSerialization() throws Exception {
+    TestAllTypes message = TestUtil.getAllSet();
+
+    ByteString rawBytes = message.toByteString();
+    assertEquals(rawBytes.size(), message.getSerializedSize());
+
+    TestAllTypes message2 = TestAllTypes.parseFrom(rawBytes);
+
+    TestUtil.assertAllFieldsSet(message2);
+  }
+
+  public void testSerializationPacked() throws Exception {
+    TestPackedTypes message = TestUtil.getPackedSet();
+
+    ByteString rawBytes = message.toByteString();
+    assertEquals(rawBytes.size(), message.getSerializedSize());
+
+    TestPackedTypes message2 = TestPackedTypes.parseFrom(rawBytes);
+
+    TestUtil.assertPackedFieldsSet(message2);
+  }
+
+  public void testSerializeExtensions() throws Exception {
+    // TestAllTypes and TestAllExtensions should have compatible wire formats,
+    // so if we serialize a TestAllExtensions then parse it as TestAllTypes
+    // it should work.
+
+    TestAllExtensions message = TestUtil.getAllExtensionsSet();
+    ByteString rawBytes = message.toByteString();
+    assertEquals(rawBytes.size(), message.getSerializedSize());
+
+    TestAllTypes message2 = TestAllTypes.parseFrom(rawBytes);
+
+    TestUtil.assertAllFieldsSet(message2);
+  }
+
+  public void testSerializePackedExtensions() throws Exception {
+    // TestPackedTypes and TestPackedExtensions should have compatible wire
+    // formats; check that they serialize to the same string.
+    TestPackedExtensions message = TestUtil.getPackedExtensionsSet();
+    ByteString rawBytes = message.toByteString();
+
+    TestPackedTypes message2 = TestUtil.getPackedSet();
+    ByteString rawBytes2 = message2.toByteString();
+
+    assertEquals(rawBytes, rawBytes2);
+  }
+
+  public void testSerializationPackedWithoutGetSerializedSize()
+      throws Exception {
+    // Write directly to an OutputStream, without invoking getSerializedSize()
+    // This used to be a bug where the size of a packed field was incorrect,
+    // since getSerializedSize() was never invoked.
+    TestPackedTypes message = TestUtil.getPackedSet();
+
+    // Directly construct a CodedOutputStream around the actual OutputStream,
+    // in case writeTo(OutputStream output) invokes getSerializedSize();
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    CodedOutputStream codedOutput = CodedOutputStream.newInstance(outputStream);
+
+    message.writeTo(codedOutput);
+
+    codedOutput.flush();
+
+    TestPackedTypes message2 = TestPackedTypes.parseFrom(
+        outputStream.toByteArray());
+
+    TestUtil.assertPackedFieldsSet(message2);
+  }
+
+  public void testSerializeExtensionsLite() throws Exception {
+    // TestAllTypes and TestAllExtensions should have compatible wire formats,
+    // so if we serialize a TestAllExtensions then parse it as TestAllTypes
+    // it should work.
+
+    TestAllExtensionsLite message = TestUtil.getAllLiteExtensionsSet();
+    ByteString rawBytes = message.toByteString();
+    assertEquals(rawBytes.size(), message.getSerializedSize());
+
+    TestAllTypes message2 = TestAllTypes.parseFrom(rawBytes);
+
+    TestUtil.assertAllFieldsSet(message2);
+  }
+
+  public void testSerializePackedExtensionsLite() throws Exception {
+    // TestPackedTypes and TestPackedExtensions should have compatible wire
+    // formats; check that they serialize to the same string.
+    TestPackedExtensionsLite message = TestUtil.getLitePackedExtensionsSet();
+    ByteString rawBytes = message.toByteString();
+
+    TestPackedTypes message2 = TestUtil.getPackedSet();
+    ByteString rawBytes2 = message2.toByteString();
+
+    assertEquals(rawBytes, rawBytes2);
+  }
+
+  public void testParseExtensions() throws Exception {
+    // TestAllTypes and TestAllExtensions should have compatible wire formats,
+    // so if we serialize a TestAllTypes then parse it as TestAllExtensions
+    // it should work.
+
+    TestAllTypes message = TestUtil.getAllSet();
+    ByteString rawBytes = message.toByteString();
+
+    ExtensionRegistry registry = TestUtil.getExtensionRegistry();
+
+    TestAllExtensions message2 =
+      TestAllExtensions.parseFrom(rawBytes, registry);
+
+    TestUtil.assertAllExtensionsSet(message2);
+  }
+
+  public void testParsePackedExtensions() throws Exception {
+    // Ensure that packed extensions can be properly parsed.
+    TestPackedExtensions message = TestUtil.getPackedExtensionsSet();
+    ByteString rawBytes = message.toByteString();
+
+    ExtensionRegistry registry = TestUtil.getExtensionRegistry();
+
+    TestPackedExtensions message2 =
+        TestPackedExtensions.parseFrom(rawBytes, registry);
+
+    TestUtil.assertPackedExtensionsSet(message2);
+  }
+
+  public void testParseExtensionsLite() throws Exception {
+    // TestAllTypes and TestAllExtensions should have compatible wire formats,
+    // so if we serialize a TestAllTypes then parse it as TestAllExtensions
+    // it should work.
+
+    TestAllTypes message = TestUtil.getAllSet();
+    ByteString rawBytes = message.toByteString();
+
+    ExtensionRegistryLite registry_lite = TestUtil.getExtensionRegistryLite();
+
+    TestAllExtensionsLite message2 =
+      TestAllExtensionsLite.parseFrom(rawBytes, registry_lite);
+
+    TestUtil.assertAllExtensionsSet(message2);
+
+    // Try again using a full extension registry.
+    ExtensionRegistry registry = TestUtil.getExtensionRegistry();
+
+    TestAllExtensionsLite message3 =
+      TestAllExtensionsLite.parseFrom(rawBytes, registry);
+
+    TestUtil.assertAllExtensionsSet(message3);
+  }
+
+  public void testParsePackedExtensionsLite() throws Exception {
+    // Ensure that packed extensions can be properly parsed.
+    TestPackedExtensionsLite message = TestUtil.getLitePackedExtensionsSet();
+    ByteString rawBytes = message.toByteString();
+
+    ExtensionRegistryLite registry = TestUtil.getExtensionRegistryLite();
+
+    TestPackedExtensionsLite message2 =
+        TestPackedExtensionsLite.parseFrom(rawBytes, registry);
+
+    TestUtil.assertPackedExtensionsSet(message2);
+  }
+
+  public void testExtensionsSerializedSize() throws Exception {
+    assertNotSame(TestUtil.getAllSet().getSerializedSize(),
+                  TestUtil.getAllExtensionsSet().getSerializedSize());
+  }
+
+  public void testSerializeDelimited() throws Exception {
+    ByteArrayOutputStream output = new ByteArrayOutputStream();
+    TestUtil.getAllSet().writeDelimitedTo(output);
+    output.write(12);
+    TestUtil.getPackedSet().writeDelimitedTo(output);
+    output.write(34);
+
+    ByteArrayInputStream input = new ByteArrayInputStream(output.toByteArray());
+
+    TestUtil.assertAllFieldsSet(TestAllTypes.parseDelimitedFrom(input));
+    assertEquals(12, input.read());
+    TestUtil.assertPackedFieldsSet(TestPackedTypes.parseDelimitedFrom(input));
+    assertEquals(34, input.read());
+    assertEquals(-1, input.read());
+
+    // We're at EOF, so parsing again should return null.
+    assertTrue(TestAllTypes.parseDelimitedFrom(input) == null);
+  }
+
+  private void assertFieldsInOrder(ByteString data) throws Exception {
+    CodedInputStream input = data.newCodedInput();
+    int previousTag = 0;
+
+    while (true) {
+      int tag = input.readTag();
+      if (tag == 0) {
+        break;
+      }
+
+      assertTrue(tag > previousTag);
+      previousTag = tag;
+      input.skipField(tag);
+    }
+  }
+
+  public void testInterleavedFieldsAndExtensions() throws Exception {
+    // Tests that fields are written in order even when extension ranges
+    // are interleaved with field numbers.
+    ByteString data =
+      TestFieldOrderings.newBuilder()
+        .setMyInt(1)
+        .setMyString("foo")
+        .setMyFloat(1.0F)
+        .setExtension(UnittestProto.myExtensionInt, 23)
+        .setExtension(UnittestProto.myExtensionString, "bar")
+        .build().toByteString();
+    assertFieldsInOrder(data);
+
+    Descriptors.Descriptor descriptor = TestFieldOrderings.getDescriptor();
+    ByteString dynamic_data =
+      DynamicMessage.newBuilder(TestFieldOrderings.getDescriptor())
+        .setField(descriptor.findFieldByName("my_int"), 1L)
+        .setField(descriptor.findFieldByName("my_string"), "foo")
+        .setField(descriptor.findFieldByName("my_float"), 1.0F)
+        .setField(UnittestProto.myExtensionInt.getDescriptor(), 23)
+        .setField(UnittestProto.myExtensionString.getDescriptor(), "bar")
+        .build().toByteString();
+    assertFieldsInOrder(dynamic_data);
+  }
+
+  private ExtensionRegistry getTestFieldOrderingsRegistry() {
+    ExtensionRegistry result = ExtensionRegistry.newInstance();
+    result.add(UnittestProto.myExtensionInt);
+    result.add(UnittestProto.myExtensionString);
+    return result;
+  }
+
+  public void testParseMultipleExtensionRanges() throws Exception {
+    // Make sure we can parse a message that contains multiple extensions
+    // ranges.
+    TestFieldOrderings source =
+      TestFieldOrderings.newBuilder()
+        .setMyInt(1)
+        .setMyString("foo")
+        .setMyFloat(1.0F)
+        .setExtension(UnittestProto.myExtensionInt, 23)
+        .setExtension(UnittestProto.myExtensionString, "bar")
+        .build();
+    TestFieldOrderings dest =
+      TestFieldOrderings.parseFrom(source.toByteString(),
+                                   getTestFieldOrderingsRegistry());
+    assertEquals(source, dest);
+  }
+
+  public void testParseMultipleExtensionRangesDynamic() throws Exception {
+    // Same as above except with DynamicMessage.
+    Descriptors.Descriptor descriptor = TestFieldOrderings.getDescriptor();
+    DynamicMessage source =
+      DynamicMessage.newBuilder(TestFieldOrderings.getDescriptor())
+        .setField(descriptor.findFieldByName("my_int"), 1L)
+        .setField(descriptor.findFieldByName("my_string"), "foo")
+        .setField(descriptor.findFieldByName("my_float"), 1.0F)
+        .setField(UnittestProto.myExtensionInt.getDescriptor(), 23)
+        .setField(UnittestProto.myExtensionString.getDescriptor(), "bar")
+        .build();
+    DynamicMessage dest =
+      DynamicMessage.parseFrom(descriptor, source.toByteString(),
+                               getTestFieldOrderingsRegistry());
+    assertEquals(source, dest);
+  }
+
+  private static final int UNKNOWN_TYPE_ID = 1550055;
+  private static final int TYPE_ID_1 =
+    TestMessageSetExtension1.getDescriptor().getExtensions().get(0).getNumber();
+  private static final int TYPE_ID_2 =
+    TestMessageSetExtension2.getDescriptor().getExtensions().get(0).getNumber();
+
+  public void testSerializeMessageSetEagerly() throws Exception {
+    testSerializeMessageSetWithFlag(true);
+  }
+
+  public void testSerializeMessageSetNotEagerly() throws Exception {
+    testSerializeMessageSetWithFlag(false);
+  }
+
+  private void testSerializeMessageSetWithFlag(boolean eagerParsing)
+      throws Exception {
+    ExtensionRegistryLite.setEagerlyParseMessageSets(eagerParsing);
+    // Set up a TestMessageSet with two known messages and an unknown one.
+    TestMessageSet messageSet =
+      TestMessageSet.newBuilder()
+        .setExtension(
+          TestMessageSetExtension1.messageSetExtension,
+          TestMessageSetExtension1.newBuilder().setI(123).build())
+        .setExtension(
+          TestMessageSetExtension2.messageSetExtension,
+          TestMessageSetExtension2.newBuilder().setStr("foo").build())
+        .setUnknownFields(
+          UnknownFieldSet.newBuilder()
+            .addField(UNKNOWN_TYPE_ID,
+              UnknownFieldSet.Field.newBuilder()
+                .addLengthDelimited(ByteString.copyFromUtf8("bar"))
+                .build())
+            .build())
+        .build();
+
+    ByteString data = messageSet.toByteString();
+
+    // Parse back using RawMessageSet and check the contents.
+    RawMessageSet raw = RawMessageSet.parseFrom(data);
+
+    assertTrue(raw.getUnknownFields().asMap().isEmpty());
+
+    assertEquals(3, raw.getItemCount());
+    assertEquals(TYPE_ID_1, raw.getItem(0).getTypeId());
+    assertEquals(TYPE_ID_2, raw.getItem(1).getTypeId());
+    assertEquals(UNKNOWN_TYPE_ID, raw.getItem(2).getTypeId());
+
+    TestMessageSetExtension1 message1 =
+      TestMessageSetExtension1.parseFrom(
+        raw.getItem(0).getMessage().toByteArray());
+    assertEquals(123, message1.getI());
+
+    TestMessageSetExtension2 message2 =
+      TestMessageSetExtension2.parseFrom(
+        raw.getItem(1).getMessage().toByteArray());
+    assertEquals("foo", message2.getStr());
+
+    assertEquals("bar", raw.getItem(2).getMessage().toStringUtf8());
+  }
+
+  public void testParseMessageSetEagerly() throws Exception {
+    testParseMessageSetWithFlag(true);
+  }
+
+  public void testParseMessageSetNotEagerly()throws Exception {
+    testParseMessageSetWithFlag(false);
+  }
+
+  private void testParseMessageSetWithFlag(boolean eagerParsing)
+      throws Exception {
+    ExtensionRegistryLite.setEagerlyParseMessageSets(eagerParsing);
+    ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
+    extensionRegistry.add(TestMessageSetExtension1.messageSetExtension);
+    extensionRegistry.add(TestMessageSetExtension2.messageSetExtension);
+
+    // Set up a RawMessageSet with two known messages and an unknown one.
+    RawMessageSet raw =
+      RawMessageSet.newBuilder()
+        .addItem(
+          RawMessageSet.Item.newBuilder()
+            .setTypeId(TYPE_ID_1)
+            .setMessage(
+              TestMessageSetExtension1.newBuilder()
+                .setI(123)
+                .build().toByteString())
+            .build())
+        .addItem(
+          RawMessageSet.Item.newBuilder()
+            .setTypeId(TYPE_ID_2)
+            .setMessage(
+              TestMessageSetExtension2.newBuilder()
+                .setStr("foo")
+                .build().toByteString())
+            .build())
+        .addItem(
+          RawMessageSet.Item.newBuilder()
+            .setTypeId(UNKNOWN_TYPE_ID)
+            .setMessage(ByteString.copyFromUtf8("bar"))
+            .build())
+        .build();
+
+    ByteString data = raw.toByteString();
+
+    // Parse as a TestMessageSet and check the contents.
+    TestMessageSet messageSet =
+      TestMessageSet.parseFrom(data, extensionRegistry);
+
+    assertEquals(123, messageSet.getExtension(
+      TestMessageSetExtension1.messageSetExtension).getI());
+    assertEquals("foo", messageSet.getExtension(
+      TestMessageSetExtension2.messageSetExtension).getStr());
+
+    // Check for unknown field with type LENGTH_DELIMITED,
+    //   number UNKNOWN_TYPE_ID, and contents "bar".
+    UnknownFieldSet unknownFields = messageSet.getUnknownFields();
+    assertEquals(1, unknownFields.asMap().size());
+    assertTrue(unknownFields.hasField(UNKNOWN_TYPE_ID));
+
+    UnknownFieldSet.Field field = unknownFields.getField(UNKNOWN_TYPE_ID);
+    assertEquals(1, field.getLengthDelimitedList().size());
+    assertEquals("bar", field.getLengthDelimitedList().get(0).toStringUtf8());
+  }
+
+  public void testParseMessageSetExtensionEagerly() throws Exception {
+    testParseMessageSetExtensionWithFlag(true);
+  }
+
+  public void testParseMessageSetExtensionNotEagerly() throws Exception {
+    testParseMessageSetExtensionWithFlag(false);
+  }
+
+  private void testParseMessageSetExtensionWithFlag(boolean eagerParsing)
+      throws Exception {
+    ExtensionRegistryLite.setEagerlyParseMessageSets(eagerParsing);
+    ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
+    extensionRegistry.add(TestMessageSetExtension1.messageSetExtension);
+
+    // Set up a RawMessageSet with a known messages.
+    int TYPE_ID_1 =
+        TestMessageSetExtension1
+            .getDescriptor().getExtensions().get(0).getNumber();
+    RawMessageSet raw =
+      RawMessageSet.newBuilder()
+        .addItem(
+          RawMessageSet.Item.newBuilder()
+            .setTypeId(TYPE_ID_1)
+            .setMessage(
+              TestMessageSetExtension1.newBuilder()
+                .setI(123)
+                .build().toByteString())
+            .build())
+        .build();
+
+    ByteString data = raw.toByteString();
+
+    // Parse as a TestMessageSet and check the contents.
+    TestMessageSet messageSet =
+        TestMessageSet.parseFrom(data, extensionRegistry);
+    assertEquals(123, messageSet.getExtension(
+        TestMessageSetExtension1.messageSetExtension).getI());
+  }
+
+  public void testMergeLazyMessageSetExtensionEagerly() throws Exception {
+    testMergeLazyMessageSetExtensionWithFlag(true);
+  }
+
+  public void testMergeLazyMessageSetExtensionNotEagerly() throws Exception {
+    testMergeLazyMessageSetExtensionWithFlag(false);
+  }
+
+  private void testMergeLazyMessageSetExtensionWithFlag(boolean eagerParsing)
+      throws Exception {
+    ExtensionRegistryLite.setEagerlyParseMessageSets(eagerParsing);
+    ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
+    extensionRegistry.add(TestMessageSetExtension1.messageSetExtension);
+
+    // Set up a RawMessageSet with a known messages.
+    int TYPE_ID_1 =
+        TestMessageSetExtension1
+            .getDescriptor().getExtensions().get(0).getNumber();
+    RawMessageSet raw =
+      RawMessageSet.newBuilder()
+        .addItem(
+          RawMessageSet.Item.newBuilder()
+            .setTypeId(TYPE_ID_1)
+            .setMessage(
+              TestMessageSetExtension1.newBuilder()
+                .setI(123)
+                .build().toByteString())
+            .build())
+        .build();
+
+    ByteString data = raw.toByteString();
+
+    // Parse as a TestMessageSet and store value into lazy field
+    TestMessageSet messageSet =
+        TestMessageSet.parseFrom(data, extensionRegistry);
+    // Merge lazy field check the contents.
+    messageSet =
+        messageSet.toBuilder().mergeFrom(data, extensionRegistry).build();
+    assertEquals(123, messageSet.getExtension(
+        TestMessageSetExtension1.messageSetExtension).getI());
+  }
+
+  public void testMergeMessageSetExtensionEagerly() throws Exception {
+    testMergeMessageSetExtensionWithFlag(true);
+  }
+
+  public void testMergeMessageSetExtensionNotEagerly() throws Exception {
+    testMergeMessageSetExtensionWithFlag(false);
+  }
+
+  private void testMergeMessageSetExtensionWithFlag(boolean eagerParsing)
+      throws Exception {
+    ExtensionRegistryLite.setEagerlyParseMessageSets(eagerParsing);
+    ExtensionRegistry extensionRegistry = ExtensionRegistry.newInstance();
+    extensionRegistry.add(TestMessageSetExtension1.messageSetExtension);
+
+    // Set up a RawMessageSet with a known messages.
+    int TYPE_ID_1 =
+        TestMessageSetExtension1
+            .getDescriptor().getExtensions().get(0).getNumber();
+    RawMessageSet raw =
+      RawMessageSet.newBuilder()
+        .addItem(
+          RawMessageSet.Item.newBuilder()
+            .setTypeId(TYPE_ID_1)
+            .setMessage(
+              TestMessageSetExtension1.newBuilder()
+                .setI(123)
+                .build().toByteString())
+            .build())
+        .build();
+
+    // Serialize RawMessageSet unnormally (message value before type id)
+    ByteString.CodedBuilder out = ByteString.newCodedBuilder(
+        raw.getSerializedSize());
+    CodedOutputStream output = out.getCodedOutput();
+    List<RawMessageSet.Item> items = raw.getItemList();
+    for (int i = 0; i < items.size(); i++) {
+      RawMessageSet.Item item = items.get(i);
+      output.writeTag(1, WireFormat.WIRETYPE_START_GROUP);
+      output.writeBytes(3, item.getMessage());
+      output.writeInt32(2, item.getTypeId());
+      output.writeTag(1, WireFormat.WIRETYPE_END_GROUP);
+    }
+    ByteString data = out.build();
+
+    // Merge bytes into TestMessageSet and check the contents.
+    TestMessageSet messageSet =
+        TestMessageSet.newBuilder().mergeFrom(data, extensionRegistry).build();
+    assertEquals(123, messageSet.getExtension(
+        TestMessageSetExtension1.messageSetExtension).getI());
+  }
+
+  // ================================================================
+  // oneof
+  public void testOneofWireFormat() throws Exception {
+    TestOneof2.Builder builder = TestOneof2.newBuilder();
+    TestUtil.setOneof(builder);
+    TestOneof2 message = builder.build();
+    ByteString rawBytes = message.toByteString();
+
+    assertEquals(rawBytes.size(), message.getSerializedSize());
+
+    TestOneof2 message2 = TestOneof2.parseFrom(rawBytes);
+    TestUtil.assertOneofSet(message2);
+  }
+
+  public void testOneofOnlyLastSet() throws Exception {
+    TestOneofBackwardsCompatible source = TestOneofBackwardsCompatible
+        .newBuilder().setFooInt(100).setFooString("101").build();
+
+    ByteString rawBytes = source.toByteString();
+    TestOneof2 message = TestOneof2.parseFrom(rawBytes);
+    assertFalse(message.hasFooInt());
+    assertTrue(message.hasFooString());
+  }
+}