Integrate from internal code base.

4 files changed, 98 insertions, 1 deletions

diff --git a/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
index 576a350f..4f5a9b77 100644
--- a/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
@@ -145,6 +145,44 @@ public abstract class CodedOutputStream extends ByteOutput {
   }
 
   /**
+   * Configures serialization to be deterministic.
+   *
+   * <p>The deterministic serialization guarantees that for a given binary, equal (defined by the
+   * {@code equals()} methods in protos) messages will always be serialized to the same bytes. This
+   * implies:
+   *
+   * <ul>
+   * <li>repeated serialization of a message will return the same bytes
+   * <li>different processes of the same binary (which may be executing on different machines) will
+   *     serialize equal messages to the same bytes.
+   * </ul>
+   *
+   * <p>Note the deterministic serialization is NOT canonical across languages; it is also unstable
+   * across different builds with schema changes due to unknown fields. Users who need canonical
+   * serialization, e.g. persistent storage in a canonical form, fingerprinting, etc, should define
+   * their own canonicalization specification and implement the serializer using reflection APIs
+   * rather than relying on this API.
+   *
+   * <p> Once set, the serializer will:  (Note this is an implementation detail and may subject to
+   * change in the future)
+   *
+   * <ul>
+   * <li> sort map entries by keys in lexicographical order or numerical order. Note: For string
+   *     keys, the order is based on comparing the Unicode value of each character in the strings.
+   *     The order may be different from the deterministic serialization in other languages where
+   *     maps are sorted on the lexicographical order of the UTF8 encoded keys.
+   * </ul>
+   */
+  public final void useDeterministicSerialization() {
+    serializationDeterministic = true;
+  }
+
+  boolean isSerializationDeterministic() {
+    return serializationDeterministic;
+  }
+  private boolean serializationDeterministic;
+
+  /**
    * Create a new {@code CodedOutputStream} that writes to the given {@link ByteBuffer}.
    *
    * @deprecated the size parameter is no longer used since use of an internal buffer is useless
diff --git a/java/core/src/main/java/com/google/protobuf/DynamicMessage.java b/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
index 859a9e8f..c54da67f 100644
--- a/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
@@ -526,6 +526,14 @@ public final class DynamicMessage extends AbstractMessage {
           fields.clearField(oldField);
         }
         oneofCases[index] = field;
+      } else if (field.getFile().getSyntax() == Descriptors.FileDescriptor.Syntax.PROTO3) {
+        if (!field.isRepeated()
+            && field.getJavaType() != FieldDescriptor.JavaType.MESSAGE
+            && value.equals(field.getDefaultValue())) {
+          // In proto3, setting a field to its default value is equivalent to clearing the field.
+          fields.clearField(field);
+          return this;
+        }
       }
       fields.setField(field, value);
       return this;
diff --git a/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
index 82f4216b..4a42c897 100644
--- a/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
+++ b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
@@ -31,6 +31,8 @@
 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.FieldPresenceTestProto.TestOptionalFieldsOnly;
@@ -253,6 +255,54 @@ public class FieldPresenceTest extends TestCase {
     assertEquals(4, message.getAllFields().size());
   }
 
+  public void testFieldPresenceDynamicMessage() {
+    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");
+    EnumDescriptor enumDescriptor = optionalNestedEnumField.getEnumType();
+    EnumValueDescriptor defaultEnumValueDescriptor = enumDescriptor.getValues().get(0);
+    EnumValueDescriptor nonDefaultEnumValueDescriptor = enumDescriptor.getValues().get(1);
+
+    DynamicMessage defaultInstance = DynamicMessage.getDefaultInstance(descriptor);
+    // Field not present.
+    DynamicMessage message = defaultInstance.newBuilderForType().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 =
+        defaultInstance
+            .newBuilderForType()
+            .setField(optionalInt32Field, 1)
+            .setField(optionalStringField, "x")
+            .setField(optionalBytesField, ByteString.copyFromUtf8("y"))
+            .setField(optionalNestedEnumField, nonDefaultEnumValueDescriptor)
+            .build();
+    assertTrue(message.hasField(optionalInt32Field));
+    assertTrue(message.hasField(optionalStringField));
+    assertTrue(message.hasField(optionalBytesField));
+    assertTrue(message.hasField(optionalNestedEnumField));
+    assertEquals(4, message.getAllFields().size());
+
+    // Field set to default value is seen as not present.
+    message = message.toBuilder()
+            .setField(optionalInt32Field, 0)
+            .setField(optionalStringField, "")
+            .setField(optionalBytesField, ByteString.EMPTY)
+            .setField(optionalNestedEnumField, defaultEnumValueDescriptor)
+            .build();
+    assertFalse(message.hasField(optionalInt32Field));
+    assertFalse(message.hasField(optionalStringField));
+    assertFalse(message.hasField(optionalBytesField));
+    assertFalse(message.hasField(optionalNestedEnumField));
+    assertEquals(0, message.getAllFields().size());
+  }
+
   public void testMessageField() {
     TestAllTypes.Builder builder = TestAllTypes.newBuilder();
     assertFalse(builder.hasOptionalNestedMessage());
diff --git a/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java b/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
index 0f42ac50..497c4df2 100644
--- a/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
@@ -35,6 +35,7 @@ import static java.util.Arrays.asList;
 import junit.framework.TestCase;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.ConcurrentModificationException;
 import java.util.Iterator;
 import java.util.List;
@@ -233,7 +234,7 @@ public class LazyStringArrayListTest extends TestCase {
     }
     
     try {
-      list.addAllByteArray(asList(BYTE_STRING_A.toByteArray()));
+      list.addAllByteArray(Collections.singletonList(BYTE_STRING_A.toByteArray()));
       fail();
     } catch (UnsupportedOperationException e) {
       // expected