Merge remote-tracking branch 'remotes/google/3.3.x' into merge-3.3-to-master

44 files changed, 1044 insertions, 290 deletions

diff --git a/java/core/pom.xml b/java/core/pom.xml
index be0da5ea..9c4e1b93 100644
--- a/java/core/pom.xml
+++ b/java/core/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.2.0</version>
+    <version>3.3.0</version>
   </parent>
 
   <artifactId>protobuf-java</artifactId>
@@ -34,6 +34,11 @@
       <artifactId>easymockclassextension</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>com.google.truth</groupId>
+      <artifactId>truth</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>
diff --git a/java/core/src/main/java/com/google/protobuf/AbstractMessage.java b/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
index 37180da8..b5043eb5 100644
--- a/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
@@ -34,7 +34,6 @@ import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
 import com.google.protobuf.Internal.EnumLite;
-
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Arrays;
@@ -328,7 +327,8 @@ public abstract class AbstractMessage
       extends AbstractMessageLite.Builder
       implements Message.Builder {
     // The compiler produces an error if this is not declared explicitly.
-    // Method isn't abstract to bypass Java 1.6 compiler issue http://bugs.java.com/view_bug.do?bug_id=6908259
+    // Method isn't abstract to bypass Java 1.6 compiler issue:
+    //     http://bugs.java.com/view_bug.do?bug_id=6908259
     @Override
     public BuilderType clone() {
       throw new UnsupportedOperationException("clone() should be implemented in subclasses.");
diff --git a/java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java b/java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java
index 4f691dfd..99787fcc 100644
--- a/java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java
@@ -30,6 +30,8 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.Internal.checkNotNull;
+
 import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -351,22 +353,23 @@ public abstract class AbstractMessageLite<
      */
     protected static <T> void addAll(final Iterable<T> values,
                                      final Collection<? super T> list) {
-      if (values == null) {
-        throw new NullPointerException();
-      }
+      checkNotNull(values);
       if (values instanceof LazyStringList) {
         // For StringOrByteStringLists, check the underlying elements to avoid
         // forcing conversions of ByteStrings to Strings.
+        // TODO(dweis): Could we just prohibit nulls in all protobuf lists and get rid of this? Is
+        // if even possible to hit this condition as all protobuf methods check for null first,
+        // right?
         checkForNullValues(((LazyStringList) values).getUnderlyingElements());
         list.addAll((Collection<T>) values);
       } else if (values instanceof Collection) {
-        checkForNullValues(values);
+        if (!(values instanceof PrimitiveNonBoxingCollection)) {
+          checkForNullValues(values);
+        }
         list.addAll((Collection<T>) values);
       } else {
         for (final T value : values) {
-          if (value == null) {
-            throw new NullPointerException();
-          }
+          checkNotNull(value);
           list.add(value);
         }
       }
@@ -374,9 +377,7 @@ public abstract class AbstractMessageLite<
 
     private static void checkForNullValues(final Iterable<?> values) {
       for (final Object value : values) {
-        if (value == null) {
-          throw new NullPointerException();
-        }
+        checkNotNull(value);
       }
     }
   }
diff --git a/java/core/src/main/java/com/google/protobuf/AbstractParser.java b/java/core/src/main/java/com/google/protobuf/AbstractParser.java
index 7ff73ba4..ba570e3d 100644
--- a/java/core/src/main/java/com/google/protobuf/AbstractParser.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractParser.java
@@ -31,9 +31,9 @@
 package com.google.protobuf;
 
 import com.google.protobuf.AbstractMessageLite.Builder.LimitedInputStream;
-
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.ByteBuffer;
 
 /**
  * A partial implementation of the {@link Parser} interface which implements
@@ -131,6 +131,30 @@ public abstract class AbstractParser<MessageType extends MessageLite>
   }
 
   @Override
+  public MessageType parseFrom(ByteBuffer data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    MessageType message;
+    try {
+      CodedInputStream input = CodedInputStream.newInstance(data);
+      message = parsePartialFrom(input, extensionRegistry);
+      try {
+        input.checkLastTagWas(0);
+      } catch (InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(message);
+      }
+    } catch (InvalidProtocolBufferException e) {
+      throw e;
+    }
+
+    return checkMessageInitialized(message);
+  }
+
+  @Override
+  public MessageType parseFrom(ByteBuffer data) throws InvalidProtocolBufferException {
+    return parseFrom(data, EMPTY_REGISTRY);
+  }
+
+  @Override
   public MessageType parsePartialFrom(
       byte[] data, int off, int len, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
diff --git a/java/core/src/main/java/com/google/protobuf/BooleanArrayList.java b/java/core/src/main/java/com/google/protobuf/BooleanArrayList.java
index 0d9f87ba..fd4c142b 100644
--- a/java/core/src/main/java/com/google/protobuf/BooleanArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/BooleanArrayList.java
@@ -30,8 +30,9 @@
 
 package com.google.protobuf;
 
-import com.google.protobuf.Internal.BooleanList;
+import static com.google.protobuf.Internal.checkNotNull;
 
+import com.google.protobuf.Internal.BooleanList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.RandomAccess;
@@ -41,9 +42,8 @@ import java.util.RandomAccess;
  *
  * @author dweis@google.com (Daniel Weis)
  */
-final class BooleanArrayList
-    extends AbstractProtobufList<Boolean>
-    implements BooleanList, RandomAccess {
+final class BooleanArrayList extends AbstractProtobufList<Boolean>
+    implements BooleanList, RandomAccess, PrimitiveNonBoxingCollection {
 
   private static final BooleanArrayList EMPTY_LIST = new BooleanArrayList();
   static {
@@ -198,9 +198,7 @@ final class BooleanArrayList
   public boolean addAll(Collection<? extends Boolean> collection) {
     ensureIsMutable();
 
-    if (collection == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(collection);
 
     // We specialize when adding another BooleanArrayList to avoid boxing elements.
     if (!(collection instanceof BooleanArrayList)) {
diff --git a/java/core/src/main/java/com/google/protobuf/CodedInputStream.java b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
index 239798e4..3dfbcb0a 100644
--- a/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
@@ -355,8 +355,8 @@ public abstract class CodedInputStream {
    * <p>Set the maximum message size. In order to prevent malicious messages from exhausting memory
    * or causing integer overflows, {@code CodedInputStream} limits how large a message may be. The
    * default limit is {@code Integer.MAX_INT}. You should set this limit as small as you can without
-   * harming your app's functionality. Note that size limits only apply when reading from an
-   * {@code InputStream}, not when constructed around a raw byte array.
+   * harming your app's functionality. Note that size limits only apply when reading from an {@code
+   * InputStream}, not when constructed around a raw byte array.
    *
    * <p>If you want to read several messages from a single CodedInputStream, you could call {@link
    * #resetSizeCounter()} after each one to avoid hitting the size limit.
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 3e32c2c5..da0e9b12 100644
--- a/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
@@ -184,7 +184,7 @@ public abstract class CodedOutputStream extends ByteOutput {
    *     maps are sorted on the lexicographical order of the UTF8 encoded keys.
    * </ul>
    */
-  void useDeterministicSerialization() {
+  public void useDeterministicSerialization() {
     serializationDeterministic = true;
   }
 
@@ -1854,7 +1854,7 @@ public abstract class CodedOutputStream extends ByteOutput {
     }
 
     static boolean isSupported() {
-      return UnsafeUtil.hasUnsafeByteBufferOperations();
+      return UnsafeUtil.hasUnsafeByteBufferOperations() && UnsafeUtil.hasUnsafeCopyMemory();
     }
 
     @Override
diff --git a/java/core/src/main/java/com/google/protobuf/Descriptors.java b/java/core/src/main/java/com/google/protobuf/Descriptors.java
index 38346f15..75b16fe3 100644
--- a/java/core/src/main/java/com/google/protobuf/Descriptors.java
+++ b/java/core/src/main/java/com/google/protobuf/Descriptors.java
@@ -30,9 +30,10 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.Internal.checkNotNull;
+
 import com.google.protobuf.DescriptorProtos.*;
 import com.google.protobuf.Descriptors.FileDescriptor.Syntax;
-
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -682,9 +683,7 @@ public final class Descriptors {
 
     /** Determines if the given field name is reserved. */
     public boolean isReservedName(final String name) {
-      if (name == null) {
-        throw new NullPointerException();
-      }
+      checkNotNull(name);
       for (final String reservedName : proto.getReservedNameList()) {
         if (reservedName.equals(name)) {
           return true;
diff --git a/java/core/src/main/java/com/google/protobuf/DoubleArrayList.java b/java/core/src/main/java/com/google/protobuf/DoubleArrayList.java
index 6177f3ca..867b85ce 100644
--- a/java/core/src/main/java/com/google/protobuf/DoubleArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/DoubleArrayList.java
@@ -30,8 +30,9 @@
 
 package com.google.protobuf;
 
-import com.google.protobuf.Internal.DoubleList;
+import static com.google.protobuf.Internal.checkNotNull;
 
+import com.google.protobuf.Internal.DoubleList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.RandomAccess;
@@ -41,9 +42,8 @@ import java.util.RandomAccess;
  *
  * @author dweis@google.com (Daniel Weis)
  */
-final class DoubleArrayList
-    extends AbstractProtobufList<Double>
-    implements DoubleList, RandomAccess {
+final class DoubleArrayList extends AbstractProtobufList<Double>
+    implements DoubleList, RandomAccess, PrimitiveNonBoxingCollection {
 
   private static final DoubleArrayList EMPTY_LIST = new DoubleArrayList();
   static {
@@ -199,9 +199,7 @@ final class DoubleArrayList
   public boolean addAll(Collection<? extends Double> collection) {
     ensureIsMutable();
 
-    if (collection == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(collection);
 
     // We specialize when adding another DoubleArrayList to avoid boxing elements.
     if (!(collection instanceof DoubleArrayList)) {
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 e6358c3b..2631db74 100644
--- a/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
@@ -30,11 +30,12 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.Internal.checkNotNull;
+
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
-
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Collections;
@@ -631,9 +632,7 @@ public final class DynamicMessage extends AbstractMessage {
     /** Verifies that the value is EnumValueDescriptor and matches Enum Type. */
     private void ensureSingularEnumValueDescriptor(
         FieldDescriptor field, Object value) {
-      if (value == null) {
-        throw new NullPointerException();
-      }
+      checkNotNull(value);
       if (!(value instanceof EnumValueDescriptor)) {
         throw new IllegalArgumentException(
           "DynamicMessage should use EnumValueDescriptor to set Enum Value.");
diff --git a/java/core/src/main/java/com/google/protobuf/FieldSet.java b/java/core/src/main/java/com/google/protobuf/FieldSet.java
index a828f30e..8a9239ed 100644
--- a/java/core/src/main/java/com/google/protobuf/FieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/FieldSet.java
@@ -30,8 +30,9 @@
 
 package com.google.protobuf;
 
-import com.google.protobuf.LazyField.LazyIterator;
+import static com.google.protobuf.Internal.checkNotNull;
 
+import com.google.protobuf.LazyField.LazyIterator;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -385,9 +386,7 @@ final class FieldSet<FieldDescriptorType extends
    */
   private static void verifyType(final WireFormat.FieldType type,
                                  final Object value) {
-    if (value == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(value);
 
     boolean isValid = false;
     switch (type.getJavaType()) {
diff --git a/java/core/src/main/java/com/google/protobuf/FloatArrayList.java b/java/core/src/main/java/com/google/protobuf/FloatArrayList.java
index 90d6154b..76645583 100644
--- a/java/core/src/main/java/com/google/protobuf/FloatArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/FloatArrayList.java
@@ -30,8 +30,9 @@
 
 package com.google.protobuf;
 
-import com.google.protobuf.Internal.FloatList;
+import static com.google.protobuf.Internal.checkNotNull;
 
+import com.google.protobuf.Internal.FloatList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.RandomAccess;
@@ -41,9 +42,8 @@ import java.util.RandomAccess;
  *
  * @author dweis@google.com (Daniel Weis)
  */
-final class FloatArrayList
-    extends AbstractProtobufList<Float>
-    implements FloatList, RandomAccess {
+final class FloatArrayList extends AbstractProtobufList<Float>
+    implements FloatList, RandomAccess, PrimitiveNonBoxingCollection {
 
   private static final FloatArrayList EMPTY_LIST = new FloatArrayList();
   static {
@@ -198,9 +198,7 @@ final class FloatArrayList
   public boolean addAll(Collection<? extends Float> collection) {
     ensureIsMutable();
 
-    if (collection == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(collection);
 
     // We specialize when adding another FloatArrayList to avoid boxing elements.
     if (!(collection instanceof FloatArrayList)) {
diff --git a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
index 2d7fd334..cf3486e1 100644
--- a/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
@@ -34,6 +34,7 @@ import com.google.protobuf.AbstractMessageLite.Builder.LimitedInputStream;
 import com.google.protobuf.GeneratedMessageLite.EqualsVisitor.NotEqualsException;
 import com.google.protobuf.Internal.BooleanList;
 import com.google.protobuf.Internal.DoubleList;
+import com.google.protobuf.Internal.EnumLiteMap;
 import com.google.protobuf.Internal.FloatList;
 import com.google.protobuf.Internal.IntList;
 import com.google.protobuf.Internal.LongList;
@@ -45,6 +46,7 @@ import java.io.ObjectStreamException;
 import java.io.Serializable;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
@@ -136,6 +138,7 @@ public abstract class GeneratedMessageLite<
       return false;
     }
 
+
     try {
       visit(EqualsVisitor.INSTANCE, (MessageType) other);
     } catch (NotEqualsException e) {
@@ -1154,6 +1157,7 @@ public abstract class GeneratedMessageLite<
     }
   }
 
+
   /**
    * Lite equivalent to {@link GeneratedMessage.GeneratedExtension}.
    *
@@ -1529,6 +1533,20 @@ public abstract class GeneratedMessageLite<
 
   // Validates last tag.
   protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, ByteBuffer data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException {
+    return checkMessageInitialized(
+        parseFrom(defaultInstance, CodedInputStream.newInstance(data), extensionRegistry));
+  }
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
+      T defaultInstance, ByteBuffer data) throws InvalidProtocolBufferException {
+    return parseFrom(defaultInstance, data, ExtensionRegistryLite.getEmptyRegistry());
+  }
+
+  // Validates last tag.
+  protected static <T extends GeneratedMessageLite<T, ?>> T parseFrom(
       T defaultInstance, ByteString data)
       throws InvalidProtocolBufferException {
     return checkMessageInitialized(
@@ -1979,13 +1997,13 @@ public abstract class GeneratedMessageLite<
   /**
    * Implements hashCode by accumulating state.
    */
-  private static class HashCodeVisitor implements Visitor {
+  static class HashCodeVisitor implements Visitor {
 
     // The caller must ensure that the visitor is invoked parameterized with this and this such that
     // other is this. This is required due to how oneof cases are handled. See the class comment
     // on Visitor for more information.
 
-    private int hashCode = 0;
+    int hashCode = 0;
 
     @Override
     public boolean visitBoolean(
diff --git a/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java
index fd051e75..b949cd17 100644
--- a/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageV3.java
@@ -41,7 +41,7 @@ import com.google.protobuf.Descriptors.OneofDescriptor;
 // class without breaking binary compatibility with old generated code that still subclasses
 // the old GeneratedMessageV3 class. To allow these different GeneratedMessageV3V? classes to
 // interoperate (e.g., a GeneratedMessageV3V3 object has a message extension field whose class
-// type is GeneratedMessageV3V4), these classes still share a common parent class AbstarctMessage
+// type is GeneratedMessageV3V4), these classes still share a common parent class AbstractMessage
 // and are using the same GeneratedMessage.GeneratedExtension class for extension definitions.
 // Since this class becomes GeneratedMessageV3V? in opensource, we have to add an import here
 // to be able to use GeneratedMessage.GeneratedExtension. The GeneratedExtension definition in
diff --git a/java/core/src/main/java/com/google/protobuf/IntArrayList.java b/java/core/src/main/java/com/google/protobuf/IntArrayList.java
index 2f526e3f..aff5c21b 100644
--- a/java/core/src/main/java/com/google/protobuf/IntArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/IntArrayList.java
@@ -30,8 +30,9 @@
 
 package com.google.protobuf;
 
-import com.google.protobuf.Internal.IntList;
+import static com.google.protobuf.Internal.checkNotNull;
 
+import com.google.protobuf.Internal.IntList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.RandomAccess;
@@ -41,9 +42,8 @@ import java.util.RandomAccess;
  *
  * @author dweis@google.com (Daniel Weis)
  */
-final class IntArrayList
-    extends AbstractProtobufList<Integer>
-    implements IntList, RandomAccess {
+final class IntArrayList extends AbstractProtobufList<Integer>
+    implements IntList, RandomAccess, PrimitiveNonBoxingCollection {
 
   private static final IntArrayList EMPTY_LIST = new IntArrayList();
   static {
@@ -198,9 +198,7 @@ final class IntArrayList
   public boolean addAll(Collection<? extends Integer> collection) {
     ensureIsMutable();
 
-    if (collection == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(collection);
 
     // We specialize when adding another IntArrayList to avoid boxing elements.
     if (!(collection instanceof IntArrayList)) {
diff --git a/java/core/src/main/java/com/google/protobuf/Internal.java b/java/core/src/main/java/com/google/protobuf/Internal.java
index c234559c..36bdece3 100644
--- a/java/core/src/main/java/com/google/protobuf/Internal.java
+++ b/java/core/src/main/java/com/google/protobuf/Internal.java
@@ -62,6 +62,16 @@ public final class Internal {
   /**
    * Throws an appropriate {@link NullPointerException} if the given objects is {@code null}.
    */
+  static <T> T checkNotNull(T obj) {
+    if (obj == null) {
+      throw new NullPointerException();
+    }
+    return obj;
+  }
+
+  /**
+   * Throws an appropriate {@link NullPointerException} if the given objects is {@code null}.
+   */
   static <T> T checkNotNull(T obj, String message) {
     if (obj == null) {
       throw new NullPointerException(message);
@@ -420,6 +430,11 @@ public final class Internal {
       CodedInputStream.newInstance(EMPTY_BYTE_ARRAY);
 
 
+  /** Helper method to merge two MessageLite instances. */
+  static Object mergeMessage(Object destination, Object source) {
+    return ((MessageLite) destination).toBuilder().mergeFrom((MessageLite) source).buildPartial();
+  }
+
   /**
    * Provides an immutable view of {@code List<T>} around a {@code List<F>}.
    *
diff --git a/java/core/src/main/java/com/google/protobuf/LazyFieldLite.java b/java/core/src/main/java/com/google/protobuf/LazyFieldLite.java
index 4b0ba0fd..49ecfc0b 100644
--- a/java/core/src/main/java/com/google/protobuf/LazyFieldLite.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyFieldLite.java
@@ -394,6 +394,7 @@ public class LazyFieldLite {
     }
   }
 
+
   /**
    * Might lazily parse the bytes that were previously passed in. Is thread-safe.
    */
diff --git a/java/core/src/main/java/com/google/protobuf/LongArrayList.java b/java/core/src/main/java/com/google/protobuf/LongArrayList.java
index 5a772e3a..fc146e23 100644
--- a/java/core/src/main/java/com/google/protobuf/LongArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/LongArrayList.java
@@ -30,8 +30,9 @@
 
 package com.google.protobuf;
 
-import com.google.protobuf.Internal.LongList;
+import static com.google.protobuf.Internal.checkNotNull;
 
+import com.google.protobuf.Internal.LongList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.RandomAccess;
@@ -41,9 +42,8 @@ import java.util.RandomAccess;
  *
  * @author dweis@google.com (Daniel Weis)
  */
-final class LongArrayList
-    extends AbstractProtobufList<Long>
-    implements LongList, RandomAccess {
+final class LongArrayList extends AbstractProtobufList<Long>
+    implements LongList, RandomAccess, PrimitiveNonBoxingCollection {
 
   private static final LongArrayList EMPTY_LIST = new LongArrayList();
   static {
@@ -198,9 +198,7 @@ final class LongArrayList
   public boolean addAll(Collection<? extends Long> collection) {
     ensureIsMutable();
 
-    if (collection == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(collection);
 
     // We specialize when adding another LongArrayList to avoid boxing elements.
     if (!(collection instanceof LongArrayList)) {
diff --git a/java/core/src/main/java/com/google/protobuf/MapEntry.java b/java/core/src/main/java/com/google/protobuf/MapEntry.java
index 7e8e9aad..0849b821 100644
--- a/java/core/src/main/java/com/google/protobuf/MapEntry.java
+++ b/java/core/src/main/java/com/google/protobuf/MapEntry.java
@@ -33,7 +33,6 @@ package com.google.protobuf;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
-
 import java.io.IOException;
 import java.util.Collections;
 import java.util.Map;
@@ -171,7 +170,7 @@ public final class MapEntry<K, V> extends AbstractMessage {
 
   @Override
   public Builder<K, V> toBuilder() {
-    return new Builder<K, V>(metadata, key, value);
+    return new Builder<K, V>(metadata, key, value, true, true);
   }
 
   @Override
@@ -247,15 +246,19 @@ public final class MapEntry<K, V> extends AbstractMessage {
     private final Metadata<K, V> metadata;
     private K key;
     private V value;
+    private boolean hasKey;
+    private boolean hasValue;
 
     private Builder(Metadata<K, V> metadata) {
-      this(metadata, metadata.defaultKey, metadata.defaultValue);
+      this(metadata, metadata.defaultKey, metadata.defaultValue, false, false);
     }
 
-    private Builder(Metadata<K, V> metadata, K key, V value) {
+    private Builder(Metadata<K, V> metadata, K key, V value, boolean hasKey, boolean hasValue) {
       this.metadata = metadata;
       this.key = key;
       this.value = value;
+      this.hasKey = hasKey;
+      this.hasValue = hasValue;
     }
 
     public K getKey() {
@@ -268,21 +271,25 @@ public final class MapEntry<K, V> extends AbstractMessage {
 
     public Builder<K, V> setKey(K key) {
       this.key = key;
+      this.hasKey = true;
       return this;
     }
 
     public Builder<K, V> clearKey() {
       this.key = metadata.defaultKey;
+      this.hasKey = false;
       return this;
     }
 
     public Builder<K, V> setValue(V value) {
       this.value = value;
+      this.hasValue = true;
       return this;
     }
 
     public Builder<K, V> clearValue() {
       this.value = metadata.defaultValue;
+      this.hasValue = false;
       return this;
     }
 
@@ -404,7 +411,7 @@ public final class MapEntry<K, V> extends AbstractMessage {
     @Override
     public boolean hasField(FieldDescriptor field) {
       checkFieldDescriptor(field);
-      return true;
+      return field.getNumber() == 1 ? hasKey : hasValue;
     }
 
     @Override
@@ -438,7 +445,7 @@ public final class MapEntry<K, V> extends AbstractMessage {
     @Override
     @SuppressWarnings("unchecked")
     public Builder<K, V> clone() {
-      return new Builder(metadata, key, value);
+      return new Builder(metadata, key, value, hasKey, hasValue);
     }
   }
 
@@ -448,4 +455,9 @@ public final class MapEntry<K, V> extends AbstractMessage {
     }
     return true;
   }
+  
+  /** Returns the metadata only for experimental runtime. */
+  final Metadata<K, V> getMetadata() {
+    return metadata;
+  }
 }
diff --git a/java/core/src/main/java/com/google/protobuf/MapEntryLite.java b/java/core/src/main/java/com/google/protobuf/MapEntryLite.java
index 22aef8f9..dcb5dfad 100644
--- a/java/core/src/main/java/com/google/protobuf/MapEntryLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MapEntryLite.java
@@ -223,4 +223,9 @@ public class MapEntryLite<K, V> {
     input.popLimit(oldLimit);
     map.put(key, value);
   }
+
+  /** For experimental runtime internal use only. */
+  Metadata<K, V> getMetadata() {
+    return metadata;
+  }
 }
diff --git a/java/core/src/main/java/com/google/protobuf/MapField.java b/java/core/src/main/java/com/google/protobuf/MapField.java
index 805defe2..ad8ceb02 100644
--- a/java/core/src/main/java/com/google/protobuf/MapField.java
+++ b/java/core/src/main/java/com/google/protobuf/MapField.java
@@ -30,6 +30,8 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.Internal.checkNotNull;
+
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -329,6 +331,8 @@ public class MapField<K, V> implements MutabilityOracle {
     @Override
     public V put(K key, V value) {
       mutabilityOracle.ensureMutable();
+      checkNotNull(key);
+      checkNotNull(value);
       return delegate.put(key, value);
     }
 
@@ -341,6 +345,10 @@ public class MapField<K, V> implements MutabilityOracle {
     @Override
     public void putAll(Map<? extends K, ? extends V> m) {
       mutabilityOracle.ensureMutable();
+      for (K key : m.keySet()) {
+        checkNotNull(key);
+        checkNotNull(m.get(key));
+      }
       delegate.putAll(m);
     }
 
diff --git a/java/core/src/main/java/com/google/protobuf/MapFieldLite.java b/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
index 42640279..a8b3dd88 100644
--- a/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
@@ -30,8 +30,9 @@
 
 package com.google.protobuf;
 
-import com.google.protobuf.Internal.EnumLite;
+import static com.google.protobuf.Internal.checkNotNull;
 
+import com.google.protobuf.Internal.EnumLite;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -88,6 +89,9 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
 
   @Override public V put(K key, V value) {
     ensureMutable();
+    checkNotNull(key);
+
+    checkNotNull(value);
     return super.put(key, value);
   }
 
@@ -97,6 +101,7 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
 
   @Override public void putAll(Map<? extends K, ? extends V> m) {
     ensureMutable();
+    checkForNullKeysAndValues(m);
     super.putAll(m);
   }
 
@@ -105,6 +110,13 @@ public final class MapFieldLite<K, V> extends LinkedHashMap<K, V> {
     return super.remove(key);
   }
 
+  private static void checkForNullKeysAndValues(Map<?, ?> m) {
+    for (Object key : m.keySet()) {
+      checkNotNull(key);
+      checkNotNull(m.get(key));
+    }
+  }
+
   private static boolean equals(Object a, Object b) {
     if (a instanceof byte[] && b instanceof byte[]) {
       return Arrays.equals((byte[]) a, (byte[]) b);
diff --git a/java/core/src/main/java/com/google/protobuf/Parser.java b/java/core/src/main/java/com/google/protobuf/Parser.java
index cfbcb442..e07c6895 100644
--- a/java/core/src/main/java/com/google/protobuf/Parser.java
+++ b/java/core/src/main/java/com/google/protobuf/Parser.java
@@ -31,6 +31,7 @@
 package com.google.protobuf;
 
 import java.io.InputStream;
+import java.nio.ByteBuffer;
 
 /**
  * Abstract interface for parsing Protocol Messages.
@@ -93,6 +94,18 @@ public interface Parser<MessageType> {
   // Convenience methods.
 
   /**
+   * Parses {@code data} as a message of {@code MessageType}. This is just a small wrapper around
+   * {@link #parseFrom(CodedInputStream)}.
+   */
+  public MessageType parseFrom(ByteBuffer data) throws InvalidProtocolBufferException;
+
+  /**
+   * Parses {@code data} as a message of {@code MessageType}. This is just a small wrapper around
+   * {@link #parseFrom(CodedInputStream, ExtensionRegistryLite)}.
+   */
+  public MessageType parseFrom(ByteBuffer data, ExtensionRegistryLite extensionRegistry)
+      throws InvalidProtocolBufferException;
+  /**
    * Parses {@code data} as a message of {@code MessageType}.
    * This is just a small wrapper around {@link #parseFrom(CodedInputStream)}.
    */
diff --git a/java/core/src/main/java/com/google/protobuf/PrimitiveNonBoxingCollection.java b/java/core/src/main/java/com/google/protobuf/PrimitiveNonBoxingCollection.java
new file mode 100644
index 00000000..79b5769d
--- /dev/null
+++ b/java/core/src/main/java/com/google/protobuf/PrimitiveNonBoxingCollection.java
@@ -0,0 +1,34 @@
+// 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 marker interface indicating that the collection supports primitives and is non-boxing. */
+interface PrimitiveNonBoxingCollection {}
diff --git a/java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilderV3.java b/java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilderV3.java
index 77b61b5f..30c991d4 100644
--- a/java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilderV3.java
+++ b/java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilderV3.java
@@ -30,6 +30,8 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.Internal.checkNotNull;
+
 import java.util.AbstractList;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -290,9 +292,7 @@ public class RepeatedFieldBuilderV3
    */
   public RepeatedFieldBuilderV3<MType, BType, IType> setMessage(
       int index, MType message) {
-    if (message == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(message);
     ensureMutableMessageList();
     messages.set(index, message);
     if (builders != null) {
@@ -315,9 +315,7 @@ public class RepeatedFieldBuilderV3
    */
   public RepeatedFieldBuilderV3<MType, BType, IType> addMessage(
       MType message) {
-    if (message == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(message);
     ensureMutableMessageList();
     messages.add(message);
     if (builders != null) {
@@ -339,9 +337,7 @@ public class RepeatedFieldBuilderV3
    */
   public RepeatedFieldBuilderV3<MType, BType, IType> addMessage(
       int index, MType message) {
-    if (message == null) {
-      throw new NullPointerException();
-    }
+    checkNotNull(message);
     ensureMutableMessageList();
     messages.add(index, message);
     if (builders != null) {
@@ -363,9 +359,7 @@ public class RepeatedFieldBuilderV3
   public RepeatedFieldBuilderV3<MType, BType, IType> addAllMessages(
       Iterable<? extends MType> values) {
     for (final MType value : values) {
-      if (value == null) {
-        throw new NullPointerException();
-      }
+      checkNotNull(value);
     }
 
     // If we can inspect the size, we can more efficiently add messages.
diff --git a/java/core/src/main/java/com/google/protobuf/SingleFieldBuilderV3.java b/java/core/src/main/java/com/google/protobuf/SingleFieldBuilderV3.java
index fb1f76a7..8ab0f26d 100644
--- a/java/core/src/main/java/com/google/protobuf/SingleFieldBuilderV3.java
+++ b/java/core/src/main/java/com/google/protobuf/SingleFieldBuilderV3.java
@@ -30,6 +30,8 @@
 
 package com.google.protobuf;
 
+import static com.google.protobuf.Internal.checkNotNull;
+
 /**
  * {@code SingleFieldBuilderV3} implements a structure that a protocol
  * message uses to hold a single field of another protocol message. It supports
@@ -84,10 +86,7 @@ public class SingleFieldBuilderV3
       MType message,
       AbstractMessage.BuilderParent parent,
       boolean isClean) {
-    if (message == null) {
-      throw new NullPointerException();
-    }
-    this.message = message;
+    this.message = checkNotNull(message);
     this.parent = parent;
     this.isClean = isClean;
   }
@@ -169,10 +168,7 @@ public class SingleFieldBuilderV3
    */
   public SingleFieldBuilderV3<MType, BType, IType> setMessage(
       MType message) {
-    if (message == null) {
-      throw new NullPointerException();
-    }
-    this.message = message;
+    this.message = checkNotNull(message);
     if (builder != null) {
       builder.dispose();
       builder = null;
diff --git a/java/core/src/main/java/com/google/protobuf/TextFormat.java b/java/core/src/main/java/com/google/protobuf/TextFormat.java
index 49708242..53dead80 100644
--- a/java/core/src/main/java/com/google/protobuf/TextFormat.java
+++ b/java/core/src/main/java/com/google/protobuf/TextFormat.java
@@ -1442,7 +1442,7 @@ public final class TextFormat {
 
     /**
      * Parse a single field from {@code tokenizer} and merge it into
-     * {@code builder}.
+     * {@code target}.
      */
     private void mergeField(final Tokenizer tokenizer,
                             final ExtensionRegistry extensionRegistry,
@@ -1712,6 +1712,8 @@ public final class TextFormat {
       }
 
       if (field.isRepeated()) {
+        // TODO(b/29122459): If field.isMapField() and FORBID_SINGULAR_OVERWRITES mode,
+        //     check for duplicate map keys here.
         target.addRepeatedField(field, value);
       } else if ((singularOverwritePolicy
               == SingularOverwritePolicy.FORBID_SINGULAR_OVERWRITES)
diff --git a/java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java b/java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java
index 2bef27e9..d9381135 100644
--- a/java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java
@@ -91,7 +91,7 @@ public final class UnknownFieldSet implements MessageLite {
    * Construct an {@code UnknownFieldSet} around the given map.  The map is
    * expected to be immutable.
    */
-  private UnknownFieldSet(final Map<Integer, Field> fields,
+  UnknownFieldSet(final Map<Integer, Field> fields,
       final Map<Integer, Field> fieldsDescending) {
     this.fields = fields;
   }
@@ -715,7 +715,7 @@ public final class UnknownFieldSet implements MessageLite {
    * @see UnknownFieldSet
    */
   public static final class Field {
-    private Field() {}
+    Field() {}
 
     /** Construct a new {@link Builder}. */
     public static Builder newBuilder() {
diff --git a/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java b/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
index 5f7bafd6..ca80d946 100644
--- a/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
+++ b/java/core/src/main/java/com/google/protobuf/UnsafeUtil.java
@@ -33,19 +33,23 @@ package com.google.protobuf;
 import java.lang.reflect.Field;
 import java.nio.Buffer;
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.security.AccessController;
 import java.security.PrivilegedExceptionAction;
-import sun.misc.Unsafe;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /** Utility class for working with unsafe operations. */
-// TODO(nathanmittler): Add support for Android Memory/MemoryBlock
 final class UnsafeUtil {
+  private static final Logger logger = Logger.getLogger(UnsafeUtil.class.getName());
   private static final sun.misc.Unsafe UNSAFE = getUnsafe();
+  private static final MemoryAccessor MEMORY_ACCESSOR = getMemoryAccessor();
   private static final boolean HAS_UNSAFE_BYTEBUFFER_OPERATIONS =
       supportsUnsafeByteBufferOperations();
   private static final boolean HAS_UNSAFE_ARRAY_OPERATIONS = supportsUnsafeArrayOperations();
+  private static final boolean HAS_UNSAFE_COPY_MEMORY = supportsUnsafeCopyMemory();
   private static final long ARRAY_BASE_OFFSET = byteArrayBaseOffset();
-  private static final long BUFFER_ADDRESS_OFFSET = fieldOffset(field(Buffer.class, "address"));
+  private static final long BUFFER_ADDRESS_OFFSET = fieldOffset(bufferAddressField());
 
   private UnsafeUtil() {}
 
@@ -53,20 +57,16 @@ final class UnsafeUtil {
     return HAS_UNSAFE_ARRAY_OPERATIONS;
   }
 
-  static boolean hasUnsafeByteBufferOperations() {
-    return HAS_UNSAFE_BYTEBUFFER_OPERATIONS;
+  static boolean hasUnsafeCopyMemory() {
+    return HAS_UNSAFE_COPY_MEMORY;
   }
 
-  static Object allocateInstance(Class<?> clazz) {
-    try {
-      return UNSAFE.allocateInstance(clazz);
-    } catch (InstantiationException e) {
-      throw new RuntimeException(e);
-    }
+  static boolean hasUnsafeByteBufferOperations() {
+    return HAS_UNSAFE_BYTEBUFFER_OPERATIONS;
   }
 
   static long objectFieldOffset(Field field) {
-    return UNSAFE.objectFieldOffset(field);
+    return MEMORY_ACCESSOR.objectFieldOffset(field);
   }
 
   static long getArrayBaseOffset() {
@@ -74,103 +74,103 @@ final class UnsafeUtil {
   }
 
   static byte getByte(Object target, long offset) {
-    return UNSAFE.getByte(target, offset);
+    return MEMORY_ACCESSOR.getByte(target, offset);
   }
 
   static void putByte(Object target, long offset, byte value) {
-    UNSAFE.putByte(target, offset, value);
+    MEMORY_ACCESSOR.putByte(target, offset, value);
   }
 
   static int getInt(Object target, long offset) {
-    return UNSAFE.getInt(target, offset);
+    return MEMORY_ACCESSOR.getInt(target, offset);
   }
 
   static void putInt(Object target, long offset, int value) {
-    UNSAFE.putInt(target, offset, value);
+    MEMORY_ACCESSOR.putInt(target, offset, value);
   }
 
   static long getLong(Object target, long offset) {
-    return UNSAFE.getLong(target, offset);
+    return MEMORY_ACCESSOR.getLong(target, offset);
   }
 
   static void putLong(Object target, long offset, long value) {
-    UNSAFE.putLong(target, offset, value);
+    MEMORY_ACCESSOR.putLong(target, offset, value);
   }
 
   static boolean getBoolean(Object target, long offset) {
-    return UNSAFE.getBoolean(target, offset);
+    return MEMORY_ACCESSOR.getBoolean(target, offset);
   }
 
   static void putBoolean(Object target, long offset, boolean value) {
-    UNSAFE.putBoolean(target, offset, value);
+    MEMORY_ACCESSOR.putBoolean(target, offset, value);
   }
 
   static float getFloat(Object target, long offset) {
-    return UNSAFE.getFloat(target, offset);
+    return MEMORY_ACCESSOR.getFloat(target, offset);
   }
 
   static void putFloat(Object target, long offset, float value) {
-    UNSAFE.putFloat(target, offset, value);
+    MEMORY_ACCESSOR.putFloat(target, offset, value);
   }
 
   static double getDouble(Object target, long offset) {
-    return UNSAFE.getDouble(target, offset);
+    return MEMORY_ACCESSOR.getDouble(target, offset);
   }
 
   static void putDouble(Object target, long offset, double value) {
-    UNSAFE.putDouble(target, offset, value);
+    MEMORY_ACCESSOR.putDouble(target, offset, value);
   }
 
   static Object getObject(Object target, long offset) {
-    return UNSAFE.getObject(target, offset);
+    return MEMORY_ACCESSOR.getObject(target, offset);
   }
 
   static void putObject(Object target, long offset, Object value) {
-    UNSAFE.putObject(target, offset, value);
+    MEMORY_ACCESSOR.putObject(target, offset, value);
   }
 
   static void copyMemory(
       Object src, long srcOffset, Object target, long targetOffset, long length) {
-    UNSAFE.copyMemory(src, srcOffset, target, targetOffset, length);
+    MEMORY_ACCESSOR.copyMemory(src, srcOffset, target, targetOffset, length);
   }
 
   static byte getByte(long address) {
-    return UNSAFE.getByte(address);
+    return MEMORY_ACCESSOR.getByte(address);
   }
 
   static void putByte(long address, byte value) {
-    UNSAFE.putByte(address, value);
+    MEMORY_ACCESSOR.putByte(address, value);
   }
 
   static int getInt(long address) {
-    return UNSAFE.getInt(address);
+    return MEMORY_ACCESSOR.getInt(address);
   }
 
   static void putInt(long address, int value) {
-    UNSAFE.putInt(address, value);
+    MEMORY_ACCESSOR.putInt(address, value);
   }
 
   static long getLong(long address) {
-    return UNSAFE.getLong(address);
+    return MEMORY_ACCESSOR.getLong(address);
   }
 
   static void putLong(long address, long value) {
-    UNSAFE.putLong(address, value);
+    MEMORY_ACCESSOR.putLong(address, value);
   }
 
   static void copyMemory(long srcAddress, long targetAddress, long length) {
-    UNSAFE.copyMemory(srcAddress, targetAddress, length);
-  }
-
-  static void setMemory(long address, long numBytes, byte value) {
-    UNSAFE.setMemory(address, numBytes, value);
+    MEMORY_ACCESSOR.copyMemory(srcAddress, targetAddress, length);
   }
 
   /**
    * Gets the offset of the {@code address} field of the given direct {@link ByteBuffer}.
    */
   static long addressOffset(ByteBuffer buffer) {
-    return UNSAFE.getLong(buffer, BUFFER_ADDRESS_OFFSET);
+    return MEMORY_ACCESSOR.getLong(buffer, BUFFER_ADDRESS_OFFSET);
+  }
+
+  static Object getStaticObject(Field field) {
+    return MEMORY_ACCESSOR.getStaticObject(field);
   }
 
   /**
@@ -181,7 +181,7 @@ final class UnsafeUtil {
     try {
       unsafe =
           AccessController.doPrivileged(
-              new PrivilegedExceptionAction<Unsafe>() {
+              new PrivilegedExceptionAction<sun.misc.Unsafe>() {
                 @Override
                 public sun.misc.Unsafe run() throws Exception {
                   Class<sun.misc.Unsafe> k = sun.misc.Unsafe.class;
@@ -204,69 +204,114 @@ final class UnsafeUtil {
     return unsafe;
   }
 
+  /** Get a {@link MemoryAccessor} appropriate for the platform, or null if not supported. */
+  private static MemoryAccessor getMemoryAccessor() {
+    if (UNSAFE == null) {
+      return null;
+    }
+    return new JvmMemoryAccessor(UNSAFE);
+  }
+
   /** Indicates whether or not unsafe array operations are supported on this platform. */
   private static boolean supportsUnsafeArrayOperations() {
-    boolean supported = false;
-    if (UNSAFE != null) {
-      try {
-        Class<?> clazz = UNSAFE.getClass();
-        clazz.getMethod("objectFieldOffset", Field.class);
-        clazz.getMethod("allocateInstance", Class.class);
-        clazz.getMethod("arrayBaseOffset", Class.class);
-        clazz.getMethod("getByte", Object.class, long.class);
-        clazz.getMethod("putByte", Object.class, long.class, byte.class);
-        clazz.getMethod("getBoolean", Object.class, long.class);
-        clazz.getMethod("putBoolean", Object.class, long.class, boolean.class);
-        clazz.getMethod("getInt", Object.class, long.class);
-        clazz.getMethod("putInt", Object.class, long.class, int.class);
-        clazz.getMethod("getLong", Object.class, long.class);
-        clazz.getMethod("putLong", Object.class, long.class, long.class);
-        clazz.getMethod("getFloat", Object.class, long.class);
-        clazz.getMethod("putFloat", Object.class, long.class, float.class);
-        clazz.getMethod("getDouble", Object.class, long.class);
-        clazz.getMethod("putDouble", Object.class, long.class, double.class);
-        clazz.getMethod("getObject", Object.class, long.class);
-        clazz.getMethod("putObject", Object.class, long.class, Object.class);
-        clazz.getMethod(
-            "copyMemory", Object.class, long.class, Object.class, long.class, long.class);
-        supported = true;
-      } catch (Throwable e) {
-        // Do nothing.
-      }
-    }
-    return supported;
+    if (UNSAFE == null) {
+      return false;
+    }
+    try {
+      Class<?> clazz = UNSAFE.getClass();
+      clazz.getMethod("objectFieldOffset", Field.class);
+      clazz.getMethod("arrayBaseOffset", Class.class);
+      clazz.getMethod("getInt", Object.class, long.class);
+      clazz.getMethod("putInt", Object.class, long.class, int.class);
+      clazz.getMethod("getLong", Object.class, long.class);
+      clazz.getMethod("putLong", Object.class, long.class, long.class);
+      clazz.getMethod("getObject", Object.class, long.class);
+      clazz.getMethod("putObject", Object.class, long.class, Object.class);
+      clazz.getMethod("getByte", Object.class, long.class);
+      clazz.getMethod("putByte", Object.class, long.class, byte.class);
+      clazz.getMethod("getBoolean", Object.class, long.class);
+      clazz.getMethod("putBoolean", Object.class, long.class, boolean.class);
+      clazz.getMethod("getFloat", Object.class, long.class);
+      clazz.getMethod("putFloat", Object.class, long.class, float.class);
+      clazz.getMethod("getDouble", Object.class, long.class);
+      clazz.getMethod("putDouble", Object.class, long.class, double.class);
+
+      return true;
+    } catch (Throwable e) {
+      logger.log(
+          Level.WARNING,
+          "platform method missing - proto runtime falling back to safer methods: " + e);
+    }
+    return false;
+  }
+
+  /**
+   * Indicates whether or not unsafe copyMemory(object, long, object, long, long) operations are
+   * supported on this platform.
+   */
+  private static boolean supportsUnsafeCopyMemory() {
+    if (UNSAFE == null) {
+      return false;
+    }
+    try {
+      Class<?> clazz = UNSAFE.getClass();
+      clazz.getMethod("copyMemory", Object.class, long.class, Object.class, long.class, long.class);
+
+      return true;
+    } catch (Throwable e) {
+      logger.log(
+          Level.WARNING,
+          "copyMemory is missing from platform - proto runtime falling back to safer methods.");
+    }
+    return false;
   }
 
   private static boolean supportsUnsafeByteBufferOperations() {
-    boolean supported = false;
-    if (UNSAFE != null) {
-      try {
-        Class<?> clazz = UNSAFE.getClass();
-        // Methods for getting direct buffer address.
-        clazz.getMethod("objectFieldOffset", Field.class);
-        clazz.getMethod("getLong", Object.class, long.class);
-
-        clazz.getMethod("getByte", long.class);
-        clazz.getMethod("putByte", long.class, byte.class);
-        clazz.getMethod("getInt", long.class);
-        clazz.getMethod("putInt", long.class, int.class);
-        clazz.getMethod("getLong", long.class);
-        clazz.getMethod("putLong", long.class, long.class);
-        clazz.getMethod("setMemory", long.class, long.class, byte.class);
-        clazz.getMethod("copyMemory", long.class, long.class, long.class);
-        supported = true;
-      } catch (Throwable e) {
-        // Do nothing.
-      }
-    }
-    return supported;
+    if (UNSAFE == null) {
+      return false;
+    }
+    try {
+      Class<?> clazz = UNSAFE.getClass();
+      // Methods for getting direct buffer address.
+      clazz.getMethod("objectFieldOffset", Field.class);
+      clazz.getMethod("getLong", Object.class, long.class);
+
+      clazz.getMethod("getByte", long.class);
+      clazz.getMethod("putByte", long.class, byte.class);
+      clazz.getMethod("getInt", long.class);
+      clazz.getMethod("putInt", long.class, int.class);
+      clazz.getMethod("getLong", long.class);
+      clazz.getMethod("putLong", long.class, long.class);
+      clazz.getMethod("copyMemory", long.class, long.class, long.class);
+      return true;
+    } catch (Throwable e) {
+      logger.log(
+          Level.WARNING,
+          "platform method missing - proto runtime falling back to safer methods: " + e);
+    }
+    return false;
+  }
+
+
+  @SuppressWarnings("unchecked")
+  private static <T> Class<T> getClassForName(String name) {
+    try {
+      return (Class<T>) Class.forName(name);
+    } catch (Throwable e) {
+      return null;
+    }
+  }
+
+  /** Finds the address field within a direct {@link Buffer}. */
+  private static Field bufferAddressField() {
+    return field(Buffer.class, "address");
   }
 
   /**
    * Get the base offset for byte arrays, or {@code -1} if {@code sun.misc.Unsafe} is not available.
    */
   private static int byteArrayBaseOffset() {
-    return HAS_UNSAFE_ARRAY_OPERATIONS ? UNSAFE.arrayBaseOffset(byte[].class) : -1;
+    return HAS_UNSAFE_ARRAY_OPERATIONS ? MEMORY_ACCESSOR.arrayBaseOffset(byte[].class) : -1;
   }
 
   /**
@@ -274,7 +319,7 @@ final class UnsafeUtil {
    * available.
    */
   private static long fieldOffset(Field field) {
-    return field == null || UNSAFE == null ? -1 : UNSAFE.objectFieldOffset(field);
+    return field == null || MEMORY_ACCESSOR == null ? -1 : MEMORY_ACCESSOR.objectFieldOffset(field);
   }
 
   /**
@@ -292,4 +337,174 @@ final class UnsafeUtil {
     }
     return field;
   }
+
+  private abstract static class MemoryAccessor {
+
+    sun.misc.Unsafe unsafe;
+
+    MemoryAccessor(sun.misc.Unsafe unsafe) {
+      this.unsafe = unsafe;
+    }
+
+    public final long objectFieldOffset(Field field) {
+      return unsafe.objectFieldOffset(field);
+    }
+
+    public abstract byte getByte(Object target, long offset);
+
+    public abstract void putByte(Object target, long offset, byte value);
+
+    public final int getInt(Object target, long offset) {
+      return unsafe.getInt(target, offset);
+    }
+
+    public final void putInt(Object target, long offset, int value) {
+      unsafe.putInt(target, offset, value);
+    }
+
+    public final long getLong(Object target, long offset) {
+      return unsafe.getLong(target, offset);
+    }
+
+    public final void putLong(Object target, long offset, long value) {
+      unsafe.putLong(target, offset, value);
+    }
+
+    public abstract boolean getBoolean(Object target, long offset);
+
+    public abstract void putBoolean(Object target, long offset, boolean value);
+
+    public abstract float getFloat(Object target, long offset);
+
+    public abstract void putFloat(Object target, long offset, float value);
+
+    public abstract double getDouble(Object target, long offset);
+
+    public abstract void putDouble(Object target, long offset, double value);
+
+    public final Object getObject(Object target, long offset) {
+      return unsafe.getObject(target, offset);
+    }
+
+    public final void putObject(Object target, long offset, Object value) {
+      unsafe.putObject(target, offset, value);
+    }
+
+    public final int arrayBaseOffset(Class<?> clazz) {
+      return unsafe.arrayBaseOffset(clazz);
+    }
+
+    public abstract byte getByte(long address);
+
+    public abstract void putByte(long address, byte value);
+
+    public abstract int getInt(long address);
+
+    public abstract void putInt(long address, int value);
+
+    public abstract long getLong(long address);
+
+    public abstract void putLong(long address, long value);
+
+    public abstract void copyMemory(long srcAddress, long targetAddress, long length);
+
+    public abstract void copyMemory(
+        Object src, long srcOffset, Object target, long targetOffset, long length);
+
+    public abstract Object getStaticObject(Field field);
+  }
+
+  private static final class JvmMemoryAccessor extends MemoryAccessor {
+
+    JvmMemoryAccessor(sun.misc.Unsafe unsafe) {
+      super(unsafe);
+    }
+
+    @Override
+    public byte getByte(long address) {
+      return unsafe.getByte(address);
+    }
+
+    @Override
+    public void putByte(long address, byte value) {
+      unsafe.putByte(address, value);
+    }
+
+    @Override
+    public int getInt(long address) {
+      return unsafe.getInt(address);
+    }
+
+    @Override
+    public void putInt(long address, int value) {
+      unsafe.putInt(address, value);
+    }
+
+    @Override
+    public long getLong(long address) {
+      return unsafe.getLong(address);
+    }
+
+    @Override
+    public void putLong(long address, long value) {
+      unsafe.putLong(address, value);
+    }
+
+    @Override
+    public byte getByte(Object target, long offset) {
+      return unsafe.getByte(target, offset);
+    }
+
+    @Override
+    public void putByte(Object target, long offset, byte value) {
+      unsafe.putByte(target, offset, value);
+    }
+
+    @Override
+    public boolean getBoolean(Object target, long offset) {
+      return unsafe.getBoolean(target, offset);
+    }
+
+    @Override
+    public void putBoolean(Object target, long offset, boolean value) {
+      unsafe.putBoolean(target, offset, value);
+    }
+
+    @Override
+    public float getFloat(Object target, long offset) {
+      return unsafe.getFloat(target, offset);
+    }
+
+    @Override
+    public void putFloat(Object target, long offset, float value) {
+      unsafe.putFloat(target, offset, value);
+    }
+
+    @Override
+    public double getDouble(Object target, long offset) {
+      return unsafe.getDouble(target, offset);
+    }
+
+    @Override
+    public void putDouble(Object target, long offset, double value) {
+      unsafe.putDouble(target, offset, value);
+    }
+
+    @Override
+    public void copyMemory(
+        Object src, long srcOffset, Object target, long targetOffset, long length) {
+      unsafe.copyMemory(src, srcOffset, target, targetOffset, length);
+    }
+
+    @Override
+    public void copyMemory(long srcAddress, long targetAddress, long length) {
+      unsafe.copyMemory(srcAddress, targetAddress, length);
+    }
+
+    @Override
+    public Object getStaticObject(Field field) {
+      return getObject(unsafe.staticFieldBase(field), unsafe.staticFieldOffset(field));
+    }
+  }
+
 }
diff --git a/java/core/src/main/java/com/google/protobuf/Utf8.java b/java/core/src/main/java/com/google/protobuf/Utf8.java
index 5b80d405..be7b746e 100644
--- a/java/core/src/main/java/com/google/protobuf/Utf8.java
+++ b/java/core/src/main/java/com/google/protobuf/Utf8.java
@@ -1332,7 +1332,7 @@ final class Utf8 {
       // the index (relative to the start of the array) is also 8-byte aligned. We do this by
       // ANDing the index with 7 to determine the number of bytes that need to be read before
       // we're 8-byte aligned.
-      final int unaligned = (int) offset & 7;
+      final int unaligned = 8 - ((int) offset & 7);
       for (int j = unaligned; j > 0; j--) {
         if (UnsafeUtil.getByte(bytes, offset++) < 0) {
           return unaligned - j;
diff --git a/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java b/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
index 5f013f3c..f27e8e51 100644
--- a/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
@@ -32,7 +32,6 @@ package com.google.protobuf;
 
 import protobuf_unittest.UnittestProto.TestAllExtensions;
 import protobuf_unittest.UnittestProto.TestAllTypes;
-import java.io.IOException;
 import junit.framework.TestCase;
 
 /**
@@ -89,6 +88,7 @@ public class LazyFieldTest extends TestCase {
     assertFalse(message.equals(lazyField.getValue()));
   }
 
+  @SuppressWarnings("EqualsIncompatibleType") // LazyField.equals() is not symmetric
   public void testEqualsObjectEx() throws Exception {
     TestAllExtensions message = TestUtil.getAllExtensionsSet();
     LazyField lazyField = createLazyFieldFromMessage(message);
diff --git a/java/core/src/test/java/com/google/protobuf/LiteTest.java b/java/core/src/test/java/com/google/protobuf/LiteTest.java
index 538432f7..98c637a9 100644
--- a/java/core/src/test/java/com/google/protobuf/LiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LiteTest.java
@@ -52,6 +52,7 @@ import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.BarPrime;
 import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.Foo;
 import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.TestOneofEquals;
 import protobuf_unittest.lite_equals_and_hash.LiteEqualsAndHash.TestRecursiveOneof;
+import java.nio.ByteBuffer;
 import junit.framework.TestCase;
 
 /**
@@ -2174,6 +2175,24 @@ public class LiteTest extends TestCase {
     assertFalse(bar.equals(barPrime));
   }
 
+  public void testEqualsAndHashCodeForTrickySchemaTypes() {
+    Foo foo1 = Foo.newBuilder()
+        .build();
+    Foo foo2 = Foo.newBuilder()
+        .setSint64(1)
+        .build();
+    Foo foo3 = Foo.newBuilder()
+        .putMyMap("key", "value2")
+        .build();
+    Foo foo4 = Foo.newBuilder()
+        .setMyGroup(Foo.MyGroup.newBuilder().setValue(4).build())
+        .build();
+
+    assertEqualsAndHashCodeAreFalse(foo1, foo2);
+    assertEqualsAndHashCodeAreFalse(foo1, foo3);
+    assertEqualsAndHashCodeAreFalse(foo1, foo4);
+  }
+
   public void testOneofEquals() throws Exception {
     TestOneofEquals.Builder builder = TestOneofEquals.newBuilder();
     TestOneofEquals message1 = builder.build();
@@ -2270,4 +2289,93 @@ public class LiteTest extends TestCase {
     // This tests that we don't infinite loop.
     TestRecursiveOneof.getDefaultInstance().hashCode();
   }
+
+  public void testParseFromByteBuffer() throws Exception {
+    TestAllTypesLite message =
+        TestAllTypesLite.newBuilder()
+            .setOptionalInt32(123)
+            .addRepeatedString("hello")
+            .setOptionalNestedMessage(TestAllTypesLite.NestedMessage.newBuilder().setBb(7))
+            .build();
+
+    TestAllTypesLite copy =
+        TestAllTypesLite.parseFrom(message.toByteString().asReadOnlyByteBuffer());
+
+    assertEquals(message, copy);
+  }
+
+  public void testParseFromByteBufferThrows() {
+    try {
+      TestAllTypesLite.parseFrom(ByteBuffer.wrap(new byte[] { 0x5 }));
+      fail();
+    } catch (InvalidProtocolBufferException expected) {
+    }
+
+    TestAllTypesLite message =
+        TestAllTypesLite.newBuilder()
+            .setOptionalInt32(123)
+            .addRepeatedString("hello")
+            .build();
+
+    ByteBuffer buffer = ByteBuffer.wrap(message.toByteArray(), 0, message.getSerializedSize() - 1);
+    try {
+      TestAllTypesLite.parseFrom(buffer);
+      fail();
+    } catch (InvalidProtocolBufferException expected) {
+      assertEquals(
+          TestAllTypesLite.newBuilder()
+              .setOptionalInt32(123)
+              .build(),
+          expected.getUnfinishedMessage());
+    }
+  }
+
+  public void testParseFromByteBuffer_extensions() throws Exception {
+    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();
+
+    ExtensionRegistryLite registry = ExtensionRegistryLite.newInstance();
+    UnittestLite.registerAllExtensions(registry);
+
+    TestAllExtensionsLite copy =
+        TestAllExtensionsLite.parseFrom(message.toByteString().asReadOnlyByteBuffer(), registry);
+
+    assertEquals(message, copy);
+  }
+
+  public void testParseFromByteBufferThrows_extensions() {
+    ExtensionRegistryLite registry = ExtensionRegistryLite.newInstance();
+    UnittestLite.registerAllExtensions(registry);
+    try {
+      TestAllExtensionsLite.parseFrom(ByteBuffer.wrap(new byte[] { 0x5 }), registry);
+      fail();
+    } catch (InvalidProtocolBufferException expected) {
+    }
+
+    TestAllExtensionsLite message =
+        TestAllExtensionsLite.newBuilder()
+            .setExtension(UnittestLite.optionalInt32ExtensionLite, 123)
+            .addExtension(UnittestLite.repeatedStringExtensionLite, "hello")
+            .build();
+
+    ByteBuffer buffer = ByteBuffer.wrap(message.toByteArray(), 0, message.getSerializedSize() - 1);
+    try {
+      TestAllExtensionsLite.parseFrom(buffer, registry);
+      fail();
+    } catch (InvalidProtocolBufferException expected) {
+      assertEquals(
+          TestAllExtensionsLite.newBuilder()
+              .setExtension(UnittestLite.optionalInt32ExtensionLite, 123)
+              .build(),
+          expected.getUnfinishedMessage());
+    }
+  }
 }
diff --git a/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
index cfe4c453..453d3928 100644
--- a/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
+++ b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
@@ -759,6 +759,7 @@ public class MapForProto2Test extends TestCase {
     assertEquals(55, message.getInt32ToInt32Field().get(55).intValue());
   }
 
+  // See additional coverage in TextFormatTest.java.
   public void testTextFormat() throws Exception {
     TestMap.Builder builder = TestMap.newBuilder();
     setMapValuesUsingAccessors(builder);
diff --git a/java/core/src/test/java/com/google/protobuf/MapTest.java b/java/core/src/test/java/com/google/protobuf/MapTest.java
index e0d3f0cd..45019537 100644
--- a/java/core/src/test/java/com/google/protobuf/MapTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MapTest.java
@@ -30,7 +30,7 @@
 
 package com.google.protobuf;
 
-
+import static org.junit.Assert.assertArrayEquals;
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.EnumDescriptor;
 import com.google.protobuf.Descriptors.EnumValueDescriptor;
@@ -864,6 +864,7 @@ public class MapTest extends TestCase {
     assertEquals(55, message.getInt32ToInt32Field().get(55).intValue());
   }
 
+  // See additional coverage in TextFormatTest.java.
   public void testTextFormat() throws Exception {
     TestMap.Builder builder = TestMap.newBuilder();
     setMapValuesUsingAccessors(builder);
@@ -1483,4 +1484,41 @@ public class MapTest extends TestCase {
     map.put(key3, value3);
     return map;
   }
+
+  public void testMap_withNulls() {
+    TestMap.Builder builder = TestMap.newBuilder();
+
+    try {
+      builder.putStringToInt32Field(null, 3);
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    try {
+      builder.putAllStringToInt32Field(newMap(null, 3, "hi", 4));
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    try {
+      builder.putInt32ToMessageField(3, null);
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    try {
+      builder.putAllInt32ToMessageField(
+          MapTest.<Integer, MessageValue>newMap(4, null, 5, null));
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    try {
+      builder.putAllInt32ToMessageField(null);
+      fail();
+    } catch (NullPointerException expected) {
+    }
+
+    assertArrayEquals(new byte[0], builder.build().toByteArray());
+  }
 }
diff --git a/java/core/src/test/java/com/google/protobuf/ParserTest.java b/java/core/src/test/java/com/google/protobuf/ParserTest.java
index 8c2e4c26..4bd34112 100644
--- a/java/core/src/test/java/com/google/protobuf/ParserTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ParserTest.java
@@ -79,6 +79,8 @@ public class ParserTest extends TestCase {
         new ByteArrayInputStream(data), registry));
     assertMessageEquals(message, parser.parseFrom(
         CodedInputStream.newInstance(data), registry));
+    assertMessageEquals(
+        message, parser.parseFrom(message.toByteString().asReadOnlyByteBuffer(), registry));
   }
 
   @SuppressWarnings("unchecked")
@@ -99,6 +101,7 @@ public class ParserTest extends TestCase {
         new ByteArrayInputStream(data)));
     assertMessageEquals(message, parser.parseFrom(
         CodedInputStream.newInstance(data)));
+    assertMessageEquals(message, parser.parseFrom(message.toByteString().asReadOnlyByteBuffer()));
   }
 
   private void assertMessageEquals(
@@ -178,6 +181,9 @@ public class ParserTest extends TestCase {
   public void testParseExtensions() throws Exception {
     assertRoundTripEquals(TestUtil.getAllExtensionsSet(),
                           TestUtil.getExtensionRegistry());
+  }
+
+  public void testParseExtensionsLite() throws Exception {
     assertRoundTripEquals(
         TestUtilLite.getAllLiteExtensionsSet(), TestUtilLite.getExtensionRegistryLite());
   }
@@ -186,6 +192,9 @@ public class ParserTest extends TestCase {
     assertRoundTripEquals(TestUtil.getPackedSet());
     assertRoundTripEquals(TestUtil.getPackedExtensionsSet(),
                           TestUtil.getExtensionRegistry());
+  }
+
+  public void testParsePackedLite() throws Exception {
     assertRoundTripEquals(
         TestUtilLite.getLitePackedExtensionsSet(), TestUtilLite.getExtensionRegistryLite());
   }
@@ -195,15 +204,26 @@ public class ParserTest extends TestCase {
     TestAllTypes normalMessage = TestUtil.getAllSet();
     ByteArrayOutputStream output = new ByteArrayOutputStream();
     normalMessage.writeDelimitedTo(output);
+    normalMessage.writeDelimitedTo(output);
 
+    InputStream input = new ByteArrayInputStream(output.toByteArray());
+    assertMessageEquals(normalMessage, normalMessage.getParserForType().parseDelimitedFrom(input));
+    assertMessageEquals(normalMessage, normalMessage.getParserForType().parseDelimitedFrom(input));
+  }
+
+  public void testParseDelimitedToLite() throws Exception {
     // Write MessageLite with packed extension fields.
     TestPackedExtensionsLite packedMessage = TestUtilLite.getLitePackedExtensionsSet();
+    ByteArrayOutputStream output = new ByteArrayOutputStream();
+    packedMessage.writeDelimitedTo(output);
     packedMessage.writeDelimitedTo(output);
 
     InputStream input = new ByteArrayInputStream(output.toByteArray());
     assertMessageEquals(
-        normalMessage,
-        normalMessage.getParserForType().parseDelimitedFrom(input));
+        packedMessage,
+        packedMessage
+            .getParserForType()
+            .parseDelimitedFrom(input, TestUtilLite.getExtensionRegistryLite()));
     assertMessageEquals(
         packedMessage,
         packedMessage
@@ -314,8 +334,7 @@ public class ParserTest extends TestCase {
 
   public void testParsingMergeLite() throws Exception {
     // Build messages.
-    TestAllTypesLite.Builder builder =
-        TestAllTypesLite.newBuilder();
+    TestAllTypesLite.Builder builder = TestAllTypesLite.newBuilder();
     TestAllTypesLite msg1 = builder.setOptionalInt32(1).build();
     builder.clear();
     TestAllTypesLite msg2 = builder.setOptionalInt64(2).build();
diff --git a/java/core/src/test/java/com/google/protobuf/TestUtil.java b/java/core/src/test/java/com/google/protobuf/TestUtil.java
index c1bd21db..e96adf07 100644
--- a/java/core/src/test/java/com/google/protobuf/TestUtil.java
+++ b/java/core/src/test/java/com/google/protobuf/TestUtil.java
@@ -2622,6 +2622,8 @@ public final class TestUtil {
         break;
       case FOO_NOT_SET:
         break;
+      default:
+        // TODO(b/18683919): go/enum-switch-lsc
     }
   }
 
diff --git a/java/core/src/test/java/com/google/protobuf/TextFormatTest.java b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
index 6a91b02f..249d7c5e 100644
--- a/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
+++ b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
@@ -30,9 +30,12 @@
 
 package com.google.protobuf;
 
+import static com.google.common.truth.Truth.assertThat;
+
 import com.google.protobuf.Descriptors.Descriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.TextFormat.Parser.SingularOverwritePolicy;
+import map_test.MapTestProto.TestMap;
 import protobuf_unittest.UnittestMset.TestMessageSetExtension1;
 import protobuf_unittest.UnittestMset.TestMessageSetExtension2;
 import protobuf_unittest.UnittestProto.OneString;
@@ -940,6 +943,7 @@ public class TextFormatTest extends TestCase {
   }
 
 
+  // See additional coverage in testOneofOverwriteForbidden and testMapOverwriteForbidden.
   public void testParseNonRepeatedFields() throws Exception {
     assertParseSuccessWithOverwriteForbidden(
         "repeated_int32: 1\n" +
@@ -950,6 +954,7 @@ public class TextFormatTest extends TestCase {
     assertParseSuccessWithOverwriteForbidden(
         "repeated_nested_message { bb: 1 }\n" +
         "repeated_nested_message { bb: 2 }\n");
+
     assertParseErrorWithOverwriteForbidden(
         "3:17: Non-repeated field " +
         "\"protobuf_unittest.TestAllTypes.optional_int32\" " +
@@ -988,6 +993,7 @@ public class TextFormatTest extends TestCase {
     assertParseSuccessWithOverwriteForbidden("repeated_int32: [ 1, 2 ]\n");
     assertParseSuccessWithOverwriteForbidden("RepeatedGroup [{ a: 1 },{ a: 2 }]\n");
     assertParseSuccessWithOverwriteForbidden("repeated_nested_message [{ bb: 1 }, { bb: 2 }]\n");
+    // See also testMapShortForm.
   }
 
   public void testParseShortRepeatedFormOfEmptyRepeatedFields() throws Exception {
@@ -995,6 +1001,7 @@ public class TextFormatTest extends TestCase {
     assertParseSuccessWithOverwriteForbidden("repeated_int32: []\n");
     assertParseSuccessWithOverwriteForbidden("RepeatedGroup []\n");
     assertParseSuccessWithOverwriteForbidden("repeated_nested_message []\n");
+    // See also testMapShortFormEmpty.
   }
 
   public void testParseShortRepeatedFormWithTrailingComma() throws Exception {
@@ -1010,6 +1017,7 @@ public class TextFormatTest extends TestCase {
     assertParseErrorWithOverwriteForbidden(
         "1:37: Expected \"{\".",
         "repeated_nested_message [{ bb: 1 }, ]\n");
+    // See also testMapShortFormTrailingComma.
   }
 
   public void testParseShortRepeatedFormOfNonRepeatedFields() throws Exception {
@@ -1058,6 +1066,90 @@ public class TextFormatTest extends TestCase {
   }
 
   // =======================================================================
+  // test map
+
+  public void testMapTextFormat() throws Exception {
+    TestMap message =
+        TestMap.newBuilder()
+            .putInt32ToStringField(10, "apple")
+            .putInt32ToStringField(20, "banana")
+            .putInt32ToStringField(30, "cherry")
+            .build();
+    String text = TextFormat.printToUnicodeString(message);
+    {
+      TestMap.Builder dest = TestMap.newBuilder();
+      TextFormat.merge(text, dest);
+      assertThat(dest.build()).isEqualTo(message);
+    }
+    {
+      TestMap.Builder dest = TestMap.newBuilder();
+      parserWithOverwriteForbidden.merge(text, dest);
+      assertThat(dest.build()).isEqualTo(message);
+    }
+  }
+
+  public void testMapShortForm() throws Exception {
+    String text =
+        "string_to_int32_field [{ key: 'x' value: 10 }, { key: 'y' value: 20 }]\n"
+        + "int32_to_message_field "
+        + "[{ key: 1 value { value: 100 } }, { key: 2 value: { value: 200 } }]\n";
+    TestMap.Builder dest = TestMap.newBuilder();
+    parserWithOverwriteForbidden.merge(text, dest);
+    TestMap message = dest.build();
+    assertThat(message.getStringToInt32Field().size()).isEqualTo(2);
+    assertThat(message.getInt32ToMessageField().size()).isEqualTo(2);
+    assertThat(message.getStringToInt32Field().get("x")).isEqualTo(10);
+    assertThat(message.getInt32ToMessageField().get(2).getValue()).isEqualTo(200);
+  }
+
+  public void testMapShortFormEmpty() throws Exception {
+    String text = "string_to_int32_field []\n"
+        + "int32_to_message_field: []\n";
+    TestMap.Builder dest = TestMap.newBuilder();
+    parserWithOverwriteForbidden.merge(text, dest);
+    TestMap message = dest.build();
+    assertThat(message.getStringToInt32Field().size()).isEqualTo(0);
+    assertThat(message.getInt32ToMessageField().size()).isEqualTo(0);
+  }
+
+  public void testMapShortFormTrailingComma() throws Exception {
+    String text = "string_to_int32_field [{ key: 'x' value: 10 }, ]\n";
+    TestMap.Builder dest = TestMap.newBuilder();
+    try {
+      parserWithOverwriteForbidden.merge(text, dest);
+      fail("Expected parse exception.");
+    } catch (TextFormat.ParseException e) {
+      assertThat(e).hasMessageThat().isEqualTo("1:48: Expected \"{\".");
+    }
+  }
+
+  public void testMapOverwrite() throws Exception {
+    String text =
+        "int32_to_int32_field { key: 1 value: 10 }\n"
+            + "int32_to_int32_field { key: 2 value: 20 }\n"
+            + "int32_to_int32_field { key: 1 value: 30 }\n";
+
+    {
+      // With default parser, last value set for the key holds.
+      TestMap.Builder builder = TestMap.newBuilder();
+      defaultParser.merge(text, builder);
+      TestMap map = builder.build();
+      assertThat(map.getInt32ToInt32Field().size()).isEqualTo(2);
+      assertThat(map.getInt32ToInt32Field().get(1).intValue()).isEqualTo(30);
+    }
+
+    {
+      // With overwrite forbidden, same behavior.
+      // TODO(b/29122459): Expect parse exception here.
+      TestMap.Builder builder = TestMap.newBuilder();
+      defaultParser.merge(text, builder);
+      TestMap map = builder.build();
+      assertThat(map.getInt32ToInt32Field().size()).isEqualTo(2);
+      assertThat(map.getInt32ToInt32Field().get(1).intValue()).isEqualTo(30);
+    }
+  }
+
+  // =======================================================================
   // test location information
 
   public void testParseInfoTreeBuilding() throws Exception {
diff --git a/java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto b/java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto
index 6eef42c5..b18b0d79 100644
--- a/java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto
+++ b/java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto
@@ -46,6 +46,14 @@ message TestOneofEquals {
 message Foo {
   optional int32 value = 1;
   repeated Bar bar = 2;
+  map<string, string> my_map = 3;
+  oneof Single {
+    sint64 sint64 = 4;
+    // LINT: ALLOW_GROUPS
+    group MyGroup = 5 {
+      optional int32 value = 1;
+    }
+  }
 
   extensions 100 to max;
 }
diff --git a/java/lite/pom.xml b/java/lite/pom.xml
index d7b15097..c902f819 100644
--- a/java/lite/pom.xml
+++ b/java/lite/pom.xml
@@ -137,6 +137,7 @@
             <include>**/MutabilityOracle.java</include>
             <include>**/NioByteString.java</include>
             <include>**/Parser.java</include>
+            <include>**/PrimitiveNonBoxingCollection.java</include>
             <include>**/ProtobufArrayList.java</include>
             <include>**/ProtocolStringList.java</include>
             <include>**/RopeByteString.java</include>
diff --git a/java/pom.xml b/java/pom.xml
index f89e4422..81ffc48a 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -11,7 +11,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-parent</artifactId>
-  <version>3.2.0</version>
+  <version>3.3.0</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [Parent]</name>
@@ -84,7 +84,13 @@
       <dependency>
         <groupId>com.google.guava</groupId>
         <artifactId>guava</artifactId>
-        <version>18.0</version>
+        <version>20.0</version>
+      </dependency>
+      <dependency>
+        <groupId>com.google.truth</groupId>
+        <artifactId>truth</artifactId>
+        <scope>test</scope>
+        <version>0.32</version>
       </dependency>
     </dependencies>
   </dependencyManagement>
diff --git a/java/util/pom.xml b/java/util/pom.xml
index ac771f6e..c72fa650 100644
--- a/java/util/pom.xml
+++ b/java/util/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.2.0</version>
+    <version>3.3.0</version>
   </parent>
 
   <artifactId>protobuf-java-util</artifactId>
diff --git a/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java b/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
index 7d6718b8..e1c2d73d 100644
--- a/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
+++ b/java/util/src/main/java/com/google/protobuf/util/JsonFormat.java
@@ -30,6 +30,7 @@
 
 package com.google.protobuf.util;
 
+import com.google.common.base.Preconditions;
 import com.google.common.io.BaseEncoding;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
@@ -102,7 +103,9 @@ public class JsonFormat {
    * Creates a {@link Printer} with default configurations.
    */
   public static Printer printer() {
-    return new Printer(TypeRegistry.getEmptyTypeRegistry(), false, false, false);
+    return new Printer(
+        TypeRegistry.getEmptyTypeRegistry(), false, Collections.<FieldDescriptor>emptySet(),
+        false, false);
   }
 
   /**
@@ -110,16 +113,27 @@ public class JsonFormat {
    */
   public static class Printer {
     private final TypeRegistry registry;
-    private final boolean includingDefaultValueFields;
+    // NOTE: There are 3 states for these *defaultValueFields variables:
+    // 1) Default - alwaysOutput is false & including is empty set. Fields only output if they are
+    //    set to non-default values.
+    // 2) No-args includingDefaultValueFields() called - alwaysOutput is true & including is
+    //    irrelevant (but set to empty set). All fields are output regardless of their values.
+    // 3) includingDefaultValueFields(Set<FieldDescriptor>) called - alwaysOutput is false &
+    //    including is set to the specified set. Fields in that set are always output & fields not
+    //    in that set are only output if set to non-default values.
+    private boolean alwaysOutputDefaultValueFields;
+    private Set<FieldDescriptor> includingDefaultValueFields;
     private final boolean preservingProtoFieldNames;
     private final boolean omittingInsignificantWhitespace;
 
     private Printer(
         TypeRegistry registry,
-        boolean includingDefaultValueFields,
+        boolean alwaysOutputDefaultValueFields,
+        Set<FieldDescriptor> includingDefaultValueFields,
         boolean preservingProtoFieldNames,
         boolean omittingInsignificantWhitespace) {
       this.registry = registry;
+      this.alwaysOutputDefaultValueFields = alwaysOutputDefaultValueFields;
       this.includingDefaultValueFields = includingDefaultValueFields;
       this.preservingProtoFieldNames = preservingProtoFieldNames;
       this.omittingInsignificantWhitespace = omittingInsignificantWhitespace;
@@ -137,6 +151,7 @@ public class JsonFormat {
       }
       return new Printer(
           registry,
+          alwaysOutputDefaultValueFields,
           includingDefaultValueFields,
           preservingProtoFieldNames,
           omittingInsignificantWhitespace);
@@ -149,8 +164,41 @@ public class JsonFormat {
      * {@link Printer}.
      */
     public Printer includingDefaultValueFields() {
+      checkUnsetIncludingDefaultValueFields();
       return new Printer(
-          registry, true, preservingProtoFieldNames, omittingInsignificantWhitespace);
+          registry,
+          true,
+          Collections.<FieldDescriptor>emptySet(),
+          preservingProtoFieldNames,
+          omittingInsignificantWhitespace);
+    }
+
+    /**
+     * Creates a new {@link Printer} that will also print default-valued fields if their
+     * FieldDescriptors are found in the supplied set. Empty repeated fields and map fields will be
+     * printed as well, if they match. The new Printer clones all other configurations from the
+     * current {@link Printer}. Call includingDefaultValueFields() with no args to unconditionally
+     * output all fields.
+     */
+    public Printer includingDefaultValueFields(Set<FieldDescriptor> fieldsToAlwaysOutput) {
+      Preconditions.checkArgument(
+          null != fieldsToAlwaysOutput && !fieldsToAlwaysOutput.isEmpty(),
+          "Non-empty Set must be supplied for includingDefaultValueFields.");
+
+      checkUnsetIncludingDefaultValueFields();
+      return new Printer(
+          registry,
+          false,
+          fieldsToAlwaysOutput,
+          preservingProtoFieldNames,
+          omittingInsignificantWhitespace);
+    }
+
+    private void checkUnsetIncludingDefaultValueFields() {
+      if (alwaysOutputDefaultValueFields || !includingDefaultValueFields.isEmpty()) {
+        throw new IllegalStateException(
+            "JsonFormat includingDefaultValueFields has already been set.");
+      }
     }
 
     /**
@@ -161,15 +209,20 @@ public class JsonFormat {
      */
     public Printer preservingProtoFieldNames() {
       return new Printer(
-          registry, includingDefaultValueFields, true, omittingInsignificantWhitespace);
+          registry,
+          alwaysOutputDefaultValueFields,
+          includingDefaultValueFields,
+          true,
+          omittingInsignificantWhitespace);
     }
 
 
     /**
-     * Create a new  {@link Printer}  that will omit all insignificant whitespace
-     * in the JSON output. This new Printer clones all other configurations from the
-     * current Printer. Insignificant whitespace is defined by the JSON spec as whitespace
-     * that appear between JSON structural elements:
+     * Create a new {@link Printer} that will omit all insignificant whitespace in the JSON output.
+     * This new Printer clones all other configurations from the current Printer. Insignificant
+     * whitespace is defined by the JSON spec as whitespace that appear between JSON structural
+     * elements:
+     *
      * <pre>
      * ws = *(
      * %x20 /              ; Space
@@ -177,18 +230,24 @@ public class JsonFormat {
      * %x0A /              ; Line feed or New line
      * %x0D )              ; Carriage return
      * </pre>
+     *
      * See <a href="https://tools.ietf.org/html/rfc7159">https://tools.ietf.org/html/rfc7159</a>
      * current {@link Printer}.
      */
     public Printer omittingInsignificantWhitespace() {
-      return new Printer(registry, includingDefaultValueFields, preservingProtoFieldNames, true);
+      return new Printer(
+          registry,
+          alwaysOutputDefaultValueFields,
+          includingDefaultValueFields,
+          preservingProtoFieldNames,
+          true);
     }
 
     /**
      * Converts a protobuf message to JSON format.
      *
-     * @throws InvalidProtocolBufferException if the message contains Any types
-     *         that can't be resolved.
+     * @throws InvalidProtocolBufferException if the message contains Any types that can't be
+     *     resolved.
      * @throws IOException if writing to the output fails.
      */
     public void appendTo(MessageOrBuilder message, Appendable output) throws IOException {
@@ -196,6 +255,7 @@ public class JsonFormat {
       // mobile.
       new PrinterImpl(
               registry,
+              alwaysOutputDefaultValueFields,
               includingDefaultValueFields,
               preservingProtoFieldNames,
               output,
@@ -428,19 +488,16 @@ public class JsonFormat {
       this.output = output;
     }
 
-    /**
-     * ignored by compact printer
-     */
+    /** ignored by compact printer */
+    @Override
     public void indent() {}
 
-    /**
-     * ignored by compact printer
-     */
+    /** ignored by compact printer */
+    @Override
     public void outdent() {}
 
-    /**
-     * Print text to the output stream.
-     */
+    /** Print text to the output stream. */
+    @Override
     public void print(final CharSequence text) throws IOException {
       output.append(text);
     }
@@ -458,18 +515,17 @@ public class JsonFormat {
     }
 
     /**
-     * Indent text by two spaces.  After calling Indent(), two spaces will be
-     * inserted at the beginning of each line of text.  Indent() may be called
-     * multiple times to produce deeper indents.
+     * Indent text by two spaces. After calling Indent(), two spaces will be inserted at the
+     * beginning of each line of text. Indent() may be called multiple times to produce deeper
+     * indents.
      */
+    @Override
     public void indent() {
       indent.append("  ");
     }
 
-    /**
-     * Reduces the current indent level by two spaces, or crashes if the indent
-     * level is zero.
-     */
+    /** Reduces the current indent level by two spaces, or crashes if the indent level is zero. */
+    @Override
     public void outdent() {
       final int length = indent.length();
       if (length < 2) {
@@ -478,9 +534,8 @@ public class JsonFormat {
       indent.delete(length - 2, length);
     }
 
-    /**
-     * Print text to the output stream.
-     */
+    /** Print text to the output stream. */
+    @Override
     public void print(final CharSequence text) throws IOException {
       final int size = text.length();
       int pos = 0;
@@ -512,7 +567,8 @@ public class JsonFormat {
    */
   private static final class PrinterImpl {
     private final TypeRegistry registry;
-    private final boolean includingDefaultValueFields;
+    private final boolean alwaysOutputDefaultValueFields;
+    private final Set<FieldDescriptor> includingDefaultValueFields;
     private final boolean preservingProtoFieldNames;
     private final TextGenerator generator;
     // We use Gson to help handle string escapes.
@@ -526,11 +582,13 @@ public class JsonFormat {
 
     PrinterImpl(
         TypeRegistry registry,
-        boolean includingDefaultValueFields,
+        boolean alwaysOutputDefaultValueFields,
+        Set<FieldDescriptor> includingDefaultValueFields,
         boolean preservingProtoFieldNames,
         Appendable jsonOutput,
         boolean omittingInsignificantWhitespace) {
       this.registry = registry;
+      this.alwaysOutputDefaultValueFields = alwaysOutputDefaultValueFields;
       this.includingDefaultValueFields = includingDefaultValueFields;
       this.preservingProtoFieldNames = preservingProtoFieldNames;
       this.gson = GsonHolder.DEFAULT_GSON;
@@ -781,23 +839,26 @@ public class JsonFormat {
         printedField = true;
       }
       Map<FieldDescriptor, Object> fieldsToPrint = null;
-      if (includingDefaultValueFields) {
-        fieldsToPrint = new TreeMap<FieldDescriptor, Object>();
+      if (alwaysOutputDefaultValueFields || !includingDefaultValueFields.isEmpty()) {
+        fieldsToPrint = new TreeMap<FieldDescriptor, Object>(message.getAllFields());
         for (FieldDescriptor field : message.getDescriptorForType().getFields()) {
           if (field.isOptional()) {
             if (field.getJavaType() == FieldDescriptor.JavaType.MESSAGE
-                && !message.hasField(field)){
+                && !message.hasField(field)) {
               // Always skip empty optional message fields. If not we will recurse indefinitely if
               // a message has itself as a sub-field.
               continue;
             }
             OneofDescriptor oneof = field.getContainingOneof();
             if (oneof != null && !message.hasField(field)) {
-                // Skip all oneof fields except the one that is actually set
+              // Skip all oneof fields except the one that is actually set
               continue;
             }
           }
-          fieldsToPrint.put(field, message.getField(field));
+          if (!fieldsToPrint.containsKey(field)
+              && (alwaysOutputDefaultValueFields || includingDefaultValueFields.contains(field))) {
+            fieldsToPrint.put(field, message.getField(field));
+          }
         }
       } else {
         fieldsToPrint = message.getAllFields();
@@ -1451,45 +1512,6 @@ public class JsonFormat {
       }
     }
 
-    /**
-     * Gets the default value for a field type. Note that we use proto3
-     * language defaults and ignore any default values set through the
-     * proto "default" option.
-     */
-    private Object getDefaultValue(FieldDescriptor field, Message.Builder builder) {
-      switch (field.getType()) {
-        case INT32:
-        case SINT32:
-        case SFIXED32:
-        case UINT32:
-        case FIXED32:
-          return 0;
-        case INT64:
-        case SINT64:
-        case SFIXED64:
-        case UINT64:
-        case FIXED64:
-          return 0L;
-        case FLOAT:
-          return 0.0f;
-        case DOUBLE:
-          return 0.0;
-        case BOOL:
-          return false;
-        case STRING:
-          return "";
-        case BYTES:
-          return ByteString.EMPTY;
-        case ENUM:
-          return field.getEnumType().getValues().get(0);
-        case MESSAGE:
-        case GROUP:
-          return builder.newBuilderForField(field).getDefaultInstanceForType();
-        default:
-          throw new IllegalStateException("Invalid field type: " + field.getType());
-      }
-    }
-
     private void mergeRepeatedField(
         FieldDescriptor field, JsonElement json, Message.Builder builder)
         throws InvalidProtocolBufferException {
diff --git a/java/util/src/main/java/com/google/protobuf/util/Timestamps.java b/java/util/src/main/java/com/google/protobuf/util/Timestamps.java
index 1d631a2c..d0bac417 100644
--- a/java/util/src/main/java/com/google/protobuf/util/Timestamps.java
+++ b/java/util/src/main/java/com/google/protobuf/util/Timestamps.java
@@ -297,7 +297,7 @@ public final class Timestamps {
    * Convert a Timestamp to the number of microseconds elapsed from the epoch.
    *
    * <p>The result will be rounded down to the nearest microsecond. E.g., if the timestamp
-   * represents "1969-12-31T23:59:59.999999999Z", it will be rounded to -1 millisecond.
+   * represents "1969-12-31T23:59:59.999999999Z", it will be rounded to -1 microsecond.
    */
   public static long toMicros(Timestamp timestamp) {
     checkValid(timestamp);
diff --git a/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java b/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
index 33bc1403..460b81f6 100644
--- a/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
+++ b/java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java
@@ -34,6 +34,7 @@ import com.google.protobuf.Any;
 import com.google.protobuf.BoolValue;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.BytesValue;
+import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.DoubleValue;
 import com.google.protobuf.FloatValue;
 import com.google.protobuf.Int32Value;
@@ -68,9 +69,12 @@ import java.io.Reader;
 import java.io.StringReader;
 import java.math.BigDecimal;
 import java.math.BigInteger;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 import junit.framework.TestCase;
 
 public class JsonFormatTest extends TestCase {
@@ -282,8 +286,8 @@ public class JsonFormatTest extends TestCase {
     assertEquals(9012, message.getOptionalSint32());
     assertEquals(3456, message.getOptionalFixed32());
     assertEquals(7890, message.getOptionalSfixed32());
-    assertEquals(1.5f, message.getOptionalFloat());
-    assertEquals(1.25, message.getOptionalDouble());
+    assertEquals(1.5f, message.getOptionalFloat(), 0.0f);
+    assertEquals(1.25, message.getOptionalDouble(), 0.0);
     assertEquals(true, message.getOptionalBool());
   }
 
@@ -1223,6 +1227,115 @@ public class JsonFormatTest extends TestCase {
             + "}",
         JsonFormat.printer().includingDefaultValueFields().print(message));
 
+    Set<FieldDescriptor> fixedFields = new HashSet<FieldDescriptor>();
+    for (FieldDescriptor fieldDesc : TestAllTypes.getDescriptor().getFields()) {
+      if (fieldDesc.getName().contains("_fixed")) {
+        fixedFields.add(fieldDesc);
+      }
+    }
+
+    assertEquals(
+        "{\n"
+            + "  \"optionalFixed32\": 0,\n"
+            + "  \"optionalFixed64\": \"0\",\n"
+            + "  \"repeatedFixed32\": [],\n"
+            + "  \"repeatedFixed64\": []\n"
+            + "}",
+        JsonFormat.printer().includingDefaultValueFields(fixedFields).print(message));
+
+    TestAllTypes messageNonDefaults =
+        message.toBuilder().setOptionalInt64(1234).setOptionalFixed32(3232).build();
+    assertEquals(
+        "{\n"
+            + "  \"optionalInt64\": \"1234\",\n"
+            + "  \"optionalFixed32\": 3232,\n"
+            + "  \"optionalFixed64\": \"0\",\n"
+            + "  \"repeatedFixed32\": [],\n"
+            + "  \"repeatedFixed64\": []\n"
+            + "}",
+        JsonFormat.printer().includingDefaultValueFields(fixedFields).print(messageNonDefaults));
+
+    try {
+      JsonFormat.printer().includingDefaultValueFields().includingDefaultValueFields();
+      fail("IllegalStateException is expected.");
+    } catch (IllegalStateException e) {
+      // Expected.
+      assertTrue(
+          "Exception message should mention includingDefaultValueFields.",
+          e.getMessage().contains("includingDefaultValueFields"));
+    }
+
+    try {
+      JsonFormat.printer().includingDefaultValueFields().includingDefaultValueFields(fixedFields);
+      fail("IllegalStateException is expected.");
+    } catch (IllegalStateException e) {
+      // Expected.
+      assertTrue(
+          "Exception message should mention includingDefaultValueFields.",
+          e.getMessage().contains("includingDefaultValueFields"));
+    }
+
+    try {
+      JsonFormat.printer().includingDefaultValueFields(fixedFields).includingDefaultValueFields();
+      fail("IllegalStateException is expected.");
+    } catch (IllegalStateException e) {
+      // Expected.
+      assertTrue(
+          "Exception message should mention includingDefaultValueFields.",
+          e.getMessage().contains("includingDefaultValueFields"));
+    }
+
+    try {
+      JsonFormat.printer()
+          .includingDefaultValueFields(fixedFields)
+          .includingDefaultValueFields(fixedFields);
+      fail("IllegalStateException is expected.");
+    } catch (IllegalStateException e) {
+      // Expected.
+      assertTrue(
+          "Exception message should mention includingDefaultValueFields.",
+          e.getMessage().contains("includingDefaultValueFields"));
+    }
+
+    Set<FieldDescriptor> intFields = new HashSet<FieldDescriptor>();
+    for (FieldDescriptor fieldDesc : TestAllTypes.getDescriptor().getFields()) {
+      if (fieldDesc.getName().contains("_int")) {
+        intFields.add(fieldDesc);
+      }
+    }
+
+    try {
+      JsonFormat.printer()
+          .includingDefaultValueFields(intFields)
+          .includingDefaultValueFields(fixedFields);
+      fail("IllegalStateException is expected.");
+    } catch (IllegalStateException e) {
+      // Expected.
+      assertTrue(
+          "Exception message should mention includingDefaultValueFields.",
+          e.getMessage().contains("includingDefaultValueFields"));
+    }
+
+    try {
+      JsonFormat.printer().includingDefaultValueFields(null);
+      fail("IllegalArgumentException is expected.");
+    } catch (IllegalArgumentException e) {
+      // Expected.
+      assertTrue(
+          "Exception message should mention includingDefaultValueFields.",
+          e.getMessage().contains("includingDefaultValueFields"));
+    }
+
+    try {
+      JsonFormat.printer().includingDefaultValueFields(Collections.<FieldDescriptor>emptySet());
+      fail("IllegalArgumentException is expected.");
+    } catch (IllegalArgumentException e) {
+      // Expected.
+      assertTrue(
+          "Exception message should mention includingDefaultValueFields.",
+          e.getMessage().contains("includingDefaultValueFields"));
+    }
+
     TestMap mapMessage = TestMap.getDefaultInstance();
     assertEquals("{\n}", JsonFormat.printer().print(mapMessage));
     assertEquals(
@@ -1291,16 +1404,17 @@ public class JsonFormatTest extends TestCase {
     assertEquals("{\n}", JsonFormat.printer().includingDefaultValueFields().print(oneofMessage));
 
     oneofMessage = TestOneof.newBuilder().setOneofInt32(42).build();
-    assertEquals("{\n  \"oneofInt32\": 42\n}",
-        JsonFormat.printer().print(oneofMessage));
-    assertEquals("{\n  \"oneofInt32\": 42\n}",
+    assertEquals("{\n  \"oneofInt32\": 42\n}", JsonFormat.printer().print(oneofMessage));
+    assertEquals(
+        "{\n  \"oneofInt32\": 42\n}",
         JsonFormat.printer().includingDefaultValueFields().print(oneofMessage));
 
     TestOneof.Builder oneofBuilder = TestOneof.newBuilder();
     mergeFromJson("{\n" + "  \"oneofNullValue\": null \n" + "}", oneofBuilder);
     oneofMessage = oneofBuilder.build();
     assertEquals("{\n  \"oneofNullValue\": null\n}", JsonFormat.printer().print(oneofMessage));
-    assertEquals("{\n  \"oneofNullValue\": null\n}",
+    assertEquals(
+        "{\n  \"oneofNullValue\": null\n}",
         JsonFormat.printer().includingDefaultValueFields().print(oneofMessage));
   }
 
@@ -1432,11 +1546,12 @@ public class JsonFormatTest extends TestCase {
 
   // Test that we are not leaking out JSON exceptions.
   public void testJsonException() throws Exception {
-    InputStream throwingInputStream = new InputStream() {
-      public int read() throws IOException {
-        throw new IOException("12345");
-      }
-    };
+    InputStream throwingInputStream =
+        new InputStream() {
+          public int read() throws IOException {
+            throw new IOException("12345");
+          }
+        };
     InputStreamReader throwingReader = new InputStreamReader(throwingInputStream);
     // When the underlying reader throws IOException, JsonFormat should forward
     // through this IOException.