173 files changed, 1518 insertions, 1018 deletions

diff --git a/Makefile.am b/Makefile.am
index 3d39a898..2f810954 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -181,160 +181,162 @@ csharp_EXTRA_DIST=                                                           \
   csharp/src/Google.Protobuf/packages.config                                 \
   csharp/src/packages/repositories.config
 
-java_EXTRA_DIST=                                                             \
-  java/src/main/java/com/google/protobuf/AbstractMessage.java                \
-  java/src/main/java/com/google/protobuf/AbstractMessageLite.java            \
-  java/src/main/java/com/google/protobuf/AbstractParser.java                 \
-  java/src/main/java/com/google/protobuf/AbstractProtobufList.java           \
-  java/src/main/java/com/google/protobuf/BlockingRpcChannel.java             \
-  java/src/main/java/com/google/protobuf/BlockingService.java                \
-  java/src/main/java/com/google/protobuf/BooleanArrayList.java               \
-  java/src/main/java/com/google/protobuf/BoundedByteString.java              \
-  java/src/main/java/com/google/protobuf/ByteString.java                     \
-  java/src/main/java/com/google/protobuf/CodedInputStream.java               \
-  java/src/main/java/com/google/protobuf/CodedOutputStream.java              \
-  java/src/main/java/com/google/protobuf/Descriptors.java                    \
-  java/src/main/java/com/google/protobuf/DoubleArrayList.java                \
-  java/src/main/java/com/google/protobuf/DynamicMessage.java                 \
-  java/src/main/java/com/google/protobuf/Extension.java                      \
-  java/src/main/java/com/google/protobuf/ExtensionLite.java                  \
-  java/src/main/java/com/google/protobuf/ExtensionRegistry.java              \
-  java/src/main/java/com/google/protobuf/ExtensionRegistryLite.java          \
-  java/src/main/java/com/google/protobuf/FieldSet.java                       \
-  java/src/main/java/com/google/protobuf/FloatArrayList.java                 \
-  java/src/main/java/com/google/protobuf/GeneratedMessage.java               \
-  java/src/main/java/com/google/protobuf/GeneratedMessageLite.java           \
-  java/src/main/java/com/google/protobuf/IntArrayList.java                   \
-  java/src/main/java/com/google/protobuf/Internal.java                       \
-  java/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java \
-  java/src/main/java/com/google/protobuf/LazyField.java                      \
-  java/src/main/java/com/google/protobuf/LazyFieldLite.java                  \
-  java/src/main/java/com/google/protobuf/LazyStringArrayList.java            \
-  java/src/main/java/com/google/protobuf/LazyStringList.java                 \
-  java/src/main/java/com/google/protobuf/LiteralByteString.java              \
-  java/src/main/java/com/google/protobuf/LongArrayList.java                  \
-  java/src/main/java/com/google/protobuf/MapEntry.java                       \
-  java/src/main/java/com/google/protobuf/MapEntryLite.java                   \
-  java/src/main/java/com/google/protobuf/MapField.java                       \
-  java/src/main/java/com/google/protobuf/MapFieldLite.java                   \
-  java/src/main/java/com/google/protobuf/Message.java                        \
-  java/src/main/java/com/google/protobuf/MessageLite.java                    \
-  java/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java           \
-  java/src/main/java/com/google/protobuf/MessageLiteToString.java            \
-  java/src/main/java/com/google/protobuf/MessageLiteToString.java            \
-  java/src/main/java/com/google/protobuf/MessageOrBuilder.java               \
-  java/src/main/java/com/google/protobuf/MessageReflection.java              \
-  java/src/main/java/com/google/protobuf/MutabilityOracle.java               \
-  java/src/main/java/com/google/protobuf/NioByteString.java                  \
-  java/src/main/java/com/google/protobuf/Parser.java                         \
-  java/src/main/java/com/google/protobuf/ProtobufArrayList.java              \
-  java/src/main/java/com/google/protobuf/ProtocolMessageEnum.java            \
-  java/src/main/java/com/google/protobuf/ProtocolStringList.java             \
-  java/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java           \
-  java/src/main/java/com/google/protobuf/RopeByteString.java                 \
-  java/src/main/java/com/google/protobuf/RpcCallback.java                    \
-  java/src/main/java/com/google/protobuf/RpcChannel.java                     \
-  java/src/main/java/com/google/protobuf/RpcController.java                  \
-  java/src/main/java/com/google/protobuf/RpcUtil.java                        \
-  java/src/main/java/com/google/protobuf/Service.java                        \
-  java/src/main/java/com/google/protobuf/ServiceException.java               \
-  java/src/main/java/com/google/protobuf/SingleFieldBuilder.java             \
-  java/src/main/java/com/google/protobuf/SmallSortedMap.java                 \
-  java/src/main/java/com/google/protobuf/TextFormat.java                     \
-  java/src/main/java/com/google/protobuf/TextFormatEscaper.java              \
-  java/src/main/java/com/google/protobuf/TextFormatEscaper.java              \
-  java/src/main/java/com/google/protobuf/UninitializedMessageException.java  \
-  java/src/main/java/com/google/protobuf/UnknownFieldSet.java                \
-  java/src/main/java/com/google/protobuf/UnknownFieldSetLite.java            \
-  java/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java     \
-  java/src/main/java/com/google/protobuf/UnsafeByteStrings.java              \
-  java/src/main/java/com/google/protobuf/Utf8.java                           \
-  java/src/main/java/com/google/protobuf/WireFormat.java                     \
-  java/src/test/java/com/google/protobuf/AbstractMessageTest.java            \
-  java/src/test/java/com/google/protobuf/AnyTest.java                        \
-  java/src/test/java/com/google/protobuf/BooleanArrayListTest.java           \
-  java/src/test/java/com/google/protobuf/BoundedByteStringTest.java          \
-  java/src/test/java/com/google/protobuf/ByteStringTest.java                 \
-  java/src/test/java/com/google/protobuf/CheckUtf8Test.java                  \
-  java/src/test/java/com/google/protobuf/CodedInputStreamTest.java           \
-  java/src/test/java/com/google/protobuf/CodedOutputStreamTest.java          \
-  java/src/test/java/com/google/protobuf/DeprecatedFieldTest.java            \
-  java/src/test/java/com/google/protobuf/DescriptorsTest.java                \
-  java/src/test/java/com/google/protobuf/DoubleArrayListTest.java            \
-  java/src/test/java/com/google/protobuf/DynamicMessageTest.java             \
-  java/src/test/java/com/google/protobuf/FieldPresenceTest.java              \
-  java/src/test/java/com/google/protobuf/FloatArrayListTest.java             \
-  java/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java       \
-  java/src/test/java/com/google/protobuf/GeneratedMessageTest.java           \
-  java/src/test/java/com/google/protobuf/IntArrayListTest.java               \
-  java/src/test/java/com/google/protobuf/IsValidUtf8Test.java                \
-  java/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java            \
-  java/src/test/java/com/google/protobuf/LazyFieldLiteTest.java              \
-  java/src/test/java/com/google/protobuf/LazyFieldTest.java                  \
-  java/src/test/java/com/google/protobuf/LazyMessageLiteTest.java            \
-  java/src/test/java/com/google/protobuf/LazyStringArrayListTest.java        \
-  java/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java         \
-  java/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java          \
-  java/src/test/java/com/google/protobuf/LiteTest.java                       \
-  java/src/test/java/com/google/protobuf/LiteralByteStringTest.java          \
-  java/src/test/java/com/google/protobuf/LongArrayListTest.java              \
-  java/src/test/java/com/google/protobuf/MapForProto2LiteTest.java           \
-  java/src/test/java/com/google/protobuf/MapForProto2Test.java               \
-  java/src/test/java/com/google/protobuf/MapTest.java                        \
-  java/src/test/java/com/google/protobuf/MessageTest.java                    \
-  java/src/test/java/com/google/protobuf/NestedBuildersTest.java             \
-  java/src/test/java/com/google/protobuf/NioByteStringTest.java              \
-  java/src/test/java/com/google/protobuf/ParserTest.java                     \
-  java/src/test/java/com/google/protobuf/ProtobufArrayListTest.java          \
-  java/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java       \
-  java/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java    \
-  java/src/test/java/com/google/protobuf/RopeByteStringTest.java             \
-  java/src/test/java/com/google/protobuf/ServiceTest.java                    \
-  java/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java         \
-  java/src/test/java/com/google/protobuf/SmallSortedMapTest.java             \
-  java/src/test/java/com/google/protobuf/TestBadIdentifiers.java             \
-  java/src/test/java/com/google/protobuf/TestUtil.java                       \
-  java/src/test/java/com/google/protobuf/TextFormatTest.java                 \
-  java/src/test/java/com/google/protobuf/UnknownEnumValueTest.java           \
-  java/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java        \
-  java/src/test/java/com/google/protobuf/UnknownFieldSetTest.java            \
-  java/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java \
-  java/src/test/java/com/google/protobuf/WellKnownTypesTest.java             \
-  java/src/test/java/com/google/protobuf/WireFormatTest.java                 \
-  java/src/test/java/com/google/protobuf/any_test.proto                      \
-  java/src/test/java/com/google/protobuf/field_presence_test.proto           \
-  java/src/test/java/com/google/protobuf/lazy_fields_lite.proto              \
-  java/src/test/java/com/google/protobuf/lite_equals_and_hash.proto          \
-  java/src/test/java/com/google/protobuf/map_for_proto2_lite_test.proto      \
-  java/src/test/java/com/google/protobuf/map_for_proto2_test.proto           \
-  java/src/test/java/com/google/protobuf/map_initialization_order_test.proto \
-  java/src/test/java/com/google/protobuf/map_test.proto                      \
-  java/src/test/java/com/google/protobuf/multiple_files_test.proto           \
-  java/src/test/java/com/google/protobuf/nested_builders_test.proto          \
-  java/src/test/java/com/google/protobuf/nested_extension.proto              \
-  java/src/test/java/com/google/protobuf/nested_extension_lite.proto         \
-  java/src/test/java/com/google/protobuf/non_nested_extension.proto          \
-  java/src/test/java/com/google/protobuf/non_nested_extension_lite.proto     \
-  java/src/test/java/com/google/protobuf/outer_class_name_test.proto         \
-  java/src/test/java/com/google/protobuf/outer_class_name_test2.proto        \
-  java/src/test/java/com/google/protobuf/outer_class_name_test3.proto        \
-  java/src/test/java/com/google/protobuf/test_bad_identifiers.proto          \
-  java/src/test/java/com/google/protobuf/test_check_utf8.proto               \
-  java/src/test/java/com/google/protobuf/test_check_utf8_size.proto          \
-  java/src/test/java/com/google/protobuf/test_custom_options.proto           \
-  java/src/test/java/com/google/protobuf/test_extra_interfaces.proto         \
-  java/util/pom.xml                                                          \
-  java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java        \
-  java/util/src/main/java/com/google/protobuf/util/FieldMaskUtil.java        \
-  java/util/src/main/java/com/google/protobuf/util/JsonFormat.java           \
-  java/util/src/main/java/com/google/protobuf/util/TimeUtil.java             \
-  java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java    \
-  java/util/src/test/java/com/google/protobuf/util/FieldMaskUtilTest.java    \
-  java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java       \
-  java/util/src/test/java/com/google/protobuf/util/TimeUtilTest.java         \
-  java/util/src/test/java/com/google/protobuf/util/json_test.proto           \
-  java/pom.xml                                                               \
-  java/README.md
+java_EXTRA_DIST=                                                                   \
+  java/README.md                                                                   \
+  java/core/generate-sources-build.xml                                             \
+  java/core/generate-test-sources-build.xml                                        \
+  java/core/pom.xml                                                                \
+  java/core/src/main/java/com/google/protobuf/AbstractMessage.java                 \
+  java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java             \
+  java/core/src/main/java/com/google/protobuf/AbstractParser.java                  \
+  java/core/src/main/java/com/google/protobuf/AbstractProtobufList.java            \
+  java/core/src/main/java/com/google/protobuf/BlockingRpcChannel.java              \
+  java/core/src/main/java/com/google/protobuf/BlockingService.java                 \
+  java/core/src/main/java/com/google/protobuf/BooleanArrayList.java                \
+  java/core/src/main/java/com/google/protobuf/BoundedByteString.java               \
+  java/core/src/main/java/com/google/protobuf/ByteString.java                      \
+  java/core/src/main/java/com/google/protobuf/CodedInputStream.java                \
+  java/core/src/main/java/com/google/protobuf/CodedOutputStream.java               \
+  java/core/src/main/java/com/google/protobuf/Descriptors.java                     \
+  java/core/src/main/java/com/google/protobuf/DoubleArrayList.java                 \
+  java/core/src/main/java/com/google/protobuf/DynamicMessage.java                  \
+  java/core/src/main/java/com/google/protobuf/Extension.java                       \
+  java/core/src/main/java/com/google/protobuf/ExtensionLite.java                   \
+  java/core/src/main/java/com/google/protobuf/ExtensionRegistry.java               \
+  java/core/src/main/java/com/google/protobuf/ExtensionRegistryLite.java           \
+  java/core/src/main/java/com/google/protobuf/FieldSet.java                        \
+  java/core/src/main/java/com/google/protobuf/FloatArrayList.java                  \
+  java/core/src/main/java/com/google/protobuf/GeneratedMessage.java                \
+  java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java            \
+  java/core/src/main/java/com/google/protobuf/IntArrayList.java                    \
+  java/core/src/main/java/com/google/protobuf/Internal.java                        \
+  java/core/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java  \
+  java/core/src/main/java/com/google/protobuf/LazyField.java                       \
+  java/core/src/main/java/com/google/protobuf/LazyFieldLite.java                   \
+  java/core/src/main/java/com/google/protobuf/LazyStringArrayList.java             \
+  java/core/src/main/java/com/google/protobuf/LazyStringList.java                  \
+  java/core/src/main/java/com/google/protobuf/LiteralByteString.java               \
+  java/core/src/main/java/com/google/protobuf/LongArrayList.java                   \
+  java/core/src/main/java/com/google/protobuf/MapEntry.java                        \
+  java/core/src/main/java/com/google/protobuf/MapEntryLite.java                    \
+  java/core/src/main/java/com/google/protobuf/MapField.java                        \
+  java/core/src/main/java/com/google/protobuf/MapFieldLite.java                    \
+  java/core/src/main/java/com/google/protobuf/Message.java                         \
+  java/core/src/main/java/com/google/protobuf/MessageLite.java                     \
+  java/core/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java            \
+  java/core/src/main/java/com/google/protobuf/MessageLiteToString.java             \
+  java/core/src/main/java/com/google/protobuf/MessageOrBuilder.java                \
+  java/core/src/main/java/com/google/protobuf/MessageReflection.java               \
+  java/core/src/main/java/com/google/protobuf/MutabilityOracle.java                \
+  java/core/src/main/java/com/google/protobuf/NioByteString.java                   \
+  java/core/src/main/java/com/google/protobuf/Parser.java                          \
+  java/core/src/main/java/com/google/protobuf/ProtobufArrayList.java               \
+  java/core/src/main/java/com/google/protobuf/ProtocolMessageEnum.java             \
+  java/core/src/main/java/com/google/protobuf/ProtocolStringList.java              \
+  java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java            \
+  java/core/src/main/java/com/google/protobuf/RopeByteString.java                  \
+  java/core/src/main/java/com/google/protobuf/RpcCallback.java                     \
+  java/core/src/main/java/com/google/protobuf/RpcChannel.java                      \
+  java/core/src/main/java/com/google/protobuf/RpcController.java                   \
+  java/core/src/main/java/com/google/protobuf/RpcUtil.java                         \
+  java/core/src/main/java/com/google/protobuf/Service.java                         \
+  java/core/src/main/java/com/google/protobuf/ServiceException.java                \
+  java/core/src/main/java/com/google/protobuf/SingleFieldBuilder.java              \
+  java/core/src/main/java/com/google/protobuf/SmallSortedMap.java                  \
+  java/core/src/main/java/com/google/protobuf/TextFormat.java                      \
+  java/core/src/main/java/com/google/protobuf/TextFormatEscaper.java               \
+  java/core/src/main/java/com/google/protobuf/UninitializedMessageException.java   \
+  java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java                 \
+  java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java             \
+  java/core/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java      \
+  java/core/src/main/java/com/google/protobuf/UnsafeByteStrings.java               \
+  java/core/src/main/java/com/google/protobuf/Utf8.java                            \
+  java/core/src/main/java/com/google/protobuf/WireFormat.java                      \
+  java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java             \
+  java/core/src/test/java/com/google/protobuf/AnyTest.java                         \
+  java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java            \
+  java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java           \
+  java/core/src/test/java/com/google/protobuf/ByteStringTest.java                  \
+  java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java                   \
+  java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java            \
+  java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java           \
+  java/core/src/test/java/com/google/protobuf/DeprecatedFieldTest.java             \
+  java/core/src/test/java/com/google/protobuf/DescriptorsTest.java                 \
+  java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java             \
+  java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java              \
+  java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java               \
+  java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java              \
+  java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java        \
+  java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java            \
+  java/core/src/test/java/com/google/protobuf/IntArrayListTest.java                \
+  java/core/src/test/java/com/google/protobuf/IsValidUtf8Test.java                 \
+  java/core/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java             \
+  java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java               \
+  java/core/src/test/java/com/google/protobuf/LazyFieldTest.java                   \
+  java/core/src/test/java/com/google/protobuf/LazyMessageLiteTest.java             \
+  java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java         \
+  java/core/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java          \
+  java/core/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java           \
+  java/core/src/test/java/com/google/protobuf/LiteTest.java                        \
+  java/core/src/test/java/com/google/protobuf/LiteralByteStringTest.java           \
+  java/core/src/test/java/com/google/protobuf/LongArrayListTest.java               \
+  java/core/src/test/java/com/google/protobuf/MapForProto2LiteTest.java            \
+  java/core/src/test/java/com/google/protobuf/MapForProto2Test.java                \
+  java/core/src/test/java/com/google/protobuf/MapTest.java                         \
+  java/core/src/test/java/com/google/protobuf/MessageTest.java                     \
+  java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java              \
+  java/core/src/test/java/com/google/protobuf/NioByteStringTest.java               \
+  java/core/src/test/java/com/google/protobuf/ParserTest.java                      \
+  java/core/src/test/java/com/google/protobuf/ProtobufArrayListTest.java           \
+  java/core/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java        \
+  java/core/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java     \
+  java/core/src/test/java/com/google/protobuf/RopeByteStringTest.java              \
+  java/core/src/test/java/com/google/protobuf/ServiceTest.java                     \
+  java/core/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java          \
+  java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java              \
+  java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java              \
+  java/core/src/test/java/com/google/protobuf/TestUtil.java                        \
+  java/core/src/test/java/com/google/protobuf/TextFormatTest.java                  \
+  java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java            \
+  java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java         \
+  java/core/src/test/java/com/google/protobuf/UnknownFieldSetTest.java             \
+  java/core/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java  \
+  java/core/src/test/java/com/google/protobuf/WellKnownTypesTest.java              \
+  java/core/src/test/java/com/google/protobuf/WireFormatTest.java                  \
+  java/core/src/test/proto/com/google/protobuf/any_test.proto                      \
+  java/core/src/test/proto/com/google/protobuf/field_presence_test.proto           \
+  java/core/src/test/proto/com/google/protobuf/lazy_fields_lite.proto              \
+  java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto          \
+  java/core/src/test/proto/com/google/protobuf/map_for_proto2_lite_test.proto      \
+  java/core/src/test/proto/com/google/protobuf/map_for_proto2_test.proto           \
+  java/core/src/test/proto/com/google/protobuf/map_initialization_order_test.proto \
+  java/core/src/test/proto/com/google/protobuf/map_test.proto                      \
+  java/core/src/test/proto/com/google/protobuf/multiple_files_test.proto           \
+  java/core/src/test/proto/com/google/protobuf/nested_builders_test.proto          \
+  java/core/src/test/proto/com/google/protobuf/nested_extension.proto              \
+  java/core/src/test/proto/com/google/protobuf/nested_extension_lite.proto         \
+  java/core/src/test/proto/com/google/protobuf/non_nested_extension.proto          \
+  java/core/src/test/proto/com/google/protobuf/non_nested_extension_lite.proto     \
+  java/core/src/test/proto/com/google/protobuf/outer_class_name_test.proto         \
+  java/core/src/test/proto/com/google/protobuf/outer_class_name_test2.proto        \
+  java/core/src/test/proto/com/google/protobuf/outer_class_name_test3.proto        \
+  java/core/src/test/proto/com/google/protobuf/test_bad_identifiers.proto          \
+  java/core/src/test/proto/com/google/protobuf/test_check_utf8.proto               \
+  java/core/src/test/proto/com/google/protobuf/test_check_utf8_size.proto          \
+  java/core/src/test/proto/com/google/protobuf/test_custom_options.proto           \
+  java/core/src/test/proto/com/google/protobuf/test_extra_interfaces.proto         \
+  java/lite/pom.xml                                                                \
+  java/pom.xml                                                                     \
+  java/util/pom.xml                                                                \
+  java/util/src/main/java/com/google/protobuf/util/FieldMaskTree.java              \
+  java/util/src/main/java/com/google/protobuf/util/FieldMaskUtil.java              \
+  java/util/src/main/java/com/google/protobuf/util/JsonFormat.java                 \
+  java/util/src/main/java/com/google/protobuf/util/TimeUtil.java                   \
+  java/util/src/test/java/com/google/protobuf/util/FieldMaskTreeTest.java          \
+  java/util/src/test/java/com/google/protobuf/util/FieldMaskUtilTest.java          \
+  java/util/src/test/java/com/google/protobuf/util/JsonFormatTest.java             \
+  java/util/src/test/java/com/google/protobuf/util/TimeUtilTest.java               \
+  java/util/src/test/proto/com/google/protobuf/util/json_test.proto
 
 javanano_EXTRA_DIST=                                                                      \
   javanano/src/main/java/com/google/protobuf/nano/CodedOutputByteBufferNano.java          \
diff --git a/Protobuf.podspec b/Protobuf.podspec
index 92ff2904..73a60222 100644
--- a/Protobuf.podspec
+++ b/Protobuf.podspec
@@ -5,7 +5,7 @@
 # dependent projects use the :git notation to refer to the library.
 Pod::Spec.new do |s|
   s.name     = 'Protobuf'
-  s.version  = '3.0.0-alpha-4.1'
+  s.version  = '3.0.0-beta-2'
   s.summary  = 'Protocol Buffers v.3 runtime library for Objective-C.'
   s.homepage = 'https://github.com/google/protobuf'
   s.license  = 'New BSD'
diff --git a/conformance/Makefile.am b/conformance/Makefile.am
index 9703101a..2a43113b 100644
--- a/conformance/Makefile.am
+++ b/conformance/Makefile.am
@@ -114,13 +114,13 @@ MAINTAINERCLEANFILES =   \
   Makefile.in
 
 javac_middleman: ConformanceJava.java protoc_middleman $(other_language_protoc_outputs)
-	jar=`ls ../java/util/target/*.jar` && javac -classpath ../java/target/classes:$$jar ConformanceJava.java com/google/protobuf/conformance/Conformance.java
+	jar=`ls ../java/util/target/*jar-with-dependencies.jar` && javac -classpath ../java/target/classes:$$jar ConformanceJava.java com/google/protobuf/conformance/Conformance.java
 	@touch javac_middleman
 
 conformance-java: javac_middleman
 	@echo "Writing shortcut script conformance-java..."
 	@echo '#! /bin/sh' > conformance-java
-	@jar=`ls ../java/util/target/*.jar` && echo java -classpath .:../java/target/classes:$$jar ConformanceJava '$$@' >> conformance-java
+	@jar=`ls ../java/util/target/*jar-with-dependencies.jar` && echo java -classpath .:../java/target/classes:$$jar ConformanceJava '$$@' >> conformance-java
 	@chmod +x conformance-java
 
 # Currently the conformance code is alongside the rest of the C#
diff --git a/conformance/failure_list_csharp.txt b/conformance/failure_list_csharp.txt
index feb17689..a46cee47 100644
--- a/conformance/failure_list_csharp.txt
+++ b/conformance/failure_list_csharp.txt
@@ -1,89 +1,16 @@
-DurationProtoInputTooLarge.JsonOutput
-DurationProtoInputTooSmall.JsonOutput
-FieldMaskNumbersDontRoundTrip.JsonOutput
-FieldMaskPathsDontRoundTrip.JsonOutput
-FieldMaskTooManyUnderscore.JsonOutput
 JsonInput.AnyWithValueForInteger.JsonOutput
 JsonInput.AnyWithValueForJsonObject.JsonOutput
-JsonInput.BoolFieldAllCapitalFalse
-JsonInput.BoolFieldAllCapitalTrue
-JsonInput.BoolFieldCamelCaseFalse
-JsonInput.BoolFieldCamelCaseTrue
-JsonInput.BoolMapFieldKeyNotQuoted
-JsonInput.BytesFieldInvalidBase64Characters
-JsonInput.BytesFieldNoPadding
-JsonInput.DoubleFieldInfinityNotQuoted
-JsonInput.DoubleFieldNanNotQuoted
-JsonInput.DoubleFieldNegativeInfinityNotQuoted
-JsonInput.DoubleFieldTooLarge
-JsonInput.DoubleFieldTooSmall
-JsonInput.DurationHas3FractionalDigits.Validator
-JsonInput.DurationHas6FractionalDigits.Validator
-JsonInput.DurationHas9FractionalDigits.Validator
-JsonInput.DurationMaxValue.JsonOutput
-JsonInput.DurationMaxValue.ProtobufOutput
-JsonInput.DurationMinValue.JsonOutput
-JsonInput.DurationMinValue.ProtobufOutput
-JsonInput.EnumFieldNotQuoted
-JsonInput.EnumFieldNumericValueNonZero.JsonOutput
-JsonInput.EnumFieldNumericValueNonZero.ProtobufOutput
-JsonInput.EnumFieldNumericValueZero.JsonOutput
-JsonInput.EnumFieldNumericValueZero.ProtobufOutput
-JsonInput.EnumFieldUnknownValue.Validator
-JsonInput.FieldMaskInvalidCharacter
-JsonInput.FieldNameDuplicate
-JsonInput.FieldNameDuplicateDifferentCasing2
 JsonInput.FieldNameInLowerCamelCase.Validator
 JsonInput.FieldNameInSnakeCase.JsonOutput
 JsonInput.FieldNameInSnakeCase.ProtobufOutput
-JsonInput.FieldNameNotQuoted
 JsonInput.FieldNameWithMixedCases.JsonOutput
 JsonInput.FieldNameWithMixedCases.ProtobufOutput
 JsonInput.FieldNameWithMixedCases.Validator
-JsonInput.FloatFieldInfinityNotQuoted
-JsonInput.FloatFieldNanNotQuoted
-JsonInput.FloatFieldNegativeInfinityNotQuoted
-JsonInput.Int32FieldLeadingZero
 JsonInput.Int32FieldMinFloatValue.JsonOutput
 JsonInput.Int32FieldMinValue.JsonOutput
-JsonInput.Int32FieldNegativeWithLeadingZero
-JsonInput.Int32FieldPlusSign
-JsonInput.Int32MapFieldKeyNotQuoted
 JsonInput.Int64FieldMaxValueNotQuoted.JsonOutput
 JsonInput.Int64FieldMaxValueNotQuoted.ProtobufOutput
-JsonInput.Int64MapFieldKeyNotQuoted
-JsonInput.JsonWithComments
-JsonInput.MapFieldKeyIsNull
-JsonInput.MapFieldValueIsNull
-JsonInput.OneofFieldDuplicate
 JsonInput.OriginalProtoFieldName.JsonOutput
-JsonInput.OriginalProtoFieldName.ProtobufOutput
-JsonInput.RepeatedBoolWrapper.ProtobufOutput
-JsonInput.RepeatedDoubleWrapper.ProtobufOutput
-JsonInput.RepeatedFieldMessageElementIsNull
-JsonInput.RepeatedFieldPrimitiveElementIsNull
-JsonInput.RepeatedFieldTrailingComma
-JsonInput.RepeatedFloatWrapper.ProtobufOutput
-JsonInput.RepeatedInt32Wrapper.ProtobufOutput
-JsonInput.RepeatedInt64Wrapper.ProtobufOutput
-JsonInput.RepeatedUint32Wrapper.ProtobufOutput
-JsonInput.RepeatedUint64Wrapper.ProtobufOutput
-JsonInput.StringFieldInvalidEscape
-JsonInput.StringFieldSurrogateInWrongOrder
 JsonInput.StringFieldSurrogatePair.JsonOutput
-JsonInput.StringFieldUnpairedHighSurrogate
-JsonInput.StringFieldUnpairedLowSurrogate
-JsonInput.StringFieldUnterminatedEscape
-JsonInput.StringFieldUppercaseEscapeLetter
-JsonInput.TimestampHas3FractionalDigits.Validator
-JsonInput.TimestampHas6FractionalDigits.Validator
-JsonInput.TimestampHas9FractionalDigits.Validator
-JsonInput.TrailingCommaInAnObject
-JsonInput.Uint32MapFieldKeyNotQuoted
 JsonInput.Uint64FieldMaxValueNotQuoted.JsonOutput
 JsonInput.Uint64FieldMaxValueNotQuoted.ProtobufOutput
-JsonInput.Uint64MapFieldKeyNotQuoted
-JsonInput.ValueAcceptNull.JsonOutput
-JsonInput.ValueAcceptNull.ProtobufOutput
-TimestampProtoInputTooLarge.JsonOutput
-TimestampProtoInputTooSmall.JsonOutput
diff --git a/conformance/failure_list_python.txt b/conformance/failure_list_python.txt
index c9934598..d2e52637 100644
--- a/conformance/failure_list_python.txt
+++ b/conformance/failure_list_python.txt
@@ -3,11 +3,10 @@ DurationProtoInputTooSmall.JsonOutput
 FieldMaskNumbersDontRoundTrip.JsonOutput
 FieldMaskPathsDontRoundTrip.JsonOutput
 FieldMaskTooManyUnderscore.JsonOutput
-JsonInput.AllFieldAcceptNull.JsonOutput
 JsonInput.Any.JsonOutput
+JsonInput.Any.ProtobufOutput
 JsonInput.AnyNested.JsonOutput
 JsonInput.AnyNested.ProtobufOutput
-JsonInput.Any.ProtobufOutput
 JsonInput.AnyUnorderedTypeTag.JsonOutput
 JsonInput.AnyUnorderedTypeTag.ProtobufOutput
 JsonInput.AnyWithDuration.JsonOutput
@@ -24,132 +23,50 @@ JsonInput.AnyWithValueForInteger.JsonOutput
 JsonInput.AnyWithValueForInteger.ProtobufOutput
 JsonInput.AnyWithValueForJsonObject.JsonOutput
 JsonInput.AnyWithValueForJsonObject.ProtobufOutput
-JsonInput.BoolFieldFalse.JsonOutput
-JsonInput.BoolFieldTrue.JsonOutput
-JsonInput.BoolMapEscapedKey.JsonOutput
-JsonInput.BoolMapField.JsonOutput
 JsonInput.BytesFieldInvalidBase64Characters
-JsonInput.BytesField.JsonOutput
-JsonInput.BytesRepeatedField.JsonOutput
-JsonInput.DoubleFieldInfinity.JsonOutput
 JsonInput.DoubleFieldInfinityNotQuoted
-JsonInput.DoubleFieldMaxNegativeValue.JsonOutput
-JsonInput.DoubleFieldMaxPositiveValue.JsonOutput
-JsonInput.DoubleFieldMinNegativeValue.JsonOutput
-JsonInput.DoubleFieldMinPositiveValue.JsonOutput
-JsonInput.DoubleFieldNan.JsonOutput
 JsonInput.DoubleFieldNanNotQuoted
-JsonInput.DoubleFieldNegativeInfinity.JsonOutput
 JsonInput.DoubleFieldNegativeInfinityNotQuoted
-JsonInput.DoubleFieldQuotedValue.JsonOutput
 JsonInput.DoubleFieldTooSmall
 JsonInput.DurationJsonInputTooLarge
 JsonInput.DurationJsonInputTooSmall
-JsonInput.DurationMaxValue.JsonOutput
-JsonInput.DurationMinValue.JsonOutput
 JsonInput.DurationMissingS
-JsonInput.DurationRepeatedValue.JsonOutput
-JsonInput.EnumField.JsonOutput
 JsonInput.EnumFieldNumericValueNonZero.JsonOutput
 JsonInput.EnumFieldNumericValueNonZero.ProtobufOutput
 JsonInput.EnumFieldNumericValueZero.JsonOutput
 JsonInput.EnumFieldNumericValueZero.ProtobufOutput
 JsonInput.EnumFieldUnknownValue.Validator
-JsonInput.EnumRepeatedField.JsonOutput
-JsonInput.FieldMaskInvalidCharacter
-JsonInput.FieldMask.JsonOutput
 JsonInput.FieldMask.ProtobufOutput
-JsonInput.FieldNameEscaped.JsonOutput
+JsonInput.FieldMaskInvalidCharacter
 JsonInput.FieldNameInLowerCamelCase.Validator
 JsonInput.FieldNameInSnakeCase.JsonOutput
 JsonInput.FieldNameInSnakeCase.ProtobufOutput
-JsonInput.FieldNameWithMixedCases.JsonOutput
-JsonInput.FieldNameWithNumbers.JsonOutput
-JsonInput.FloatFieldInfinity.JsonOutput
 JsonInput.FloatFieldInfinityNotQuoted
-JsonInput.FloatFieldMaxNegativeValue.JsonOutput
-JsonInput.FloatFieldMaxPositiveValue.JsonOutput
-JsonInput.FloatFieldMinNegativeValue.JsonOutput
-JsonInput.FloatFieldMinPositiveValue.JsonOutput
-JsonInput.FloatFieldNan.JsonOutput
 JsonInput.FloatFieldNanNotQuoted
-JsonInput.FloatFieldNegativeInfinity.JsonOutput
 JsonInput.FloatFieldNegativeInfinityNotQuoted
-JsonInput.FloatFieldQuotedValue.JsonOutput
 JsonInput.FloatFieldTooLarge
 JsonInput.FloatFieldTooSmall
-JsonInput.HelloWorld.JsonOutput
 JsonInput.Int32FieldExponentialFormat.JsonOutput
 JsonInput.Int32FieldExponentialFormat.ProtobufOutput
 JsonInput.Int32FieldFloatTrailingZero.JsonOutput
 JsonInput.Int32FieldFloatTrailingZero.ProtobufOutput
 JsonInput.Int32FieldMaxFloatValue.JsonOutput
 JsonInput.Int32FieldMaxFloatValue.ProtobufOutput
-JsonInput.Int32FieldMaxValue.JsonOutput
 JsonInput.Int32FieldMinFloatValue.JsonOutput
 JsonInput.Int32FieldMinFloatValue.ProtobufOutput
 JsonInput.Int32FieldMinValue.JsonOutput
-JsonInput.Int32FieldStringValueEscaped.JsonOutput
-JsonInput.Int32FieldStringValue.JsonOutput
-JsonInput.Int32MapEscapedKey.JsonOutput
-JsonInput.Int32MapField.JsonOutput
-JsonInput.Int64FieldMaxValue.JsonOutput
-JsonInput.Int64FieldMaxValueNotQuoted.JsonOutput
-JsonInput.Int64FieldMinValue.JsonOutput
-JsonInput.Int64FieldMinValueNotQuoted.JsonOutput
-JsonInput.Int64MapEscapedKey.JsonOutput
-JsonInput.Int64MapField.JsonOutput
-JsonInput.MessageField.JsonOutput
-JsonInput.MessageMapField.JsonOutput
-JsonInput.MessageRepeatedField.JsonOutput
-JsonInput.OptionalBoolWrapper.JsonOutput
-JsonInput.OptionalBytesWrapper.JsonOutput
-JsonInput.OptionalDoubleWrapper.JsonOutput
-JsonInput.OptionalFloatWrapper.JsonOutput
-JsonInput.OptionalInt32Wrapper.JsonOutput
-JsonInput.OptionalInt64Wrapper.JsonOutput
-JsonInput.OptionalStringWrapper.JsonOutput
-JsonInput.OptionalUint32Wrapper.JsonOutput
-JsonInput.OptionalUint64Wrapper.JsonOutput
-JsonInput.OptionalWrapperTypesWithNonDefaultValue.JsonOutput
 JsonInput.OriginalProtoFieldName.JsonOutput
 JsonInput.OriginalProtoFieldName.ProtobufOutput
-JsonInput.PrimitiveRepeatedField.JsonOutput
-JsonInput.RepeatedBoolWrapper.JsonOutput
-JsonInput.RepeatedBytesWrapper.JsonOutput
-JsonInput.RepeatedDoubleWrapper.JsonOutput
 JsonInput.RepeatedFieldMessageElementIsNull
 JsonInput.RepeatedFieldPrimitiveElementIsNull
 JsonInput.RepeatedFieldWrongElementTypeExpectingIntegersGotBool
-JsonInput.RepeatedFloatWrapper.JsonOutput
-JsonInput.RepeatedInt32Wrapper.JsonOutput
-JsonInput.RepeatedInt64Wrapper.JsonOutput
-JsonInput.RepeatedStringWrapper.JsonOutput
-JsonInput.RepeatedUint32Wrapper.JsonOutput
-JsonInput.RepeatedUint64Wrapper.JsonOutput
-JsonInput.StringFieldEscape.JsonOutput
-JsonInput.StringField.JsonOutput
 JsonInput.StringFieldSurrogatePair.JsonOutput
-JsonInput.StringFieldUnicodeEscape.JsonOutput
-JsonInput.StringFieldUnicodeEscapeWithLowercaseHexLetters.JsonOutput
-JsonInput.StringFieldUnicode.JsonOutput
 JsonInput.StringFieldUnpairedLowSurrogate
-JsonInput.StringRepeatedField.JsonOutput
 JsonInput.Struct.JsonOutput
 JsonInput.Struct.ProtobufOutput
 JsonInput.TimestampJsonInputLowercaseT
-JsonInput.TimestampMaxValue.JsonOutput
-JsonInput.TimestampMinValue.JsonOutput
-JsonInput.TimestampRepeatedValue.JsonOutput
-JsonInput.TimestampWithNegativeOffset.JsonOutput
-JsonInput.TimestampWithPositiveOffset.JsonOutput
 JsonInput.Uint32FieldMaxFloatValue.JsonOutput
 JsonInput.Uint32FieldMaxFloatValue.ProtobufOutput
-JsonInput.Uint32FieldMaxValue.JsonOutput
-JsonInput.Uint32MapField.JsonOutput
-JsonInput.Uint64FieldMaxValue.JsonOutput
-JsonInput.Uint64FieldMaxValueNotQuoted.JsonOutput
-JsonInput.Uint64MapField.JsonOutput
 JsonInput.ValueAcceptBool.JsonOutput
 JsonInput.ValueAcceptBool.ProtobufOutput
 JsonInput.ValueAcceptFloat.JsonOutput
@@ -164,10 +81,5 @@ JsonInput.ValueAcceptObject.JsonOutput
 JsonInput.ValueAcceptObject.ProtobufOutput
 JsonInput.ValueAcceptString.JsonOutput
 JsonInput.ValueAcceptString.ProtobufOutput
-JsonInput.WrapperTypesWithNullValue.JsonOutput
-ProtobufInput.DoubleFieldNormalizeQuietNan.JsonOutput
-ProtobufInput.DoubleFieldNormalizeSignalingNan.JsonOutput
-ProtobufInput.FloatFieldNormalizeQuietNan.JsonOutput
-ProtobufInput.FloatFieldNormalizeSignalingNan.JsonOutput
 TimestampProtoInputTooLarge.JsonOutput
 TimestampProtoInputTooSmall.JsonOutput
diff --git a/conformance/failure_list_python_cpp.txt b/conformance/failure_list_python_cpp.txt
index 9c710e99..7b5e45f9 100644
--- a/conformance/failure_list_python_cpp.txt
+++ b/conformance/failure_list_python_cpp.txt
@@ -12,11 +12,10 @@ DurationProtoInputTooSmall.JsonOutput
 FieldMaskNumbersDontRoundTrip.JsonOutput
 FieldMaskPathsDontRoundTrip.JsonOutput
 FieldMaskTooManyUnderscore.JsonOutput
-JsonInput.AllFieldAcceptNull.JsonOutput
 JsonInput.Any.JsonOutput
+JsonInput.Any.ProtobufOutput
 JsonInput.AnyNested.JsonOutput
 JsonInput.AnyNested.ProtobufOutput
-JsonInput.Any.ProtobufOutput
 JsonInput.AnyUnorderedTypeTag.JsonOutput
 JsonInput.AnyUnorderedTypeTag.ProtobufOutput
 JsonInput.AnyWithDuration.JsonOutput
@@ -33,132 +32,50 @@ JsonInput.AnyWithValueForInteger.JsonOutput
 JsonInput.AnyWithValueForInteger.ProtobufOutput
 JsonInput.AnyWithValueForJsonObject.JsonOutput
 JsonInput.AnyWithValueForJsonObject.ProtobufOutput
-JsonInput.BoolFieldFalse.JsonOutput
-JsonInput.BoolFieldTrue.JsonOutput
-JsonInput.BoolMapEscapedKey.JsonOutput
-JsonInput.BoolMapField.JsonOutput
 JsonInput.BytesFieldInvalidBase64Characters
-JsonInput.BytesField.JsonOutput
-JsonInput.BytesRepeatedField.JsonOutput
-JsonInput.DoubleFieldInfinity.JsonOutput
 JsonInput.DoubleFieldInfinityNotQuoted
-JsonInput.DoubleFieldMaxNegativeValue.JsonOutput
-JsonInput.DoubleFieldMaxPositiveValue.JsonOutput
-JsonInput.DoubleFieldMinNegativeValue.JsonOutput
-JsonInput.DoubleFieldMinPositiveValue.JsonOutput
-JsonInput.DoubleFieldNan.JsonOutput
 JsonInput.DoubleFieldNanNotQuoted
-JsonInput.DoubleFieldNegativeInfinity.JsonOutput
 JsonInput.DoubleFieldNegativeInfinityNotQuoted
-JsonInput.DoubleFieldQuotedValue.JsonOutput
 JsonInput.DoubleFieldTooSmall
 JsonInput.DurationJsonInputTooLarge
 JsonInput.DurationJsonInputTooSmall
-JsonInput.DurationMaxValue.JsonOutput
-JsonInput.DurationMinValue.JsonOutput
 JsonInput.DurationMissingS
-JsonInput.DurationRepeatedValue.JsonOutput
-JsonInput.EnumField.JsonOutput
 JsonInput.EnumFieldNumericValueNonZero.JsonOutput
 JsonInput.EnumFieldNumericValueNonZero.ProtobufOutput
 JsonInput.EnumFieldNumericValueZero.JsonOutput
 JsonInput.EnumFieldNumericValueZero.ProtobufOutput
 JsonInput.EnumFieldUnknownValue.Validator
-JsonInput.EnumRepeatedField.JsonOutput
-JsonInput.FieldMaskInvalidCharacter
-JsonInput.FieldMask.JsonOutput
 JsonInput.FieldMask.ProtobufOutput
-JsonInput.FieldNameEscaped.JsonOutput
+JsonInput.FieldMaskInvalidCharacter
 JsonInput.FieldNameInLowerCamelCase.Validator
 JsonInput.FieldNameInSnakeCase.JsonOutput
 JsonInput.FieldNameInSnakeCase.ProtobufOutput
-JsonInput.FieldNameWithMixedCases.JsonOutput
-JsonInput.FieldNameWithNumbers.JsonOutput
-JsonInput.FloatFieldInfinity.JsonOutput
 JsonInput.FloatFieldInfinityNotQuoted
-JsonInput.FloatFieldMaxNegativeValue.JsonOutput
-JsonInput.FloatFieldMaxPositiveValue.JsonOutput
-JsonInput.FloatFieldMinNegativeValue.JsonOutput
-JsonInput.FloatFieldMinPositiveValue.JsonOutput
-JsonInput.FloatFieldNan.JsonOutput
 JsonInput.FloatFieldNanNotQuoted
-JsonInput.FloatFieldNegativeInfinity.JsonOutput
 JsonInput.FloatFieldNegativeInfinityNotQuoted
-JsonInput.FloatFieldQuotedValue.JsonOutput
 JsonInput.FloatFieldTooLarge
 JsonInput.FloatFieldTooSmall
-JsonInput.HelloWorld.JsonOutput
 JsonInput.Int32FieldExponentialFormat.JsonOutput
 JsonInput.Int32FieldExponentialFormat.ProtobufOutput
 JsonInput.Int32FieldFloatTrailingZero.JsonOutput
 JsonInput.Int32FieldFloatTrailingZero.ProtobufOutput
 JsonInput.Int32FieldMaxFloatValue.JsonOutput
 JsonInput.Int32FieldMaxFloatValue.ProtobufOutput
-JsonInput.Int32FieldMaxValue.JsonOutput
 JsonInput.Int32FieldMinFloatValue.JsonOutput
 JsonInput.Int32FieldMinFloatValue.ProtobufOutput
 JsonInput.Int32FieldMinValue.JsonOutput
-JsonInput.Int32FieldStringValueEscaped.JsonOutput
-JsonInput.Int32FieldStringValue.JsonOutput
-JsonInput.Int32MapEscapedKey.JsonOutput
-JsonInput.Int32MapField.JsonOutput
-JsonInput.Int64FieldMaxValue.JsonOutput
-JsonInput.Int64FieldMaxValueNotQuoted.JsonOutput
-JsonInput.Int64FieldMinValue.JsonOutput
-JsonInput.Int64FieldMinValueNotQuoted.JsonOutput
-JsonInput.Int64MapEscapedKey.JsonOutput
-JsonInput.Int64MapField.JsonOutput
-JsonInput.MessageField.JsonOutput
-JsonInput.MessageMapField.JsonOutput
-JsonInput.MessageRepeatedField.JsonOutput
-JsonInput.OptionalBoolWrapper.JsonOutput
-JsonInput.OptionalBytesWrapper.JsonOutput
-JsonInput.OptionalDoubleWrapper.JsonOutput
-JsonInput.OptionalFloatWrapper.JsonOutput
-JsonInput.OptionalInt32Wrapper.JsonOutput
-JsonInput.OptionalInt64Wrapper.JsonOutput
-JsonInput.OptionalStringWrapper.JsonOutput
-JsonInput.OptionalUint32Wrapper.JsonOutput
-JsonInput.OptionalUint64Wrapper.JsonOutput
-JsonInput.OptionalWrapperTypesWithNonDefaultValue.JsonOutput
 JsonInput.OriginalProtoFieldName.JsonOutput
 JsonInput.OriginalProtoFieldName.ProtobufOutput
-JsonInput.PrimitiveRepeatedField.JsonOutput
-JsonInput.RepeatedBoolWrapper.JsonOutput
-JsonInput.RepeatedBytesWrapper.JsonOutput
-JsonInput.RepeatedDoubleWrapper.JsonOutput
 JsonInput.RepeatedFieldMessageElementIsNull
 JsonInput.RepeatedFieldPrimitiveElementIsNull
 JsonInput.RepeatedFieldWrongElementTypeExpectingIntegersGotBool
-JsonInput.RepeatedFloatWrapper.JsonOutput
-JsonInput.RepeatedInt32Wrapper.JsonOutput
-JsonInput.RepeatedInt64Wrapper.JsonOutput
-JsonInput.RepeatedStringWrapper.JsonOutput
-JsonInput.RepeatedUint32Wrapper.JsonOutput
-JsonInput.RepeatedUint64Wrapper.JsonOutput
-JsonInput.StringFieldEscape.JsonOutput
-JsonInput.StringField.JsonOutput
 JsonInput.StringFieldSurrogatePair.JsonOutput
-JsonInput.StringFieldUnicodeEscape.JsonOutput
-JsonInput.StringFieldUnicodeEscapeWithLowercaseHexLetters.JsonOutput
-JsonInput.StringFieldUnicode.JsonOutput
 JsonInput.StringFieldUnpairedLowSurrogate
-JsonInput.StringRepeatedField.JsonOutput
 JsonInput.Struct.JsonOutput
 JsonInput.Struct.ProtobufOutput
 JsonInput.TimestampJsonInputLowercaseT
-JsonInput.TimestampMaxValue.JsonOutput
-JsonInput.TimestampMinValue.JsonOutput
-JsonInput.TimestampRepeatedValue.JsonOutput
-JsonInput.TimestampWithNegativeOffset.JsonOutput
-JsonInput.TimestampWithPositiveOffset.JsonOutput
 JsonInput.Uint32FieldMaxFloatValue.JsonOutput
 JsonInput.Uint32FieldMaxFloatValue.ProtobufOutput
-JsonInput.Uint32FieldMaxValue.JsonOutput
-JsonInput.Uint32MapField.JsonOutput
-JsonInput.Uint64FieldMaxValue.JsonOutput
-JsonInput.Uint64FieldMaxValueNotQuoted.JsonOutput
-JsonInput.Uint64MapField.JsonOutput
 JsonInput.ValueAcceptBool.JsonOutput
 JsonInput.ValueAcceptBool.ProtobufOutput
 JsonInput.ValueAcceptFloat.JsonOutput
@@ -173,11 +90,6 @@ JsonInput.ValueAcceptObject.JsonOutput
 JsonInput.ValueAcceptObject.ProtobufOutput
 JsonInput.ValueAcceptString.JsonOutput
 JsonInput.ValueAcceptString.ProtobufOutput
-JsonInput.WrapperTypesWithNullValue.JsonOutput
-ProtobufInput.DoubleFieldNormalizeQuietNan.JsonOutput
-ProtobufInput.DoubleFieldNormalizeSignalingNan.JsonOutput
-ProtobufInput.FloatFieldNormalizeQuietNan.JsonOutput
-ProtobufInput.FloatFieldNormalizeSignalingNan.JsonOutput
 ProtobufInput.PrematureEofInDelimitedDataForKnownNonRepeatedValue.MESSAGE
 ProtobufInput.PrematureEofInDelimitedDataForKnownRepeatedValue.MESSAGE
 ProtobufInput.PrematureEofInPackedField.BOOL
diff --git a/csharp/src/Google.Protobuf.Conformance/Program.cs b/csharp/src/Google.Protobuf.Conformance/Program.cs
index 8f72c8f9..f3f7e295 100644
--- a/csharp/src/Google.Protobuf.Conformance/Program.cs
+++ b/csharp/src/Google.Protobuf.Conformance/Program.cs
@@ -101,15 +101,26 @@ namespace Google.Protobuf.Conformance
             {
                 return new ConformanceResponse { ParseError = e.Message };
             }
-            switch (request.RequestedOutputFormat)
+            catch (InvalidJsonException e)
             {
-                case global::Conformance.WireFormat.JSON:
-                    var formatter = new JsonFormatter(new JsonFormatter.Settings(false, typeRegistry));
-                    return new ConformanceResponse { JsonPayload = formatter.Format(message) };
-                case global::Conformance.WireFormat.PROTOBUF:
-                    return new ConformanceResponse { ProtobufPayload = message.ToByteString() };
-                default:
-                    throw new Exception("Unsupported request output format: " + request.PayloadCase);
+                return new ConformanceResponse { ParseError = e.Message };
+            }
+            try
+            {
+                switch (request.RequestedOutputFormat)
+                {
+                    case global::Conformance.WireFormat.JSON:
+                        var formatter = new JsonFormatter(new JsonFormatter.Settings(false, typeRegistry));
+                        return new ConformanceResponse { JsonPayload = formatter.Format(message) };
+                    case global::Conformance.WireFormat.PROTOBUF:
+                        return new ConformanceResponse { ProtobufPayload = message.ToByteString() };
+                    default:
+                        throw new Exception("Unsupported request output format: " + request.PayloadCase);
+                }
+            }
+            catch (InvalidOperationException e)
+            {
+                return new ConformanceResponse { SerializeError = e.Message };
             }
         }
 
diff --git a/csharp/src/Google.Protobuf.Test/JsonFormatterTest.cs b/csharp/src/Google.Protobuf.Test/JsonFormatterTest.cs
index ace70b00..9e994a6a 100644
--- a/csharp/src/Google.Protobuf.Test/JsonFormatterTest.cs
+++ b/csharp/src/Google.Protobuf.Test/JsonFormatterTest.cs
@@ -165,34 +165,31 @@ namespace Google.Protobuf
         }
 
         [Test]
-        public void UnknownEnumValueOmitted_SingleField()
+        public void UnknownEnumValueNumeric_SingleField()
         {
             var message = new TestAllTypes { SingleForeignEnum = (ForeignEnum) 100 };
-            AssertJson("{ }", JsonFormatter.Default.Format(message));
+            AssertJson("{ 'singleForeignEnum': 100 }", JsonFormatter.Default.Format(message));
         }
 
         [Test]
-        public void UnknownEnumValueOmitted_RepeatedField()
+        public void UnknownEnumValueNumeric_RepeatedField()
         {
             var message = new TestAllTypes { RepeatedForeignEnum = { ForeignEnum.FOREIGN_BAZ, (ForeignEnum) 100, ForeignEnum.FOREIGN_FOO } };
-            AssertJson("{ 'repeatedForeignEnum': [ 'FOREIGN_BAZ', 'FOREIGN_FOO' ] }", JsonFormatter.Default.Format(message));
+            AssertJson("{ 'repeatedForeignEnum': [ 'FOREIGN_BAZ', 100, 'FOREIGN_FOO' ] }", JsonFormatter.Default.Format(message));
         }
 
         [Test]
-        public void UnknownEnumValueOmitted_MapField()
+        public void UnknownEnumValueNumeric_MapField()
         {
-            // This matches the C++ behaviour.
             var message = new TestMap { MapInt32Enum = { { 1, MapEnum.MAP_ENUM_FOO }, { 2, (MapEnum) 100 }, { 3, MapEnum.MAP_ENUM_BAR } } };
-            AssertJson("{ 'mapInt32Enum': { '1': 'MAP_ENUM_FOO', '3': 'MAP_ENUM_BAR' } }", JsonFormatter.Default.Format(message));
+            AssertJson("{ 'mapInt32Enum': { '1': 'MAP_ENUM_FOO', '2': 100, '3': 'MAP_ENUM_BAR' } }", JsonFormatter.Default.Format(message));
         }
 
         [Test]
-        public void UnknownEnumValueOmitted_RepeatedField_AllEntriesUnknown()
+        public void UnknownEnumValue_RepeatedField_AllEntriesUnknown()
         {
-            // *Maybe* we should hold off on writing the "[" until we find that we've got at least one value to write...
-            // but this is what happens at the moment, and it doesn't seem too awful.
             var message = new TestAllTypes { RepeatedForeignEnum = { (ForeignEnum) 200, (ForeignEnum) 100 } };
-            AssertJson("{ 'repeatedForeignEnum': [ ] }", JsonFormatter.Default.Format(message));
+            AssertJson("{ 'repeatedForeignEnum': [ 200, 100 ] }", JsonFormatter.Default.Format(message));
         }
 
         [Test]
@@ -315,6 +312,15 @@ namespace Google.Protobuf
 
         [Test]
         [TestCase("1970-01-01T00:00:00Z", 0)]
+        [TestCase("1970-01-01T00:00:00.000000001Z", 1)]
+        [TestCase("1970-01-01T00:00:00.000000010Z", 10)]
+        [TestCase("1970-01-01T00:00:00.000000100Z", 100)]
+        [TestCase("1970-01-01T00:00:00.000001Z", 1000)]
+        [TestCase("1970-01-01T00:00:00.000010Z", 10000)]
+        [TestCase("1970-01-01T00:00:00.000100Z", 100000)]
+        [TestCase("1970-01-01T00:00:00.001Z", 1000000)]
+        [TestCase("1970-01-01T00:00:00.010Z", 10000000)]
+        [TestCase("1970-01-01T00:00:00.100Z", 100000000)]
         [TestCase("1970-01-01T00:00:00.100Z", 100000000)]
         [TestCase("1970-01-01T00:00:00.120Z", 120000000)]
         [TestCase("1970-01-01T00:00:00.123Z", 123000000)]
@@ -350,6 +356,14 @@ namespace Google.Protobuf
         [TestCase(0, 0, "0s")]
         [TestCase(1, 0, "1s")]
         [TestCase(-1, 0, "-1s")]
+        [TestCase(0, 1, "0.000000001s")]
+        [TestCase(0, 10, "0.000000010s")]
+        [TestCase(0, 100, "0.000000100s")]
+        [TestCase(0, 1000, "0.000001s")]
+        [TestCase(0, 10000, "0.000010s")]
+        [TestCase(0, 100000, "0.000100s")]
+        [TestCase(0, 1000000, "0.001s")]
+        [TestCase(0, 10000000, "0.010s")]
         [TestCase(0, 100000000, "0.100s")]
         [TestCase(0, 120000000, "0.120s")]
         [TestCase(0, 123000000, "0.123s")]
@@ -362,15 +376,20 @@ namespace Google.Protobuf
         [TestCase(0, -100000000, "-0.100s")]
         [TestCase(1, 100000000, "1.100s")]
         [TestCase(-1, -100000000, "-1.100s")]
-        // Non-normalized examples
-        [TestCase(1, 2123456789, "3.123456789s")]
-        [TestCase(1, -100000000, "0.900s")]
         public void DurationStandalone(long seconds, int nanoseconds, string expected)
         {
             Assert.AreEqual(WrapInQuotes(expected), new Duration { Seconds = seconds, Nanos = nanoseconds }.ToString());
         }
 
         [Test]
+        [TestCase(1, 2123456789)]
+        [TestCase(1, -100000000)]
+        public void DurationStandalone_NonNormalized(long seconds, int nanoseconds)
+        {
+            Assert.Throws<InvalidOperationException>(() => new Duration { Seconds = seconds, Nanos = nanoseconds }.ToString());
+        }
+
+        [Test]
         public void DurationField()
         {
             var message = new TestWellKnownTypes { DurationField = new Duration() };
@@ -396,6 +415,16 @@ namespace Google.Protobuf
         }
 
         [Test]
+        [TestCase("foo__bar")]
+        [TestCase("foo_3_ar")]
+        [TestCase("fooBar")]
+        public void FieldMaskInvalid(string input)
+        {
+            var mask = new FieldMask { Paths = { input } };
+            Assert.Throws<InvalidOperationException>(() => JsonFormatter.Default.Format(mask));
+        }
+
+        [Test]
         public void FieldMaskStandalone()
         {
             var fieldMask = new FieldMask { Paths = { "", "single", "with_underscore", "nested.field.name", "nested..double_dot" } };
diff --git a/csharp/src/Google.Protobuf.Test/JsonParserTest.cs b/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
index 4443ab4a..c4f6dfb4 100644
--- a/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
+++ b/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
@@ -72,6 +72,14 @@ namespace Google.Protobuf
         }
 
         [Test]
+        public void OriginalFieldNameAccepted()
+        {
+            var json = "{ \"single_int32\": 10 }";
+            var expected = new TestAllTypes { SingleInt32 = 10 };
+            Assert.AreEqual(expected, TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
         public void SourceContextRoundtrip()
         {
             AssertRoundtrip(new SourceContext { FileName = "foo.proto" });
@@ -116,7 +124,9 @@ namespace Google.Protobuf
         [Test]
         public void SingularWrappers_ExplicitNulls()
         {
-            var message = new TestWellKnownTypes();
+            // When we parse the "valueField": null part, we remember it... basically, it's one case
+            // where explicit default values don't fully roundtrip.
+            var message = new TestWellKnownTypes { ValueField = Value.ForNull() };
             var json = new JsonFormatter(new JsonFormatter.Settings(true)).Format(message);
             var parsed = JsonParser.Default.Parse<TestWellKnownTypes>(json);
             Assert.AreEqual(message, parsed);
@@ -143,6 +153,14 @@ namespace Google.Protobuf
         }
 
         [Test]
+        public void ExplicitNullValue()
+        {
+            string json = "{\"valueField\": null}";
+            var message = JsonParser.Default.Parse<TestWellKnownTypes>(json);
+            Assert.AreEqual(new TestWellKnownTypes { ValueField = Value.ForNull() }, message);
+        }
+
+        [Test]
         public void BytesWrapper_Standalone()
         {
             ByteString data = ByteString.CopyFrom(1, 2, 3);
@@ -171,6 +189,36 @@ namespace Google.Protobuf
         }
 
         [Test]
+        public void RepeatedField_NullElementProhibited()
+        {
+            string json = "{ \"repeated_foreign_message\": [null] }";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        public void RepeatedField_NullOverallValueAllowed()
+        {
+            string json = "{ \"repeated_foreign_message\": null }";
+            Assert.AreEqual(new TestAllTypes(), TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("{ \"mapInt32Int32\": { \"10\": null }")]
+        [TestCase("{ \"mapStringString\": { \"abc\": null }")]
+        [TestCase("{ \"mapInt32ForeignMessage\": { \"10\": null }")]
+        public void MapField_NullValueProhibited(string json)
+        {
+            Assert.Throws<InvalidProtocolBufferException>(() => TestMap.Parser.ParseJson(json));
+        }
+
+        [Test]
+        public void MapField_NullOverallValueAllowed()
+        {
+            string json = "{ \"mapInt32Int32\": null }";
+            Assert.AreEqual(new TestMap(), TestMap.Parser.ParseJson(json));
+        }
+
+        [Test]
         public void IndividualWrapperTypes()
         {
             Assert.AreEqual(new StringValue { Value = "foo" }, StringValue.Parser.ParseJson("\"foo\""));
@@ -715,7 +763,6 @@ namespace Google.Protobuf
         [TestCase("--0.123456789s", Description = "Double minus sign")]
         // Violate upper/lower bounds in various ways
         [TestCase("315576000001s", Description = "Integer part too large")]
-        [TestCase("315576000000.000000001s", Description = "Integer part is upper bound; non-zero fraction")]
         [TestCase("3155760000000s", Description = "Integer part too long (positive)")]
         [TestCase("-3155760000000s", Description = "Integer part too long (negative)")]
         public void Duration_Invalid(string jsonValue)
@@ -742,6 +789,14 @@ namespace Google.Protobuf
         }
 
         [Test]
+        [TestCase("foo_bar")]
+        public void FieldMask_Invalid(string jsonValue)
+        {
+            string json = WrapInQuotes(jsonValue);
+            Assert.Throws<InvalidProtocolBufferException>(() => FieldMask.Parser.ParseJson(json));
+        }
+
+        [Test]
         public void Any_RegularMessage()
         {
             var registry = TypeRegistry.FromMessages(TestAllTypes.Descriptor);
@@ -763,6 +818,13 @@ namespace Google.Protobuf
         }
 
         [Test]
+        public void Any_NoTypeUrl()
+        {
+            string json = "{ \"foo\": \"bar\" }";
+            Assert.Throws<InvalidProtocolBufferException>(() => Any.Parser.ParseJson(json));
+        }
+
+        [Test]
         public void Any_WellKnownType()
         {
             var registry = TypeRegistry.FromMessages(Timestamp.Descriptor);
@@ -814,6 +876,42 @@ namespace Google.Protobuf
             Assert.Throws<InvalidProtocolBufferException>(() => parser63.Parse<TestRecursiveMessage>(data64));
         }
 
+        [Test]
+        [TestCase("AQI")]
+        [TestCase("_-==")]
+        public void Bytes_InvalidBase64(string badBase64)
+        {
+            string json = "{ \"singleBytes\": \"" + badBase64 + "\" }";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        [TestCase("\"FOREIGN_BAR\"", ForeignEnum.FOREIGN_BAR)]
+        [TestCase("5", ForeignEnum.FOREIGN_BAR)]
+        [TestCase("100", (ForeignEnum) 100)]
+        public void EnumValid(string value, ForeignEnum expectedValue)
+        {
+            string json = "{ \"singleForeignEnum\": " + value + " }";
+            var parsed = TestAllTypes.Parser.ParseJson(json);
+            Assert.AreEqual(new TestAllTypes { SingleForeignEnum = expectedValue }, parsed);
+        }
+
+        [Test]
+        [TestCase("\"NOT_A_VALID_VALUE\"")]
+        [TestCase("5.5")]
+        public void Enum_Invalid(string value)
+        {
+            string json = "{ \"singleForeignEnum\": " + value + " }";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
+        [Test]
+        public void OneofDuplicate_Invalid()
+        {
+            string json = "{ \"oneofString\": \"x\", \"oneofUint32\": 10 }";
+            Assert.Throws<InvalidProtocolBufferException>(() => TestAllTypes.Parser.ParseJson(json));
+        }
+
         /// <summary>
         /// Various tests use strings which have quotes round them for parsing or as the result
         /// of formatting, but without those quotes being specified in the tests (for the sake of readability).
diff --git a/csharp/src/Google.Protobuf.Test/TestProtos/UnittestWellKnownTypes.cs b/csharp/src/Google.Protobuf.Test/TestProtos/UnittestWellKnownTypes.cs
index dfada6bd..2079a960 100644
--- a/csharp/src/Google.Protobuf.Test/TestProtos/UnittestWellKnownTypes.cs
+++ b/csharp/src/Google.Protobuf.Test/TestProtos/UnittestWellKnownTypes.cs
@@ -31,7 +31,7 @@ namespace Google.Protobuf.TestProtos {
             "L3Byb3RvYnVmL3NvdXJjZV9jb250ZXh0LnByb3RvGhxnb29nbGUvcHJvdG9i",
             "dWYvc3RydWN0LnByb3RvGh9nb29nbGUvcHJvdG9idWYvdGltZXN0YW1wLnBy",
             "b3RvGhpnb29nbGUvcHJvdG9idWYvdHlwZS5wcm90bxoeZ29vZ2xlL3Byb3Rv",
-            "YnVmL3dyYXBwZXJzLnByb3RvIpEHChJUZXN0V2VsbEtub3duVHlwZXMSJwoJ",
+            "YnVmL3dyYXBwZXJzLnByb3RvIr4HChJUZXN0V2VsbEtub3duVHlwZXMSJwoJ",
             "YW55X2ZpZWxkGAEgASgLMhQuZ29vZ2xlLnByb3RvYnVmLkFueRInCglhcGlf",
             "ZmllbGQYAiABKAsyFC5nb29nbGUucHJvdG9idWYuQXBpEjEKDmR1cmF0aW9u",
             "X2ZpZWxkGAMgASgLMhkuZ29vZ2xlLnByb3RvYnVmLkR1cmF0aW9uEisKC2Vt",
@@ -51,7 +51,8 @@ namespace Google.Protobuf.TestProtos {
             "cm90b2J1Zi5VSW50MzJWYWx1ZRIuCgpib29sX2ZpZWxkGBAgASgLMhouZ29v",
             "Z2xlLnByb3RvYnVmLkJvb2xWYWx1ZRIyCgxzdHJpbmdfZmllbGQYESABKAsy",
             "HC5nb29nbGUucHJvdG9idWYuU3RyaW5nVmFsdWUSMAoLYnl0ZXNfZmllbGQY",
-            "EiABKAsyGy5nb29nbGUucHJvdG9idWYuQnl0ZXNWYWx1ZSKVBwoWUmVwZWF0",
+            "EiABKAsyGy5nb29nbGUucHJvdG9idWYuQnl0ZXNWYWx1ZRIrCgt2YWx1ZV9m",
+            "aWVsZBgTIAEoCzIWLmdvb2dsZS5wcm90b2J1Zi5WYWx1ZSKVBwoWUmVwZWF0",
             "ZWRXZWxsS25vd25UeXBlcxInCglhbnlfZmllbGQYASADKAsyFC5nb29nbGUu",
             "cHJvdG9idWYuQW55EicKCWFwaV9maWVsZBgCIAMoCzIULmdvb2dsZS5wcm90",
             "b2J1Zi5BcGkSMQoOZHVyYXRpb25fZmllbGQYAyADKAsyGS5nb29nbGUucHJv",
@@ -162,7 +163,7 @@ namespace Google.Protobuf.TestProtos {
       descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
           new pbr::FileDescriptor[] { global::Google.Protobuf.WellKnownTypes.AnyReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.ApiReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.DurationReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.EmptyReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.FieldMaskReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.SourceContextReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.StructReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.TimestampReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.TypeReflection.Descriptor, global::Google.Protobuf.WellKnownTypes.WrappersReflection.Descriptor, },
           new pbr::GeneratedCodeInfo(null, new pbr::GeneratedCodeInfo[] {
-            new pbr::GeneratedCodeInfo(typeof(global::Google.Protobuf.TestProtos.TestWellKnownTypes), global::Google.Protobuf.TestProtos.TestWellKnownTypes.Parser, new[]{ "AnyField", "ApiField", "DurationField", "EmptyField", "FieldMaskField", "SourceContextField", "StructField", "TimestampField", "TypeField", "DoubleField", "FloatField", "Int64Field", "Uint64Field", "Int32Field", "Uint32Field", "BoolField", "StringField", "BytesField" }, null, null, null),
+            new pbr::GeneratedCodeInfo(typeof(global::Google.Protobuf.TestProtos.TestWellKnownTypes), global::Google.Protobuf.TestProtos.TestWellKnownTypes.Parser, new[]{ "AnyField", "ApiField", "DurationField", "EmptyField", "FieldMaskField", "SourceContextField", "StructField", "TimestampField", "TypeField", "DoubleField", "FloatField", "Int64Field", "Uint64Field", "Int32Field", "Uint32Field", "BoolField", "StringField", "BytesField", "ValueField" }, null, null, null),
             new pbr::GeneratedCodeInfo(typeof(global::Google.Protobuf.TestProtos.RepeatedWellKnownTypes), global::Google.Protobuf.TestProtos.RepeatedWellKnownTypes.Parser, new[]{ "AnyField", "ApiField", "DurationField", "EmptyField", "FieldMaskField", "SourceContextField", "StructField", "TimestampField", "TypeField", "DoubleField", "FloatField", "Int64Field", "Uint64Field", "Int32Field", "Uint32Field", "BoolField", "StringField", "BytesField" }, null, null, null),
             new pbr::GeneratedCodeInfo(typeof(global::Google.Protobuf.TestProtos.OneofWellKnownTypes), global::Google.Protobuf.TestProtos.OneofWellKnownTypes.Parser, new[]{ "AnyField", "ApiField", "DurationField", "EmptyField", "FieldMaskField", "SourceContextField", "StructField", "TimestampField", "TypeField", "DoubleField", "FloatField", "Int64Field", "Uint64Field", "Int32Field", "Uint32Field", "BoolField", "StringField", "BytesField" }, new[]{ "OneofField" }, null, null),
             new pbr::GeneratedCodeInfo(typeof(global::Google.Protobuf.TestProtos.MapWellKnownTypes), global::Google.Protobuf.TestProtos.MapWellKnownTypes.Parser, new[]{ "AnyField", "ApiField", "DurationField", "EmptyField", "FieldMaskField", "SourceContextField", "StructField", "TimestampField", "TypeField", "DoubleField", "FloatField", "Int64Field", "Uint64Field", "Int32Field", "Uint32Field", "BoolField", "StringField", "BytesField" }, null, null, new pbr::GeneratedCodeInfo[] { null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, })
@@ -215,6 +216,7 @@ namespace Google.Protobuf.TestProtos {
       BoolField = other.BoolField;
       StringField = other.StringField;
       BytesField = other.BytesField;
+      ValueField = other.valueField_ != null ? other.ValueField.Clone() : null;
     }
 
     public TestWellKnownTypes Clone() {
@@ -410,6 +412,19 @@ namespace Google.Protobuf.TestProtos {
       }
     }
 
+    /// <summary>Field number for the "value_field" field.</summary>
+    public const int ValueFieldFieldNumber = 19;
+    private global::Google.Protobuf.WellKnownTypes.Value valueField_;
+    /// <summary>
+    ///  Part of struct, but useful to be able to test separately
+    /// </summary>
+    public global::Google.Protobuf.WellKnownTypes.Value ValueField {
+      get { return valueField_; }
+      set {
+        valueField_ = value;
+      }
+    }
+
     public override bool Equals(object other) {
       return Equals(other as TestWellKnownTypes);
     }
@@ -439,6 +454,7 @@ namespace Google.Protobuf.TestProtos {
       if (BoolField != other.BoolField) return false;
       if (StringField != other.StringField) return false;
       if (BytesField != other.BytesField) return false;
+      if (!object.Equals(ValueField, other.ValueField)) return false;
       return true;
     }
 
@@ -462,6 +478,7 @@ namespace Google.Protobuf.TestProtos {
       if (boolField_ != null) hash ^= BoolField.GetHashCode();
       if (stringField_ != null) hash ^= StringField.GetHashCode();
       if (bytesField_ != null) hash ^= BytesField.GetHashCode();
+      if (valueField_ != null) hash ^= ValueField.GetHashCode();
       return hash;
     }
 
@@ -533,6 +550,10 @@ namespace Google.Protobuf.TestProtos {
       if (bytesField_ != null) {
         _single_bytesField_codec.WriteTagAndValue(output, BytesField);
       }
+      if (valueField_ != null) {
+        output.WriteRawTag(154, 1);
+        output.WriteMessage(ValueField);
+      }
     }
 
     public int CalculateSize() {
@@ -591,6 +612,9 @@ namespace Google.Protobuf.TestProtos {
       if (bytesField_ != null) {
         size += _single_bytesField_codec.CalculateSizeWithTag(BytesField);
       }
+      if (valueField_ != null) {
+        size += 2 + pb::CodedOutputStream.ComputeMessageSize(ValueField);
+      }
       return size;
     }
 
@@ -697,6 +721,12 @@ namespace Google.Protobuf.TestProtos {
           BytesField = other.BytesField;
         }
       }
+      if (other.valueField_ != null) {
+        if (valueField_ == null) {
+          valueField_ = new global::Google.Protobuf.WellKnownTypes.Value();
+        }
+        ValueField.MergeFrom(other.ValueField);
+      }
     }
 
     public void MergeFrom(pb::CodedInputStream input) {
@@ -832,6 +862,13 @@ namespace Google.Protobuf.TestProtos {
             }
             break;
           }
+          case 154: {
+            if (valueField_ == null) {
+              valueField_ = new global::Google.Protobuf.WellKnownTypes.Value();
+            }
+            input.ReadMessage(valueField_);
+            break;
+          }
         }
       }
     }
diff --git a/csharp/src/Google.Protobuf.Test/WellKnownTypes/DurationTest.cs b/csharp/src/Google.Protobuf.Test/WellKnownTypes/DurationTest.cs
index 36012e63..1aa02e16 100644
--- a/csharp/src/Google.Protobuf.Test/WellKnownTypes/DurationTest.cs
+++ b/csharp/src/Google.Protobuf.Test/WellKnownTypes/DurationTest.cs
@@ -50,11 +50,6 @@ namespace Google.Protobuf.WellKnownTypes
             // Rounding is towards 0
             Assert.AreEqual(TimeSpan.FromTicks(2), new Duration { Nanos = 250 }.ToTimeSpan());
             Assert.AreEqual(TimeSpan.FromTicks(-2), new Duration { Nanos = -250 }.ToTimeSpan());
-
-            // Non-normalized durations
-            Assert.AreEqual(TimeSpan.FromSeconds(3), new Duration { Seconds = 1, Nanos = 2 * Duration.NanosecondsPerSecond }.ToTimeSpan());
-            Assert.AreEqual(TimeSpan.FromSeconds(1), new Duration { Seconds = 3, Nanos = -2 * Duration.NanosecondsPerSecond }.ToTimeSpan());
-            Assert.AreEqual(TimeSpan.FromSeconds(-1), new Duration { Seconds = 1, Nanos = -2 * Duration.NanosecondsPerSecond }.ToTimeSpan());
         }
 
         [Test]
@@ -100,5 +95,30 @@ namespace Google.Protobuf.WellKnownTypes
             Assert.AreEqual(new Duration { Seconds = 1 }, Duration.FromTimeSpan(TimeSpan.FromSeconds(1)));
             Assert.AreEqual(new Duration { Nanos = Duration.NanosecondsPerTick }, Duration.FromTimeSpan(TimeSpan.FromTicks(1)));
         }
+
+        [Test]
+        [TestCase(0, Duration.MaxNanoseconds + 1)]
+        [TestCase(0, Duration.MinNanoseconds - 1)]
+        [TestCase(Duration.MinSeconds - 1, 0)]
+        [TestCase(Duration.MaxSeconds + 1, 0)]
+        [TestCase(1, -1)]
+        [TestCase(-1, 1)]
+        public void ToTimeSpan_Invalid(long seconds, int nanoseconds)
+        {
+            var duration = new Duration { Seconds = seconds, Nanos = nanoseconds };
+            Assert.Throws<InvalidOperationException>(() => duration.ToTimeSpan());
+        }
+
+        [Test]
+        [TestCase(0, Duration.MaxNanoseconds)]
+        [TestCase(0, Duration.MinNanoseconds)]
+        [TestCase(Duration.MinSeconds, Duration.MinNanoseconds)]
+        [TestCase(Duration.MaxSeconds, Duration.MaxNanoseconds)]
+        public void ToTimeSpan_Valid(long seconds, int nanoseconds)
+        {
+            // Only testing that these values don't throw, unlike their similar tests in ToTimeSpan_Invalid
+            var duration = new Duration { Seconds = seconds, Nanos = nanoseconds };
+            duration.ToTimeSpan();
+        }
     }
 }
diff --git a/csharp/src/Google.Protobuf.Test/WellKnownTypes/TimestampTest.cs b/csharp/src/Google.Protobuf.Test/WellKnownTypes/TimestampTest.cs
index 597539eb..84717d66 100644
--- a/csharp/src/Google.Protobuf.Test/WellKnownTypes/TimestampTest.cs
+++ b/csharp/src/Google.Protobuf.Test/WellKnownTypes/TimestampTest.cs
@@ -61,6 +61,29 @@ namespace Google.Protobuf.WellKnownTypes
             Assert.AreEqual(new DateTime(1969, 12, 31, 23, 59, 59).AddMilliseconds(1), t2.ToDateTime());
         }
 
+        [Test]
+        [TestCase(Timestamp.UnixSecondsAtBclMinValue - 1, Timestamp.MaxNanos)]
+        [TestCase(Timestamp.UnixSecondsAtBclMaxValue + 1, 0)]
+        [TestCase(0, -1)]
+        [TestCase(0, Timestamp.MaxNanos + 1)]
+        public void ToDateTime_OutOfRange(long seconds, int nanoseconds)
+        {
+            var value = new Timestamp { Seconds = seconds, Nanos = nanoseconds };
+            Assert.Throws<InvalidOperationException>(() => value.ToDateTime());
+        }
+
+        // 1ns larger or smaller than the above values
+        [Test]
+        [TestCase(Timestamp.UnixSecondsAtBclMinValue, 0)]
+        [TestCase(Timestamp.UnixSecondsAtBclMaxValue, Timestamp.MaxNanos)]
+        [TestCase(0, 0)]
+        [TestCase(0, Timestamp.MaxNanos)]
+        public void ToDateTime_ValidBoundaries(long seconds, int nanoseconds)
+        {
+            var value = new Timestamp { Seconds = seconds, Nanos = nanoseconds };
+            value.ToDateTime();
+        }
+
         private static void AssertRoundtrip(Timestamp timestamp, DateTime dateTime)
         {
             Assert.AreEqual(timestamp, Timestamp.FromDateTime(dateTime));
diff --git a/csharp/src/Google.Protobuf.Test/WellKnownTypes/WrappersTest.cs b/csharp/src/Google.Protobuf.Test/WellKnownTypes/WrappersTest.cs
index b72ef982..a2c833fe 100644
--- a/csharp/src/Google.Protobuf.Test/WellKnownTypes/WrappersTest.cs
+++ b/csharp/src/Google.Protobuf.Test/WellKnownTypes/WrappersTest.cs
@@ -149,6 +149,30 @@ namespace Google.Protobuf.WellKnownTypes
         }
 
         [Test]
+        public void RepeatedWrappersBinaryFormat()
+        {
+            // At one point we accidentally used a packed format for repeated wrappers, which is wrong (and weird).
+            // This test is just to prove that we use the right format.
+
+            var rawOutput = new MemoryStream();
+            var output = new CodedOutputStream(rawOutput);
+            // Write a value of 5
+            output.WriteTag(RepeatedWellKnownTypes.Int32FieldFieldNumber, WireFormat.WireType.LengthDelimited);
+            output.WriteLength(2);
+            output.WriteTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint);
+            output.WriteInt32(5);
+            // Write a value of 0 (empty message)
+            output.WriteTag(RepeatedWellKnownTypes.Int32FieldFieldNumber, WireFormat.WireType.LengthDelimited);
+            output.WriteLength(0);
+            output.Flush();
+            var expectedBytes = rawOutput.ToArray();
+
+            var message = new RepeatedWellKnownTypes { Int32Field = { 5, 0 } };
+            var actualBytes = message.ToByteArray();
+            Assert.AreEqual(expectedBytes, actualBytes);
+        }
+
+        [Test]
         public void MapWrappersSerializeDeserialize()
         {
             // Note: no null values here, as they are prohibited in map fields
diff --git a/csharp/src/Google.Protobuf/Collections/RepeatedField.cs b/csharp/src/Google.Protobuf/Collections/RepeatedField.cs
index e3f65afe..1cde03bc 100644
--- a/csharp/src/Google.Protobuf/Collections/RepeatedField.cs
+++ b/csharp/src/Google.Protobuf/Collections/RepeatedField.cs
@@ -34,7 +34,6 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Text;
-using Google.Protobuf.Compatibility;
 
 namespace Google.Protobuf.Collections
 {
@@ -96,8 +95,8 @@ namespace Google.Protobuf.Collections
             // iteration.
             uint tag = input.LastTag;
             var reader = codec.ValueReader;
-            // Value types can be packed or not.
-            if (typeof(T).IsValueType() && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
+            // Non-nullable value types can be packed or not.
+            if (FieldCodec<T>.IsPackedRepeatedField(tag))
             {
                 int length = input.ReadLength();
                 if (length > 0)
@@ -134,7 +133,7 @@ namespace Google.Protobuf.Collections
                 return 0;
             }
             uint tag = codec.Tag;
-            if (typeof(T).IsValueType() && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
+            if (codec.PackedRepeatedField)
             {
                 int dataSize = CalculatePackedDataSize(codec);
                 return CodedOutputStream.ComputeRawVarint32Size(tag) +
@@ -186,7 +185,7 @@ namespace Google.Protobuf.Collections
             }
             var writer = codec.ValueWriter;
             var tag = codec.Tag;
-            if (typeof(T).IsValueType() && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited)
+            if (codec.PackedRepeatedField)
             {
                 // Packed primitive type
                 uint size = (uint)CalculatePackedDataSize(codec);
diff --git a/csharp/src/Google.Protobuf/FieldCodec.cs b/csharp/src/Google.Protobuf/FieldCodec.cs
index c2b8d268..98313088 100644
--- a/csharp/src/Google.Protobuf/FieldCodec.cs
+++ b/csharp/src/Google.Protobuf/FieldCodec.cs
@@ -30,6 +30,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endregion
 
+using Google.Protobuf.Compatibility;
 using Google.Protobuf.WellKnownTypes;
 using System;
 using System.Collections.Generic;
@@ -329,17 +330,24 @@ namespace Google.Protobuf
     }
 
     /// <summary>
+    /// <para>
     /// An encode/decode pair for a single field. This effectively encapsulates
     /// all the information needed to read or write the field value from/to a coded
     /// stream.
+    /// </para>
+    /// <para>
+    /// This class is public and has to be as it is used by generated code, but its public
+    /// API is very limited - just what the generated code needs to call directly.
+    /// </para>
     /// </summary>
     /// <remarks>
-    /// This never writes default values to the stream, and is not currently designed
-    /// to play well with packed arrays.
+    /// This never writes default values to the stream, and does not address "packedness"
+    /// in repeated fields itself, other than to know whether or not the field *should* be packed.
     /// </remarks>
     public sealed class FieldCodec<T>
     {
         private static readonly T DefaultDefault;
+        private static readonly bool TypeSupportsPacking = typeof(T).IsValueType() && Nullable.GetUnderlyingType(typeof(T)) == null;
 
         static FieldCodec()
         {
@@ -354,75 +362,31 @@ namespace Google.Protobuf
             // Otherwise it's the default value of the CLR type
         }
 
-        private readonly Func<CodedInputStream, T> reader;
-        private readonly Action<CodedOutputStream, T> writer;
-        private readonly Func<T, int> sizeCalculator;
-        private readonly uint tag;
-        private readonly int tagSize;
-        private readonly int fixedSize;
-        // Default value for this codec. Usually the same for every instance of the same type, but
-        // for string/ByteString wrapper fields the codec's default value is null, whereas for
-        // other string/ByteString fields it's "" or ByteString.Empty.
-        private readonly T defaultValue;
+        internal static bool IsPackedRepeatedField(uint tag) =>
+            TypeSupportsPacking && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited;
 
-        internal FieldCodec(
-            Func<CodedInputStream, T> reader,
-            Action<CodedOutputStream, T> writer,
-            Func<T, int> sizeCalculator,
-            uint tag) : this(reader, writer, sizeCalculator, tag, DefaultDefault)
-        {
-        }
-
-        internal FieldCodec(
-            Func<CodedInputStream, T> reader,
-            Action<CodedOutputStream, T> writer,
-            Func<T, int> sizeCalculator,
-            uint tag,
-            T defaultValue)
-        {
-            this.reader = reader;
-            this.writer = writer;
-            this.sizeCalculator = sizeCalculator;
-            this.fixedSize = 0;
-            this.tag = tag;
-            this.defaultValue = defaultValue;
-            tagSize = CodedOutputStream.ComputeRawVarint32Size(tag);
-        }
-
-        internal FieldCodec(
-            Func<CodedInputStream, T> reader,
-            Action<CodedOutputStream, T> writer,
-            int fixedSize,
-            uint tag)
-        {
-            this.reader = reader;
-            this.writer = writer;
-            this.sizeCalculator = _ => fixedSize;
-            this.fixedSize = fixedSize;
-            this.tag = tag;
-            tagSize = CodedOutputStream.ComputeRawVarint32Size(tag);
-        }
+        internal bool PackedRepeatedField { get; }
 
         /// <summary>
-        /// Returns the size calculator for just a value.
+        /// Returns a delegate to write a value (unconditionally) to a coded output stream.
         /// </summary>
-        internal Func<T, int> ValueSizeCalculator { get { return sizeCalculator; } }
+        internal Action<CodedOutputStream, T> ValueWriter { get; }
 
         /// <summary>
-        /// Returns a delegate to write a value (unconditionally) to a coded output stream.
+        /// Returns the size calculator for just a value.
         /// </summary>
-        internal Action<CodedOutputStream, T> ValueWriter { get { return writer; } }
+        internal Func<T, int> ValueSizeCalculator { get; }
 
         /// <summary>
         /// Returns a delegate to read a value from a coded input stream. It is assumed that
         /// the stream is already positioned on the appropriate tag.
         /// </summary>
-        internal Func<CodedInputStream, T> ValueReader { get { return reader; } }
+        internal Func<CodedInputStream, T> ValueReader { get; }
 
         /// <summary>
         /// Returns the fixed size for an entry, or 0 if sizes vary.
         /// </summary>
-        internal int FixedSize { get { return fixedSize; } }
+        internal int FixedSize { get; }
 
         /// <summary>
         /// Gets the tag of the codec.
@@ -430,15 +394,54 @@ namespace Google.Protobuf
         /// <value>
         /// The tag of the codec.
         /// </value>
-        public uint Tag { get { return tag; } }
+        internal uint Tag { get; }
 
         /// <summary>
-        /// Gets the default value of the codec's type.
+        /// Default value for this codec. Usually the same for every instance of the same type, but
+        /// for string/ByteString wrapper fields the codec's default value is null, whereas for
+        /// other string/ByteString fields it's "" or ByteString.Empty.
         /// </summary>
         /// <value>
         /// The default value of the codec's type.
         /// </value>
-        public T DefaultValue { get { return defaultValue; } }
+        internal T DefaultValue { get; }
+
+        private readonly int tagSize;
+        
+        internal FieldCodec(
+                Func<CodedInputStream, T> reader,
+                Action<CodedOutputStream, T> writer,
+                int fixedSize,
+                uint tag) : this(reader, writer, _ => fixedSize, tag)
+        {
+            FixedSize = fixedSize;
+        }
+
+        internal FieldCodec(
+            Func<CodedInputStream, T> reader,
+            Action<CodedOutputStream, T> writer,
+            Func<T, int> sizeCalculator,
+            uint tag) : this(reader, writer, sizeCalculator, tag, DefaultDefault)
+        {
+        }
+
+        internal FieldCodec(
+            Func<CodedInputStream, T> reader,
+            Action<CodedOutputStream, T> writer,
+            Func<T, int> sizeCalculator,
+            uint tag,
+            T defaultValue)
+        {
+            ValueReader = reader;
+            ValueWriter = writer;
+            ValueSizeCalculator = sizeCalculator;
+            FixedSize = 0;
+            Tag = tag;
+            DefaultValue = defaultValue;
+            tagSize = CodedOutputStream.ComputeRawVarint32Size(tag);
+            // Detect packed-ness once, so we can check for it within RepeatedField<T>.
+            PackedRepeatedField = IsPackedRepeatedField(tag);
+        }
 
         /// <summary>
         /// Write a tag and the given value, *if* the value is not the default.
@@ -447,8 +450,8 @@ namespace Google.Protobuf
         {
             if (!IsDefault(value))
             {
-                output.WriteTag(tag);
-                writer(output, value);
+                output.WriteTag(Tag);
+                ValueWriter(output, value);
             }
         }
 
@@ -457,23 +460,14 @@ namespace Google.Protobuf
         /// </summary>
         /// <param name="input">The input stream to read from.</param>
         /// <returns>The value read from the stream.</returns>
-        public T Read(CodedInputStream input)
-        {
-            return reader(input);
-        }
+        public T Read(CodedInputStream input) => ValueReader(input);
 
         /// <summary>
         /// Calculates the size required to write the given value, with a tag,
         /// if the value is not the default.
         /// </summary>
-        public int CalculateSizeWithTag(T value)
-        {
-            return IsDefault(value) ? 0 : sizeCalculator(value) + tagSize;
-        }
+        public int CalculateSizeWithTag(T value) => IsDefault(value) ? 0 : ValueSizeCalculator(value) + tagSize;
 
-        private bool IsDefault(T value)
-        {
-            return EqualityComparer<T>.Default.Equals(value, defaultValue);
-        }
+        private bool IsDefault(T value) => EqualityComparer<T>.Default.Equals(value, DefaultValue);
     }
 }
diff --git a/csharp/src/Google.Protobuf/InvalidProtocolBufferException.cs b/csharp/src/Google.Protobuf/InvalidProtocolBufferException.cs
index cacda648..eeb0f13a 100644
--- a/csharp/src/Google.Protobuf/InvalidProtocolBufferException.cs
+++ b/csharp/src/Google.Protobuf/InvalidProtocolBufferException.cs
@@ -30,6 +30,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 #endregion

 

+using System;

 using System.IO;

 

 namespace Google.Protobuf

@@ -45,6 +46,11 @@ namespace Google.Protobuf
         {

         }

 

+        internal InvalidProtocolBufferException(string message, Exception innerException)

+            : base(message, innerException)

+        {

+        }

+

         internal static InvalidProtocolBufferException MoreDataAvailable()

         {

             return new InvalidProtocolBufferException(

@@ -82,6 +88,11 @@ namespace Google.Protobuf
                 "Protocol message contained an invalid tag (zero).");

         }

 

+        internal static InvalidProtocolBufferException InvalidBase64(Exception innerException)

+        {

+            return new InvalidProtocolBufferException("Invalid base64 data", innerException);

+        }

+

         internal static InvalidProtocolBufferException InvalidEndTag()

         {

             return new InvalidProtocolBufferException(

diff --git a/csharp/src/Google.Protobuf/JsonFormatter.cs b/csharp/src/Google.Protobuf/JsonFormatter.cs
index e89154b4..21239cf2 100644
--- a/csharp/src/Google.Protobuf/JsonFormatter.cs
+++ b/csharp/src/Google.Protobuf/JsonFormatter.cs
@@ -214,11 +214,6 @@ namespace Google.Protobuf
                 {
                     continue;
                 }
-                // Omit awkward (single) values such as unknown enum values
-                if (!field.IsRepeated && !field.IsMap && !CanWriteSingleValue(value))
-                {
-                    continue;
-                }
 
                 // Okay, all tests complete: let's write the field value...
                 if (!first)
@@ -233,6 +228,31 @@ namespace Google.Protobuf
             return !first;
         }
 
+        /// <summary>
+        /// Camel-case converter with added strictness for field mask formatting.
+        /// </summary>
+        /// <exception cref="InvalidOperationException">The field mask is invalid for JSON representation</exception>
+        private static string ToCamelCaseForFieldMask(string input)
+        {
+            for (int i = 0; i < input.Length; i++)
+            {
+                char c = input[i];
+                if (c >= 'A' && c <= 'Z')
+                {
+                    throw new InvalidOperationException($"Invalid field mask to be converted to JSON: {input}");
+                }
+                if (c == '_' && i < input.Length - 1)
+                {
+                    char next = input[i + 1];
+                    if (next < 'a' || next > 'z')
+                    {
+                        throw new InvalidOperationException($"Invalid field mask to be converted to JSON: {input}");
+                    }
+                }
+            }
+            return ToCamelCase(input);
+        }
+
         // Converted from src/google/protobuf/util/internal/utility.cc ToCamelCase
         // TODO: Use the new field in FieldDescriptor.
         internal static string ToCamelCase(string input)
@@ -381,7 +401,14 @@ namespace Google.Protobuf
             }
             else if (value is System.Enum)
             {
-                WriteString(builder, value.ToString());
+                if (System.Enum.IsDefined(value.GetType(), value))
+                {
+                    WriteString(builder, value.ToString());
+                }
+                else
+                {
+                    WriteValue(builder, (int) value);
+                }
             }
             else if (value is float || value is double)
             {
@@ -494,13 +521,14 @@ namespace Google.Protobuf
             int nanos = (int) value.Descriptor.Fields[Timestamp.NanosFieldNumber].Accessor.GetValue(value);
             long seconds = (long) value.Descriptor.Fields[Timestamp.SecondsFieldNumber].Accessor.GetValue(value);
 
-            // Even if the original message isn't using the built-in classes, we can still build one... and then
-            // rely on it being normalized.
-            Timestamp normalized = Timestamp.Normalize(seconds, nanos);
+            // Even if the original message isn't using the built-in classes, we can still build one... and its
+            // conversion will check whether or not it's normalized.
+            // TODO: Perhaps the diagnostic-only formatter should not throw for non-normalized values?
+            Timestamp ts = new Timestamp { Seconds = seconds, Nanos = nanos };
             // Use .NET's formatting for the value down to the second, including an opening double quote (as it's a string value)
-            DateTime dateTime = normalized.ToDateTime();
+            DateTime dateTime = ts.ToDateTime();
             builder.Append(dateTime.ToString("yyyy'-'MM'-'dd'T'HH:mm:ss", CultureInfo.InvariantCulture));
-            AppendNanoseconds(builder, Math.Abs(normalized.Nanos));
+            AppendNanoseconds(builder, Math.Abs(ts.Nanos));
             builder.Append("Z\"");
         }
 
@@ -511,25 +539,29 @@ namespace Google.Protobuf
             int nanos = (int) value.Descriptor.Fields[Duration.NanosFieldNumber].Accessor.GetValue(value);
             long seconds = (long) value.Descriptor.Fields[Duration.SecondsFieldNumber].Accessor.GetValue(value);
 
+            // TODO: Perhaps the diagnostic-only formatter should not throw for non-normalized values?
             // Even if the original message isn't using the built-in classes, we can still build one... and then
             // rely on it being normalized.
-            Duration normalized = Duration.Normalize(seconds, nanos);
+            if (!Duration.IsNormalized(seconds, nanos))
+            {
+                throw new InvalidOperationException("Non-normalized duration value");
+            }
 
             // The seconds part will normally provide the minus sign if we need it, but not if it's 0...
-            if (normalized.Seconds == 0 && normalized.Nanos < 0)
+            if (seconds == 0 && nanos < 0)
             {
                 builder.Append('-');
             }
 
-            builder.Append(normalized.Seconds.ToString("d", CultureInfo.InvariantCulture));
-            AppendNanoseconds(builder, Math.Abs(normalized.Nanos));
+            builder.Append(seconds.ToString("d", CultureInfo.InvariantCulture));
+            AppendNanoseconds(builder, Math.Abs(nanos));
             builder.Append("s\"");
         }
 
         private void WriteFieldMask(StringBuilder builder, IMessage value)
         {
             IList paths = (IList) value.Descriptor.Fields[FieldMask.PathsFieldNumber].Accessor.GetValue(value);
-            WriteString(builder, string.Join(",", paths.Cast<string>().Select(ToCamelCase)));
+            WriteString(builder, string.Join(",", paths.Cast<string>().Select(ToCamelCaseForFieldMask)));
         }
 
         private void WriteAny(StringBuilder builder, IMessage value)
@@ -607,15 +639,15 @@ namespace Google.Protobuf
                 // Output to 3, 6 or 9 digits.
                 if (nanos % 1000000 == 0)
                 {
-                    builder.Append((nanos / 1000000).ToString("d", CultureInfo.InvariantCulture));
+                    builder.Append((nanos / 1000000).ToString("d3", CultureInfo.InvariantCulture));
                 }
                 else if (nanos % 1000 == 0)
                 {
-                    builder.Append((nanos / 1000).ToString("d", CultureInfo.InvariantCulture));
+                    builder.Append((nanos / 1000).ToString("d6", CultureInfo.InvariantCulture));
                 }
                 else
                 {
-                    builder.Append(nanos.ToString("d", CultureInfo.InvariantCulture));
+                    builder.Append(nanos.ToString("d9", CultureInfo.InvariantCulture));
                 }
             }
         }
@@ -683,10 +715,6 @@ namespace Google.Protobuf
             bool first = true;
             foreach (var value in list)
             {
-                if (!CanWriteSingleValue(value))
-                {
-                    continue;
-                }
                 if (!first)
                 {
                     builder.Append(PropertySeparator);
@@ -704,10 +732,6 @@ namespace Google.Protobuf
             // This will box each pair. Could use IDictionaryEnumerator, but that's ugly in terms of disposal.
             foreach (DictionaryEntry pair in dictionary)
             {
-                if (!CanWriteSingleValue(pair.Value))
-                {
-                    continue;
-                }
                 if (!first)
                 {
                     builder.Append(PropertySeparator);
diff --git a/csharp/src/Google.Protobuf/JsonParser.cs b/csharp/src/Google.Protobuf/JsonParser.cs
index 300a66b4..c07b16ea 100644
--- a/csharp/src/Google.Protobuf/JsonParser.cs
+++ b/csharp/src/Google.Protobuf/JsonParser.cs
@@ -168,6 +168,10 @@ namespace Google.Protobuf
             }
             var descriptor = message.Descriptor;
             var jsonFieldMap = descriptor.Fields.ByJsonName();
+            // All the oneof fields we've already accounted for - we can only see each of them once.
+            // The set is created lazily to avoid the overhead of creating a set for every message
+            // we parsed, when oneofs are relatively rare.
+            HashSet<OneofDescriptor> seenOneofs = null;
             while (true)
             {
                 token = tokenizer.Next();
@@ -183,6 +187,17 @@ namespace Google.Protobuf
                 FieldDescriptor field;
                 if (jsonFieldMap.TryGetValue(name, out field))
                 {
+                    if (field.ContainingOneof != null)
+                    {
+                        if (seenOneofs == null)
+                        {
+                            seenOneofs = new HashSet<OneofDescriptor>();
+                        }
+                        if (!seenOneofs.Add(field.ContainingOneof))
+                        {
+                            throw new InvalidProtocolBufferException($"Multiple values specified for oneof {field.ContainingOneof.Name}");
+                        }
+                    }
                     MergeField(message, field, tokenizer);
                 }
                 else
@@ -200,10 +215,15 @@ namespace Google.Protobuf
             var token = tokenizer.Next();
             if (token.Type == JsonToken.TokenType.Null)
             {
+                // Clear the field if we see a null token, unless it's for a singular field of type
+                // google.protobuf.Value.
                 // Note: different from Java API, which just ignores it.
                 // TODO: Bring it more in line? Discuss...
-                field.Accessor.Clear(message);
-                return;
+                if (field.IsMap || field.IsRepeated || !IsGoogleProtobufValueField(field))
+                {
+                    field.Accessor.Clear(message);
+                    return;
+                }
             }
             tokenizer.PushBack(token);
 
@@ -239,6 +259,10 @@ namespace Google.Protobuf
                     return;
                 }
                 tokenizer.PushBack(token);
+                if (token.Type == JsonToken.TokenType.Null)
+                {
+                    throw new InvalidProtocolBufferException("Repeated field elements cannot be null");
+                }
                 list.Add(ParseSingleValue(field, tokenizer));
             }
         }
@@ -270,19 +294,30 @@ namespace Google.Protobuf
                 }
                 object key = ParseMapKey(keyField, token.StringValue);
                 object value = ParseSingleValue(valueField, tokenizer);
-                // TODO: Null handling
+                if (value == null)
+                {
+                    throw new InvalidProtocolBufferException("Map values must not be null");
+                }
                 dictionary[key] = value;
             }
         }
 
+        private static bool IsGoogleProtobufValueField(FieldDescriptor field)
+        {
+            return field.FieldType == FieldType.Message &&
+                field.MessageType.FullName == Value.Descriptor.FullName;
+        }
+
         private object ParseSingleValue(FieldDescriptor field, JsonTokenizer tokenizer)
         {
             var token = tokenizer.Next();
             if (token.Type == JsonToken.TokenType.Null)
             {
-                if (field.FieldType == FieldType.Message && field.MessageType.FullName == Value.Descriptor.FullName)
+                // TODO: In order to support dynamic messages, we should really build this up
+                // dynamically.
+                if (IsGoogleProtobufValueField(field))
                 {
-                    return new Value { NullValue = NullValue.NULL_VALUE };
+                    return Value.ForNull();
                 }
                 return null;
             }
@@ -464,6 +499,11 @@ namespace Google.Protobuf
             {
                 tokens.Add(token);
                 token = tokenizer.Next();
+
+                if (tokenizer.ObjectDepth < typeUrlObjectDepth)
+                {
+                    throw new InvalidProtocolBufferException("Any message with no @type");
+                }
             }
 
             // Don't add the @type property or its value to the recorded token list
@@ -603,6 +643,11 @@ namespace Google.Protobuf
                                 throw new InvalidProtocolBufferException($"Value out of range: {value}");
                             }
                             return (float) value;
+                        case FieldType.Enum:
+                            CheckInteger(value);
+                            // Just return it as an int, and let the CLR convert it.
+                            // Note that we deliberately don't check that it's a known value.
+                            return (int) value;
                         default:
                             throw new InvalidProtocolBufferException($"Unsupported conversion from JSON number for field type {field.FieldType}");
                     }
@@ -633,7 +678,14 @@ namespace Google.Protobuf
                 case FieldType.String:
                     return text;
                 case FieldType.Bytes:
-                    return ByteString.FromBase64(text);
+                    try
+                    {
+                        return ByteString.FromBase64(text);
+                    }
+                    catch (FormatException e)
+                    {
+                        throw InvalidProtocolBufferException.InvalidBase64(e);
+                    }
                 case FieldType.Int32:
                 case FieldType.SInt32:
                 case FieldType.SFixed32:
@@ -826,28 +878,24 @@ namespace Google.Protobuf
 
             try
             {
-                long seconds = long.Parse(secondsText, CultureInfo.InvariantCulture);
+                long seconds = long.Parse(secondsText, CultureInfo.InvariantCulture) * multiplier;
                 int nanos = 0;
                 if (subseconds != "")
                 {
                     // This should always work, as we've got 1-9 digits.
                     int parsedFraction = int.Parse(subseconds.Substring(1));
-                    nanos = parsedFraction * SubsecondScalingFactors[subseconds.Length];
+                    nanos = parsedFraction * SubsecondScalingFactors[subseconds.Length] * multiplier;
                 }
-                if (seconds >= Duration.MaxSeconds)
+                if (!Duration.IsNormalized(seconds, nanos))
                 {
-                    // Allow precisely 315576000000 seconds, but prohibit even 1ns more.
-                    if (seconds > Duration.MaxSeconds || nanos > 0)
-                    {
-                        throw new InvalidProtocolBufferException("Invalid Duration value: " + token.StringValue);
-                    }
+                    throw new InvalidProtocolBufferException($"Invalid Duration value: {token.StringValue}");
                 }
-                message.Descriptor.Fields[Duration.SecondsFieldNumber].Accessor.SetValue(message, seconds * multiplier);
-                message.Descriptor.Fields[Duration.NanosFieldNumber].Accessor.SetValue(message, nanos * multiplier);
+                message.Descriptor.Fields[Duration.SecondsFieldNumber].Accessor.SetValue(message, seconds);
+                message.Descriptor.Fields[Duration.NanosFieldNumber].Accessor.SetValue(message, nanos);
             }
             catch (FormatException)
             {
-                throw new InvalidProtocolBufferException("Invalid Duration value: " + token.StringValue);
+                throw new InvalidProtocolBufferException($"Invalid Duration value: {token.StringValue}");
             }
         }
 
@@ -870,6 +918,8 @@ namespace Google.Protobuf
         private static string ToSnakeCase(string text)
         {
             var builder = new StringBuilder(text.Length * 2);
+            // Note: this is probably unnecessary now, but currently retained to be as close as possible to the
+            // C++, whilst still throwing an exception on underscores.
             bool wasNotUnderscore = false;  // Initialize to false for case 1 (below)
             bool wasNotCap = false;
 
@@ -903,7 +953,11 @@ namespace Google.Protobuf
                 else
                 {
                     builder.Append(c);
-                    wasNotUnderscore = c != '_';
+                    if (c == '_')
+                    {
+                        throw new InvalidProtocolBufferException($"Invalid field mask: {text}");
+                    }
+                    wasNotUnderscore = true;
                     wasNotCap = true;
                 }
             }
diff --git a/csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs b/csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs
index d1732b2e..f43803a6 100644
--- a/csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs
+++ b/csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs
@@ -92,11 +92,22 @@ namespace Google.Protobuf.Reflection
                 new FieldDescriptor(field, file, this, index, generatedCodeInfo?.PropertyNames[index]));
             fieldsInNumberOrder = new ReadOnlyCollection<FieldDescriptor>(fieldsInDeclarationOrder.OrderBy(field => field.FieldNumber).ToArray());
             // TODO: Use field => field.Proto.JsonName when we're confident it's appropriate. (And then use it in the formatter, too.)
-            jsonFieldMap = new ReadOnlyDictionary<string, FieldDescriptor>(fieldsInNumberOrder.ToDictionary(field => JsonFormatter.ToCamelCase(field.Name)));
+            jsonFieldMap = CreateJsonFieldMap(fieldsInNumberOrder);
             file.DescriptorPool.AddSymbol(this);
             Fields = new FieldCollection(this);
         }
 
+        private static ReadOnlyDictionary<string, FieldDescriptor> CreateJsonFieldMap(IList<FieldDescriptor> fields)
+        {
+            var map = new Dictionary<string, FieldDescriptor>();
+            foreach (var field in fields)
+            {
+                map[JsonFormatter.ToCamelCase(field.Name)] = field;
+                map[field.Name] = field;
+            }
+            return new ReadOnlyDictionary<string, FieldDescriptor>(map);
+        }
+
         /// <summary>
         /// The brief name of the descriptor's target.
         /// </summary>
@@ -255,9 +266,10 @@ namespace Google.Protobuf.Reflection
             // TODO: consider making this public in the future. (Being conservative for now...)
 
             /// <value>
-            /// Returns a read-only dictionary mapping the field names in this message as they're used
+            /// Returns a read-only dictionary mapping the field names in this message as they're available
             /// in the JSON representation to the field descriptors. For example, a field <c>foo_bar</c>
-            /// in the message would result in an entry with a key <c>fooBar</c>.
+            /// in the message would result two entries, one with a key <c>fooBar</c> and one with a key
+            /// <c>foo_bar</c>, both referring to the same field.
             /// </value>
             internal IDictionary<string, FieldDescriptor> ByJsonName() => messageDescriptor.jsonFieldMap;
 
diff --git a/csharp/src/Google.Protobuf/WellKnownTypes/DurationPartial.cs b/csharp/src/Google.Protobuf/WellKnownTypes/DurationPartial.cs
index 324f48fc..b8eba9d3 100644
--- a/csharp/src/Google.Protobuf/WellKnownTypes/DurationPartial.cs
+++ b/csharp/src/Google.Protobuf/WellKnownTypes/DurationPartial.cs
@@ -57,15 +57,38 @@ namespace Google.Protobuf.WellKnownTypes
         /// </summary>
         public const long MinSeconds = -315576000000L;
 
+        internal const int MaxNanoseconds = NanosecondsPerSecond - 1;
+        internal const int MinNanoseconds = -NanosecondsPerSecond + 1;
+
+        internal static bool IsNormalized(long seconds, int nanoseconds)
+        {
+            // Simple boundaries
+            if (seconds < MinSeconds || seconds > MaxSeconds ||
+                nanoseconds < MinNanoseconds || nanoseconds > MaxNanoseconds)
+            {
+                return false;
+            }
+            // We only have a problem is one is strictly negative and the other is
+            // strictly positive.
+            return Math.Sign(seconds) * Math.Sign(nanoseconds) != -1;
+        }
+
+
         /// <summary>
         /// Converts this <see cref="Duration"/> to a <see cref="TimeSpan"/>.
         /// </summary>
         /// <remarks>If the duration is not a precise number of ticks, it is truncated towards 0.</remarks>
         /// <returns>The value of this duration, as a <c>TimeSpan</c>.</returns>
+        /// <exception cref="InvalidOperationException">This value isn't a valid normalized duration, as
+        /// described in the documentation.</exception>
         public TimeSpan ToTimeSpan()
         {
             checked
             {
+                if (!IsNormalized(Seconds, Nanos))
+                {
+                    throw new InvalidOperationException("Duration was not a valid normalized duration");
+                }
                 long ticks = Seconds * TimeSpan.TicksPerSecond + Nanos / NanosecondsPerTick;
                 return TimeSpan.FromTicks(ticks);
             }
diff --git a/csharp/src/Google.Protobuf/WellKnownTypes/TimestampPartial.cs b/csharp/src/Google.Protobuf/WellKnownTypes/TimestampPartial.cs
index d284acd6..7c50a3d7 100644
--- a/csharp/src/Google.Protobuf/WellKnownTypes/TimestampPartial.cs
+++ b/csharp/src/Google.Protobuf/WellKnownTypes/TimestampPartial.cs
@@ -37,9 +37,17 @@ namespace Google.Protobuf.WellKnownTypes
     public partial class Timestamp
     {
         private static readonly DateTime UnixEpoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
-        private static readonly long BclSecondsAtUnixEpoch = UnixEpoch.Ticks / TimeSpan.TicksPerSecond;
-        internal static readonly long UnixSecondsAtBclMinValue = -BclSecondsAtUnixEpoch;
-        internal static readonly long UnixSecondsAtBclMaxValue = (DateTime.MaxValue.Ticks / TimeSpan.TicksPerSecond) - BclSecondsAtUnixEpoch;
+        // Constants determined programmatically, but then hard-coded so they can be constant expressions.
+        private const long BclSecondsAtUnixEpoch = 62135596800;
+        internal const long UnixSecondsAtBclMaxValue = 253402300799;
+        internal const long UnixSecondsAtBclMinValue = -BclSecondsAtUnixEpoch;
+        internal const int MaxNanos = Duration.NanosecondsPerSecond - 1;
+
+        private bool IsNormalized =>
+            Nanos >= 0 &&
+            Nanos <= MaxNanos &&
+            Seconds >= UnixSecondsAtBclMinValue &&
+            Seconds <= UnixSecondsAtBclMaxValue;
 
         /// <summary>
         /// Returns the difference between one <see cref="Timestamp"/> and another, as a <see cref="Duration"/>.
@@ -99,8 +107,14 @@ namespace Google.Protobuf.WellKnownTypes
         /// <see cref="DateTime"/> value precisely on a second.
         /// </remarks>
         /// <returns>This timestamp as a <c>DateTime</c>.</returns>
+        /// <exception cref="InvalidOperationException">The timestamp contains invalid values; either it is
+        /// incorrectly normalized or is outside the valid range.</exception>
         public DateTime ToDateTime()
         {
+            if (!IsNormalized)
+            {
+                throw new InvalidOperationException(@"Timestamp contains invalid values: Seconds={Seconds}; Nanos={Nanos}");
+            }
             return UnixEpoch.AddSeconds(Seconds).AddTicks(Nanos / Duration.NanosecondsPerTick);
         }
 
@@ -114,6 +128,8 @@ namespace Google.Protobuf.WellKnownTypes
         /// <see cref="DateTimeOffset"/> value precisely on a second.
         /// </remarks>
         /// <returns>This timestamp as a <c>DateTimeOffset</c>.</returns>
+        /// <exception cref="InvalidOperationException">The timestamp contains invalid values; either it is
+        /// incorrectly normalized or is outside the valid range.</exception>
         public DateTimeOffset ToDateTimeOffset()
         {
             return new DateTimeOffset(ToDateTime(), TimeSpan.Zero);
diff --git a/java/core/generate-sources-build.xml b/java/core/generate-sources-build.xml
new file mode 100644
index 00000000..0996e5ff
--- /dev/null
+++ b/java/core/generate-sources-build.xml
@@ -0,0 +1,20 @@
+<project name="generate-sources">
+    <echo message="Running protoc ..."/>
+    <mkdir dir="${generated.sources.dir}"/>
+    <exec executable="${protoc}">
+        <arg value="--java_out=${generated.sources.dir}"/>
+        <arg value="--proto_path=${protobuf.source.dir}"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/any.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/api.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/descriptor.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/duration.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/empty.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/field_mask.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/source_context.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/struct.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/timestamp.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/type.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/wrappers.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/compiler/plugin.proto"/>
+    </exec>
+</project>
\ No newline at end of file
diff --git a/java/core/generate-test-sources-build.xml b/java/core/generate-test-sources-build.xml
new file mode 100644
index 00000000..ab415db6
--- /dev/null
+++ b/java/core/generate-test-sources-build.xml
@@ -0,0 +1,43 @@
+<project name="generate-test-sources">
+    <mkdir dir="${generated.testsources.dir}"/>
+    <exec executable="${protoc}">
+        <arg value="--java_out=${generated.testsources.dir}"/>
+        <arg value="--proto_path=${protobuf.source.dir}"/>
+        <arg value="--proto_path=${test.proto.dir}"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_public.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_mset.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_mset_wire_format.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_optimize_for.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_custom_options.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_import_public_lite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_lite_imports_nonlite.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_enormous_descriptor.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_no_generic_services.proto"/>
+        <arg value="${protobuf.source.dir}/google/protobuf/unittest_well_known_types.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/lazy_fields_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/lite_equals_and_hash.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/multiple_files_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_builders_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_extension.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/nested_extension_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/non_nested_extension.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/non_nested_extension_lite.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test2.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/outer_class_name_test3.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_bad_identifiers.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_check_utf8.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_check_utf8_size.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/test_custom_options.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/any_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/field_presence_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_for_proto2_lite_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_for_proto2_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_test.proto"/>
+        <arg value="${test.proto.dir}/com/google/protobuf/map_initialization_order_test.proto"/>
+    </exec>
+</project>
\ No newline at end of file
diff --git a/java/core/pom.xml b/java/core/pom.xml
new file mode 100644
index 00000000..74d5ead3
--- /dev/null
+++ b/java/core/pom.xml
@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.google.protobuf</groupId>
+    <artifactId>protobuf-parent</artifactId>
+    <version>3.0.0-beta-2</version>
+  </parent>
+
+  <artifactId>protobuf-java</artifactId>
+  <packaging>bundle</packaging>
+
+  <name>Protocol Buffers [Core]</name>
+  <description>
+    Core Protocol Buffers library. Protocol Buffers are a way of encoding structured data in an
+    efficient yet extensible format.
+  </description>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymock</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymockclassextension</artifactId>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <!-- Include core protos in the bundle as resources -->
+    <resources>
+      <resource>
+        <directory>${protobuf.source.dir}</directory>
+        <includes>
+          <include>google/protobuf/any.proto</include>
+          <include>google/protobuf/api.proto</include>
+          <include>google/protobuf/descriptor.proto</include>
+          <include>google/protobuf/duration.proto</include>
+          <include>google/protobuf/empty.proto</include>
+          <include>google/protobuf/field_mask.proto</include>
+          <include>google/protobuf/source_context.proto</include>
+          <include>google/protobuf/struct.proto</include>
+          <include>google/protobuf/timestamp.proto</include>
+          <include>google/protobuf/type.proto</include>
+          <include>google/protobuf/wrappers.proto</include>
+          <include>google/protobuf/compiler/plugin.proto</include>
+        </includes>
+      </resource>
+    </resources>
+
+    <plugins>
+      <!-- Use Antrun plugin to generate sources with protoc -->
+      <plugin>
+        <artifactId>maven-antrun-plugin</artifactId>
+        <executions>
+          <!-- Generate core protos -->
+          <execution>
+            <id>generate-sources</id>
+            <phase>generate-sources</phase>
+            <configuration>
+              <target>
+                <ant antfile="generate-sources-build.xml"/>
+              </target>
+            </configuration>
+            <goals>
+              <goal>run</goal>
+            </goals>
+          </execution>
+
+          <!-- Generate the test protos -->
+          <execution>
+            <id>generate-test-sources</id>
+            <phase>generate-test-sources</phase>
+            <configuration>
+              <target>
+                <ant antfile="generate-test-sources-build.xml"/>
+              </target>
+            </configuration>
+            <goals>
+              <goal>run</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+
+      <!-- Add the generated sources to the build -->
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <generatedSourcesDirectory>${generated.sources.dir}</generatedSourcesDirectory>
+          <generatedTestSourcesDirectory>${generated.testsources.dir}</generatedTestSourcesDirectory>
+        </configuration>
+      </plugin>
+
+      <!-- OSGI bundle configuration -->
+      <plugin>
+        <groupId>org.apache.felix</groupId>
+        <artifactId>maven-bundle-plugin</artifactId>
+        <extensions>true</extensions>
+        <configuration>
+          <instructions>
+            <Bundle-DocURL>https://developers.google.com/protocol-buffers/</Bundle-DocURL>
+            <Bundle-SymbolicName>com.google.protobuf</Bundle-SymbolicName>
+            <Export-Package>com.google.protobuf;version=${project.version}</Export-Package>
+          </instructions>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>
diff --git a/java/src/main/java/com/google/protobuf/AbstractMessage.java b/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
index 9f418f2b..9f418f2b 100644
--- a/java/src/main/java/com/google/protobuf/AbstractMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractMessage.java
diff --git a/java/src/main/java/com/google/protobuf/AbstractMessageLite.java b/java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java
index 12384983..12384983 100644
--- a/java/src/main/java/com/google/protobuf/AbstractMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractMessageLite.java
diff --git a/java/src/main/java/com/google/protobuf/AbstractParser.java b/java/core/src/main/java/com/google/protobuf/AbstractParser.java
index 1a4c6311..1a4c6311 100644
--- a/java/src/main/java/com/google/protobuf/AbstractParser.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractParser.java
diff --git a/java/src/main/java/com/google/protobuf/AbstractProtobufList.java b/java/core/src/main/java/com/google/protobuf/AbstractProtobufList.java
index bb6446b2..bb6446b2 100644
--- a/java/src/main/java/com/google/protobuf/AbstractProtobufList.java
+++ b/java/core/src/main/java/com/google/protobuf/AbstractProtobufList.java
diff --git a/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java b/java/core/src/main/java/com/google/protobuf/BlockingRpcChannel.java
index d535efb9..d535efb9 100644
--- a/java/src/main/java/com/google/protobuf/BlockingRpcChannel.java
+++ b/java/core/src/main/java/com/google/protobuf/BlockingRpcChannel.java
diff --git a/java/src/main/java/com/google/protobuf/BlockingService.java b/java/core/src/main/java/com/google/protobuf/BlockingService.java
index d01f0b8f..d01f0b8f 100644
--- a/java/src/main/java/com/google/protobuf/BlockingService.java
+++ b/java/core/src/main/java/com/google/protobuf/BlockingService.java
diff --git a/java/src/main/java/com/google/protobuf/BooleanArrayList.java b/java/core/src/main/java/com/google/protobuf/BooleanArrayList.java
index 70e042f5..70e042f5 100644
--- a/java/src/main/java/com/google/protobuf/BooleanArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/BooleanArrayList.java
diff --git a/java/src/main/java/com/google/protobuf/BoundedByteString.java b/java/core/src/main/java/com/google/protobuf/BoundedByteString.java
index 934c9030..934c9030 100644
--- a/java/src/main/java/com/google/protobuf/BoundedByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/BoundedByteString.java
diff --git a/java/src/main/java/com/google/protobuf/ByteString.java b/java/core/src/main/java/com/google/protobuf/ByteString.java
index 68f20d51..68f20d51 100644
--- a/java/src/main/java/com/google/protobuf/ByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/ByteString.java
diff --git a/java/src/main/java/com/google/protobuf/CodedInputStream.java b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
index adc91536..adc91536 100644
--- a/java/src/main/java/com/google/protobuf/CodedInputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedInputStream.java
diff --git a/java/src/main/java/com/google/protobuf/CodedOutputStream.java b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
index d8ebad21..d8ebad21 100644
--- a/java/src/main/java/com/google/protobuf/CodedOutputStream.java
+++ b/java/core/src/main/java/com/google/protobuf/CodedOutputStream.java
diff --git a/java/src/main/java/com/google/protobuf/Descriptors.java b/java/core/src/main/java/com/google/protobuf/Descriptors.java
index 5e15cfbe..5e15cfbe 100644
--- a/java/src/main/java/com/google/protobuf/Descriptors.java
+++ b/java/core/src/main/java/com/google/protobuf/Descriptors.java
diff --git a/java/src/main/java/com/google/protobuf/DoubleArrayList.java b/java/core/src/main/java/com/google/protobuf/DoubleArrayList.java
index bcc9d6ee..bcc9d6ee 100644
--- a/java/src/main/java/com/google/protobuf/DoubleArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/DoubleArrayList.java
diff --git a/java/src/main/java/com/google/protobuf/DynamicMessage.java b/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
index 3ea1b688..3ea1b688 100644
--- a/java/src/main/java/com/google/protobuf/DynamicMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/DynamicMessage.java
diff --git a/java/src/main/java/com/google/protobuf/Extension.java b/java/core/src/main/java/com/google/protobuf/Extension.java
index 68d29f33..68d29f33 100644
--- a/java/src/main/java/com/google/protobuf/Extension.java
+++ b/java/core/src/main/java/com/google/protobuf/Extension.java
diff --git a/java/src/main/java/com/google/protobuf/ExtensionLite.java b/java/core/src/main/java/com/google/protobuf/ExtensionLite.java
index f8f5bd2c..f8f5bd2c 100644
--- a/java/src/main/java/com/google/protobuf/ExtensionLite.java
+++ b/java/core/src/main/java/com/google/protobuf/ExtensionLite.java
diff --git a/java/src/main/java/com/google/protobuf/ExtensionRegistry.java b/java/core/src/main/java/com/google/protobuf/ExtensionRegistry.java
index 0067392f..0067392f 100644
--- a/java/src/main/java/com/google/protobuf/ExtensionRegistry.java
+++ b/java/core/src/main/java/com/google/protobuf/ExtensionRegistry.java
diff --git a/java/src/main/java/com/google/protobuf/ExtensionRegistryLite.java b/java/core/src/main/java/com/google/protobuf/ExtensionRegistryLite.java
index 65cf7385..65cf7385 100644
--- a/java/src/main/java/com/google/protobuf/ExtensionRegistryLite.java
+++ b/java/core/src/main/java/com/google/protobuf/ExtensionRegistryLite.java
diff --git a/java/src/main/java/com/google/protobuf/FieldSet.java b/java/core/src/main/java/com/google/protobuf/FieldSet.java
index 47924b65..47924b65 100644
--- a/java/src/main/java/com/google/protobuf/FieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/FieldSet.java
diff --git a/java/src/main/java/com/google/protobuf/FloatArrayList.java b/java/core/src/main/java/com/google/protobuf/FloatArrayList.java
index 033b5eed..033b5eed 100644
--- a/java/src/main/java/com/google/protobuf/FloatArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/FloatArrayList.java
diff --git a/java/src/main/java/com/google/protobuf/GeneratedMessage.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessage.java
index d84fa75c..ceb97a4e 100644
--- a/java/src/main/java/com/google/protobuf/GeneratedMessage.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessage.java
@@ -36,15 +36,13 @@ import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
 import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
-import com.google.protobuf.GeneratedMessageLite.ExtendableMessage;
-import com.google.protobuf.GeneratedMessageLite.GeneratedExtension;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.ObjectStreamException;
 import java.io.Serializable;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Iterator;
@@ -276,6 +274,60 @@ public abstract class GeneratedMessage extends AbstractMessage
     return unknownFields.mergeFieldFrom(tag, input);
   }
 
+  protected static <M extends Message> M parseWithIOException(Parser<M> parser, InputStream input)
+      throws IOException {
+    try {
+      return parser.parseFrom(input);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseWithIOException(Parser<M> parser, InputStream input,
+      ExtensionRegistryLite extensions) throws IOException {
+    try {
+      return parser.parseFrom(input, extensions);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseWithIOException(Parser<M> parser,
+      CodedInputStream input) throws IOException {
+    try {
+      return parser.parseFrom(input);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseWithIOException(Parser<M> parser,
+      CodedInputStream input, ExtensionRegistryLite extensions) throws IOException {
+    try {
+      return parser.parseFrom(input, extensions);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseDelimitedWithIOException(Parser<M> parser,
+      InputStream input) throws IOException {
+    try {
+      return parser.parseDelimitedFrom(input);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
+  protected static <M extends Message> M parseDelimitedWithIOException(Parser<M> parser,
+      InputStream input, ExtensionRegistryLite extensions) throws IOException {
+    try {
+      return parser.parseDelimitedFrom(input, extensions);
+    } catch (InvalidProtocolBufferException e) {
+      throw e.unwrapIOException();
+    }
+  }
+
   @Override
   public void writeTo(final CodedOutputStream output) throws IOException {
     MessageReflection.writeMessageTo(this, getAllFieldsRaw(), output, false);
@@ -667,7 +719,7 @@ public abstract class GeneratedMessage extends AbstractMessage
           "No map fields found in " + getClass().getName());
     }
 
-    /** Like {@link internalGetMapField} but return a mutable version. */
+    /** Like {@link #internalGetMapField} but return a mutable version. */
     @SuppressWarnings({"unused", "rawtypes"})
     protected MapField internalGetMutableMapField(int fieldNumber) {
       // Note that we can't use descriptor names here because this method will
diff --git a/java/src/main/java/com/google/protobuf/GeneratedMessageLite.java b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
index 81e1862c..81e1862c 100644
--- a/java/src/main/java/com/google/protobuf/GeneratedMessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/GeneratedMessageLite.java
diff --git a/java/src/main/java/com/google/protobuf/IntArrayList.java b/java/core/src/main/java/com/google/protobuf/IntArrayList.java
index f4e68ed8..f4e68ed8 100644
--- a/java/src/main/java/com/google/protobuf/IntArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/IntArrayList.java
diff --git a/java/src/main/java/com/google/protobuf/Internal.java b/java/core/src/main/java/com/google/protobuf/Internal.java
index 11901998..11901998 100644
--- a/java/src/main/java/com/google/protobuf/Internal.java
+++ b/java/core/src/main/java/com/google/protobuf/Internal.java
diff --git a/java/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java b/java/core/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java
index 0a761052..85ce7b24 100644
--- a/java/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java
+++ b/java/core/src/main/java/com/google/protobuf/InvalidProtocolBufferException.java
@@ -46,6 +46,10 @@ public class InvalidProtocolBufferException extends IOException {
     super(description);
   }
 
+  public InvalidProtocolBufferException(IOException e) {
+    super(e.getMessage(), e);
+  }
+
   /**
    * Attaches an unfinished message to the exception to support best-effort
    * parsing in {@code Parser} interface.
@@ -66,6 +70,14 @@ public class InvalidProtocolBufferException extends IOException {
     return unfinishedMessage;
   }
 
+  /**
+   * Unwraps the underlying {@link IOException} if this exception was caused by an I/O
+   * problem. Otherwise, returns {@code this}.
+   */
+  public IOException unwrapIOException() {
+    return getCause() instanceof IOException ? (IOException) getCause() : this;
+  }
+
   static InvalidProtocolBufferException truncatedMessage() {
     return new InvalidProtocolBufferException(
       "While parsing a protocol message, the input ended unexpectedly " +
diff --git a/java/src/main/java/com/google/protobuf/LazyField.java b/java/core/src/main/java/com/google/protobuf/LazyField.java
index 5e0a485c..5e0a485c 100644
--- a/java/src/main/java/com/google/protobuf/LazyField.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyField.java
diff --git a/java/src/main/java/com/google/protobuf/LazyFieldLite.java b/java/core/src/main/java/com/google/protobuf/LazyFieldLite.java
index eea1fe3c..eea1fe3c 100644
--- a/java/src/main/java/com/google/protobuf/LazyFieldLite.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyFieldLite.java
diff --git a/java/src/main/java/com/google/protobuf/LazyStringArrayList.java b/java/core/src/main/java/com/google/protobuf/LazyStringArrayList.java
index c3be3cca..c3be3cca 100644
--- a/java/src/main/java/com/google/protobuf/LazyStringArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyStringArrayList.java
diff --git a/java/src/main/java/com/google/protobuf/LazyStringList.java b/java/core/src/main/java/com/google/protobuf/LazyStringList.java
index 3eeedca1..3eeedca1 100644
--- a/java/src/main/java/com/google/protobuf/LazyStringList.java
+++ b/java/core/src/main/java/com/google/protobuf/LazyStringList.java
diff --git a/java/src/main/java/com/google/protobuf/LiteralByteString.java b/java/core/src/main/java/com/google/protobuf/LiteralByteString.java
index a18c2792..a18c2792 100644
--- a/java/src/main/java/com/google/protobuf/LiteralByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/LiteralByteString.java
diff --git a/java/src/main/java/com/google/protobuf/LongArrayList.java b/java/core/src/main/java/com/google/protobuf/LongArrayList.java
index ebe62029..ebe62029 100644
--- a/java/src/main/java/com/google/protobuf/LongArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/LongArrayList.java
diff --git a/java/src/main/java/com/google/protobuf/MapEntry.java b/java/core/src/main/java/com/google/protobuf/MapEntry.java
index 31414bb4..31414bb4 100644
--- a/java/src/main/java/com/google/protobuf/MapEntry.java
+++ b/java/core/src/main/java/com/google/protobuf/MapEntry.java
diff --git a/java/src/main/java/com/google/protobuf/MapEntryLite.java b/java/core/src/main/java/com/google/protobuf/MapEntryLite.java
index bcffa946..bcffa946 100644
--- a/java/src/main/java/com/google/protobuf/MapEntryLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MapEntryLite.java
diff --git a/java/src/main/java/com/google/protobuf/MapField.java b/java/core/src/main/java/com/google/protobuf/MapField.java
index b290993c..b290993c 100644
--- a/java/src/main/java/com/google/protobuf/MapField.java
+++ b/java/core/src/main/java/com/google/protobuf/MapField.java
diff --git a/java/src/main/java/com/google/protobuf/MapFieldLite.java b/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
index 16d3e6d2..16d3e6d2 100644
--- a/java/src/main/java/com/google/protobuf/MapFieldLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MapFieldLite.java
diff --git a/java/src/main/java/com/google/protobuf/Message.java b/java/core/src/main/java/com/google/protobuf/Message.java
index 9516d71f..9516d71f 100644
--- a/java/src/main/java/com/google/protobuf/Message.java
+++ b/java/core/src/main/java/com/google/protobuf/Message.java
diff --git a/java/src/main/java/com/google/protobuf/MessageLite.java b/java/core/src/main/java/com/google/protobuf/MessageLite.java
index 798b7943..798b7943 100644
--- a/java/src/main/java/com/google/protobuf/MessageLite.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageLite.java
diff --git a/java/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java b/java/core/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java
index 818386ce..818386ce 100644
--- a/java/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageLiteOrBuilder.java
diff --git a/java/src/main/java/com/google/protobuf/MessageLiteToString.java b/java/core/src/main/java/com/google/protobuf/MessageLiteToString.java
index e69de29b..e69de29b 100644
--- a/java/src/main/java/com/google/protobuf/MessageLiteToString.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageLiteToString.java
diff --git a/java/src/main/java/com/google/protobuf/MessageOrBuilder.java b/java/core/src/main/java/com/google/protobuf/MessageOrBuilder.java
index f0fc4859..f0fc4859 100644
--- a/java/src/main/java/com/google/protobuf/MessageOrBuilder.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageOrBuilder.java
diff --git a/java/src/main/java/com/google/protobuf/MessageReflection.java b/java/core/src/main/java/com/google/protobuf/MessageReflection.java
index de4bfd3e..de4bfd3e 100644
--- a/java/src/main/java/com/google/protobuf/MessageReflection.java
+++ b/java/core/src/main/java/com/google/protobuf/MessageReflection.java
diff --git a/java/src/main/java/com/google/protobuf/MutabilityOracle.java b/java/core/src/main/java/com/google/protobuf/MutabilityOracle.java
index 82b723c9..82b723c9 100644
--- a/java/src/main/java/com/google/protobuf/MutabilityOracle.java
+++ b/java/core/src/main/java/com/google/protobuf/MutabilityOracle.java
diff --git a/java/src/main/java/com/google/protobuf/NioByteString.java b/java/core/src/main/java/com/google/protobuf/NioByteString.java
index f71e41b2..f71e41b2 100644
--- a/java/src/main/java/com/google/protobuf/NioByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/NioByteString.java
diff --git a/java/src/main/java/com/google/protobuf/Parser.java b/java/core/src/main/java/com/google/protobuf/Parser.java
index 227c02b7..3fa11c3b 100644
--- a/java/src/main/java/com/google/protobuf/Parser.java
+++ b/java/core/src/main/java/com/google/protobuf/Parser.java
@@ -30,6 +30,7 @@
 
 package com.google.protobuf;
 
+import java.io.IOException;
 import java.io.InputStream;
 
 /**
@@ -37,9 +38,20 @@ import java.io.InputStream;
  *
  * The implementation should be stateless and thread-safe.
  *
+ * <p>All methods may throw {@link InvalidProtocolBufferException}. In the event of invalid data,
+ * like an encoding error, the cause of the thrown exception will be {@code null}. However, if an
+ * I/O problem occurs, an exception is thrown with an {@link IOException} cause.
+ *
  * @author liujisi@google.com (Pherl Liu)
  */
 public interface Parser<MessageType> {
+
+  // NB(jh): Other parts of the protobuf API that parse messages distinguish between an I/O problem
+  // (like failure reading bytes from a socket) and invalid data (encoding error) via the type of
+  // thrown exception. But it would be source-incompatible to make the methods in this interface do
+  // so since they were originally spec'ed to only throw InvalidProtocolBufferException. So callers
+  // must inspect the cause of the exception to distinguish these two cases.
+
   /**
    * Parses a message of {@code MessageType} from the input.
    *
diff --git a/java/src/main/java/com/google/protobuf/ProtobufArrayList.java b/java/core/src/main/java/com/google/protobuf/ProtobufArrayList.java
index d2f82ac5..d2f82ac5 100644
--- a/java/src/main/java/com/google/protobuf/ProtobufArrayList.java
+++ b/java/core/src/main/java/com/google/protobuf/ProtobufArrayList.java
diff --git a/java/src/main/java/com/google/protobuf/ProtocolMessageEnum.java b/java/core/src/main/java/com/google/protobuf/ProtocolMessageEnum.java
index 0c8df989..0c8df989 100644
--- a/java/src/main/java/com/google/protobuf/ProtocolMessageEnum.java
+++ b/java/core/src/main/java/com/google/protobuf/ProtocolMessageEnum.java
diff --git a/java/src/main/java/com/google/protobuf/ProtocolStringList.java b/java/core/src/main/java/com/google/protobuf/ProtocolStringList.java
index d553b41e..d553b41e 100644
--- a/java/src/main/java/com/google/protobuf/ProtocolStringList.java
+++ b/java/core/src/main/java/com/google/protobuf/ProtocolStringList.java
diff --git a/java/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java b/java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java
index f91cdbce..f91cdbce 100644
--- a/java/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java
+++ b/java/core/src/main/java/com/google/protobuf/RepeatedFieldBuilder.java
diff --git a/java/src/main/java/com/google/protobuf/RopeByteString.java b/java/core/src/main/java/com/google/protobuf/RopeByteString.java
index 6e8eb724..6e8eb724 100644
--- a/java/src/main/java/com/google/protobuf/RopeByteString.java
+++ b/java/core/src/main/java/com/google/protobuf/RopeByteString.java
diff --git a/java/src/main/java/com/google/protobuf/RpcCallback.java b/java/core/src/main/java/com/google/protobuf/RpcCallback.java
index 10752968..10752968 100644
--- a/java/src/main/java/com/google/protobuf/RpcCallback.java
+++ b/java/core/src/main/java/com/google/protobuf/RpcCallback.java
diff --git a/java/src/main/java/com/google/protobuf/RpcChannel.java b/java/core/src/main/java/com/google/protobuf/RpcChannel.java
index f272f4ad..f272f4ad 100644
--- a/java/src/main/java/com/google/protobuf/RpcChannel.java
+++ b/java/core/src/main/java/com/google/protobuf/RpcChannel.java
diff --git a/java/src/main/java/com/google/protobuf/RpcController.java b/java/core/src/main/java/com/google/protobuf/RpcController.java
index a92dd7be..a92dd7be 100644
--- a/java/src/main/java/com/google/protobuf/RpcController.java
+++ b/java/core/src/main/java/com/google/protobuf/RpcController.java
diff --git a/java/src/main/java/com/google/protobuf/RpcUtil.java b/java/core/src/main/java/com/google/protobuf/RpcUtil.java
index 694b8d13..694b8d13 100644
--- a/java/src/main/java/com/google/protobuf/RpcUtil.java
+++ b/java/core/src/main/java/com/google/protobuf/RpcUtil.java
diff --git a/java/src/main/java/com/google/protobuf/Service.java b/java/core/src/main/java/com/google/protobuf/Service.java
index ba7b033e..ba7b033e 100644
--- a/java/src/main/java/com/google/protobuf/Service.java
+++ b/java/core/src/main/java/com/google/protobuf/Service.java
diff --git a/java/src/main/java/com/google/protobuf/ServiceException.java b/java/core/src/main/java/com/google/protobuf/ServiceException.java
index 00d57075..00d57075 100644
--- a/java/src/main/java/com/google/protobuf/ServiceException.java
+++ b/java/core/src/main/java/com/google/protobuf/ServiceException.java
diff --git a/java/src/main/java/com/google/protobuf/SingleFieldBuilder.java b/java/core/src/main/java/com/google/protobuf/SingleFieldBuilder.java
index aba65e32..aba65e32 100644
--- a/java/src/main/java/com/google/protobuf/SingleFieldBuilder.java
+++ b/java/core/src/main/java/com/google/protobuf/SingleFieldBuilder.java
diff --git a/java/src/main/java/com/google/protobuf/SmallSortedMap.java b/java/core/src/main/java/com/google/protobuf/SmallSortedMap.java
index 0674d2e2..0674d2e2 100644
--- a/java/src/main/java/com/google/protobuf/SmallSortedMap.java
+++ b/java/core/src/main/java/com/google/protobuf/SmallSortedMap.java
diff --git a/java/src/main/java/com/google/protobuf/TextFormat.java b/java/core/src/main/java/com/google/protobuf/TextFormat.java
index c99b5285..c99b5285 100644
--- a/java/src/main/java/com/google/protobuf/TextFormat.java
+++ b/java/core/src/main/java/com/google/protobuf/TextFormat.java
diff --git a/java/src/main/java/com/google/protobuf/TextFormatEscaper.java b/java/core/src/main/java/com/google/protobuf/TextFormatEscaper.java
index e69de29b..e69de29b 100644
--- a/java/src/main/java/com/google/protobuf/TextFormatEscaper.java
+++ b/java/core/src/main/java/com/google/protobuf/TextFormatEscaper.java
diff --git a/java/src/main/java/com/google/protobuf/UninitializedMessageException.java b/java/core/src/main/java/com/google/protobuf/UninitializedMessageException.java
index 5714c063..5714c063 100644
--- a/java/src/main/java/com/google/protobuf/UninitializedMessageException.java
+++ b/java/core/src/main/java/com/google/protobuf/UninitializedMessageException.java
diff --git a/java/src/main/java/com/google/protobuf/UnknownFieldSet.java b/java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java
index 7cd2250e..7cd2250e 100644
--- a/java/src/main/java/com/google/protobuf/UnknownFieldSet.java
+++ b/java/core/src/main/java/com/google/protobuf/UnknownFieldSet.java
diff --git a/java/src/main/java/com/google/protobuf/UnknownFieldSetLite.java b/java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
index 435ad4d4..435ad4d4 100644
--- a/java/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
+++ b/java/core/src/main/java/com/google/protobuf/UnknownFieldSetLite.java
diff --git a/java/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java b/java/core/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java
index 5257c5a2..5257c5a2 100644
--- a/java/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java
+++ b/java/core/src/main/java/com/google/protobuf/UnmodifiableLazyStringList.java
diff --git a/java/src/main/java/com/google/protobuf/UnsafeByteStrings.java b/java/core/src/main/java/com/google/protobuf/UnsafeByteStrings.java
index c1997515..c1997515 100644
--- a/java/src/main/java/com/google/protobuf/UnsafeByteStrings.java
+++ b/java/core/src/main/java/com/google/protobuf/UnsafeByteStrings.java
diff --git a/java/src/main/java/com/google/protobuf/Utf8.java b/java/core/src/main/java/com/google/protobuf/Utf8.java
index 48c7e9e6..48c7e9e6 100644
--- a/java/src/main/java/com/google/protobuf/Utf8.java
+++ b/java/core/src/main/java/com/google/protobuf/Utf8.java
diff --git a/java/src/main/java/com/google/protobuf/WireFormat.java b/java/core/src/main/java/com/google/protobuf/WireFormat.java
index 8dbe1ae3..8dbe1ae3 100644
--- a/java/src/main/java/com/google/protobuf/WireFormat.java
+++ b/java/core/src/main/java/com/google/protobuf/WireFormat.java
diff --git a/java/src/test/java/com/google/protobuf/AbstractMessageTest.java b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
index d964ef59..d964ef59 100644
--- a/java/src/test/java/com/google/protobuf/AbstractMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/AbstractMessageTest.java
diff --git a/java/src/test/java/com/google/protobuf/AnyTest.java b/java/core/src/test/java/com/google/protobuf/AnyTest.java
index e169f69d..e169f69d 100644
--- a/java/src/test/java/com/google/protobuf/AnyTest.java
+++ b/java/core/src/test/java/com/google/protobuf/AnyTest.java
diff --git a/java/src/test/java/com/google/protobuf/BooleanArrayListTest.java b/java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java
index b8ad1fe4..b8ad1fe4 100644
--- a/java/src/test/java/com/google/protobuf/BooleanArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/BooleanArrayListTest.java
diff --git a/java/src/test/java/com/google/protobuf/BoundedByteStringTest.java b/java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java
index 2dfae2e6..2dfae2e6 100644
--- a/java/src/test/java/com/google/protobuf/BoundedByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/BoundedByteStringTest.java
diff --git a/java/src/test/java/com/google/protobuf/ByteStringTest.java b/java/core/src/test/java/com/google/protobuf/ByteStringTest.java
index 36f64251..36f64251 100644
--- a/java/src/test/java/com/google/protobuf/ByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ByteStringTest.java
diff --git a/java/src/test/java/com/google/protobuf/CheckUtf8Test.java b/java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java
index 3d6381c9..3d6381c9 100644
--- a/java/src/test/java/com/google/protobuf/CheckUtf8Test.java
+++ b/java/core/src/test/java/com/google/protobuf/CheckUtf8Test.java
diff --git a/java/src/test/java/com/google/protobuf/CodedInputStreamTest.java b/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
index 18d8142c..18d8142c 100644
--- a/java/src/test/java/com/google/protobuf/CodedInputStreamTest.java
+++ b/java/core/src/test/java/com/google/protobuf/CodedInputStreamTest.java
diff --git a/java/src/test/java/com/google/protobuf/CodedOutputStreamTest.java b/java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
index 6018ea55..6018ea55 100644
--- a/java/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
+++ b/java/core/src/test/java/com/google/protobuf/CodedOutputStreamTest.java
diff --git a/java/src/test/java/com/google/protobuf/DeprecatedFieldTest.java b/java/core/src/test/java/com/google/protobuf/DeprecatedFieldTest.java
index e7905f79..e7905f79 100644
--- a/java/src/test/java/com/google/protobuf/DeprecatedFieldTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DeprecatedFieldTest.java
diff --git a/java/src/test/java/com/google/protobuf/DescriptorsTest.java b/java/core/src/test/java/com/google/protobuf/DescriptorsTest.java
index 82ff34af..82ff34af 100644
--- a/java/src/test/java/com/google/protobuf/DescriptorsTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DescriptorsTest.java
diff --git a/java/src/test/java/com/google/protobuf/DoubleArrayListTest.java b/java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java
index d3deaa07..d3deaa07 100644
--- a/java/src/test/java/com/google/protobuf/DoubleArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DoubleArrayListTest.java
diff --git a/java/src/test/java/com/google/protobuf/DynamicMessageTest.java b/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java
index 55144e7c..55144e7c 100644
--- a/java/src/test/java/com/google/protobuf/DynamicMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/DynamicMessageTest.java
diff --git a/java/src/test/java/com/google/protobuf/FieldPresenceTest.java b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
index eaeec0b8..eaeec0b8 100644
--- a/java/src/test/java/com/google/protobuf/FieldPresenceTest.java
+++ b/java/core/src/test/java/com/google/protobuf/FieldPresenceTest.java
diff --git a/java/src/test/java/com/google/protobuf/FloatArrayListTest.java b/java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java
index a5e65424..a5e65424 100644
--- a/java/src/test/java/com/google/protobuf/FloatArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/FloatArrayListTest.java
diff --git a/java/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java b/java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java
index a92ba374..a92ba374 100644
--- a/java/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java
+++ b/java/core/src/test/java/com/google/protobuf/ForceFieldBuildersPreRun.java
diff --git a/java/src/test/java/com/google/protobuf/GeneratedMessageTest.java b/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java
index 70812b95..70812b95 100644
--- a/java/src/test/java/com/google/protobuf/GeneratedMessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/GeneratedMessageTest.java
diff --git a/java/src/test/java/com/google/protobuf/IntArrayListTest.java b/java/core/src/test/java/com/google/protobuf/IntArrayListTest.java
index 3733eb30..3733eb30 100644
--- a/java/src/test/java/com/google/protobuf/IntArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/IntArrayListTest.java
diff --git a/java/src/test/java/com/google/protobuf/IsValidUtf8Test.java b/java/core/src/test/java/com/google/protobuf/IsValidUtf8Test.java
index 8751baae..8751baae 100644
--- a/java/src/test/java/com/google/protobuf/IsValidUtf8Test.java
+++ b/java/core/src/test/java/com/google/protobuf/IsValidUtf8Test.java
diff --git a/java/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java b/java/core/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java
index 321669f3..321669f3 100644
--- a/java/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java
+++ b/java/core/src/test/java/com/google/protobuf/IsValidUtf8TestUtil.java
diff --git a/java/src/test/java/com/google/protobuf/LazyFieldLiteTest.java b/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
index 211b5697..211b5697 100644
--- a/java/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyFieldLiteTest.java
diff --git a/java/src/test/java/com/google/protobuf/LazyFieldTest.java b/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
index 2b900065..2b900065 100644
--- a/java/src/test/java/com/google/protobuf/LazyFieldTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyFieldTest.java
diff --git a/java/src/test/java/com/google/protobuf/LazyMessageLiteTest.java b/java/core/src/test/java/com/google/protobuf/LazyMessageLiteTest.java
index afe0fffd..afe0fffd 100644
--- a/java/src/test/java/com/google/protobuf/LazyMessageLiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyMessageLiteTest.java
diff --git a/java/src/test/java/com/google/protobuf/LazyStringArrayListTest.java b/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
index 0f42ac50..0f42ac50 100644
--- a/java/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyStringArrayListTest.java
diff --git a/java/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java b/java/core/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java
index 0ef414aa..0ef414aa 100644
--- a/java/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LazyStringEndToEndTest.java
diff --git a/java/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java b/java/core/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java
index 035917c8..035917c8 100644
--- a/java/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LiteEqualsAndHashTest.java
diff --git a/java/src/test/java/com/google/protobuf/LiteTest.java b/java/core/src/test/java/com/google/protobuf/LiteTest.java
index b1f298ff..b1f298ff 100644
--- a/java/src/test/java/com/google/protobuf/LiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LiteTest.java
diff --git a/java/src/test/java/com/google/protobuf/LiteralByteStringTest.java b/java/core/src/test/java/com/google/protobuf/LiteralByteStringTest.java
index c8495633..c8495633 100644
--- a/java/src/test/java/com/google/protobuf/LiteralByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LiteralByteStringTest.java
diff --git a/java/src/test/java/com/google/protobuf/LongArrayListTest.java b/java/core/src/test/java/com/google/protobuf/LongArrayListTest.java
index 1bd094f7..1bd094f7 100644
--- a/java/src/test/java/com/google/protobuf/LongArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/LongArrayListTest.java
diff --git a/java/src/test/java/com/google/protobuf/MapForProto2LiteTest.java b/java/core/src/test/java/com/google/protobuf/MapForProto2LiteTest.java
index 3d8c9bc4..3d8c9bc4 100644
--- a/java/src/test/java/com/google/protobuf/MapForProto2LiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MapForProto2LiteTest.java
diff --git a/java/src/test/java/com/google/protobuf/MapForProto2Test.java b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
index 1fa3cbdb..1fa3cbdb 100644
--- a/java/src/test/java/com/google/protobuf/MapForProto2Test.java
+++ b/java/core/src/test/java/com/google/protobuf/MapForProto2Test.java
diff --git a/java/src/test/java/com/google/protobuf/MapTest.java b/java/core/src/test/java/com/google/protobuf/MapTest.java
index 0e5c1284..0e5c1284 100644
--- a/java/src/test/java/com/google/protobuf/MapTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MapTest.java
diff --git a/java/src/test/java/com/google/protobuf/MessageTest.java b/java/core/src/test/java/com/google/protobuf/MessageTest.java
index abcd3a1d..abcd3a1d 100644
--- a/java/src/test/java/com/google/protobuf/MessageTest.java
+++ b/java/core/src/test/java/com/google/protobuf/MessageTest.java
diff --git a/java/src/test/java/com/google/protobuf/NestedBuildersTest.java b/java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java
index 23653126..23653126 100644
--- a/java/src/test/java/com/google/protobuf/NestedBuildersTest.java
+++ b/java/core/src/test/java/com/google/protobuf/NestedBuildersTest.java
diff --git a/java/src/test/java/com/google/protobuf/NioByteStringTest.java b/java/core/src/test/java/com/google/protobuf/NioByteStringTest.java
index 0679937f..0679937f 100644
--- a/java/src/test/java/com/google/protobuf/NioByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/NioByteStringTest.java
diff --git a/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java b/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java
new file mode 100644
index 00000000..37fa242d
--- /dev/null
+++ b/java/core/src/test/java/com/google/protobuf/ParseExceptionsTest.java
@@ -0,0 +1,211 @@
+package com.google.protobuf;
+
+import com.google.protobuf.DescriptorProtos.DescriptorProto;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+/**
+ * Tests the exceptions thrown when parsing from a stream. The methods on the {@link Parser}
+ * interface are specified to only throw {@link InvalidProtocolBufferException}. But we really want
+ * to distinguish between invalid protos vs. actual I/O errors (like failures reading from a
+ * socket, etc.). So, when we're not using the parser directly, an {@link IOException} should be
+ * thrown where appropriate, instead of always an {@link InvalidProtocolBufferException}.
+ *
+ * @author jh@squareup.com (Joshua Humphries)
+ */
+public class ParseExceptionsTest {
+
+  private interface ParseTester {
+    DescriptorProto parse(InputStream in) throws IOException;
+  }
+
+  private byte serializedProto[];
+
+  private void setup() {
+    serializedProto = DescriptorProto.getDescriptor().toProto().toByteArray();
+  }
+
+  private void setupDelimited() {
+    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+    try {
+      DescriptorProto.getDescriptor().toProto().writeDelimitedTo(bos);
+    } catch (IOException e) {
+      fail("Exception not expected: " + e);
+    }
+    serializedProto = bos.toByteArray();
+  }
+
+  @Test public void message_parseFrom_InputStream() {
+    setup();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.parseFrom(in);
+      }
+    });
+  }
+
+  @Test public void message_parseFrom_InputStreamAndExtensionRegistry() {
+    setup();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.parseFrom(in, ExtensionRegistry.newInstance());
+      }
+    });
+  }
+
+  @Test public void message_parseFrom_CodedInputStream() {
+    setup();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.parseFrom(CodedInputStream.newInstance(in));
+      }
+    });
+  }
+
+  @Test public void message_parseFrom_CodedInputStreamAndExtensionRegistry() {
+    setup();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.parseFrom(CodedInputStream.newInstance(in),
+            ExtensionRegistry.newInstance());
+      }
+    });
+  }
+
+  @Test public void message_parseDelimitedFrom_InputStream() {
+    setupDelimited();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.parseDelimitedFrom(in);
+      }
+    });
+  }
+
+  @Test public void message_parseDelimitedFrom_InputStreamAndExtensionRegistry() {
+    setupDelimited();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.parseDelimitedFrom(in, ExtensionRegistry.newInstance());
+      }
+    });
+  }
+
+  @Test public void messageBuilder_mergeFrom_InputStream() {
+    setup();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.newBuilder().mergeFrom(in).build();
+      }
+    });
+  }
+
+  @Test public void messageBuilder_mergeFrom_InputStreamAndExtensionRegistry() {
+    setup();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.newBuilder().mergeFrom(in, ExtensionRegistry.newInstance()).build();
+      }
+    });
+  }
+
+  @Test public void messageBuilder_mergeFrom_CodedInputStream() {
+    setup();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.newBuilder().mergeFrom(CodedInputStream.newInstance(in)).build();
+      }
+    });
+  }
+
+  @Test public void messageBuilder_mergeFrom_CodedInputStreamAndExtensionRegistry() {
+    setup();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        return DescriptorProto.newBuilder()
+            .mergeFrom(CodedInputStream.newInstance(in), ExtensionRegistry.newInstance()).build();
+      }
+    });
+  }
+
+  @Test public void messageBuilder_mergeDelimitedFrom_InputStream() {
+    setupDelimited();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        DescriptorProto.Builder builder = DescriptorProto.newBuilder();
+        builder.mergeDelimitedFrom(in);
+        return builder.build();
+      }
+    });
+  }
+
+  @Test public void messageBuilder_mergeDelimitedFrom_InputStreamAndExtensionRegistry() {
+    setupDelimited();
+    verifyExceptions(new ParseTester() {
+      public DescriptorProto parse(InputStream in) throws IOException {
+        DescriptorProto.Builder builder = DescriptorProto.newBuilder();
+        builder.mergeDelimitedFrom(in, ExtensionRegistry.newInstance());
+        return builder.build();
+      }
+    });
+  }
+
+  private void verifyExceptions(ParseTester parseTester) {
+    // No exception
+    try {
+      assertEquals(DescriptorProto.getDescriptor().toProto(),
+          parseTester.parse(new ByteArrayInputStream(serializedProto)));
+    } catch (IOException e) {
+      fail("No exception expected: " + e);
+    }
+
+    // IOException
+    try {
+      // using a "broken" stream that will throw part-way through reading the message
+      parseTester.parse(broken(new ByteArrayInputStream(serializedProto)));
+      fail("IOException expected but not thrown");
+    } catch (IOException e) {
+      assertFalse(e instanceof InvalidProtocolBufferException);
+    }
+
+    // InvalidProtocolBufferException
+    try {
+      // make the serialized proto invalid
+      for (int i = 0; i < 50; i++) {
+        serializedProto[i] = -1;
+      }
+      parseTester.parse(new ByteArrayInputStream(serializedProto));
+      fail("InvalidProtocolBufferException expected but not thrown");
+    } catch (IOException e) {
+      assertTrue(e instanceof InvalidProtocolBufferException);
+    }
+  }
+
+  private InputStream broken(InputStream i) {
+    return new FilterInputStream(i) {
+      int count = 0;
+
+      @Override public int read() throws IOException {
+        if (count++ >= 50) {
+          throw new IOException("I'm broken!");
+        }
+        return super.read();
+      }
+
+      @Override public int read(byte b[], int off, int len) throws IOException {
+        if ((count += len) >= 50) {
+          throw new IOException("I'm broken!");
+        }
+        return super.read(b, off, len);
+      }
+    };
+  }
+}
diff --git a/java/src/test/java/com/google/protobuf/ParserTest.java b/java/core/src/test/java/com/google/protobuf/ParserTest.java
index 5a92bacf..5a92bacf 100644
--- a/java/src/test/java/com/google/protobuf/ParserTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ParserTest.java
diff --git a/java/src/test/java/com/google/protobuf/ProtobufArrayListTest.java b/java/core/src/test/java/com/google/protobuf/ProtobufArrayListTest.java
index 245c3dee..245c3dee 100644
--- a/java/src/test/java/com/google/protobuf/ProtobufArrayListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ProtobufArrayListTest.java
diff --git a/java/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java b/java/core/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java
index 49d52321..49d52321 100644
--- a/java/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java
+++ b/java/core/src/test/java/com/google/protobuf/RepeatedFieldBuilderTest.java
diff --git a/java/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java b/java/core/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java
index dc56f2e9..dc56f2e9 100644
--- a/java/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/RopeByteStringSubstringTest.java
diff --git a/java/src/test/java/com/google/protobuf/RopeByteStringTest.java b/java/core/src/test/java/com/google/protobuf/RopeByteStringTest.java
index 4ec3a409..4ec3a409 100644
--- a/java/src/test/java/com/google/protobuf/RopeByteStringTest.java
+++ b/java/core/src/test/java/com/google/protobuf/RopeByteStringTest.java
diff --git a/java/src/test/java/com/google/protobuf/ServiceTest.java b/java/core/src/test/java/com/google/protobuf/ServiceTest.java
index ff980d66..ff980d66 100644
--- a/java/src/test/java/com/google/protobuf/ServiceTest.java
+++ b/java/core/src/test/java/com/google/protobuf/ServiceTest.java
diff --git a/java/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java b/java/core/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java
index 58b80007..58b80007 100644
--- a/java/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java
+++ b/java/core/src/test/java/com/google/protobuf/SingleFieldBuilderTest.java
diff --git a/java/src/test/java/com/google/protobuf/SmallSortedMapTest.java b/java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java
index 366086d3..366086d3 100644
--- a/java/src/test/java/com/google/protobuf/SmallSortedMapTest.java
+++ b/java/core/src/test/java/com/google/protobuf/SmallSortedMapTest.java
diff --git a/java/src/test/java/com/google/protobuf/TestBadIdentifiers.java b/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java
index 2c60fe0e..2c60fe0e 100644
--- a/java/src/test/java/com/google/protobuf/TestBadIdentifiers.java
+++ b/java/core/src/test/java/com/google/protobuf/TestBadIdentifiers.java
diff --git a/java/src/test/java/com/google/protobuf/TestUtil.java b/java/core/src/test/java/com/google/protobuf/TestUtil.java
index 01acb884..01acb884 100644
--- a/java/src/test/java/com/google/protobuf/TestUtil.java
+++ b/java/core/src/test/java/com/google/protobuf/TestUtil.java
diff --git a/java/src/test/java/com/google/protobuf/TextFormatTest.java b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
index 1df4fad7..1df4fad7 100644
--- a/java/src/test/java/com/google/protobuf/TextFormatTest.java
+++ b/java/core/src/test/java/com/google/protobuf/TextFormatTest.java
diff --git a/java/src/test/java/com/google/protobuf/UnknownEnumValueTest.java b/java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java
index 8f45976f..8f45976f 100644
--- a/java/src/test/java/com/google/protobuf/UnknownEnumValueTest.java
+++ b/java/core/src/test/java/com/google/protobuf/UnknownEnumValueTest.java
diff --git a/java/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java
index dc987379..dc987379 100644
--- a/java/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java
+++ b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetLiteTest.java
diff --git a/java/src/test/java/com/google/protobuf/UnknownFieldSetTest.java b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetTest.java
index 8c9dcafe..8c9dcafe 100644
--- a/java/src/test/java/com/google/protobuf/UnknownFieldSetTest.java
+++ b/java/core/src/test/java/com/google/protobuf/UnknownFieldSetTest.java
diff --git a/java/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java b/java/core/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java
index b1c75fc3..b1c75fc3 100644
--- a/java/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java
+++ b/java/core/src/test/java/com/google/protobuf/UnmodifiableLazyStringListTest.java
diff --git a/java/src/test/java/com/google/protobuf/WellKnownTypesTest.java b/java/core/src/test/java/com/google/protobuf/WellKnownTypesTest.java
index 982e200f..982e200f 100644
--- a/java/src/test/java/com/google/protobuf/WellKnownTypesTest.java
+++ b/java/core/src/test/java/com/google/protobuf/WellKnownTypesTest.java
diff --git a/java/src/test/java/com/google/protobuf/WireFormatTest.java b/java/core/src/test/java/com/google/protobuf/WireFormatTest.java
index 0175005d..0175005d 100644
--- a/java/src/test/java/com/google/protobuf/WireFormatTest.java
+++ b/java/core/src/test/java/com/google/protobuf/WireFormatTest.java
diff --git a/java/src/test/java/com/google/protobuf/any_test.proto b/java/core/src/test/proto/com/google/protobuf/any_test.proto
index 80173d8a..80173d8a 100644
--- a/java/src/test/java/com/google/protobuf/any_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/any_test.proto
diff --git a/java/src/test/java/com/google/protobuf/field_presence_test.proto b/java/core/src/test/proto/com/google/protobuf/field_presence_test.proto
index 8f3ca8c6..8f3ca8c6 100644
--- a/java/src/test/java/com/google/protobuf/field_presence_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/field_presence_test.proto
diff --git a/java/src/test/java/com/google/protobuf/lazy_fields_lite.proto b/java/core/src/test/proto/com/google/protobuf/lazy_fields_lite.proto
index 5580f72d..5580f72d 100644
--- a/java/src/test/java/com/google/protobuf/lazy_fields_lite.proto
+++ b/java/core/src/test/proto/com/google/protobuf/lazy_fields_lite.proto
diff --git a/java/src/test/java/com/google/protobuf/lite_equals_and_hash.proto b/java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto
index 86837250..86837250 100644
--- a/java/src/test/java/com/google/protobuf/lite_equals_and_hash.proto
+++ b/java/core/src/test/proto/com/google/protobuf/lite_equals_and_hash.proto
diff --git a/java/src/test/java/com/google/protobuf/map_for_proto2_lite_test.proto b/java/core/src/test/proto/com/google/protobuf/map_for_proto2_lite_test.proto
index d5418f28..d5418f28 100644
--- a/java/src/test/java/com/google/protobuf/map_for_proto2_lite_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/map_for_proto2_lite_test.proto
diff --git a/java/src/test/java/com/google/protobuf/map_for_proto2_test.proto b/java/core/src/test/proto/com/google/protobuf/map_for_proto2_test.proto
index a9be5166..a9be5166 100644
--- a/java/src/test/java/com/google/protobuf/map_for_proto2_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/map_for_proto2_test.proto
diff --git a/java/src/test/java/com/google/protobuf/map_initialization_order_test.proto b/java/core/src/test/proto/com/google/protobuf/map_initialization_order_test.proto
index b02ac599..b02ac599 100644
--- a/java/src/test/java/com/google/protobuf/map_initialization_order_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/map_initialization_order_test.proto
diff --git a/java/src/test/java/com/google/protobuf/map_test.proto b/java/core/src/test/proto/com/google/protobuf/map_test.proto
index 2280ac03..2280ac03 100644
--- a/java/src/test/java/com/google/protobuf/map_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/map_test.proto
diff --git a/java/src/test/java/com/google/protobuf/multiple_files_test.proto b/java/core/src/test/proto/com/google/protobuf/multiple_files_test.proto
index 92790506..92790506 100644
--- a/java/src/test/java/com/google/protobuf/multiple_files_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/multiple_files_test.proto
diff --git a/java/src/test/java/com/google/protobuf/nested_builders_test.proto b/java/core/src/test/proto/com/google/protobuf/nested_builders_test.proto
index a5dd66d8..a5dd66d8 100644
--- a/java/src/test/java/com/google/protobuf/nested_builders_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/nested_builders_test.proto
diff --git a/java/src/test/java/com/google/protobuf/nested_extension.proto b/java/core/src/test/proto/com/google/protobuf/nested_extension.proto
index 704e649e..704e649e 100644
--- a/java/src/test/java/com/google/protobuf/nested_extension.proto
+++ b/java/core/src/test/proto/com/google/protobuf/nested_extension.proto
diff --git a/java/src/test/java/com/google/protobuf/nested_extension_lite.proto b/java/core/src/test/proto/com/google/protobuf/nested_extension_lite.proto
index a95c38b2..a95c38b2 100644
--- a/java/src/test/java/com/google/protobuf/nested_extension_lite.proto
+++ b/java/core/src/test/proto/com/google/protobuf/nested_extension_lite.proto
diff --git a/java/src/test/java/com/google/protobuf/non_nested_extension.proto b/java/core/src/test/proto/com/google/protobuf/non_nested_extension.proto
index 31fac552..31fac552 100644
--- a/java/src/test/java/com/google/protobuf/non_nested_extension.proto
+++ b/java/core/src/test/proto/com/google/protobuf/non_nested_extension.proto
diff --git a/java/src/test/java/com/google/protobuf/non_nested_extension_lite.proto b/java/core/src/test/proto/com/google/protobuf/non_nested_extension_lite.proto
index 37c369ed..37c369ed 100644
--- a/java/src/test/java/com/google/protobuf/non_nested_extension_lite.proto
+++ b/java/core/src/test/proto/com/google/protobuf/non_nested_extension_lite.proto
diff --git a/java/src/test/java/com/google/protobuf/outer_class_name_test.proto b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test.proto
index 42083681..42083681 100644
--- a/java/src/test/java/com/google/protobuf/outer_class_name_test.proto
+++ b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test.proto
diff --git a/java/src/test/java/com/google/protobuf/outer_class_name_test2.proto b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test2.proto
index 3e5956b0..3e5956b0 100644
--- a/java/src/test/java/com/google/protobuf/outer_class_name_test2.proto
+++ b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test2.proto
diff --git a/java/src/test/java/com/google/protobuf/outer_class_name_test3.proto b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test3.proto
index 74a8ba3c..74a8ba3c 100644
--- a/java/src/test/java/com/google/protobuf/outer_class_name_test3.proto
+++ b/java/core/src/test/proto/com/google/protobuf/outer_class_name_test3.proto
diff --git a/java/src/test/java/com/google/protobuf/test_bad_identifiers.proto b/java/core/src/test/proto/com/google/protobuf/test_bad_identifiers.proto
index 2b1f65e4..2b1f65e4 100644
--- a/java/src/test/java/com/google/protobuf/test_bad_identifiers.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_bad_identifiers.proto
diff --git a/java/src/test/java/com/google/protobuf/test_check_utf8.proto b/java/core/src/test/proto/com/google/protobuf/test_check_utf8.proto
index 119c1dcb..119c1dcb 100644
--- a/java/src/test/java/com/google/protobuf/test_check_utf8.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_check_utf8.proto
diff --git a/java/src/test/java/com/google/protobuf/test_check_utf8_size.proto b/java/core/src/test/proto/com/google/protobuf/test_check_utf8_size.proto
index f06d76d6..f06d76d6 100644
--- a/java/src/test/java/com/google/protobuf/test_check_utf8_size.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_check_utf8_size.proto
diff --git a/java/src/test/java/com/google/protobuf/test_custom_options.proto b/java/core/src/test/proto/com/google/protobuf/test_custom_options.proto
index f8efd455..f8efd455 100644
--- a/java/src/test/java/com/google/protobuf/test_custom_options.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_custom_options.proto
diff --git a/java/src/test/java/com/google/protobuf/test_extra_interfaces.proto b/java/core/src/test/proto/com/google/protobuf/test_extra_interfaces.proto
index 645f57b4..645f57b4 100644
--- a/java/src/test/java/com/google/protobuf/test_extra_interfaces.proto
+++ b/java/core/src/test/proto/com/google/protobuf/test_extra_interfaces.proto
diff --git a/java/lite/pom.xml b/java/lite/pom.xml
new file mode 100644
index 00000000..29d8c8c4
--- /dev/null
+++ b/java/lite/pom.xml
@@ -0,0 +1,158 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>com.google.protobuf</groupId>
+    <artifactId>protobuf-parent</artifactId>
+    <version>3.0.0-beta-2</version>
+  </parent>
+
+  <artifactId>protobuf-lite</artifactId>
+  <packaging>bundle</packaging>
+
+  <name>Protocol Buffers [Lite]</name>
+  <description>A trimmed-down version of the Protocol Buffers library.</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymock</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.easymock</groupId>
+      <artifactId>easymockclassextension</artifactId>
+    </dependency>
+  </dependencies>
+
+  <properties>
+    <core.root>../core</core.root>
+    <test.proto.dir>${core.root}/src/test/proto</test.proto.dir>
+  </properties>
+
+  <build>
+    <sourceDirectory>${core.root}/src/main/java</sourceDirectory>
+    <testSourceDirectory>${core.root}/src/test/java</testSourceDirectory>
+
+    <plugins>
+      <!-- Use Antrun plugin to generate sources with protoc -->
+      <plugin>
+        <artifactId>maven-antrun-plugin</artifactId>
+        <executions>
+          <!-- Generate core protos -->
+          <execution>
+            <id>generate-sources</id>
+            <phase>generate-sources</phase>
+            <configuration>
+              <target>
+                <ant antfile="${core.root}/generate-sources-build.xml"/>
+              </target>
+            </configuration>
+            <goals>
+              <goal>run</goal>
+            </goals>
+          </execution>
+
+          <!-- Generate the test protos -->
+          <execution>
+            <id>generate-test-sources</id>
+            <phase>generate-test-sources</phase>
+            <configuration>
+              <target>
+                <ant antfile="${core.root}/generate-test-sources-build.xml"/>
+              </target>
+            </configuration>
+            <goals>
+              <goal>run</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+
+      <!-- Only compile a subset of the files -->
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <generatedSourcesDirectory>${generated.sources.dir}</generatedSourcesDirectory>
+          <generatedTestSourcesDirectory>${generated.testsources.dir}</generatedTestSourcesDirectory>
+          <includes>
+            <include>**/AbstractMessageLite.java</include>
+            <include>**/AbstractParser.java</include>
+            <include>**/AbstractProtobufList.java</include>
+            <include>**/BoundedByteString.java</include>
+            <include>**/BooleanArrayList.java</include>
+            <include>**/ByteString.java</include>
+            <include>**/CodedInputStream.java</include>
+            <include>**/CodedOutputStream.java</include>
+            <include>**/DoubleArrayList.java</include>
+            <include>**/ExtensionLite.java</include>
+            <include>**/ExtensionRegistryLite.java</include>
+            <include>**/FieldSet.java</include>
+            <include>**/FloatArrayList.java</include>
+            <include>**/GeneratedMessageLite.java</include>
+            <include>**/IntArrayList.java</include>
+            <include>**/Internal.java</include>
+            <include>**/InvalidProtocolBufferException.java</include>
+            <include>**/LazyFieldLite.java</include>
+            <include>**/LazyStringArrayList.java</include>
+            <include>**/LazyStringList.java</include>
+            <include>**/LiteralByteString.java</include>
+            <include>**/LongArrayList.java</include>
+            <include>**/MapEntryLite.java</include>
+            <include>**/MapFieldLite.java</include>
+            <include>**/MessageLite.java</include>
+            <include>**/MessageLiteOrBuilder.java</include>
+            <include>**/MessageLiteToString.java</include>
+            <include>**/MutabilityOracle.java</include>
+            <include>**/NioByteString.java</include>
+            <include>**/Parser.java</include>
+            <include>**/ProtobufArrayList.java</include>
+            <include>**/ProtocolStringList.java</include>
+            <include>**/RopeByteString.java</include>
+            <include>**/SmallSortedMap.java</include>
+            <include>**/TextFormatEscaper.java</include>
+            <include>**/UninitializedMessageException.java</include>
+            <include>**/UnknownFieldSetLite.java</include>
+            <include>**/UnmodifiableLazyStringList.java</include>
+            <include>**/UnsafeByteStrings.java</include>
+            <include>**/Utf8.java</include>
+            <include>**/WireFormat.java</include>
+          </includes>
+          <testIncludes>
+            <testInclude>**/*Lite.java</testInclude>
+            <testInclude>**/BooleanArrayListTest.java</testInclude>
+            <testInclude>**/DoubleArrayListTest.java</testInclude>
+            <testInclude>**/FloatArrayListTest.java</testInclude>
+            <testInclude>**/IntArrayListTest.java</testInclude>
+            <testInclude>**/LazyMessageLiteTest.java</testInclude>
+            <testInclude>**/LiteTest.java</testInclude>
+            <testInclude>**/LongArrayListTest.java</testInclude>
+            <testInclude>**/NioByteStringTest.java</testInclude>
+            <testInclude>**/ProtobufArrayListTest.java</testInclude>
+            <testInclude>**/UnknownFieldSetLiteTest.java</testInclude>
+          </testIncludes>
+        </configuration>
+      </plugin>
+
+      <!-- OSGI bundle configuration -->
+      <plugin>
+        <groupId>org.apache.felix</groupId>
+        <artifactId>maven-bundle-plugin</artifactId>
+        <extensions>true</extensions>
+        <configuration>
+          <instructions>
+            <Bundle-DocURL>https://developers.google.com/protocol-buffers/</Bundle-DocURL>
+            <Bundle-SymbolicName>com.google.protobuf</Bundle-SymbolicName>
+            <Export-Package>com.google.${project.artifactId};version=${project.version}</Export-Package>
+          </instructions>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>
diff --git a/java/pom.xml b/java/pom.xml
index 3eab00ad..d5719edf 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -8,17 +8,33 @@
     <artifactId>google</artifactId>
     <version>1</version>
   </parent>
+
   <groupId>com.google.protobuf</groupId>
-  <artifactId>protobuf-java</artifactId>
+  <artifactId>protobuf-parent</artifactId>
   <version>3.0.0-beta-2</version>
-  <packaging>bundle</packaging>
-  <name>Protocol Buffer Java API</name>
+  <packaging>pom</packaging>
+
+  <name>Protocol Buffers [Parent]</name>
+  <inceptionYear>2008</inceptionYear>
+  <url>https://developers.google.com/protocol-buffers/</url>
   <description>
     Protocol Buffers are a way of encoding structured data in an efficient yet
     extensible format.
   </description>
-  <inceptionYear>2008</inceptionYear>
-  <url>https://developers.google.com/protocol-buffers/</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+
+    <!-- These are relative to the submodules -->
+    <protobuf.basedir>${project.basedir}/../..</protobuf.basedir>
+    <protobuf.source.dir>${protobuf.basedir}/src</protobuf.source.dir>
+    <protoc>${protobuf.source.dir}/protoc</protoc>
+    <test.proto.dir>src/test/proto</test.proto.dir>
+    <generated.sources.dir>${project.build.directory}/generated-sources</generated.sources.dir>
+    <generated.testsources.dir>${project.build.directory}/generated-test-sources</generated.testsources.dir>
+  </properties>
+
   <licenses>
     <license>
       <name>New BSD license</name>
@@ -26,217 +42,116 @@
       <distribution>repo</distribution>
     </license>
   </licenses>
+
   <scm>
     <url>https://github.com/google/protobuf</url>
-    <connection>
-      scm:git:https://github.com/google/protobuf.git
-    </connection>
+    <connection>scm:git:https://github.com/google/protobuf.git</connection>
   </scm>
-  <dependencies>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <version>4.4</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.easymock</groupId>
-      <artifactId>easymock</artifactId>
-      <version>2.2</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.easymock</groupId>
-      <artifactId>easymockclassextension</artifactId>
-      <version>2.2.1</version>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+
+  <distributionManagement>
+    <snapshotRepository>
+      <id>sonatype-nexus-staging</id>
+      <url>https://oss.sonatype.org/content/repositories/snapshots</url>
+    </snapshotRepository>
+    <repository>
+      <id>sonatype-nexus-staging</id>
+      <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
+    </repository>
+  </distributionManagement>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>junit</groupId>
+        <artifactId>junit</artifactId>
+        <version>4.4</version>
+        <scope>test</scope>
+      </dependency>
+      <dependency>
+        <groupId>org.easymock</groupId>
+        <artifactId>easymock</artifactId>
+        <version>2.2</version>
+        <scope>test</scope>
+      </dependency>
+      <dependency>
+        <groupId>org.easymock</groupId>
+        <artifactId>easymockclassextension</artifactId>
+        <version>2.2.1</version>
+        <scope>test</scope>
+      </dependency>
+      <dependency>
+        <groupId>com.google.guava</groupId>
+        <artifactId>guava</artifactId>
+        <version>18.0</version>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+
   <build>
-    <plugins>
-      <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration>
-          <source>1.5</source>
-          <target>1.5</target>
-        </configuration>
-      </plugin>
-      <plugin>
-        <artifactId>maven-surefire-plugin</artifactId>
-        <configuration>
-          <includes>
-            <include>**/*Test.java</include>
-          </includes>
-        </configuration>
-      </plugin>
-      <plugin>
-        <artifactId>maven-antrun-plugin</artifactId>
-        <executions>
-          <execution>
-            <id>generate-sources</id>
-            <phase>generate-sources</phase>
-            <configuration>
-              <tasks>
-                <mkdir dir="target/generated-sources" />
-                <exec executable="../src/protoc">
-                  <arg value="--java_out=target/generated-sources" />
-                  <arg value="--proto_path=../src" />
-                  <arg value="../src/google/protobuf/any.proto" />
-                  <arg value="../src/google/protobuf/api.proto" />
-                  <arg value="../src/google/protobuf/descriptor.proto" />
-                  <arg value="../src/google/protobuf/duration.proto" />
-                  <arg value="../src/google/protobuf/empty.proto" />
-                  <arg value="../src/google/protobuf/field_mask.proto" />
-                  <arg value="../src/google/protobuf/source_context.proto" />
-                  <arg value="../src/google/protobuf/struct.proto" />
-                  <arg value="../src/google/protobuf/timestamp.proto" />
-                  <arg value="../src/google/protobuf/type.proto" />
-                  <arg value="../src/google/protobuf/wrappers.proto" />
-                  <arg value="../src/google/protobuf/compiler/plugin.proto" />
-                </exec>
-              </tasks>
-              <sourceRoot>target/generated-sources</sourceRoot>
-            </configuration>
-            <goals>
-              <goal>run</goal>
-            </goals>
-          </execution>
-          <execution>
-            <id>generate-test-sources</id>
-            <phase>generate-test-sources</phase>
-            <configuration>
-              <tasks>
-                <mkdir dir="target/generated-test-sources" />
-                <exec executable="../src/protoc">
-                  <arg value="--java_out=target/generated-test-sources" />
-                  <arg value="--proto_path=../src" />
-                  <arg value="--proto_path=src/test/java" />
-                  <arg value="../src/google/protobuf/unittest.proto" />
-                  <arg value="../src/google/protobuf/unittest_import.proto" />
-                  <arg value="../src/google/protobuf/unittest_import_public.proto" />
-                  <arg value="../src/google/protobuf/unittest_mset.proto" />
-                  <arg value="../src/google/protobuf/unittest_mset_wire_format.proto" />
-                  <arg value="src/test/java/com/google/protobuf/lazy_fields_lite.proto" />
-                  <arg value="src/test/java/com/google/protobuf/lite_equals_and_hash.proto" />
-                  <arg
-                    value="src/test/java/com/google/protobuf/multiple_files_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/nested_builders_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/nested_extension.proto" />
-                  <arg value="src/test/java/com/google/protobuf/nested_extension_lite.proto" />
-                  <arg value="src/test/java/com/google/protobuf/non_nested_extension.proto" />
-                  <arg value="src/test/java/com/google/protobuf/non_nested_extension_lite.proto" />
-                  <arg value="src/test/java/com/google/protobuf/outer_class_name_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/outer_class_name_test2.proto" />
-                  <arg value="src/test/java/com/google/protobuf/outer_class_name_test3.proto" />
-                  <arg value="src/test/java/com/google/protobuf/test_bad_identifiers.proto" />
-                  <arg value="src/test/java/com/google/protobuf/test_check_utf8.proto" />
-                  <arg value="src/test/java/com/google/protobuf/test_check_utf8_size.proto" />
-                  <arg value="src/test/java/com/google/protobuf/test_custom_options.proto" />
-                  <arg
-                    value="../src/google/protobuf/unittest_optimize_for.proto" />
-                  <arg
-                    value="../src/google/protobuf/unittest_custom_options.proto" />
-                  <arg value="../src/google/protobuf/unittest_lite.proto" />
-                  <arg value="../src/google/protobuf/unittest_import_lite.proto" />
-                  <arg value="../src/google/protobuf/unittest_import_public_lite.proto" />
-                  <arg value="../src/google/protobuf/unittest_lite_imports_nonlite.proto" />
-                  <arg value="../src/google/protobuf/unittest_enormous_descriptor.proto" />
-                  <arg value="../src/google/protobuf/unittest_no_generic_services.proto" />
-                  <arg value="../src/google/protobuf/unittest_well_known_types.proto" />
-                  <arg value="src/test/java/com/google/protobuf/any_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/field_presence_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/map_for_proto2_lite_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/map_for_proto2_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/map_test.proto" />
-                  <arg value="src/test/java/com/google/protobuf/map_initialization_order_test.proto" />
-                </exec>
-              </tasks>
-              <testSourceRoot>target/generated-test-sources</testSourceRoot>
-            </configuration>
-            <goals>
-              <goal>run</goal>
-            </goals>
-          </execution>
-        </executions>
-      </plugin>
-      <plugin>
-        <groupId>org.apache.felix</groupId>
-        <artifactId>maven-bundle-plugin</artifactId>
-        <extensions>true</extensions>
-        <configuration>
-          <instructions>
-            <Bundle-DocURL>https://developers.google.com/protocol-buffers/</Bundle-DocURL>
-            <Bundle-SymbolicName>com.google.protobuf</Bundle-SymbolicName>
-            <Export-Package>com.google.protobuf;version=3.0.0-beta-2</Export-Package>
-          </instructions>
-        </configuration>
-      </plugin>
-    </plugins>
-    <resources>
-      <resource>
-        <directory>../src</directory>
-        <includes>
-          <include>google/protobuf/any.proto</include>
-          <include>google/protobuf/api.proto</include>
-          <include>google/protobuf/descriptor.proto</include>
-          <include>google/protobuf/duration.proto</include>
-          <include>google/protobuf/empty.proto</include>
-          <include>google/protobuf/field_mask.proto</include>
-          <include>google/protobuf/source_context.proto</include>
-          <include>google/protobuf/struct.proto</include>
-          <include>google/protobuf/timestamp.proto</include>
-          <include>google/protobuf/type.proto</include>
-          <include>google/protobuf/wrappers.proto</include>
-          <include>google/protobuf/compiler/plugin.proto</include>
-        </includes>
-      </resource>
-    </resources>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <version>3.3</version>
+          <configuration>
+            <source>1.6</source>
+            <target>1.6</target>
+          </configuration>
+        </plugin>
+        <plugin>
+          <artifactId>maven-source-plugin</artifactId>
+          <version>2.4</version>
+          <executions>
+            <execution>
+              <id>attach-sources</id>
+              <goals>
+                <goal>jar-no-fork</goal>
+              </goals>
+            </execution>
+          </executions>
+        </plugin>
+        <plugin>
+          <artifactId>maven-javadoc-plugin</artifactId>
+          <version>2.10.3</version>
+          <executions>
+            <execution>
+              <id>attach-javadocs</id>
+              <goals>
+                <goal>jar</goal>
+              </goals>
+            </execution>
+          </executions>
+        </plugin>
+        <plugin>
+          <artifactId>maven-jar-plugin</artifactId>
+          <version>2.6</version>
+        </plugin>
+        <plugin>
+          <groupId>org.codehaus.mojo</groupId>
+          <artifactId>build-helper-maven-plugin</artifactId>
+          <version>1.10</version>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.felix</groupId>
+          <artifactId>maven-bundle-plugin</artifactId>
+          <version>3.0.1</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-antrun-plugin</artifactId>
+          <version>1.8</version>
+        </plugin>
+      </plugins>
+    </pluginManagement>
   </build>
+
   <profiles>
     <profile>
       <id>release</id>
-      <distributionManagement>
-        <snapshotRepository>
-          <id>sonatype-nexus-staging</id>
-          <url>https://oss.sonatype.org/content/repositories/snapshots</url>
-        </snapshotRepository>
-        <repository>
-          <id>sonatype-nexus-staging</id>
-          <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
-        </repository>
-      </distributionManagement>
       <build>
         <plugins>
           <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-source-plugin</artifactId>
-            <version>2.2.1</version>
-            <executions>
-              <execution>
-                <id>attach-sources</id>
-                <goals>
-                  <goal>jar-no-fork</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-javadoc-plugin</artifactId>
-            <version>2.9.1</version>
-            <executions>
-              <execution>
-                <id>attach-javadocs</id>
-                <goals>
-                  <goal>jar</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-gpg-plugin</artifactId>
-            <version>1.5</version>
+            <version>1.6</version>
             <executions>
               <execution>
                 <id>sign-artifacts</id>
@@ -250,98 +165,23 @@
           <plugin>
             <groupId>org.sonatype.plugins</groupId>
             <artifactId>nexus-staging-maven-plugin</artifactId>
-            <version>1.6.3</version>
+            <version>1.6.6</version>
             <extensions>true</extensions>
             <configuration>
-               <serverId>sonatype-nexus-staging</serverId>
-               <nexusUrl>https://oss.sonatype.org/</nexusUrl>
-               <autoReleaseAfterClose>false</autoReleaseAfterClose>
-            </configuration>
-          </plugin>
-        </plugins>
-      </build>
-    </profile>
-    <profile>
-      <id>lite</id>
-      <build>
-        <plugins>
-          <plugin>
-            <artifactId>maven-compiler-plugin</artifactId>
-            <configuration>
-              <includes>
-                <include>**/AbstractMessageLite.java</include>
-                <include>**/AbstractParser.java</include>
-                <include>**/AbstractProtobufList.java</include>
-                <include>**/BoundedByteString.java</include>
-                <include>**/BooleanArrayList.java</include>
-                <include>**/ByteString.java</include>
-                <include>**/CodedInputStream.java</include>
-                <include>**/CodedOutputStream.java</include>
-                <include>**/DoublerrayList.java</include>
-                <include>**/ExtensionLite.java</include>
-                <include>**/ExtensionRegistryLite.java</include>
-                <include>**/FieldSet.java</include>
-                <include>**/FloatArrayList.java</include>
-                <include>**/GeneratedMessageLite.java</include>
-                <include>**/IntArrayList.java</include>
-                <include>**/Internal.java</include>
-                <include>**/InvalidProtocolBufferException.java</include>
-                <include>**/LazyFieldLite.java</include>
-                <include>**/LazyStringArrayList.java</include>
-                <include>**/LazyStringList.java</include>
-                <include>**/LiteralByteString.java</include>
-                <include>**/LongArrayList.java</include>
-                <include>**/MapEntryLite.java</include>
-                <include>**/MapFieldLite.java</include>
-                <include>**/MessageLite.java</include>
-                <include>**/MessageLiteOrBuilder.java</include>
-                <include>**/MessageLiteToString.java</include>
-                <include>**/MutabilityOracle.java</include>
-                <include>**/NioByteString.java</include>
-                <include>**/Parser.java</include>
-                <include>**/ProtobufArrayList.java</include>
-                <include>**/ProtocolStringList.java</include>
-                <include>**/RopeByteString.java</include>
-                <include>**/SmallSortedMap.java</include>
-                <include>**/TextFormatEscaper.java</include>
-                <include>**/UninitializedMessageException.java</include>
-                <include>**/UnknownFieldSetLite.java</include>
-                <include>**/UnmodifiableLazyStringList.java</include>
-                <include>**/UnsafeByteStrings.java</include>
-                <include>**/Utf8.java</include>
-                <include>**/WireFormat.java</include>
-              </includes>
-              <testIncludes>
-                <testInclude>**/*Lite.java</testInclude>
-                <testInclude>**/BooleanArrayListTest.java</testInclude>
-                <testInclude>**/DoubleArrayListTest.java</testInclude>
-                <testInclude>**/FloatArrayListTest.java</testInclude>
-                <testInclude>**/IntArrayListTest.java</testInclude>
-                <testInclude>**/LazyMessageLiteTest.java</testInclude>
-                <testInclude>**/LiteTest.java</testInclude>
-                <testInclude>**/LongArrayListTest.java</testInclude>
-                <testInclude>**/NioByteStringTest.java</testInclude>
-                <testInclude>**/ProtobufArrayListTest.java</testInclude>
-                <testInclude>**/UnknownFieldSetLiteTest.java</testInclude>
-              </testIncludes>
-            </configuration>
-          </plugin>
-          <plugin>
-            <artifactId>maven-surefire-plugin</artifactId>
-            <configuration>
-              <includes>
-                <include>**/*Test.java</include>
-              </includes>
-            </configuration>
-          </plugin>
-          <plugin>
-            <artifactId>maven-jar-plugin</artifactId>
-            <configuration>
-              <classifier>lite</classifier>
+              <serverId>sonatype-nexus-staging</serverId>
+              <nexusUrl>https://oss.sonatype.org/</nexusUrl>
+              <autoReleaseAfterClose>false</autoReleaseAfterClose>
             </configuration>
           </plugin>
         </plugins>
       </build>
     </profile>
   </profiles>
+
+  <modules>
+    <module>core</module>
+    <module>lite</module>
+    <module>util</module>
+  </modules>
+
 </project>
diff --git a/java/util/pom.xml b/java/util/pom.xml
index 70401a4b..26c12c82 100644
--- a/java/util/pom.xml
+++ b/java/util/pom.xml
@@ -4,110 +4,73 @@
   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
-    <groupId>com.google</groupId>
-    <artifactId>google</artifactId>
-    <version>1</version>
+    <groupId>com.google.protobuf</groupId>
+    <artifactId>protobuf-parent</artifactId>
+    <version>3.0.0-beta-2</version>
   </parent>
-  <groupId>com.google.protobuf</groupId>
+
   <artifactId>protobuf-java-util</artifactId>
-  <version>3.0.0-beta-2</version>
   <packaging>bundle</packaging>
-  <name>Protocol Buffer Java API</name>
-  <description>
-    Protocol Buffers are a way of encoding structured data in an efficient yet
-    extensible format.
-  </description>
-  <inceptionYear>2008</inceptionYear>
-  <url>https://developers.google.com/protocol-buffers/</url>
-  <licenses>
-    <license>
-      <name>New BSD license</name>
-      <url>http://www.opensource.org/licenses/bsd-license.php</url>
-      <distribution>repo</distribution>
-    </license>
-  </licenses>
-  <scm>
-    <url>https://github.com/google/protobuf</url>
-    <connection>
-      scm:git:https://github.com/google/protobuf.git
-    </connection>
-  </scm>
+
+  <name>Protocol Buffers [Util]</name>
+  <description>Utilities for Protocol Buffers</description>
+
   <dependencies>
     <dependency>
-      <groupId>com.google.protobuf</groupId>
+      <groupId>${project.groupId}</groupId>
       <artifactId>protobuf-java</artifactId>
-      <version>3.0.0-beta-2</version>
-      <scope>compile</scope>
+      <version>${project.version}</version>
     </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>
-      <version>18.0</version>
-      <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>
       <version>2.3</version>
-      <scope>compile</scope>
     </dependency>
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>4.4</version>
-      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.easymock</groupId>
       <artifactId>easymock</artifactId>
-      <version>2.2</version>
-      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.easymock</groupId>
       <artifactId>easymockclassextension</artifactId>
-      <version>2.2.1</version>
-      <scope>test</scope>
     </dependency>
   </dependencies>
+
+  <properties>
+    <!-- Use the core proto dir so that we can call the core generation script -->
+    <test.proto.dir>../core/src/test/proto</test.proto.dir>
+  </properties>
+
   <build>
     <plugins>
       <plugin>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <configuration>
-          <source>1.5</source>
-          <target>1.5</target>
-        </configuration>
-      </plugin>
-      <plugin>
-        <artifactId>maven-surefire-plugin</artifactId>
-        <configuration>
-          <includes>
-            <include>**/*Test.java</include>
-            <include>../src/main/java/com/google/protobuf/TestUtil.java</include>
-          </includes>
-        </configuration>
-      </plugin>
-      <plugin>
         <artifactId>maven-antrun-plugin</artifactId>
         <executions>
+          <!-- Generate the test protos -->
           <execution>
             <id>generate-test-sources</id>
             <phase>generate-test-sources</phase>
             <configuration>
-              <tasks>
-                <mkdir dir="target/generated-test-sources" />
-                <exec executable="../../src/protoc">
-                  <arg value="--java_out=target/generated-test-sources" />
-                  <arg value="--proto_path=../../src" />
-                  <arg value="--proto_path=src/test/java" />
-                  <arg value="../../src/google/protobuf/unittest.proto" />
-                  <arg value="../../src/google/protobuf/unittest_import.proto" />
-                  <arg value="../../src/google/protobuf/unittest_import_public.proto" />
-                  <arg value="src/test/java/com/google/protobuf/util/json_test.proto" />
+              <target>
+                <!-- Generate all of the test protos from the core module -->
+                <ant antfile="../core/generate-test-sources-build.xml"/>
+
+                <!-- Generate additional test protos for this module -->
+                <exec executable="${protoc}">
+                  <arg value="--java_out=${generated.testsources.dir}" />
+                  <arg value="--proto_path=${protobuf.source.dir}" />
+                  <arg value="--proto_path=src/test/proto" />
+                  <arg value="src/test/proto/com/google/protobuf/util/json_test.proto" />
                 </exec>
-              </tasks>
-              <testSourceRoot>target/generated-test-sources</testSourceRoot>
+              </target>
             </configuration>
             <goals>
               <goal>run</goal>
@@ -115,6 +78,16 @@
           </execution>
         </executions>
       </plugin>
+
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <!-- Add the generated test sources to the build -->
+          <generatedTestSourcesDirectory>${generated.testsources.dir}</generatedTestSourcesDirectory>
+        </configuration>
+      </plugin>
+
+      <!-- Configure the OSGI bundle -->
       <plugin>
         <groupId>org.apache.felix</groupId>
         <artifactId>maven-bundle-plugin</artifactId>
@@ -123,88 +96,20 @@
           <instructions>
             <Bundle-DocURL>https://developers.google.com/protocol-buffers/</Bundle-DocURL>
             <Bundle-SymbolicName>com.google.protobuf.util</Bundle-SymbolicName>
-            <Export-Package>com.google.protobuf.util;version=3.0.0-beta-2</Export-Package>
+            <Export-Package>com.google.protobuf.util;version=${project.version}</Export-Package>
           </instructions>
         </configuration>
       </plugin>
+
+      <!-- Configure the fat jar to include all dependencies -->
       <plugin>
-          <artifactId>maven-assembly-plugin</artifactId>
-          <configuration>
-              <descriptorRefs>
-                  <descriptorRef>jar-with-dependencies</descriptorRef>
-              </descriptorRefs>
-          </configuration>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <configuration>
+          <descriptorRefs>
+            <descriptorRef>jar-with-dependencies</descriptorRef>
+          </descriptorRefs>
+        </configuration>
       </plugin>
     </plugins>
   </build>
-  <profiles>
-    <profile>
-      <id>release</id>
-      <distributionManagement>
-        <snapshotRepository>
-          <id>sonatype-nexus-staging</id>
-          <url>https://oss.sonatype.org/content/repositories/snapshots</url>
-        </snapshotRepository>
-        <repository>
-          <id>sonatype-nexus-staging</id>
-          <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
-        </repository>
-      </distributionManagement>
-      <build>
-        <plugins>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-source-plugin</artifactId>
-            <version>2.2.1</version>
-            <executions>
-              <execution>
-                <id>attach-sources</id>
-                <goals>
-                  <goal>jar-no-fork</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-javadoc-plugin</artifactId>
-            <version>2.9.1</version>
-            <executions>
-              <execution>
-                <id>attach-javadocs</id>
-                <goals>
-                  <goal>jar</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.apache.maven.plugins</groupId>
-            <artifactId>maven-gpg-plugin</artifactId>
-            <version>1.5</version>
-            <executions>
-              <execution>
-                <id>sign-artifacts</id>
-                <phase>verify</phase>
-                <goals>
-                  <goal>sign</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-          <plugin>
-            <groupId>org.sonatype.plugins</groupId>
-            <artifactId>nexus-staging-maven-plugin</artifactId>
-            <version>1.6.3</version>
-            <extensions>true</extensions>
-            <configuration>
-               <serverId>sonatype-nexus-staging</serverId>
-               <nexusUrl>https://oss.sonatype.org/</nexusUrl>
-               <autoReleaseAfterClose>false</autoReleaseAfterClose>
-            </configuration>
-          </plugin>
-        </plugins>
-      </build>
-    </profile>
-  </profiles>
 </project>
diff --git a/java/util/src/test/java/com/google/protobuf/util/json_test.proto b/java/util/src/test/proto/com/google/protobuf/util/json_test.proto
index 509c1d69..509c1d69 100644
--- a/java/util/src/test/java/com/google/protobuf/util/json_test.proto
+++ b/java/util/src/test/proto/com/google/protobuf/util/json_test.proto
diff --git a/python/google/protobuf/pyext/map_container.cc b/python/google/protobuf/pyext/map_container.cc
index 516662ee..df9138a4 100644
--- a/python/google/protobuf/pyext/map_container.cc
+++ b/python/google/protobuf/pyext/map_container.cc
@@ -797,7 +797,7 @@ static PyMethodDef MessageMapMethods[] = {
 
   PyType_Spec MessageMapContainer_Type_spec = {
       FULL_MODULE_NAME ".MessageMapContainer",
-      sizeof(MapContainer),
+      sizeof(MessageMapContainer),
       0,
       Py_TPFLAGS_DEFAULT,
       MessageMapContainer_Type_slots
diff --git a/src/google/protobuf/compiler/java/java_message.cc b/src/google/protobuf/compiler/java/java_message.cc
index 5715a432..22a70c32 100644
--- a/src/google/protobuf/compiler/java/java_message.cc
+++ b/src/google/protobuf/compiler/java/java_message.cc
@@ -664,34 +664,34 @@ GenerateParseFromMethods(io::Printer* printer) {
     "}\n"
     "public static $classname$ parseFrom(java.io.InputStream input)\n"
     "    throws java.io.IOException {\n"
-    "  return PARSER.parseFrom(input);\n"
+    "  return com.google.protobuf.GeneratedMessage.parseWithIOException(PARSER, input);"
     "}\n"
     "public static $classname$ parseFrom(\n"
     "    java.io.InputStream input,\n"
     "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws java.io.IOException {\n"
-    "  return PARSER.parseFrom(input, extensionRegistry);\n"
+    "  return com.google.protobuf.GeneratedMessage.parseWithIOException(PARSER, input, extensionRegistry);"
     "}\n"
     "public static $classname$ parseDelimitedFrom(java.io.InputStream input)\n"
     "    throws java.io.IOException {\n"
-    "  return PARSER.parseDelimitedFrom(input);\n"
+    "  return com.google.protobuf.GeneratedMessage.parseDelimitedWithIOException(PARSER, input);"
     "}\n"
     "public static $classname$ parseDelimitedFrom(\n"
     "    java.io.InputStream input,\n"
     "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws java.io.IOException {\n"
-    "  return PARSER.parseDelimitedFrom(input, extensionRegistry);\n"
+    "  return com.google.protobuf.GeneratedMessage.parseDelimitedWithIOException(PARSER, input, extensionRegistry);"
     "}\n"
     "public static $classname$ parseFrom(\n"
     "    com.google.protobuf.CodedInputStream input)\n"
     "    throws java.io.IOException {\n"
-    "  return PARSER.parseFrom(input);\n"
+    "  return com.google.protobuf.GeneratedMessage.parseWithIOException(PARSER, input);"
     "}\n"
     "public static $classname$ parseFrom(\n"
     "    com.google.protobuf.CodedInputStream input,\n"
     "    com.google.protobuf.ExtensionRegistryLite extensionRegistry)\n"
     "    throws java.io.IOException {\n"
-    "  return PARSER.parseFrom(input, extensionRegistry);\n"
+    "  return com.google.protobuf.GeneratedMessage.parseWithIOException(PARSER, input, extensionRegistry);"
     "}\n"
     "\n",
     "classname", name_resolver_->GetImmutableClassName(descriptor_));
@@ -1217,9 +1217,8 @@ GenerateParsingConstructor(io::Printer* printer) {
       "} catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
       "  throw new RuntimeException(e.setUnfinishedMessage(this));\n"
       "} catch (java.io.IOException e) {\n"
-      "  throw new RuntimeException(\n"
-      "      new com.google.protobuf.InvalidProtocolBufferException(\n"
-      "          e.getMessage()).setUnfinishedMessage(this));\n"
+      "  throw new RuntimeException(new com.google.protobuf.InvalidProtocolBufferException(e)\n"
+      "      .setUnfinishedMessage(this));\n"
       "} finally {\n");
   printer->Indent();
 
diff --git a/src/google/protobuf/compiler/java/java_message_builder.cc b/src/google/protobuf/compiler/java/java_message_builder.cc
index 72694119..5d535034 100644
--- a/src/google/protobuf/compiler/java/java_message_builder.cc
+++ b/src/google/protobuf/compiler/java/java_message_builder.cc
@@ -538,7 +538,7 @@ GenerateBuilderParsingMethods(io::Printer* printer) {
     "    parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);\n"
     "  } catch (com.google.protobuf.InvalidProtocolBufferException e) {\n"
     "    parsedMessage = ($classname$) e.getUnfinishedMessage();\n"
-    "    throw e;\n"
+    "    throw e.unwrapIOException();\n"
     "  } finally {\n"
     "    if (parsedMessage != null) {\n"
     "      mergeFrom(parsedMessage);\n"
diff --git a/src/google/protobuf/repeated_field.h b/src/google/protobuf/repeated_field.h
index 432236ce..61f3f558 100644
--- a/src/google/protobuf/repeated_field.h
+++ b/src/google/protobuf/repeated_field.h
@@ -692,7 +692,7 @@ class LIBPROTOBUF_EXPORT StringTypeHandlerBase {
 class StringTypeHandler : public StringTypeHandlerBase {
  public:
   static int SpaceUsed(const string& value)  {
-    return sizeof(value) + StringSpaceUsedExcludingSelf(value);
+    return static_cast<int>(sizeof(value)) + StringSpaceUsedExcludingSelf(value);
   }
 };
 
diff --git a/src/google/protobuf/unittest_well_known_types.proto b/src/google/protobuf/unittest_well_known_types.proto
index 2cb7775c..c9075244 100644
--- a/src/google/protobuf/unittest_well_known_types.proto
+++ b/src/google/protobuf/unittest_well_known_types.proto
@@ -39,6 +39,8 @@ message TestWellKnownTypes {
   google.protobuf.BoolValue bool_field = 16;
   google.protobuf.StringValue string_field = 17;
   google.protobuf.BytesValue bytes_field = 18;
+  // Part of struct, but useful to be able to test separately
+  google.protobuf.Value value_field = 19;
 }
 
 // A repeated field for each well-known type.