Squashed 'third_party/protobuf/' content from commit e35e248

Change-Id: I6cbe123d09fe50fdcad0e51466665daeee7433c7
git-subtree-dir: third_party/protobuf
git-subtree-split: e35e24800fb8d694bdeea5fd63dc7d1b14d68723
diff --git a/src/google/protobuf/extension_set_unittest.cc b/src/google/protobuf/extension_set_unittest.cc
new file mode 100644
index 0000000..f40fcbc
--- /dev/null
+++ b/src/google/protobuf/extension_set_unittest.cc
@@ -0,0 +1,1207 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <google/protobuf/extension_set.h>
+#include <google/protobuf/unittest.pb.h>
+#include <google/protobuf/unittest_mset.pb.h>
+#include <google/protobuf/test_util.h>
+#include <google/protobuf/descriptor.pb.h>
+#include <google/protobuf/arena.h>
+#include <google/protobuf/descriptor.h>
+#include <google/protobuf/dynamic_message.h>
+#include <google/protobuf/wire_format.h>
+#include <google/protobuf/io/coded_stream.h>
+#include <google/protobuf/io/zero_copy_stream_impl.h>
+
+#include <google/protobuf/stubs/logging.h>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/stubs/strutil.h>
+#include <google/protobuf/testing/googletest.h>
+#include <gtest/gtest.h>
+#include <google/protobuf/stubs/stl_util.h>
+
+namespace google {
+
+namespace protobuf {
+namespace internal {
+namespace {
+
+// This test closely mirrors google/protobuf/compiler/cpp/unittest.cc
+// except that it uses extensions rather than regular fields.
+
+TEST(ExtensionSetTest, Defaults) {
+  // Check that all default values are set correctly in the initial message.
+  unittest::TestAllExtensions message;
+
+  TestUtil::ExpectExtensionsClear(message);
+
+  // Messages should return pointers to default instances until first use.
+  // (This is not checked by ExpectClear() since it is not actually true after
+  // the fields have been set and then cleared.)
+  EXPECT_EQ(&unittest::OptionalGroup_extension::default_instance(),
+            &message.GetExtension(unittest::optionalgroup_extension));
+  EXPECT_EQ(&unittest::TestAllTypes::NestedMessage::default_instance(),
+            &message.GetExtension(unittest::optional_nested_message_extension));
+  EXPECT_EQ(&unittest::ForeignMessage::default_instance(),
+            &message.GetExtension(
+              unittest::optional_foreign_message_extension));
+  EXPECT_EQ(&unittest_import::ImportMessage::default_instance(),
+            &message.GetExtension(unittest::optional_import_message_extension));
+}
+
+TEST(ExtensionSetTest, Accessors) {
+  // Set every field to a unique value then go back and check all those
+  // values.
+  unittest::TestAllExtensions message;
+
+  TestUtil::SetAllExtensions(&message);
+  TestUtil::ExpectAllExtensionsSet(message);
+
+  TestUtil::ModifyRepeatedExtensions(&message);
+  TestUtil::ExpectRepeatedExtensionsModified(message);
+}
+
+TEST(ExtensionSetTest, Clear) {
+  // Set every field to a unique value, clear the message, then check that
+  // it is cleared.
+  unittest::TestAllExtensions message;
+
+  TestUtil::SetAllExtensions(&message);
+  message.Clear();
+  TestUtil::ExpectExtensionsClear(message);
+
+  // Unlike with the defaults test, we do NOT expect that requesting embedded
+  // messages will return a pointer to the default instance.  Instead, they
+  // should return the objects that were created when mutable_blah() was
+  // called.
+  EXPECT_NE(&unittest::OptionalGroup_extension::default_instance(),
+            &message.GetExtension(unittest::optionalgroup_extension));
+  EXPECT_NE(&unittest::TestAllTypes::NestedMessage::default_instance(),
+            &message.GetExtension(unittest::optional_nested_message_extension));
+  EXPECT_NE(&unittest::ForeignMessage::default_instance(),
+            &message.GetExtension(
+              unittest::optional_foreign_message_extension));
+  EXPECT_NE(&unittest_import::ImportMessage::default_instance(),
+            &message.GetExtension(unittest::optional_import_message_extension));
+
+  // Make sure setting stuff again after clearing works.  (This takes slightly
+  // different code paths since the objects are reused.)
+  TestUtil::SetAllExtensions(&message);
+  TestUtil::ExpectAllExtensionsSet(message);
+}
+
+TEST(ExtensionSetTest, ClearOneField) {
+  // Set every field to a unique value, then clear one value and insure that
+  // only that one value is cleared.
+  unittest::TestAllExtensions message;
+
+  TestUtil::SetAllExtensions(&message);
+  int64 original_value =
+    message.GetExtension(unittest::optional_int64_extension);
+
+  // Clear the field and make sure it shows up as cleared.
+  message.ClearExtension(unittest::optional_int64_extension);
+  EXPECT_FALSE(message.HasExtension(unittest::optional_int64_extension));
+  EXPECT_EQ(0, message.GetExtension(unittest::optional_int64_extension));
+
+  // Other adjacent fields should not be cleared.
+  EXPECT_TRUE(message.HasExtension(unittest::optional_int32_extension));
+  EXPECT_TRUE(message.HasExtension(unittest::optional_uint32_extension));
+
+  // Make sure if we set it again, then all fields are set.
+  message.SetExtension(unittest::optional_int64_extension, original_value);
+  TestUtil::ExpectAllExtensionsSet(message);
+}
+
+TEST(ExtensionSetTest, SetAllocatedExtension) {
+  unittest::TestAllExtensions message;
+  EXPECT_FALSE(message.HasExtension(
+      unittest::optional_foreign_message_extension));
+  // Add a extension using SetAllocatedExtension
+  unittest::ForeignMessage* foreign_message = new unittest::ForeignMessage();
+  message.SetAllocatedExtension(unittest::optional_foreign_message_extension,
+                                foreign_message);
+  EXPECT_TRUE(message.HasExtension(
+      unittest::optional_foreign_message_extension));
+  EXPECT_EQ(foreign_message,
+            message.MutableExtension(
+                unittest::optional_foreign_message_extension));
+  EXPECT_EQ(foreign_message,
+            &message.GetExtension(
+                unittest::optional_foreign_message_extension));
+
+  // SetAllocatedExtension should delete the previously existing extension.
+  // (We reply on unittest to check memory leaks for this case)
+  message.SetAllocatedExtension(unittest::optional_foreign_message_extension,
+                                new unittest::ForeignMessage());
+
+  // SetAllocatedExtension with a NULL parameter is equivalent to ClearExtenion.
+  message.SetAllocatedExtension(unittest::optional_foreign_message_extension,
+                                NULL);
+  EXPECT_FALSE(message.HasExtension(
+      unittest::optional_foreign_message_extension));
+}
+
+TEST(ExtensionSetTest, ReleaseExtension) {
+  proto2_wireformat_unittest::TestMessageSet message;
+  EXPECT_FALSE(message.HasExtension(
+      unittest::TestMessageSetExtension1::message_set_extension));
+  // Add a extension using SetAllocatedExtension
+  unittest::TestMessageSetExtension1* extension =
+      new unittest::TestMessageSetExtension1();
+  message.SetAllocatedExtension(
+      unittest::TestMessageSetExtension1::message_set_extension,
+      extension);
+  EXPECT_TRUE(message.HasExtension(
+      unittest::TestMessageSetExtension1::message_set_extension));
+  // Release the extension using ReleaseExtension
+  unittest::TestMessageSetExtension1* released_extension =
+      message.ReleaseExtension(
+          unittest::TestMessageSetExtension1::message_set_extension);
+  EXPECT_EQ(extension, released_extension);
+  EXPECT_FALSE(message.HasExtension(
+      unittest::TestMessageSetExtension1::message_set_extension));
+  // ReleaseExtension will return the underlying object even after
+  // ClearExtension is called.
+  message.SetAllocatedExtension(
+      unittest::TestMessageSetExtension1::message_set_extension,
+      extension);
+  message.ClearExtension(
+      unittest::TestMessageSetExtension1::message_set_extension);
+  released_extension = message.ReleaseExtension(
+      unittest::TestMessageSetExtension1::message_set_extension);
+  EXPECT_TRUE(released_extension != NULL);
+  delete released_extension;
+}
+
+
+TEST(ExtensionSetTest, CopyFrom) {
+  unittest::TestAllExtensions message1, message2;
+
+  TestUtil::SetAllExtensions(&message1);
+  message2.CopyFrom(message1);
+  TestUtil::ExpectAllExtensionsSet(message2);
+  message2.CopyFrom(message1);  // exercise copy when fields already exist
+  TestUtil::ExpectAllExtensionsSet(message2);
+}
+
+TEST(ExtensioSetTest, CopyFromPacked) {
+  unittest::TestPackedExtensions message1, message2;
+
+  TestUtil::SetPackedExtensions(&message1);
+  message2.CopyFrom(message1);
+  TestUtil::ExpectPackedExtensionsSet(message2);
+  message2.CopyFrom(message1);  // exercise copy when fields already exist
+  TestUtil::ExpectPackedExtensionsSet(message2);
+}
+
+TEST(ExtensionSetTest, CopyFromUpcasted) {
+  unittest::TestAllExtensions message1, message2;
+  const Message& upcasted_message = message1;
+
+  TestUtil::SetAllExtensions(&message1);
+  message2.CopyFrom(upcasted_message);
+  TestUtil::ExpectAllExtensionsSet(message2);
+  // exercise copy when fields already exist
+  message2.CopyFrom(upcasted_message);
+  TestUtil::ExpectAllExtensionsSet(message2);
+}
+
+TEST(ExtensionSetTest, SwapWithEmpty) {
+  unittest::TestAllExtensions message1, message2;
+  TestUtil::SetAllExtensions(&message1);
+
+  TestUtil::ExpectAllExtensionsSet(message1);
+  TestUtil::ExpectExtensionsClear(message2);
+  message1.Swap(&message2);
+  TestUtil::ExpectAllExtensionsSet(message2);
+  TestUtil::ExpectExtensionsClear(message1);
+}
+
+TEST(ExtensionSetTest, SwapWithSelf) {
+  unittest::TestAllExtensions message;
+  TestUtil::SetAllExtensions(&message);
+
+  TestUtil::ExpectAllExtensionsSet(message);
+  message.Swap(&message);
+  TestUtil::ExpectAllExtensionsSet(message);
+}
+
+TEST(ExtensionSetTest, SwapExtension) {
+  unittest::TestAllExtensions message1;
+  unittest::TestAllExtensions message2;
+
+  TestUtil::SetAllExtensions(&message1);
+  vector<const FieldDescriptor*> fields;
+
+  // Swap empty fields.
+  const Reflection* reflection = message1.GetReflection();
+  reflection->SwapFields(&message1, &message2, fields);
+  TestUtil::ExpectAllExtensionsSet(message1);
+  TestUtil::ExpectExtensionsClear(message2);
+
+  // Swap two extensions.
+  fields.push_back(
+      reflection->FindKnownExtensionByNumber(12));
+  fields.push_back(
+      reflection->FindKnownExtensionByNumber(25));
+  reflection->SwapFields(&message1, &message2, fields);
+
+  EXPECT_TRUE(message1.HasExtension(unittest::optional_int32_extension));
+  EXPECT_FALSE(message1.HasExtension(unittest::optional_double_extension));
+  EXPECT_FALSE(message1.HasExtension(unittest::optional_cord_extension));
+
+  EXPECT_FALSE(message2.HasExtension(unittest::optional_int32_extension));
+  EXPECT_TRUE(message2.HasExtension(unittest::optional_double_extension));
+  EXPECT_TRUE(message2.HasExtension(unittest::optional_cord_extension));
+}
+
+TEST(ExtensionSetTest, SwapExtensionWithEmpty) {
+  unittest::TestAllExtensions message1;
+  unittest::TestAllExtensions message2;
+  unittest::TestAllExtensions message3;
+
+  TestUtil::SetAllExtensions(&message3);
+
+  const Reflection* reflection = message3.GetReflection();
+  vector<const FieldDescriptor*> fields;
+  reflection->ListFields(message3, &fields);
+
+  reflection->SwapFields(&message1, &message2, fields);
+
+  TestUtil::ExpectExtensionsClear(message1);
+  TestUtil::ExpectExtensionsClear(message2);
+}
+
+TEST(ExtensionSetTest, SwapExtensionBothFull) {
+  unittest::TestAllExtensions message1;
+  unittest::TestAllExtensions message2;
+
+  TestUtil::SetAllExtensions(&message1);
+  TestUtil::SetAllExtensions(&message2);
+
+  const Reflection* reflection = message1.GetReflection();
+  vector<const FieldDescriptor*> fields;
+  reflection->ListFields(message1, &fields);
+
+  reflection->SwapFields(&message1, &message2, fields);
+
+  TestUtil::ExpectAllExtensionsSet(message1);
+  TestUtil::ExpectAllExtensionsSet(message2);
+}
+
+TEST(ExtensionSetTest, ArenaSetAllExtension) {
+  ::google::protobuf::Arena arena1;
+  unittest::TestAllExtensions* message1 =
+      ::google::protobuf::Arena::CreateMessage<unittest::TestAllExtensions>(&arena1);
+  TestUtil::SetAllExtensions(message1);
+  TestUtil::ExpectAllExtensionsSet(*message1);
+}
+
+TEST(ExtensionSetTest, ArenaCopyConstructor) {
+  ::google::protobuf::Arena arena1;
+  unittest::TestAllExtensions* message1 =
+      ::google::protobuf::Arena::CreateMessage<unittest::TestAllExtensions>(&arena1);
+  TestUtil::SetAllExtensions(message1);
+  unittest::TestAllExtensions message2(*message1);
+  arena1.Reset();
+  TestUtil::ExpectAllExtensionsSet(message2);
+}
+
+TEST(ExtensionSetTest, ArenaMergeFrom) {
+  ::google::protobuf::Arena arena1;
+  unittest::TestAllExtensions* message1 =
+      ::google::protobuf::Arena::CreateMessage<unittest::TestAllExtensions>(&arena1);
+  TestUtil::SetAllExtensions(message1);
+  unittest::TestAllExtensions message2;
+  message2.MergeFrom(*message1);
+  arena1.Reset();
+  TestUtil::ExpectAllExtensionsSet(message2);
+}
+
+TEST(ExtensionSetTest, ArenaSetAllocatedMessageAndRelease) {
+  ::google::protobuf::Arena arena;
+  unittest::TestAllExtensions* message =
+      ::google::protobuf::Arena::CreateMessage<unittest::TestAllExtensions>(&arena);
+  EXPECT_FALSE(message->HasExtension(
+      unittest::optional_foreign_message_extension));
+  // Add a extension using SetAllocatedExtension
+  unittest::ForeignMessage* foreign_message = new unittest::ForeignMessage();
+  message->SetAllocatedExtension(unittest::optional_foreign_message_extension,
+                                 foreign_message);
+  // foreign_message is now owned by the arena.
+  EXPECT_EQ(foreign_message,
+            message->MutableExtension(
+                unittest::optional_foreign_message_extension));
+
+  // Underlying message is copied, and returned.
+  unittest::ForeignMessage* released_message = message->ReleaseExtension(
+      unittest::optional_foreign_message_extension);
+  delete released_message;
+  EXPECT_FALSE(message->HasExtension(
+      unittest::optional_foreign_message_extension));
+}
+
+TEST(ExtensionSetTest, SwapExtensionBothFullWithArena) {
+  ::google::protobuf::Arena arena1;
+  google::protobuf::scoped_ptr<google::protobuf::Arena> arena2(new ::google::protobuf::Arena());
+
+  unittest::TestAllExtensions* message1 =
+      Arena::CreateMessage<unittest::TestAllExtensions>(&arena1);
+  unittest::TestAllExtensions* message2 =
+      Arena::CreateMessage<unittest::TestAllExtensions>(arena2.get());
+
+  TestUtil::SetAllExtensions(message1);
+  TestUtil::SetAllExtensions(message2);
+  message1->SetExtension(unittest::optional_int32_extension, 1);
+  message2->SetExtension(unittest::optional_int32_extension, 2);
+  message1->Swap(message2);
+  EXPECT_EQ(2, message1->GetExtension(unittest::optional_int32_extension));
+  EXPECT_EQ(1, message2->GetExtension(unittest::optional_int32_extension));
+  // Re-set the original values so ExpectAllExtensionsSet is happy.
+  message1->SetExtension(unittest::optional_int32_extension, 101);
+  message2->SetExtension(unittest::optional_int32_extension, 101);
+  TestUtil::ExpectAllExtensionsSet(*message1);
+  TestUtil::ExpectAllExtensionsSet(*message2);
+  arena2.reset(NULL);
+  TestUtil::ExpectAllExtensionsSet(*message1);
+  // Test corner cases, when one is empty and other is not.
+  ::google::protobuf::Arena arena3, arena4;
+
+  unittest::TestAllExtensions* message3 =
+      Arena::CreateMessage<unittest::TestAllExtensions>(&arena3);
+  unittest::TestAllExtensions* message4 =
+      Arena::CreateMessage<unittest::TestAllExtensions>(&arena4);
+  TestUtil::SetAllExtensions(message3);
+  message3->Swap(message4);
+  arena3.Reset();
+  TestUtil::ExpectAllExtensionsSet(*message4);
+}
+
+TEST(ExtensionSetTest, SwapFieldsOfExtensionBothFullWithArena) {
+  google::protobuf::Arena arena1;
+  google::protobuf::Arena* arena2 = new ::google::protobuf::Arena();
+
+  unittest::TestAllExtensions* message1 =
+      Arena::CreateMessage<unittest::TestAllExtensions>(&arena1);
+  unittest::TestAllExtensions* message2 =
+      Arena::CreateMessage<unittest::TestAllExtensions>(arena2);
+
+  TestUtil::SetAllExtensions(message1);
+  TestUtil::SetAllExtensions(message2);
+
+  const Reflection* reflection = message1->GetReflection();
+  vector<const FieldDescriptor*> fields;
+  reflection->ListFields(*message1, &fields);
+  reflection->SwapFields(message1, message2, fields);
+  TestUtil::ExpectAllExtensionsSet(*message1);
+  TestUtil::ExpectAllExtensionsSet(*message2);
+  delete arena2;
+  TestUtil::ExpectAllExtensionsSet(*message1);
+}
+
+TEST(ExtensionSetTest, SwapExtensionWithSelf) {
+  unittest::TestAllExtensions message1;
+
+  TestUtil::SetAllExtensions(&message1);
+
+  vector<const FieldDescriptor*> fields;
+  const Reflection* reflection = message1.GetReflection();
+  reflection->ListFields(message1, &fields);
+  reflection->SwapFields(&message1, &message1, fields);
+
+  TestUtil::ExpectAllExtensionsSet(message1);
+}
+
+TEST(ExtensionSetTest, SerializationToArray) {
+  // Serialize as TestAllExtensions and parse as TestAllTypes to insure wire
+  // compatibility of extensions.
+  //
+  // This checks serialization to a flat array by explicitly reserving space in
+  // the string and calling the generated message's
+  // SerializeWithCachedSizesToArray.
+  unittest::TestAllExtensions source;
+  unittest::TestAllTypes destination;
+  TestUtil::SetAllExtensions(&source);
+  int size = source.ByteSize();
+  string data;
+  data.resize(size);
+  uint8* target = reinterpret_cast<uint8*>(string_as_array(&data));
+  uint8* end = source.SerializeWithCachedSizesToArray(target);
+  EXPECT_EQ(size, end - target);
+  EXPECT_TRUE(destination.ParseFromString(data));
+  TestUtil::ExpectAllFieldsSet(destination);
+}
+
+TEST(ExtensionSetTest, SerializationToStream) {
+  // Serialize as TestAllExtensions and parse as TestAllTypes to insure wire
+  // compatibility of extensions.
+  //
+  // This checks serialization to an output stream by creating an array output
+  // stream that can only buffer 1 byte at a time - this prevents the message
+  // from ever jumping to the fast path, ensuring that serialization happens via
+  // the CodedOutputStream.
+  unittest::TestAllExtensions source;
+  unittest::TestAllTypes destination;
+  TestUtil::SetAllExtensions(&source);
+  int size = source.ByteSize();
+  string data;
+  data.resize(size);
+  {
+    io::ArrayOutputStream array_stream(string_as_array(&data), size, 1);
+    io::CodedOutputStream output_stream(&array_stream);
+    source.SerializeWithCachedSizes(&output_stream);
+    ASSERT_FALSE(output_stream.HadError());
+  }
+  EXPECT_TRUE(destination.ParseFromString(data));
+  TestUtil::ExpectAllFieldsSet(destination);
+}
+
+TEST(ExtensionSetTest, PackedSerializationToArray) {
+  // Serialize as TestPackedExtensions and parse as TestPackedTypes to insure
+  // wire compatibility of extensions.
+  //
+  // This checks serialization to a flat array by explicitly reserving space in
+  // the string and calling the generated message's
+  // SerializeWithCachedSizesToArray.
+  unittest::TestPackedExtensions source;
+  unittest::TestPackedTypes destination;
+  TestUtil::SetPackedExtensions(&source);
+  int size = source.ByteSize();
+  string data;
+  data.resize(size);
+  uint8* target = reinterpret_cast<uint8*>(string_as_array(&data));
+  uint8* end = source.SerializeWithCachedSizesToArray(target);
+  EXPECT_EQ(size, end - target);
+  EXPECT_TRUE(destination.ParseFromString(data));
+  TestUtil::ExpectPackedFieldsSet(destination);
+}
+
+TEST(ExtensionSetTest, PackedSerializationToStream) {
+  // Serialize as TestPackedExtensions and parse as TestPackedTypes to insure
+  // wire compatibility of extensions.
+  //
+  // This checks serialization to an output stream by creating an array output
+  // stream that can only buffer 1 byte at a time - this prevents the message
+  // from ever jumping to the fast path, ensuring that serialization happens via
+  // the CodedOutputStream.
+  unittest::TestPackedExtensions source;
+  unittest::TestPackedTypes destination;
+  TestUtil::SetPackedExtensions(&source);
+  int size = source.ByteSize();
+  string data;
+  data.resize(size);
+  {
+    io::ArrayOutputStream array_stream(string_as_array(&data), size, 1);
+    io::CodedOutputStream output_stream(&array_stream);
+    source.SerializeWithCachedSizes(&output_stream);
+    ASSERT_FALSE(output_stream.HadError());
+  }
+  EXPECT_TRUE(destination.ParseFromString(data));
+  TestUtil::ExpectPackedFieldsSet(destination);
+}
+
+TEST(ExtensionSetTest, Parsing) {
+  // Serialize as TestAllTypes and parse as TestAllExtensions.
+  unittest::TestAllTypes source;
+  unittest::TestAllExtensions destination;
+  string data;
+
+  TestUtil::SetAllFields(&source);
+  source.SerializeToString(&data);
+  EXPECT_TRUE(destination.ParseFromString(data));
+  TestUtil::SetOneofFields(&destination);
+  TestUtil::ExpectAllExtensionsSet(destination);
+}
+
+TEST(ExtensionSetTest, PackedParsing) {
+  // Serialize as TestPackedTypes and parse as TestPackedExtensions.
+  unittest::TestPackedTypes source;
+  unittest::TestPackedExtensions destination;
+  string data;
+
+  TestUtil::SetPackedFields(&source);
+  source.SerializeToString(&data);
+  EXPECT_TRUE(destination.ParseFromString(data));
+  TestUtil::ExpectPackedExtensionsSet(destination);
+}
+
+TEST(ExtensionSetTest, PackedToUnpackedParsing) {
+  unittest::TestPackedTypes source;
+  unittest::TestUnpackedExtensions destination;
+  string data;
+
+  TestUtil::SetPackedFields(&source);
+  source.SerializeToString(&data);
+  EXPECT_TRUE(destination.ParseFromString(data));
+  TestUtil::ExpectUnpackedExtensionsSet(destination);
+
+  // Reserialize
+  unittest::TestUnpackedTypes unpacked;
+  TestUtil::SetUnpackedFields(&unpacked);
+  EXPECT_TRUE(unpacked.SerializeAsString() == destination.SerializeAsString());
+
+  // Make sure we can add extensions.
+  destination.AddExtension(unittest::unpacked_int32_extension, 1);
+  destination.AddExtension(unittest::unpacked_enum_extension,
+                           protobuf_unittest::FOREIGN_BAR);
+}
+
+TEST(ExtensionSetTest, UnpackedToPackedParsing) {
+  unittest::TestUnpackedTypes source;
+  unittest::TestPackedExtensions destination;
+  string data;
+
+  TestUtil::SetUnpackedFields(&source);
+  source.SerializeToString(&data);
+  EXPECT_TRUE(destination.ParseFromString(data));
+  TestUtil::ExpectPackedExtensionsSet(destination);
+
+  // Reserialize
+  unittest::TestPackedTypes packed;
+  TestUtil::SetPackedFields(&packed);
+  EXPECT_TRUE(packed.SerializeAsString() == destination.SerializeAsString());
+
+  // Make sure we can add extensions.
+  destination.AddExtension(unittest::packed_int32_extension, 1);
+  destination.AddExtension(unittest::packed_enum_extension,
+                           protobuf_unittest::FOREIGN_BAR);
+}
+
+TEST(ExtensionSetTest, IsInitialized) {
+  // Test that IsInitialized() returns false if required fields in nested
+  // extensions are missing.
+  unittest::TestAllExtensions message;
+
+  EXPECT_TRUE(message.IsInitialized());
+
+  message.MutableExtension(unittest::TestRequired::single);
+  EXPECT_FALSE(message.IsInitialized());
+
+  message.MutableExtension(unittest::TestRequired::single)->set_a(1);
+  EXPECT_FALSE(message.IsInitialized());
+  message.MutableExtension(unittest::TestRequired::single)->set_b(2);
+  EXPECT_FALSE(message.IsInitialized());
+  message.MutableExtension(unittest::TestRequired::single)->set_c(3);
+  EXPECT_TRUE(message.IsInitialized());
+
+  message.AddExtension(unittest::TestRequired::multi);
+  EXPECT_FALSE(message.IsInitialized());
+
+  message.MutableExtension(unittest::TestRequired::multi, 0)->set_a(1);
+  EXPECT_FALSE(message.IsInitialized());
+  message.MutableExtension(unittest::TestRequired::multi, 0)->set_b(2);
+  EXPECT_FALSE(message.IsInitialized());
+  message.MutableExtension(unittest::TestRequired::multi, 0)->set_c(3);
+  EXPECT_TRUE(message.IsInitialized());
+}
+
+TEST(ExtensionSetTest, MutableString) {
+  // Test the mutable string accessors.
+  unittest::TestAllExtensions message;
+
+  message.MutableExtension(unittest::optional_string_extension)->assign("foo");
+  EXPECT_TRUE(message.HasExtension(unittest::optional_string_extension));
+  EXPECT_EQ("foo", message.GetExtension(unittest::optional_string_extension));
+
+  message.AddExtension(unittest::repeated_string_extension)->assign("bar");
+  ASSERT_EQ(1, message.ExtensionSize(unittest::repeated_string_extension));
+  EXPECT_EQ("bar",
+            message.GetExtension(unittest::repeated_string_extension, 0));
+}
+
+TEST(ExtensionSetTest, SpaceUsedExcludingSelf) {
+  // Scalar primitive extensions should increase the extension set size by a
+  // minimum of the size of the primitive type.
+#define TEST_SCALAR_EXTENSIONS_SPACE_USED(type, value)                        \
+  do {                                                                        \
+    unittest::TestAllExtensions message;                                      \
+    const int base_size = message.SpaceUsed();                                \
+    message.SetExtension(unittest::optional_##type##_extension, value);       \
+    int min_expected_size = base_size +                                       \
+        sizeof(message.GetExtension(unittest::optional_##type##_extension));  \
+    EXPECT_LE(min_expected_size, message.SpaceUsed());                        \
+  } while (0)
+
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(int32   , 101);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(int64   , 102);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(uint32  , 103);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(uint64  , 104);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(sint32  , 105);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(sint64  , 106);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(fixed32 , 107);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(fixed64 , 108);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(sfixed32, 109);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(sfixed64, 110);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(float   , 111);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(double  , 112);
+  TEST_SCALAR_EXTENSIONS_SPACE_USED(bool    , true);
+#undef TEST_SCALAR_EXTENSIONS_SPACE_USED
+  {
+    unittest::TestAllExtensions message;
+    const int base_size = message.SpaceUsed();
+    message.SetExtension(unittest::optional_nested_enum_extension,
+                         unittest::TestAllTypes::FOO);
+    int min_expected_size = base_size +
+        sizeof(message.GetExtension(unittest::optional_nested_enum_extension));
+    EXPECT_LE(min_expected_size, message.SpaceUsed());
+  }
+  {
+    // Strings may cause extra allocations depending on their length; ensure
+    // that gets included as well.
+    unittest::TestAllExtensions message;
+    const int base_size = message.SpaceUsed();
+    const string s("this is a fairly large string that will cause some "
+                   "allocation in order to store it in the extension");
+    message.SetExtension(unittest::optional_string_extension, s);
+    int min_expected_size = base_size + s.length();
+    EXPECT_LE(min_expected_size, message.SpaceUsed());
+  }
+  {
+    // Messages also have additional allocation that need to be counted.
+    unittest::TestAllExtensions message;
+    const int base_size = message.SpaceUsed();
+    unittest::ForeignMessage foreign;
+    foreign.set_c(42);
+    message.MutableExtension(unittest::optional_foreign_message_extension)->
+        CopyFrom(foreign);
+    int min_expected_size = base_size + foreign.SpaceUsed();
+    EXPECT_LE(min_expected_size, message.SpaceUsed());
+  }
+
+  // Repeated primitive extensions will increase space used by at least a
+  // RepeatedField<T>, and will cause additional allocations when the array
+  // gets too big for the initial space.
+  // This macro:
+  //   - Adds a value to the repeated extension, then clears it, establishing
+  //     the base size.
+  //   - Adds a small number of values, testing that it doesn't increase the
+  //     SpaceUsed()
+  //   - Adds a large number of values (requiring allocation in the repeated
+  //     field), and ensures that that allocation is included in SpaceUsed()
+#define TEST_REPEATED_EXTENSIONS_SPACE_USED(type, cpptype, value)              \
+  do {                                                                         \
+    unittest::TestAllExtensions message;                                       \
+    const int base_size = message.SpaceUsed();                                 \
+    int min_expected_size = sizeof(RepeatedField<cpptype>) + base_size;        \
+    message.AddExtension(unittest::repeated_##type##_extension, value);        \
+    message.ClearExtension(unittest::repeated_##type##_extension);             \
+    const int empty_repeated_field_size = message.SpaceUsed();                 \
+    EXPECT_LE(min_expected_size, empty_repeated_field_size) << #type;          \
+    message.AddExtension(unittest::repeated_##type##_extension, value);        \
+    message.AddExtension(unittest::repeated_##type##_extension, value);        \
+    EXPECT_EQ(empty_repeated_field_size, message.SpaceUsed()) << #type;        \
+    message.ClearExtension(unittest::repeated_##type##_extension);             \
+    for (int i = 0; i < 16; ++i) {                                             \
+      message.AddExtension(unittest::repeated_##type##_extension, value);      \
+    }                                                                          \
+    int expected_size = sizeof(cpptype) * (16 -                                \
+        kMinRepeatedFieldAllocationSize) + empty_repeated_field_size;          \
+    EXPECT_EQ(expected_size, message.SpaceUsed()) << #type;                    \
+  } while (0)
+
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(int32   , int32 , 101);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(int64   , int64 , 102);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(uint32  , uint32, 103);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(uint64  , uint64, 104);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(sint32  , int32 , 105);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(sint64  , int64 , 106);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(fixed32 , uint32, 107);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(fixed64 , uint64, 108);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(sfixed32, int32 , 109);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(sfixed64, int64 , 110);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(float   , float , 111);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(double  , double, 112);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(bool    , bool  , true);
+  TEST_REPEATED_EXTENSIONS_SPACE_USED(nested_enum, int,
+                                      unittest::TestAllTypes::FOO);
+#undef TEST_REPEATED_EXTENSIONS_SPACE_USED
+  // Repeated strings
+  {
+    unittest::TestAllExtensions message;
+    const int base_size = message.SpaceUsed();
+    int min_expected_size = sizeof(RepeatedPtrField<string>) + base_size;
+    const string value(256, 'x');
+    // Once items are allocated, they may stick around even when cleared so
+    // without the hardcore memory management accessors there isn't a notion of
+    // the empty repeated field memory usage as there is with primitive types.
+    for (int i = 0; i < 16; ++i) {
+      message.AddExtension(unittest::repeated_string_extension, value);
+    }
+    min_expected_size += (sizeof(value) + value.size()) *
+        (16 - kMinRepeatedFieldAllocationSize);
+    EXPECT_LE(min_expected_size, message.SpaceUsed());
+  }
+  // Repeated messages
+  {
+    unittest::TestAllExtensions message;
+    const int base_size = message.SpaceUsed();
+    int min_expected_size = sizeof(RepeatedPtrField<unittest::ForeignMessage>) +
+        base_size;
+    unittest::ForeignMessage prototype;
+    prototype.set_c(2);
+    for (int i = 0; i < 16; ++i) {
+      message.AddExtension(unittest::repeated_foreign_message_extension)->
+          CopyFrom(prototype);
+    }
+    min_expected_size +=
+        (16 - kMinRepeatedFieldAllocationSize) * prototype.SpaceUsed();
+    EXPECT_LE(min_expected_size, message.SpaceUsed());
+  }
+}
+
+// N.B.: We do not test range-based for here because we remain C++03 compatible.
+template<typename T, typename M, typename ID>
+inline T SumAllExtensions(const M& message, ID extension, T zero) {
+  T sum = zero;
+  typename RepeatedField<T>::const_iterator iter =
+      message.GetRepeatedExtension(extension).begin();
+  typename RepeatedField<T>::const_iterator end =
+      message.GetRepeatedExtension(extension).end();
+  for (; iter != end; ++iter) {
+    sum += *iter;
+  }
+  return sum;
+}
+
+template<typename T, typename M, typename ID>
+inline void IncAllExtensions(M* message, ID extension,
+                          T val) {
+  typename RepeatedField<T>::iterator iter =
+      message->MutableRepeatedExtension(extension)->begin();
+  typename RepeatedField<T>::iterator end  =
+      message->MutableRepeatedExtension(extension)->end();
+  for (; iter != end; ++iter) {
+    *iter += val;
+  }
+}
+
+TEST(ExtensionSetTest, RepeatedFields) {
+  unittest::TestAllExtensions message;
+
+  // Test empty repeated-field case (b/12926163)
+  ASSERT_EQ(0, message.GetRepeatedExtension(
+      unittest::repeated_int32_extension).size());
+  ASSERT_EQ(0, message.GetRepeatedExtension(
+      unittest::repeated_nested_enum_extension).size());
+  ASSERT_EQ(0, message.GetRepeatedExtension(
+      unittest::repeated_string_extension).size());
+  ASSERT_EQ(0, message.GetRepeatedExtension(
+      unittest::repeated_nested_message_extension).size());
+
+  unittest::TestAllTypes::NestedMessage nested_message;
+  nested_message.set_bb(42);
+  unittest::TestAllTypes::NestedEnum nested_enum =
+      unittest::TestAllTypes::NestedEnum_MIN;
+
+  for (int i = 0; i < 10; ++i) {
+    message.AddExtension(unittest::repeated_int32_extension, 1);
+    message.AddExtension(unittest::repeated_int64_extension, 2);
+    message.AddExtension(unittest::repeated_uint32_extension, 3);
+    message.AddExtension(unittest::repeated_uint64_extension, 4);
+    message.AddExtension(unittest::repeated_sint32_extension, 5);
+    message.AddExtension(unittest::repeated_sint64_extension, 6);
+    message.AddExtension(unittest::repeated_fixed32_extension, 7);
+    message.AddExtension(unittest::repeated_fixed64_extension, 8);
+    message.AddExtension(unittest::repeated_sfixed32_extension, 7);
+    message.AddExtension(unittest::repeated_sfixed64_extension, 8);
+    message.AddExtension(unittest::repeated_float_extension, 9.0);
+    message.AddExtension(unittest::repeated_double_extension, 10.0);
+    message.AddExtension(unittest::repeated_bool_extension, true);
+    message.AddExtension(unittest::repeated_nested_enum_extension, nested_enum);
+    message.AddExtension(unittest::repeated_string_extension,
+                         ::std::string("test"));
+    message.AddExtension(unittest::repeated_bytes_extension,
+                         ::std::string("test\xFF"));
+    message.AddExtension(
+        unittest::repeated_nested_message_extension)->CopyFrom(nested_message);
+    message.AddExtension(unittest::repeated_nested_enum_extension,
+                         nested_enum);
+  }
+
+  ASSERT_EQ(10, SumAllExtensions<int32>(
+      message, unittest::repeated_int32_extension, 0));
+  IncAllExtensions<int32>(
+      &message, unittest::repeated_int32_extension, 1);
+  ASSERT_EQ(20, SumAllExtensions<int32>(
+      message, unittest::repeated_int32_extension, 0));
+
+  ASSERT_EQ(20, SumAllExtensions<int64>(
+      message, unittest::repeated_int64_extension, 0));
+  IncAllExtensions<int64>(
+      &message, unittest::repeated_int64_extension, 1);
+  ASSERT_EQ(30, SumAllExtensions<int64>(
+      message, unittest::repeated_int64_extension, 0));
+
+  ASSERT_EQ(30, SumAllExtensions<uint32>(
+      message, unittest::repeated_uint32_extension, 0));
+  IncAllExtensions<uint32>(
+      &message, unittest::repeated_uint32_extension, 1);
+  ASSERT_EQ(40, SumAllExtensions<uint32>(
+      message, unittest::repeated_uint32_extension, 0));
+
+  ASSERT_EQ(40, SumAllExtensions<uint64>(
+      message, unittest::repeated_uint64_extension, 0));
+  IncAllExtensions<uint64>(
+      &message, unittest::repeated_uint64_extension, 1);
+  ASSERT_EQ(50, SumAllExtensions<uint64>(
+      message, unittest::repeated_uint64_extension, 0));
+
+  ASSERT_EQ(50, SumAllExtensions<int32>(
+      message, unittest::repeated_sint32_extension, 0));
+  IncAllExtensions<int32>(
+      &message, unittest::repeated_sint32_extension, 1);
+  ASSERT_EQ(60, SumAllExtensions<int32>(
+      message, unittest::repeated_sint32_extension, 0));
+
+  ASSERT_EQ(60, SumAllExtensions<int64>(
+      message, unittest::repeated_sint64_extension, 0));
+  IncAllExtensions<int64>(
+      &message, unittest::repeated_sint64_extension, 1);
+  ASSERT_EQ(70, SumAllExtensions<int64>(
+      message, unittest::repeated_sint64_extension, 0));
+
+  ASSERT_EQ(70, SumAllExtensions<uint32>(
+      message, unittest::repeated_fixed32_extension, 0));
+  IncAllExtensions<uint32>(
+      &message, unittest::repeated_fixed32_extension, 1);
+  ASSERT_EQ(80, SumAllExtensions<uint32>(
+      message, unittest::repeated_fixed32_extension, 0));
+
+  ASSERT_EQ(80, SumAllExtensions<uint64>(
+      message, unittest::repeated_fixed64_extension, 0));
+  IncAllExtensions<uint64>(
+      &message, unittest::repeated_fixed64_extension, 1);
+  ASSERT_EQ(90, SumAllExtensions<uint64>(
+      message, unittest::repeated_fixed64_extension, 0));
+
+  // Usually, floating-point arithmetic cannot be trusted to be exact, so it is
+  // a Bad Idea to assert equality in a test like this. However, we're dealing
+  // with integers with a small number of significant mantissa bits, so we
+  // should actually have exact precision here.
+  ASSERT_EQ(90, SumAllExtensions<float>(
+      message, unittest::repeated_float_extension, 0));
+  IncAllExtensions<float>(
+      &message, unittest::repeated_float_extension, 1);
+  ASSERT_EQ(100, SumAllExtensions<float>(
+      message, unittest::repeated_float_extension, 0));
+
+  ASSERT_EQ(100, SumAllExtensions<double>(
+      message, unittest::repeated_double_extension, 0));
+  IncAllExtensions<double>(
+      &message, unittest::repeated_double_extension, 1);
+  ASSERT_EQ(110, SumAllExtensions<double>(
+      message, unittest::repeated_double_extension, 0));
+
+  RepeatedPtrField< ::std::string>::iterator string_iter;
+  RepeatedPtrField< ::std::string>::iterator string_end;
+  for (string_iter = message.MutableRepeatedExtension(
+          unittest::repeated_string_extension)->begin(),
+       string_end  = message.MutableRepeatedExtension(
+           unittest::repeated_string_extension)->end();
+       string_iter != string_end; ++string_iter) {
+    *string_iter += "test";
+  }
+  RepeatedPtrField< ::std::string>::const_iterator string_const_iter;
+  RepeatedPtrField< ::std::string>::const_iterator string_const_end;
+  for (string_const_iter = message.GetRepeatedExtension(
+           unittest::repeated_string_extension).begin(),
+       string_const_end  = message.GetRepeatedExtension(
+           unittest::repeated_string_extension).end();
+       string_iter != string_end; ++string_iter) {
+    ASSERT_TRUE(*string_iter == "testtest");
+  }
+
+  RepeatedField<unittest::TestAllTypes_NestedEnum>::iterator enum_iter;
+  RepeatedField<unittest::TestAllTypes_NestedEnum>::iterator enum_end;
+  for (enum_iter = message.MutableRepeatedExtension(
+           unittest::repeated_nested_enum_extension)->begin(),
+       enum_end  = message.MutableRepeatedExtension(
+           unittest::repeated_nested_enum_extension)->end();
+       enum_iter != enum_end; ++enum_iter) {
+    *enum_iter = unittest::TestAllTypes::NestedEnum_MAX;
+  }
+  RepeatedField<unittest::TestAllTypes_NestedEnum>::const_iterator
+      enum_const_iter;
+  RepeatedField<unittest::TestAllTypes_NestedEnum>::const_iterator
+      enum_const_end;
+  for (enum_const_iter = message.GetRepeatedExtension(
+           unittest::repeated_nested_enum_extension).begin(),
+       enum_const_end  = message.GetRepeatedExtension(
+           unittest::repeated_nested_enum_extension).end();
+       enum_iter != enum_end; ++enum_iter) {
+    ASSERT_EQ(*enum_const_iter, unittest::TestAllTypes::NestedEnum_MAX);
+  }
+
+  RepeatedPtrField<unittest::TestAllTypes_NestedMessage>::iterator
+      msg_iter;
+  RepeatedPtrField<unittest::TestAllTypes_NestedMessage>::iterator
+      msg_end;
+  for (msg_iter = message.MutableRepeatedExtension(
+           unittest::repeated_nested_message_extension)->begin(),
+       msg_end  = message.MutableRepeatedExtension(
+           unittest::repeated_nested_message_extension)->end();
+       msg_iter != msg_end; ++msg_iter) {
+    msg_iter->set_bb(1234);
+  }
+  RepeatedPtrField<unittest::TestAllTypes_NestedMessage>::
+      const_iterator msg_const_iter;
+  RepeatedPtrField<unittest::TestAllTypes_NestedMessage>::
+      const_iterator msg_const_end;
+  for (msg_const_iter = message.GetRepeatedExtension(
+           unittest::repeated_nested_message_extension).begin(),
+       msg_const_end  = message.GetRepeatedExtension(
+           unittest::repeated_nested_message_extension).end();
+       msg_const_iter != msg_const_end; ++msg_const_iter) {
+    ASSERT_EQ(msg_const_iter->bb(), 1234);
+  }
+
+  // Test range-based for as well, but only if compiled as C++11.
+#if __cplusplus >= 201103L
+  // Test one primitive field.
+  for (auto& x : *message.MutableRepeatedExtension(
+          unittest::repeated_int32_extension)) {
+    x = 4321;
+  }
+  for (const auto& x : message.GetRepeatedExtension(
+          unittest::repeated_int32_extension)) {
+    ASSERT_EQ(x, 4321);
+  }
+  // Test one string field.
+  for (auto& x : *message.MutableRepeatedExtension(
+          unittest::repeated_string_extension)) {
+    x = "test_range_based_for";
+  }
+  for (const auto& x : message.GetRepeatedExtension(
+          unittest::repeated_string_extension)) {
+    ASSERT_TRUE(x == "test_range_based_for");
+  }
+  // Test one message field.
+  for (auto& x : *message.MutableRepeatedExtension(
+          unittest::repeated_nested_message_extension)) {
+    x.set_bb(4321);
+  }
+  for (const auto& x : *message.MutableRepeatedExtension(
+          unittest::repeated_nested_message_extension)) {
+    ASSERT_EQ(x.bb(), 4321);
+  }
+#endif
+}
+
+// From b/12926163
+TEST(ExtensionSetTest, AbsentExtension) {
+  unittest::TestAllExtensions message;
+  message.MutableRepeatedExtension(unittest::repeated_nested_message_extension)
+      ->Add()->set_bb(123);
+  ASSERT_EQ(1, message.ExtensionSize(
+      unittest::repeated_nested_message_extension));
+  EXPECT_EQ(
+      123, message.GetExtension(
+          unittest::repeated_nested_message_extension, 0).bb());
+}
+
+#ifdef PROTOBUF_HAS_DEATH_TEST
+
+TEST(ExtensionSetTest, InvalidEnumDeath) {
+  unittest::TestAllExtensions message;
+  EXPECT_DEBUG_DEATH(
+    message.SetExtension(unittest::optional_foreign_enum_extension,
+                         static_cast<unittest::ForeignEnum>(53)),
+    "IsValid");
+}
+
+#endif  // PROTOBUF_HAS_DEATH_TEST
+
+TEST(ExtensionSetTest, DynamicExtensions) {
+  // Test adding a dynamic extension to a compiled-in message object.
+
+  FileDescriptorProto dynamic_proto;
+  dynamic_proto.set_name("dynamic_extensions_test.proto");
+  dynamic_proto.add_dependency(
+      unittest::TestAllExtensions::descriptor()->file()->name());
+  dynamic_proto.set_package("dynamic_extensions");
+
+  // Copy the fields and nested types from TestDynamicExtensions into our new
+  // proto, converting the fields into extensions.
+  const Descriptor* template_descriptor =
+      unittest::TestDynamicExtensions::descriptor();
+  DescriptorProto template_descriptor_proto;
+  template_descriptor->CopyTo(&template_descriptor_proto);
+  dynamic_proto.mutable_message_type()->MergeFrom(
+      template_descriptor_proto.nested_type());
+  dynamic_proto.mutable_enum_type()->MergeFrom(
+      template_descriptor_proto.enum_type());
+  dynamic_proto.mutable_extension()->MergeFrom(
+      template_descriptor_proto.field());
+
+  // For each extension that we added...
+  for (int i = 0; i < dynamic_proto.extension_size(); i++) {
+    // Set its extendee to TestAllExtensions.
+    FieldDescriptorProto* extension = dynamic_proto.mutable_extension(i);
+    extension->set_extendee(
+        unittest::TestAllExtensions::descriptor()->full_name());
+
+    // If the field refers to one of the types nested in TestDynamicExtensions,
+    // make it refer to the type in our dynamic proto instead.
+    string prefix = "." + template_descriptor->full_name() + ".";
+    if (extension->has_type_name()) {
+      string* type_name = extension->mutable_type_name();
+      if (HasPrefixString(*type_name, prefix)) {
+        type_name->replace(0, prefix.size(), ".dynamic_extensions.");
+      }
+    }
+  }
+
+  // Now build the file, using the generated pool as an underlay.
+  DescriptorPool dynamic_pool(DescriptorPool::generated_pool());
+  const FileDescriptor* file = dynamic_pool.BuildFile(dynamic_proto);
+  ASSERT_TRUE(file != NULL);
+  DynamicMessageFactory dynamic_factory(&dynamic_pool);
+  dynamic_factory.SetDelegateToGeneratedFactory(true);
+
+  // Construct a message that we can parse with the extensions we defined.
+  // Since the extensions were based off of the fields of TestDynamicExtensions,
+  // we can use that message to create this test message.
+  string data;
+  {
+    unittest::TestDynamicExtensions message;
+    message.set_scalar_extension(123);
+    message.set_enum_extension(unittest::FOREIGN_BAR);
+    message.set_dynamic_enum_extension(
+        unittest::TestDynamicExtensions::DYNAMIC_BAZ);
+    message.mutable_message_extension()->set_c(456);
+    message.mutable_dynamic_message_extension()->set_dynamic_field(789);
+    message.add_repeated_extension("foo");
+    message.add_repeated_extension("bar");
+    message.add_packed_extension(12);
+    message.add_packed_extension(-34);
+    message.add_packed_extension(56);
+    message.add_packed_extension(-78);
+
+    // Also add some unknown fields.
+
+    // An unknown enum value (for a known field).
+    message.mutable_unknown_fields()->AddVarint(
+      unittest::TestDynamicExtensions::kDynamicEnumExtensionFieldNumber,
+      12345);
+    // A regular unknown field.
+    message.mutable_unknown_fields()->AddLengthDelimited(54321, "unknown");
+
+    message.SerializeToString(&data);
+  }
+
+  // Now we can parse this using our dynamic extension definitions...
+  unittest::TestAllExtensions message;
+  {
+    io::ArrayInputStream raw_input(data.data(), data.size());
+    io::CodedInputStream input(&raw_input);
+    input.SetExtensionRegistry(&dynamic_pool, &dynamic_factory);
+    ASSERT_TRUE(message.ParseFromCodedStream(&input));
+    ASSERT_TRUE(input.ConsumedEntireMessage());
+  }
+
+  // Can we print it?
+  EXPECT_EQ(
+    "[dynamic_extensions.scalar_extension]: 123\n"
+    "[dynamic_extensions.enum_extension]: FOREIGN_BAR\n"
+    "[dynamic_extensions.dynamic_enum_extension]: DYNAMIC_BAZ\n"
+    "[dynamic_extensions.message_extension] {\n"
+    "  c: 456\n"
+    "}\n"
+    "[dynamic_extensions.dynamic_message_extension] {\n"
+    "  dynamic_field: 789\n"
+    "}\n"
+    "[dynamic_extensions.repeated_extension]: \"foo\"\n"
+    "[dynamic_extensions.repeated_extension]: \"bar\"\n"
+    "[dynamic_extensions.packed_extension]: 12\n"
+    "[dynamic_extensions.packed_extension]: -34\n"
+    "[dynamic_extensions.packed_extension]: 56\n"
+    "[dynamic_extensions.packed_extension]: -78\n"
+    "2002: 12345\n"
+    "54321: \"unknown\"\n",
+    message.DebugString());
+
+  // Can we serialize it?
+  // (Don't use EXPECT_EQ because we don't want to dump raw binary data to the
+  // terminal on failure.)
+  EXPECT_TRUE(message.SerializeAsString() == data);
+
+  // What if we parse using the reflection-based parser?
+  {
+    unittest::TestAllExtensions message2;
+    io::ArrayInputStream raw_input(data.data(), data.size());
+    io::CodedInputStream input(&raw_input);
+    input.SetExtensionRegistry(&dynamic_pool, &dynamic_factory);
+    ASSERT_TRUE(WireFormat::ParseAndMergePartial(&input, &message2));
+    ASSERT_TRUE(input.ConsumedEntireMessage());
+    EXPECT_EQ(message.DebugString(), message2.DebugString());
+  }
+
+  // Are the embedded generated types actually using the generated objects?
+  {
+    const FieldDescriptor* message_extension =
+        file->FindExtensionByName("message_extension");
+    ASSERT_TRUE(message_extension != NULL);
+    const Message& sub_message =
+        message.GetReflection()->GetMessage(message, message_extension);
+    const unittest::ForeignMessage* typed_sub_message =
+#ifdef GOOGLE_PROTOBUF_NO_RTTI
+        static_cast<const unittest::ForeignMessage*>(&sub_message);
+#else
+        dynamic_cast<const unittest::ForeignMessage*>(&sub_message);
+#endif
+    ASSERT_TRUE(typed_sub_message != NULL);
+    EXPECT_EQ(456, typed_sub_message->c());
+  }
+
+  // What does GetMessage() return for the embedded dynamic type if it isn't
+  // present?
+  {
+    const FieldDescriptor* dynamic_message_extension =
+        file->FindExtensionByName("dynamic_message_extension");
+    ASSERT_TRUE(dynamic_message_extension != NULL);
+    const Message& parent = unittest::TestAllExtensions::default_instance();
+    const Message& sub_message =
+        parent.GetReflection()->GetMessage(parent, dynamic_message_extension,
+                                           &dynamic_factory);
+    const Message* prototype =
+        dynamic_factory.GetPrototype(dynamic_message_extension->message_type());
+    EXPECT_EQ(prototype, &sub_message);
+  }
+}
+
+}  // namespace
+}  // namespace internal
+}  // namespace protobuf
+}  // namespace google