Down-integrate from internal code base (C++ maps support).

15 files changed, 553 insertions, 61 deletions

diff --git a/src/google/protobuf/compiler/cpp/cpp_field.cc b/src/google/protobuf/compiler/cpp/cpp_field.cc
index 85838ac3..43df1d88 100644
--- a/src/google/protobuf/compiler/cpp/cpp_field.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_field.cc
@@ -42,6 +42,7 @@
 #include <google/protobuf/compiler/cpp/cpp_primitive_field.h>
 #include <google/protobuf/compiler/cpp/cpp_string_field.h>
 #include <google/protobuf/compiler/cpp/cpp_enum_field.h>
+#include <google/protobuf/compiler/cpp/cpp_map_field.h>
 #include <google/protobuf/compiler/cpp/cpp_message_field.h>
 #include <google/protobuf/descriptor.pb.h>
 #include <google/protobuf/wire_format.h>
@@ -65,6 +66,12 @@ void SetCommonFieldVariables(const FieldDescriptor* descriptor,
   (*variables)["classname"] = ClassName(FieldScope(descriptor), false);
   (*variables)["declared_type"] = DeclaredTypeMethodName(descriptor->type());
 
+  // non_null_ptr_to_name is usable only if has_$name$ is true.  It yields a
+  // pointer that will not be NULL.  Subclasses of FieldGenerator may set
+  // (*variables)["non_null_ptr_to_name"] differently.
+  (*variables)["non_null_ptr_to_name"] =
+      StrCat("&this->", FieldName(descriptor), "()");
+
   (*variables)["tag_size"] = SimpleItoa(
     WireFormat::TagSize(descriptor->number(), descriptor->type()));
   (*variables)["deprecation"] = descriptor->options().deprecated()
@@ -89,8 +96,11 @@ void SetCommonFieldVariables(const FieldDescriptor* descriptor,
 
 void SetCommonOneofFieldVariables(const FieldDescriptor* descriptor,
                                   map<string, string>* variables) {
-  (*variables)["oneof_prefix"] = descriptor->containing_oneof()->name() + "_.";
+  const string prefix = descriptor->containing_oneof()->name() + "_.";
+  (*variables)["oneof_prefix"] = prefix;
   (*variables)["oneof_name"] = descriptor->containing_oneof()->name();
+  (*variables)["non_null_ptr_to_name"] =
+      StrCat(prefix, (*variables)["name"], "_");
 }
 
 FieldGenerator::~FieldGenerator() {}
@@ -111,7 +121,7 @@ FieldGeneratorMap::FieldGeneratorMap(const Descriptor* descriptor,
                                      const Options& options)
     : descriptor_(descriptor),
       field_generators_(
-          new scoped_ptr<FieldGenerator>[descriptor->field_count()]) {
+          new google::protobuf::scoped_ptr<FieldGenerator>[descriptor->field_count()]) {
   // Construct all the FieldGenerators.
   for (int i = 0; i < descriptor->field_count(); i++) {
     field_generators_[i].reset(MakeGenerator(descriptor->field(i), options));
@@ -123,7 +133,11 @@ FieldGenerator* FieldGeneratorMap::MakeGenerator(const FieldDescriptor* field,
   if (field->is_repeated()) {
     switch (field->cpp_type()) {
       case FieldDescriptor::CPPTYPE_MESSAGE:
-        return new RepeatedMessageFieldGenerator(field, options);
+        if (field->is_map()) {
+          return new MapFieldGenerator(field, options);
+        } else {
+          return new RepeatedMessageFieldGenerator(field, options);
+        }
       case FieldDescriptor::CPPTYPE_STRING:
         switch (field->options().ctype()) {
           default:  // RepeatedStringFieldGenerator handles unknown ctypes.
diff --git a/src/google/protobuf/compiler/cpp/cpp_field.h b/src/google/protobuf/compiler/cpp/cpp_field.h
index 088e5063..c37fe0be 100644
--- a/src/google/protobuf/compiler/cpp/cpp_field.h
+++ b/src/google/protobuf/compiler/cpp/cpp_field.h
@@ -182,7 +182,7 @@ class FieldGeneratorMap {
 
  private:
   const Descriptor* descriptor_;
-  scoped_array<scoped_ptr<FieldGenerator> > field_generators_;
+  google::protobuf::scoped_array<google::protobuf::scoped_ptr<FieldGenerator> > field_generators_;
 
   static FieldGenerator* MakeGenerator(const FieldDescriptor* field,
                                        const Options& options);
diff --git a/src/google/protobuf/compiler/cpp/cpp_file.cc b/src/google/protobuf/compiler/cpp/cpp_file.cc
index dc8bf613..8745577f 100644
--- a/src/google/protobuf/compiler/cpp/cpp_file.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_file.cc
@@ -59,13 +59,13 @@ namespace cpp {
 FileGenerator::FileGenerator(const FileDescriptor* file, const Options& options)
     : file_(file),
       message_generators_(
-          new scoped_ptr<MessageGenerator>[file->message_type_count()]),
+          new google::protobuf::scoped_ptr<MessageGenerator>[file->message_type_count()]),
       enum_generators_(
-          new scoped_ptr<EnumGenerator>[file->enum_type_count()]),
+          new google::protobuf::scoped_ptr<EnumGenerator>[file->enum_type_count()]),
       service_generators_(
-          new scoped_ptr<ServiceGenerator>[file->service_count()]),
+          new google::protobuf::scoped_ptr<ServiceGenerator>[file->service_count()]),
       extension_generators_(
-          new scoped_ptr<ExtensionGenerator>[file->extension_count()]),
+          new google::protobuf::scoped_ptr<ExtensionGenerator>[file->extension_count()]),
       options_(options) {
 
   for (int i = 0; i < file->message_type_count(); i++) {
@@ -151,6 +151,11 @@ void FileGenerator::GenerateHeader(io::Printer* printer) {
   printer->Print(
     "#include <google/protobuf/repeated_field.h>\n"
     "#include <google/protobuf/extension_set.h>\n");
+  if (HasMapFields(file_)) {
+    printer->Print(
+      "#include <google/protobuf/map.h>\n"
+      "#include <google/protobuf/map_field_inl.h>\n");
+  }
 
   if (HasDescriptorMethods(file_) && HasEnumDefinitions(file_)) {
     printer->Print(
@@ -396,6 +401,19 @@ void FileGenerator::GenerateSource(io::Printer* printer) {
 
   // Generate classes.
   for (int i = 0; i < file_->message_type_count(); i++) {
+    if (i == 0 && HasGeneratedMethods(file_)) {
+      printer->Print(
+          "\n"
+          "namespace {\n"
+          "\n"
+          "static void MergeFromFail(int line) GOOGLE_ATTRIBUTE_COLD;\n"
+          "static void MergeFromFail(int line) {\n"
+          "  GOOGLE_CHECK(false) << __FILE__ << \":\" << line;\n"
+          "}\n"
+          "\n"
+          "}  // namespace\n"
+          "\n");
+    }
     printer->Print("\n");
     printer->Print(kThickSeparator);
     printer->Print("\n");
diff --git a/src/google/protobuf/compiler/cpp/cpp_file.h b/src/google/protobuf/compiler/cpp/cpp_file.h
index 13d06f98..0e06547d 100644
--- a/src/google/protobuf/compiler/cpp/cpp_file.h
+++ b/src/google/protobuf/compiler/cpp/cpp_file.h
@@ -82,10 +82,10 @@ class FileGenerator {
 
   const FileDescriptor* file_;
 
-  scoped_array<scoped_ptr<MessageGenerator> > message_generators_;
-  scoped_array<scoped_ptr<EnumGenerator> > enum_generators_;
-  scoped_array<scoped_ptr<ServiceGenerator> > service_generators_;
-  scoped_array<scoped_ptr<ExtensionGenerator> > extension_generators_;
+  google::protobuf::scoped_array<google::protobuf::scoped_ptr<MessageGenerator> > message_generators_;
+  google::protobuf::scoped_array<google::protobuf::scoped_ptr<EnumGenerator> > enum_generators_;
+  google::protobuf::scoped_array<google::protobuf::scoped_ptr<ServiceGenerator> > service_generators_;
+  google::protobuf::scoped_array<google::protobuf::scoped_ptr<ExtensionGenerator> > extension_generators_;
 
   // E.g. if the package is foo.bar, package_parts_ is {"foo", "bar"}.
   vector<string> package_parts_;
diff --git a/src/google/protobuf/compiler/cpp/cpp_generator.cc b/src/google/protobuf/compiler/cpp/cpp_generator.cc
index a2fb7162..c999b93f 100644
--- a/src/google/protobuf/compiler/cpp/cpp_generator.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_generator.cc
@@ -105,7 +105,7 @@ bool CppGenerator::Generate(const FileDescriptor* file,
 
   // Generate header.
   {
-    scoped_ptr<io::ZeroCopyOutputStream> output(
+    google::protobuf::scoped_ptr<io::ZeroCopyOutputStream> output(
         generator_context->Open(basename + ".h"));
     io::Printer printer(output.get(), '$');
     file_generator.GenerateHeader(&printer);
@@ -113,7 +113,7 @@ bool CppGenerator::Generate(const FileDescriptor* file,
 
   // Generate cc file.
   {
-    scoped_ptr<io::ZeroCopyOutputStream> output(
+    google::protobuf::scoped_ptr<io::ZeroCopyOutputStream> output(
         generator_context->Open(basename + ".cc"));
     io::Printer printer(output.get(), '$');
     file_generator.GenerateSource(&printer);
diff --git a/src/google/protobuf/compiler/cpp/cpp_helpers.cc b/src/google/protobuf/compiler/cpp/cpp_helpers.cc
index 63b0265e..28c4dd54 100644
--- a/src/google/protobuf/compiler/cpp/cpp_helpers.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_helpers.cc
@@ -453,6 +453,25 @@ void PrintHandlingOptionalStaticInitializers(
 }
 
 
+static bool HasMapFields(const Descriptor* descriptor) {
+  for (int i = 0; i < descriptor->field_count(); ++i) {
+    if (descriptor->field(i)->is_map()) {
+      return true;
+    }
+  }
+  for (int i = 0; i < descriptor->nested_type_count(); ++i) {
+    if (HasMapFields(descriptor->nested_type(i))) return true;
+  }
+  return false;
+}
+
+bool HasMapFields(const FileDescriptor* file) {
+  for (int i = 0; i < file->message_type_count(); ++i) {
+    if (HasMapFields(file->message_type(i))) return true;
+  }
+  return false;
+}
+
 static bool HasEnumDefinitions(const Descriptor* message_type) {
   if (message_type->enum_type_count() > 0) return true;
   for (int i = 0; i < message_type->nested_type_count(); ++i) {
diff --git a/src/google/protobuf/compiler/cpp/cpp_helpers.h b/src/google/protobuf/compiler/cpp/cpp_helpers.h
index 1cff17c8..e60fa7c2 100644
--- a/src/google/protobuf/compiler/cpp/cpp_helpers.h
+++ b/src/google/protobuf/compiler/cpp/cpp_helpers.h
@@ -149,6 +149,10 @@ inline bool UseUnknownFieldSet(const FileDescriptor* file) {
 }
 
 
+// Does the file have any map fields, necessitating the file to include
+// map_field_inl.h and map.h.
+bool HasMapFields(const FileDescriptor* file);
+
 // Does this file have any enum type definitions?
 bool HasEnumDefinitions(const FileDescriptor* file);
 
@@ -200,6 +204,10 @@ void PrintHandlingOptionalStaticInitializers(
     const char* without_static_init);
 
 
+inline bool IsMapEntryMessage(const Descriptor* descriptor) {
+  return descriptor->options().map_entry();
+}
+
 // Returns true if the field's CPPTYPE is string or message.
 bool IsStringOrMessage(const FieldDescriptor* field);
 
@@ -216,7 +224,7 @@ inline bool HasPreservingUnknownEnumSemantics(const FileDescriptor* file) {
 }
 
 inline bool SupportsArenas(const FileDescriptor* file) {
-  return true;
+  return file->options().cc_enable_arenas();
 }
 
 inline bool SupportsArenas(const Descriptor* desc) {
diff --git a/src/google/protobuf/compiler/cpp/cpp_map_field.cc b/src/google/protobuf/compiler/cpp/cpp_map_field.cc
new file mode 100644
index 00000000..0154eeb8
--- /dev/null
+++ b/src/google/protobuf/compiler/cpp/cpp_map_field.cc
@@ -0,0 +1,255 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <google/protobuf/compiler/cpp/cpp_map_field.h>
+#include <google/protobuf/compiler/cpp/cpp_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace cpp {
+
+bool IsProto3Field(const FieldDescriptor* field_descriptor) {
+  const FileDescriptor* file_descriptor = field_descriptor->file();
+  return file_descriptor->syntax() == FileDescriptor::SYNTAX_PROTO3;
+}
+
+void SetMessageVariables(const FieldDescriptor* descriptor,
+                         map<string, string>* variables,
+                         const Options& options) {
+  SetCommonFieldVariables(descriptor, variables, options);
+  (*variables)["type"] = FieldMessageTypeName(descriptor);
+  (*variables)["stream_writer"] = (*variables)["declared_type"] +
+      (HasFastArraySerialization(descriptor->message_type()->file()) ?
+       "MaybeToArray" :
+       "");
+  (*variables)["full_name"] = descriptor->full_name();
+
+  const FieldDescriptor* key =
+      descriptor->message_type()->FindFieldByName("key");
+  const FieldDescriptor* val =
+      descriptor->message_type()->FindFieldByName("value");
+  (*variables)["key_cpp"] = PrimitiveTypeName(key->cpp_type());
+  switch (val->cpp_type()) {
+    case FieldDescriptor::CPPTYPE_MESSAGE:
+      (*variables)["val_cpp"] = FieldMessageTypeName(val);
+      (*variables)["wrapper"] = "EntryWrapper";
+      break;
+    case FieldDescriptor::CPPTYPE_ENUM:
+      (*variables)["val_cpp"] = ClassName(val->enum_type(), false);
+      (*variables)["wrapper"] = "EnumEntryWrapper";
+      break;
+    default:
+      (*variables)["val_cpp"] = PrimitiveTypeName(val->cpp_type());
+      (*variables)["wrapper"] = "EntryWrapper";
+  }
+  (*variables)["key_type"] =
+      "::google::protobuf::FieldDescriptor::TYPE_" +
+      ToUpper(DeclaredTypeMethodName(key->type()));
+  (*variables)["val_type"] =
+      "::google::protobuf::FieldDescriptor::TYPE_" +
+      ToUpper(DeclaredTypeMethodName(val->type()));
+  (*variables)["map_classname"] = ClassName(descriptor->message_type(), false);
+  (*variables)["number"] = Int32ToString(descriptor->number());
+
+  if (!IsProto3Field(descriptor) &&
+      val->type() == FieldDescriptor::TYPE_ENUM) {
+    const EnumValueDescriptor* default_value = val->default_value_enum();
+    (*variables)["default_enum_value"] = Int32ToString(default_value->number());
+  } else {
+    (*variables)["default_enum_value"] = "0";
+  }
+}
+
+MapFieldGenerator::
+MapFieldGenerator(const FieldDescriptor* descriptor,
+                              const Options& options)
+    : descriptor_(descriptor) {
+  SetMessageVariables(descriptor, &variables_, options);
+}
+
+MapFieldGenerator::~MapFieldGenerator() {}
+
+void MapFieldGenerator::
+GeneratePrivateMembers(io::Printer* printer) const {
+  printer->Print(variables_,
+      "typedef ::google::protobuf::internal::MapEntry<\n"
+      "    $key_cpp$, $val_cpp$,\n"
+      "    $key_type$,\n"
+      "    $val_type$, $default_enum_value$>\n"
+      "    $map_classname$;\n"
+      "::google::protobuf::internal::MapField< $key_cpp$, $val_cpp$,"
+      "$key_type$, $val_type$, $default_enum_value$ > $name$_;\n");
+}
+
+void MapFieldGenerator::
+GenerateAccessorDeclarations(io::Printer* printer) const {
+  printer->Print(variables_,
+      "inline const ::google::protobuf::Map< $key_cpp$, $val_cpp$ >&\n"
+      "    $name$() const$deprecation$;\n"
+      "inline ::google::protobuf::Map< $key_cpp$, $val_cpp$ >*\n"
+      "    mutable_$name$()$deprecation$;\n");
+}
+
+void MapFieldGenerator::
+GenerateInlineAccessorDefinitions(io::Printer* printer) const {
+  printer->Print(variables_,
+      "inline const ::google::protobuf::Map< $key_cpp$, $val_cpp$ >&\n"
+      "$classname$::$name$() const {\n"
+      "  // @@protoc_insertion_point(field_map:$full_name$)\n"
+      "  return $name$_.GetMap();\n"
+      "}\n"
+      "inline ::google::protobuf::Map< $key_cpp$, $val_cpp$ >*\n"
+      "$classname$::mutable_$name$() {\n"
+      "  // @@protoc_insertion_point(field_mutable_map:$full_name$)\n"
+      "  return $name$_.MutableMap();\n"
+      "}\n");
+}
+
+void MapFieldGenerator::
+GenerateClearingCode(io::Printer* printer) const {
+  printer->Print(variables_, "$name$_.Clear();\n");
+}
+
+void MapFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_, "$name$_.MergeFrom(from.$name$_);\n");
+}
+
+void MapFieldGenerator::
+GenerateSwappingCode(io::Printer* printer) const {
+  printer->Print(variables_, "$name$_.Swap(&other->$name$_);\n");
+}
+
+void MapFieldGenerator::
+GenerateConstructorCode(io::Printer* printer) const {
+  if (HasDescriptorMethods(descriptor_->file())) {
+    printer->Print(variables_,
+        "$name$_.SetAssignDescriptorCallback(\n"
+        "    protobuf_AssignDescriptorsOnce);\n"
+        "$name$_.SetEntryDescriptor(\n"
+        "    &$type$_descriptor_);\n");
+  }
+}
+
+void MapFieldGenerator::
+GenerateMergeFromCodedStream(io::Printer* printer) const {
+  const FieldDescriptor* value_field =
+      descriptor_->message_type()->FindFieldByName("value");
+  printer->Print(variables_,
+      "::google::protobuf::scoped_ptr<$map_classname$> entry($name$_.NewEntry());\n");
+
+  if (IsProto3Field(descriptor_) ||
+      value_field->type() != FieldDescriptor::TYPE_ENUM) {
+    printer->Print(variables_,
+        "DO_(::google::protobuf::internal::WireFormatLite::ReadMessageNoVirtual(\n"
+        "    input, entry.get()));\n");
+    switch (value_field->cpp_type()) {
+      case FieldDescriptor::CPPTYPE_MESSAGE:
+        printer->Print(variables_,
+            "(*mutable_$name$())[entry->key()].Swap("
+            "entry->mutable_value());\n");
+        break;
+      case FieldDescriptor::CPPTYPE_ENUM:
+        printer->Print(variables_,
+            "(*mutable_$name$())[entry->key()] =\n"
+            "    static_cast<$val_cpp$>(*entry->mutable_value());\n");
+        break;
+      default:
+        printer->Print(variables_,
+            "(*mutable_$name$())[entry->key()] = *entry->mutable_value();\n");
+        break;
+    }
+  } else {
+    printer->Print(variables_,
+        "{\n"
+        "  ::std::string data;\n"
+        "  DO_(::google::protobuf::internal::WireFormatLite::ReadString(input, &data));\n"
+        "  DO_(entry->ParseFromString(data));\n"
+        "  if ($val_cpp$_IsValid(*entry->mutable_value())) {\n"
+        "    (*mutable_$name$())[entry->key()] =\n"
+        "        static_cast<$val_cpp$>(*entry->mutable_value());\n"
+        "  } else {\n"
+        "    mutable_unknown_fields()->AddLengthDelimited($number$, data);\n"
+        "  }\n"
+        "}\n");
+  }
+}
+
+void MapFieldGenerator::
+GenerateSerializeWithCachedSizes(io::Printer* printer) const {
+  printer->Print(variables_,
+      "{\n"
+      "  ::google::protobuf::scoped_ptr<$map_classname$> entry;\n"
+      "  for (::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_iterator\n"
+      "      it = $name$().begin(); it != $name$().end(); ++it) {\n"
+      "    entry.reset($name$_.New$wrapper$(it->first, it->second));\n"
+      "    ::google::protobuf::internal::WireFormatLite::Write$stream_writer$(\n"
+      "        $number$, *entry, output);\n"
+      "  }\n"
+      "}\n");
+}
+
+void MapFieldGenerator::
+GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
+  printer->Print(variables_,
+      "{\n"
+      "  ::google::protobuf::scoped_ptr<$map_classname$> entry;\n"
+      "  for (::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_iterator\n"
+      "      it = $name$().begin(); it != $name$().end(); ++it) {\n"
+      "    entry.reset($name$_.New$wrapper$(it->first, it->second));\n"
+      "    target = ::google::protobuf::internal::WireFormatLite::\n"
+      "        Write$declared_type$NoVirtualToArray(\n"
+      "            $number$, *entry, target);\n"
+      "  }\n"
+      "}\n");
+}
+
+void MapFieldGenerator::
+GenerateByteSize(io::Printer* printer) const {
+  printer->Print(variables_,
+      "total_size += $tag_size$ * this->$name$_size();\n"
+      "{\n"
+      "  ::google::protobuf::scoped_ptr<$map_classname$> entry;\n"
+      "  for (::google::protobuf::Map< $key_cpp$, $val_cpp$ >::const_iterator\n"
+      "      it = $name$().begin(); it != $name$().end(); ++it) {\n"
+      "    entry.reset($name$_.New$wrapper$(it->first, it->second));\n"
+      "    total_size += ::google::protobuf::internal::WireFormatLite::\n"
+      "        $declared_type$SizeNoVirtual(*entry);\n"
+      "  }\n"
+      "}\n");
+}
+
+}  // namespace cpp
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google
diff --git a/src/google/protobuf/compiler/cpp/cpp_map_field.h b/src/google/protobuf/compiler/cpp/cpp_map_field.h
new file mode 100644
index 00000000..0ff032fd
--- /dev/null
+++ b/src/google/protobuf/compiler/cpp/cpp_map_field.h
@@ -0,0 +1,75 @@
+// 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.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_CPP_MAP_FIELD_H__
+#define GOOGLE_PROTOBUF_COMPILER_CPP_MAP_FIELD_H__
+
+#include <map>
+#include <string>
+
+#include <google/protobuf/compiler/cpp/cpp_message_field.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace cpp {
+
+class MapFieldGenerator : public FieldGenerator {
+ public:
+  explicit MapFieldGenerator(const FieldDescriptor* descriptor,
+                             const Options& options);
+  ~MapFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GeneratePrivateMembers(io::Printer* printer) const;
+  void GenerateAccessorDeclarations(io::Printer* printer) const;
+  void GenerateInlineAccessorDefinitions(io::Printer* printer) const;
+  void GenerateClearingCode(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateSwappingCode(io::Printer* printer) const;
+  void GenerateConstructorCode(io::Printer* printer) const;
+  void GenerateMergeFromCodedStream(io::Printer* printer) const;
+  void GenerateSerializeWithCachedSizes(io::Printer* printer) const;
+  void GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const;
+  void GenerateByteSize(io::Printer* printer) const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MapFieldGenerator);
+};
+
+}  // namespace cpp
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_CPP_MAP_FIELD_H__
diff --git a/src/google/protobuf/compiler/cpp/cpp_message.cc b/src/google/protobuf/compiler/cpp/cpp_message.cc
index 54a92ae4..28ee3a9d 100644
--- a/src/google/protobuf/compiler/cpp/cpp_message.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_message.cc
@@ -334,6 +334,31 @@ bool HasHasMethod(const FieldDescriptor* field) {
   return field->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE;
 }
 
+// Collects map entry message type information.
+void CollectMapInfo(const Descriptor* descriptor,
+                    map<string, string>* variables) {
+  GOOGLE_CHECK(IsMapEntryMessage(descriptor));
+  const FieldDescriptor* key = descriptor->FindFieldByName("key");
+  const FieldDescriptor* val = descriptor->FindFieldByName("value");
+  (*variables)["key"] = PrimitiveTypeName(key->cpp_type());
+  switch (val->cpp_type()) {
+    case FieldDescriptor::CPPTYPE_MESSAGE:
+      (*variables)["val"] = FieldMessageTypeName(val);
+      break;
+    case FieldDescriptor::CPPTYPE_ENUM:
+      (*variables)["val"] = ClassName(val->enum_type(), false);
+      break;
+    default:
+      (*variables)["val"] = PrimitiveTypeName(val->cpp_type());
+  }
+  (*variables)["key_type"] =
+      "::google::protobuf::FieldDescriptor::TYPE_" +
+      ToUpper(DeclaredTypeMethodName(key->type()));
+  (*variables)["val_type"] =
+      "::google::protobuf::FieldDescriptor::TYPE_" +
+      ToUpper(DeclaredTypeMethodName(val->type()));
+}
+
 // Does the given field have a private (internal helper only) has_$name$()
 // method?
 bool HasPrivateHasMethod(const FieldDescriptor* field) {
@@ -353,11 +378,11 @@ MessageGenerator::MessageGenerator(const Descriptor* descriptor,
       classname_(ClassName(descriptor, false)),
       options_(options),
       field_generators_(descriptor, options),
-      nested_generators_(new scoped_ptr<
+      nested_generators_(new google::protobuf::scoped_ptr<
           MessageGenerator>[descriptor->nested_type_count()]),
       enum_generators_(
-          new scoped_ptr<EnumGenerator>[descriptor->enum_type_count()]),
-      extension_generators_(new scoped_ptr<
+          new google::protobuf::scoped_ptr<EnumGenerator>[descriptor->enum_type_count()]),
+      extension_generators_(new google::protobuf::scoped_ptr<
           ExtensionGenerator>[descriptor->extension_count()]) {
 
   for (int i = 0; i < descriptor->nested_type_count(); i++) {
@@ -391,6 +416,10 @@ GenerateForwardDeclaration(io::Printer* printer) {
                  "classname", classname_);
 
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    // map entry message doesn't need forward declaration. Since map entry
+    // message cannot be a top level class, we just need to avoid calling
+    // GenerateForwardDeclaration here.
+    if (IsMapEntryMessage(descriptor_->nested_type(i))) continue;
     nested_generators_[i]->GenerateForwardDeclaration(printer);
   }
 }
@@ -622,6 +651,10 @@ static bool CanClearByZeroing(const FieldDescriptor* field) {
 void MessageGenerator::
 GenerateClassDefinition(io::Printer* printer) {
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    // map entry message doesn't need class definition. Since map entry message
+    // cannot be a top level class, we just need to avoid calling
+    // GenerateClassDefinition here.
+    if (IsMapEntryMessage(descriptor_->nested_type(i))) continue;
     nested_generators_[i]->GenerateClassDefinition(printer);
     printer->Print("\n");
     printer->Print(kThinSeparator);
@@ -876,9 +909,11 @@ GenerateClassDefinition(io::Printer* printer) {
   // Import all nested message classes into this class's scope with typedefs.
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
     const Descriptor* nested_type = descriptor_->nested_type(i);
-    printer->Print("typedef $nested_full_name$ $nested_name$;\n",
-                   "nested_name", nested_type->name(),
-                   "nested_full_name", ClassName(nested_type, false));
+    if (!IsMapEntryMessage(nested_type)) {
+      printer->Print("typedef $nested_full_name$ $nested_name$;\n",
+                     "nested_name", nested_type->name(),
+                     "nested_full_name", ClassName(nested_type, false));
+    }
   }
 
   if (descriptor_->nested_type_count() > 0) {
@@ -1124,6 +1159,10 @@ GenerateClassDefinition(io::Printer* printer) {
 void MessageGenerator::
 GenerateInlineMethods(io::Printer* printer) {
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    // map entry message doesn't need inline methods. Since map entry message
+    // cannot be a top level class, we just need to avoid calling
+    // GenerateInlineMethods here.
+    if (IsMapEntryMessage(descriptor_->nested_type(i))) continue;
     nested_generators_[i]->GenerateInlineMethods(printer);
     printer->Print(kThinSeparator);
     printer->Print("\n");
@@ -1151,11 +1190,17 @@ GenerateInlineMethods(io::Printer* printer) {
 
 void MessageGenerator::
 GenerateDescriptorDeclarations(io::Printer* printer) {
-  printer->Print(
-    "const ::google::protobuf::Descriptor* $name$_descriptor_ = NULL;\n"
-    "const ::google::protobuf::internal::GeneratedMessageReflection*\n"
-    "  $name$_reflection_ = NULL;\n",
-    "name", classname_);
+  if (!IsMapEntryMessage(descriptor_)) {
+    printer->Print(
+      "const ::google::protobuf::Descriptor* $name$_descriptor_ = NULL;\n"
+      "const ::google::protobuf::internal::GeneratedMessageReflection*\n"
+      "  $name$_reflection_ = NULL;\n",
+      "name", classname_);
+  } else {
+    printer->Print(
+      "const ::google::protobuf::Descriptor* $name$_descriptor_ = NULL;\n",
+      "name", classname_);
+  }
 
   // Generate oneof default instance for reflection usage.
   if (descriptor_->oneof_decl_count() > 0) {
@@ -1206,13 +1251,20 @@ GenerateDescriptorInitializer(io::Printer* printer, int index) {
         "$parent$_descriptor_->nested_type($index$);\n");
   }
 
+  if (IsMapEntryMessage(descriptor_)) return;
+
   // Generate the offsets.
   GenerateOffsets(printer);
 
+  const bool pass_pool_and_factory = false;
+  vars["fn"] = pass_pool_and_factory ?
+      "new ::google::protobuf::internal::GeneratedMessageReflection" :
+      "::google::protobuf::internal::GeneratedMessageReflection"
+      "::NewGeneratedMessageReflection";
   // Construct the reflection object.
   printer->Print(vars,
     "$classname$_reflection_ =\n"
-    "  new ::google::protobuf::internal::GeneratedMessageReflection(\n"
+    "  $fn$(\n"
     "    $classname$_descriptor_,\n"
     "    $classname$::default_instance_,\n"
     "    $classname$_offsets_,\n");
@@ -1254,10 +1306,12 @@ GenerateDescriptorInitializer(io::Printer* printer, int index) {
       "$classname$, _oneof_case_[0]),\n");
   }
 
-  printer->Print(
-    "    ::google::protobuf::DescriptorPool::generated_pool(),\n");
-  printer->Print(vars,
-    "    ::google::protobuf::MessageFactory::generated_factory(),\n");
+  if (pass_pool_and_factory) {
+    printer->Print(
+        "    ::google::protobuf::DescriptorPool::generated_pool(),\n");
+      printer->Print(vars,
+                     "    ::google::protobuf::MessageFactory::generated_factory(),\n");
+  }
 
   printer->Print(vars,
     "    sizeof($classname$),\n");
@@ -1289,10 +1343,37 @@ GenerateDescriptorInitializer(io::Printer* printer, int index) {
 void MessageGenerator::
 GenerateTypeRegistrations(io::Printer* printer) {
   // Register this message type with the message factory.
-  printer->Print(
-    "::google::protobuf::MessageFactory::InternalRegisterGeneratedMessage(\n"
-    "  $classname$_descriptor_, &$classname$::default_instance());\n",
-    "classname", classname_);
+  if (!IsMapEntryMessage(descriptor_)) {
+    printer->Print(
+      "::google::protobuf::MessageFactory::InternalRegisterGeneratedMessage(\n"
+      "    $classname$_descriptor_, &$classname$::default_instance());\n",
+      "classname", classname_);
+  }
+  else {
+    map<string, string> vars;
+    CollectMapInfo(descriptor_, &vars);
+    vars["classname"] = classname_;
+
+    const FieldDescriptor* val = descriptor_->FindFieldByName("value");
+    if (descriptor_->file()->syntax() == FileDescriptor::SYNTAX_PROTO2 &&
+        val->type() == FieldDescriptor::TYPE_ENUM) {
+      const EnumValueDescriptor* default_value = val->default_value_enum();
+      vars["default_enum_value"] = Int32ToString(default_value->number());
+    } else {
+      vars["default_enum_value"] = "0";
+    }
+
+    printer->Print(vars,
+      "::google::protobuf::MessageFactory::InternalRegisterGeneratedMessage(\n"
+      "      $classname$_descriptor_,\n"
+      "      ::google::protobuf::internal::MapEntry<\n"
+      "          $key$,\n"
+      "          $val$,\n"
+      "          $key_type$,\n"
+      "          $val_type$,\n"
+      "          $default_enum_value$>::CreateDefaultInstance(\n"
+      "              $classname$_descriptor_));\n");
+  }
 
   // Handle nested types.
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
@@ -1309,6 +1390,8 @@ GenerateDefaultInstanceAllocator(io::Printer* printer) {
                      .GenerateDefaultInstanceAllocator(printer);
   }
 
+  if (IsMapEntryMessage(descriptor_)) return;
+
   // Construct the default instance.  We can't call InitAsDefaultInstance() yet
   // because we need to make sure all default instances that this one might
   // depend on are constructed first.
@@ -1343,6 +1426,10 @@ GenerateDefaultInstanceInitializer(io::Printer* printer) {
 
   // Handle nested types.
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    // map entry message doesn't need to initialize default instance manually.
+    // Since map entry message cannot be a top level class, we just need to
+    // avoid calling DefaultInstanceInitializer here.
+    if (IsMapEntryMessage(descriptor_->nested_type(i))) continue;
     nested_generators_[i]->GenerateDefaultInstanceInitializer(printer);
   }
 }
@@ -1372,6 +1459,7 @@ GenerateShutdownCode(io::Printer* printer) {
 
   // Handle nested types.
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    if (IsMapEntryMessage(descriptor_->nested_type(i))) continue;
     nested_generators_[i]->GenerateShutdownCode(printer);
   }
 }
@@ -1383,6 +1471,10 @@ GenerateClassMethods(io::Printer* printer) {
   }
 
   for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    // map entry message doesn't need class methods. Since map entry message
+    // cannot be a top level class, we just need to avoid calling
+    // GenerateClassMethods here.
+    if (IsMapEntryMessage(descriptor_->nested_type(i))) continue;
     nested_generators_[i]->GenerateClassMethods(printer);
     printer->Print("\n");
     printer->Print(kThinSeparator);
@@ -2195,7 +2287,7 @@ GenerateMergeFrom(io::Printer* printer) {
     // base class as a parameter).
     printer->Print(
       "void $classname$::MergeFrom(const ::google::protobuf::Message& from) {\n"
-      "  GOOGLE_CHECK_NE(&from, this);\n",
+      "  if (GOOGLE_PREDICT_FALSE(&from == this)) MergeFromFail(__LINE__);\n",
       "classname", classname_);
     printer->Indent();
 
@@ -2230,7 +2322,7 @@ GenerateMergeFrom(io::Printer* printer) {
   // Generate the class-specific MergeFrom, which avoids the GOOGLE_CHECK and cast.
   printer->Print(
     "void $classname$::MergeFrom(const $classname$& from) {\n"
-    "  GOOGLE_CHECK_NE(&from, this);\n",
+    "  if (GOOGLE_PREDICT_FALSE(&from == this)) MergeFromFail(__LINE__);\n",
     "classname", classname_);
   printer->Indent();
 
@@ -2429,7 +2521,7 @@ GenerateMergeFromCodedStream(io::Printer* printer) {
   printer->Print("for (;;) {\n");
   printer->Indent();
 
-  scoped_array<const FieldDescriptor*> ordered_fields(
+  google::protobuf::scoped_array<const FieldDescriptor * > ordered_fields(
       SortFieldsByNumber(descriptor_));
   uint32 maxtag = descriptor_->field_count() == 0 ? 0 :
       WireFormat::MakeTag(ordered_fields[descriptor_->field_count() - 1]);
@@ -2788,7 +2880,7 @@ GenerateSerializeWithCachedSizesToArray(io::Printer* printer) {
 
 void MessageGenerator::
 GenerateSerializeWithCachedSizesBody(io::Printer* printer, bool to_array) {
-  scoped_array<const FieldDescriptor*> ordered_fields(
+  google::protobuf::scoped_array<const FieldDescriptor * > ordered_fields(
       SortFieldsByNumber(descriptor_));
 
   vector<const Descriptor::ExtensionRange*> sorted_extensions;
@@ -3186,14 +3278,14 @@ GenerateIsInitialized(io::Printer* printer) {
           " return false;\n",
           "name", FieldName(field));
       } else {
-        if (field->options().weak()) {
+        if (field->options().weak() || !field->containing_oneof()) {
           // For weak fields, use the data member (::google::protobuf::Message*) instead
           // of the getter to avoid a link dependency on the weak message type
           // which is only forward declared.
           printer->Print(
-            "if (has_$name$()) {\n"
-            "  if (!this->$name$_->IsInitialized()) return false;\n"
-            "}\n",
+              "if (has_$name$()) {\n"
+              "  if (!this->$name$_->IsInitialized()) return false;\n"
+              "}\n",
             "name", FieldName(field));
         } else {
           printer->Print(
diff --git a/src/google/protobuf/compiler/cpp/cpp_message.h b/src/google/protobuf/compiler/cpp/cpp_message.h
index a781c234..dfbc9af5 100644
--- a/src/google/protobuf/compiler/cpp/cpp_message.h
+++ b/src/google/protobuf/compiler/cpp/cpp_message.h
@@ -163,9 +163,9 @@ class MessageGenerator {
   Options options_;
   FieldGeneratorMap field_generators_;
   vector< vector<string> > runs_of_fields_;  // that might be trivially cleared
-  scoped_array<scoped_ptr<MessageGenerator> > nested_generators_;
-  scoped_array<scoped_ptr<EnumGenerator> > enum_generators_;
-  scoped_array<scoped_ptr<ExtensionGenerator> > extension_generators_;
+  google::protobuf::scoped_array<google::protobuf::scoped_ptr<MessageGenerator> > nested_generators_;
+  google::protobuf::scoped_array<google::protobuf::scoped_ptr<EnumGenerator> > enum_generators_;
+  google::protobuf::scoped_array<google::protobuf::scoped_ptr<ExtensionGenerator> > extension_generators_;
   int num_required_fields_;
   bool uses_string_;
 
diff --git a/src/google/protobuf/compiler/cpp/cpp_message_field.cc b/src/google/protobuf/compiler/cpp/cpp_message_field.cc
index da1ec60b..b3cd0ba1 100644
--- a/src/google/protobuf/compiler/cpp/cpp_message_field.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_message_field.cc
@@ -49,6 +49,10 @@ void SetMessageVariables(const FieldDescriptor* descriptor,
                          const Options& options) {
   SetCommonFieldVariables(descriptor, variables, options);
   (*variables)["type"] = FieldMessageTypeName(descriptor);
+  if (descriptor->options().weak() || !descriptor->containing_oneof()) {
+    (*variables)["non_null_ptr_to_name"] =
+        StrCat("this->", (*variables)["name"], "_");
+  }
   (*variables)["stream_writer"] = (*variables)["declared_type"] +
       (HasFastArraySerialization(descriptor->message_type()->file()) ?
        "MaybeToArray" :
@@ -293,7 +297,7 @@ void MessageFieldGenerator::
 GenerateSerializeWithCachedSizes(io::Printer* printer) const {
   printer->Print(variables_,
     "::google::protobuf::internal::WireFormatLite::Write$stream_writer$(\n"
-    "  $number$, this->$name$(), output);\n");
+    "  $number$, *$non_null_ptr_to_name$, output);\n");
 }
 
 void MessageFieldGenerator::
@@ -301,7 +305,7 @@ GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
   printer->Print(variables_,
     "target = ::google::protobuf::internal::WireFormatLite::\n"
     "  Write$declared_type$NoVirtualToArray(\n"
-    "    $number$, this->$name$(), target);\n");
+    "    $number$, *$non_null_ptr_to_name$, target);\n");
 }
 
 void MessageFieldGenerator::
@@ -309,7 +313,7 @@ GenerateByteSize(io::Printer* printer) const {
   printer->Print(variables_,
     "total_size += $tag_size$ +\n"
     "  ::google::protobuf::internal::WireFormatLite::$declared_type$SizeNoVirtual(\n"
-    "    this->$name$());\n");
+    "    *$non_null_ptr_to_name$);\n");
 }
 
 // ===================================================================
@@ -591,7 +595,7 @@ GenerateMergeFromCodedStream(io::Printer* printer) const {
 void RepeatedMessageFieldGenerator::
 GenerateSerializeWithCachedSizes(io::Printer* printer) const {
   printer->Print(variables_,
-    "for (int i = 0; i < this->$name$_size(); i++) {\n"
+    "for (unsigned int i = 0, n = this->$name$_size(); i < n; i++) {\n"
     "  ::google::protobuf::internal::WireFormatLite::Write$stream_writer$(\n"
     "    $number$, this->$name$(i), output);\n"
     "}\n");
@@ -600,7 +604,7 @@ GenerateSerializeWithCachedSizes(io::Printer* printer) const {
 void RepeatedMessageFieldGenerator::
 GenerateSerializeWithCachedSizesToArray(io::Printer* printer) const {
   printer->Print(variables_,
-    "for (int i = 0; i < this->$name$_size(); i++) {\n"
+    "for (unsigned int i = 0, n = this->$name$_size(); i < n; i++) {\n"
     "  target = ::google::protobuf::internal::WireFormatLite::\n"
     "    Write$declared_type$NoVirtualToArray(\n"
     "      $number$, this->$name$(i), target);\n"
diff --git a/src/google/protobuf/compiler/cpp/cpp_plugin_unittest.cc b/src/google/protobuf/compiler/cpp/cpp_plugin_unittest.cc
index 26cefb2e..d1efbfe6 100644
--- a/src/google/protobuf/compiler/cpp/cpp_plugin_unittest.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_plugin_unittest.cc
@@ -171,7 +171,7 @@ class TestGenerator : public CodeGenerator {
 
   void TryInsert(const string& filename, const string& insertion_point,
                  GeneratorContext* context) const {
-    scoped_ptr<io::ZeroCopyOutputStream> output(
+    google::protobuf::scoped_ptr<io::ZeroCopyOutputStream> output(
         context->OpenForInsert(filename, insertion_point));
     io::Printer printer(output.get(), '$');
     printer.Print("// inserted $name$\n", "name", insertion_point);
diff --git a/src/google/protobuf/compiler/cpp/cpp_string_field.cc b/src/google/protobuf/compiler/cpp/cpp_string_field.cc
index a2a8c81c..a7f95044 100644
--- a/src/google/protobuf/compiler/cpp/cpp_string_field.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_string_field.cc
@@ -306,7 +306,14 @@ GenerateClearingCode(io::Printer* printer) const {
 
 void StringFieldGenerator::
 GenerateMergingCode(io::Printer* printer) const {
-  printer->Print(variables_, "set_$name$(from.$name$());\n");
+  if (SupportsArenas(descriptor_) || descriptor_->containing_oneof() != NULL) {
+    // TODO(gpike): improve this
+    printer->Print(variables_, "set_$name$(from.$name$());\n");
+  } else {
+    printer->Print(variables_,
+      "$set_hasbit$\n"
+      "$name$_.AssignWithDefault($default_variable$, from.$name$_);\n");
+  }
 }
 
 void StringFieldGenerator::
diff --git a/src/google/protobuf/compiler/cpp/cpp_unittest.cc b/src/google/protobuf/compiler/cpp/cpp_unittest.cc
index 74a277e0..20fcfa62 100644
--- a/src/google/protobuf/compiler/cpp/cpp_unittest.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_unittest.cc
@@ -251,7 +251,7 @@ TEST(GeneratedMessageTest, ReleaseString) {
 
   message.set_default_string("blah");
   EXPECT_TRUE(message.has_default_string());
-  scoped_ptr<string> str(message.release_default_string());
+  google::protobuf::scoped_ptr<string> str(message.release_default_string());
   EXPECT_FALSE(message.has_default_string());
   ASSERT_TRUE(str != NULL);
   EXPECT_EQ("blah", *str);
@@ -270,7 +270,7 @@ TEST(GeneratedMessageTest, ReleaseMessage) {
   EXPECT_FALSE(message.has_optional_nested_message());
 
   message.mutable_optional_nested_message()->set_bb(1);
-  scoped_ptr<unittest::TestAllTypes::NestedMessage> nest(
+  google::protobuf::scoped_ptr<unittest::TestAllTypes::NestedMessage> nest(
       message.release_optional_nested_message());
   EXPECT_FALSE(message.has_optional_nested_message());
   ASSERT_TRUE(nest != NULL);
@@ -534,7 +534,7 @@ TEST(GeneratedMessageTest, DynamicMessageCopyFrom) {
 
   // Construct a new version of the dynamic message via the factory.
   DynamicMessageFactory factory;
-  scoped_ptr<Message> message1;
+  google::protobuf::scoped_ptr<Message> message1;
   message1.reset(factory.GetPrototype(
                      unittest::TestAllTypes::descriptor())->New());
 
@@ -581,9 +581,9 @@ TEST(GeneratedMessageTest, NonEmptyMergeFrom) {
 
 TEST(GeneratedMessageTest, MergeFromSelf) {
   unittest::TestAllTypes message;
-  EXPECT_DEATH(message.MergeFrom(message), "&from");
+  EXPECT_DEATH(message.MergeFrom(message), "Check failed:.*pb[.]cc");
   EXPECT_DEATH(message.MergeFrom(implicit_cast<const Message&>(message)),
-               "&from");
+               "Check failed:.*pb[.]cc");
 }
 
 #endif  // PROTOBUF_HAS_DEATH_TEST
@@ -1221,7 +1221,7 @@ class GeneratedServiceTest : public testing::Test {
   unittest::FooResponse foo_response_;
   unittest::BarRequest bar_request_;
   unittest::BarResponse bar_response_;
-  scoped_ptr<Closure> done_;
+  google::protobuf::scoped_ptr<Closure> done_;
 };
 
 TEST_F(GeneratedServiceTest, GetDescriptor) {
@@ -1519,7 +1519,7 @@ TEST_F(OneofTest, ReleaseString) {
 
   message.set_foo_string("blah");
   EXPECT_TRUE(message.has_foo_string());
-  scoped_ptr<string> str(message.release_foo_string());
+  google::protobuf::scoped_ptr<string> str(message.release_foo_string());
   EXPECT_FALSE(message.has_foo_string());
   ASSERT_TRUE(str != NULL);
   EXPECT_EQ("blah", *str);
@@ -1573,7 +1573,7 @@ TEST_F(OneofTest, ReleaseMessage) {
 
   message.mutable_foo_message()->set_qux_int(1);
   EXPECT_TRUE(message.has_foo_message());
-  scoped_ptr<unittest::TestOneof2_NestedMessage> mes(
+  google::protobuf::scoped_ptr<unittest::TestOneof2_NestedMessage> mes(
       message.release_foo_message());
   EXPECT_FALSE(message.has_foo_message());
   ASSERT_TRUE(mes != NULL);