Integrate changes from internal code.

protoc
* Enum values may now have custom options, using syntax similar to field
  options.
* Fixed bug where .proto files which use custom options but don't actually
  define them (i.e. they import another .proto file defining the options)
  had to explicitly import descriptor.proto.
* Adjacent string literals in .proto files will now be concatenated, like in
  C.

C++
* Generated message classes now have a Swap() method which efficiently swaps
  the contents of two objects.
* All message classes now have a SpaceUsed() method which returns an estimate
  of the number of bytes of allocated memory currently owned by the object.
  This is particularly useful when you are reusing a single message object
  to improve performance but want to make sure it doesn't bloat up too large.
* New method Message::SerializeAsString() returns a string containing the
  serialized data.  May be more convenient than calling
  SerializeToString(string*).
* In debug mode, log error messages when string-type fields are found to
  contain bytes that are not valid UTF-8.
* Fixed bug where a message with multiple extension ranges couldn't parse
  extensions.
* Fixed bug where MergeFrom(const Message&) didn't do anything if invoked on
  a message that contained no fields (but possibly contained extensions).
* Fixed ShortDebugString() to not be O(n^2).  Durr.
* Fixed crash in TextFormat parsing if the first token in the input caused a
  tokenization error.

Java
* New overload of mergeFrom() which parses a slice of a byte array instead
  of the whole thing.
* New method ByteString.asReadOnlyByteBuffer() does what it sounds like.
* Improved performance of isInitialized() when optimizing for code size.

Python
* Corrected ListFields() signature in Message base class to match what
  subclasses actually implement.
* Some minor refactoring.

1 files changed, 19 insertions, 9 deletions

diff --git a/src/google/protobuf/compiler/cpp/cpp_string_field.cc b/src/google/protobuf/compiler/cpp/cpp_string_field.cc
index 66a0496c..3e694ab7 100644
--- a/src/google/protobuf/compiler/cpp/cpp_string_field.cc
+++ b/src/google/protobuf/compiler/cpp/cpp_string_field.cc
@@ -163,12 +163,12 @@ GenerateInlineAccessorDefinitions(io::Printer* printer) const {
     "inline ::std::string* $classname$::mutable_$name$() {\n"
     "  _set_bit($index$);\n"
     "  if ($name$_ == &_default_$name$_) {\n");
-  if (descriptor_->has_default_value()) {
+  if (descriptor_->default_value_string().empty()) {
     printer->Print(variables_,
-      "    $name$_ = new ::std::string(_default_$name$_);\n");
+      "    $name$_ = new ::std::string;\n");
   } else {
     printer->Print(variables_,
-      "    $name$_ = new ::std::string;\n");
+      "    $name$_ = new ::std::string(_default_$name$_);\n");
   }
   printer->Print(variables_,
     "  }\n"
@@ -178,26 +178,26 @@ GenerateInlineAccessorDefinitions(io::Printer* printer) const {
 
 void StringFieldGenerator::
 GenerateNonInlineAccessorDefinitions(io::Printer* printer) const {
-  if (descriptor_->has_default_value()) {
+  if (descriptor_->default_value_string().empty()) {
     printer->Print(variables_,
-      "const ::std::string $classname$::_default_$name$_($default$);");
+      "const ::std::string $classname$::_default_$name$_;");
   } else {
     printer->Print(variables_,
-      "const ::std::string $classname$::_default_$name$_;");
+      "const ::std::string $classname$::_default_$name$_($default$);");
   }
 }
 
 void StringFieldGenerator::
 GenerateClearingCode(io::Printer* printer) const {
-  if (descriptor_->has_default_value()) {
+  if (descriptor_->default_value_string().empty()) {
     printer->Print(variables_,
       "if ($name$_ != &_default_$name$_) {\n"
-      "  $name$_->assign(_default_$name$_);\n"
+      "  $name$_->clear();\n"
       "}\n");
   } else {
     printer->Print(variables_,
       "if ($name$_ != &_default_$name$_) {\n"
-      "  $name$_->clear();\n"
+      "  $name$_->assign(_default_$name$_);\n"
       "}\n");
   }
 }
@@ -208,6 +208,11 @@ GenerateMergingCode(io::Printer* printer) const {
 }
 
 void StringFieldGenerator::
+GenerateSwappingCode(io::Printer* printer) const {
+  printer->Print(variables_, "std::swap($name$_, other->$name$_);\n");
+}
+
+void StringFieldGenerator::
 GenerateInitializer(io::Printer* printer) const {
   printer->Print(variables_,
     ",\n$name$_(const_cast< ::std::string*>(&_default_$name$_))");
@@ -350,6 +355,11 @@ GenerateMergingCode(io::Printer* printer) const {
 }
 
 void RepeatedStringFieldGenerator::
+GenerateSwappingCode(io::Printer* printer) const {
+  printer->Print(variables_, "$name$_.Swap(&other->$name$_);\n");
+}
+
+void RepeatedStringFieldGenerator::
 GenerateInitializer(io::Printer* printer) const {
   // Not needed for repeated fields.
 }