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, 6 insertions, 0 deletions

diff --git a/src/google/protobuf/extension_set.h b/src/google/protobuf/extension_set.h
index 1acc2c5c..9ad241f2 100644
--- a/src/google/protobuf/extension_set.h
+++ b/src/google/protobuf/extension_set.h
@@ -209,6 +209,7 @@ class LIBPROTOBUF_EXPORT ExtensionSet {
 
   void Clear();
   void MergeFrom(const ExtensionSet& other);
+  void Swap(ExtensionSet* other);
   bool IsInitialized() const;
 
   // These parsing and serialization functions all want a pointer to the
@@ -234,6 +235,10 @@ class LIBPROTOBUF_EXPORT ExtensionSet {
   // Returns the total serialized size of all the extensions.
   int ByteSize(const Message& message) const;
 
+  // Returns (an estimate of) the total number of bytes used for storing the
+  // extensions in memory, excluding sizeof(*this).
+  int SpaceUsedExcludingSelf() const;
+
  private:
   // Like FindKnownExtension(), but GOOGLE_CHECK-fail if not found.
   const FieldDescriptor* FindKnownExtensionOrDie(int number) const;
@@ -286,6 +291,7 @@ class LIBPROTOBUF_EXPORT ExtensionSet {
     void Clear();
     int GetSize() const;
     void Free();
+    int SpaceUsedExcludingSelf() const;
   };
 
   // The Extension struct is small enough to be passed by value, so we use it