convention to use when printing errors. Default is GCC, but Microsoft
Visual Studio is another option. This allows errors to be clickable in
the MSVS error log.
All Languages
* Repeated fields of primitive types (types other that string, group, and
nested messages) may now use the option [packed = true] to get a more
efficient encoding. In the new encoding, the entire list is written
as a single byte blob using the "length-delimited" wire type. Within
this blob, the individual values are encoded the same way they would
be normally except without a tag before each value (thus, they are
tightly "packed").
C++
* UnknownFieldSet now supports STL-like iteration.
* Message interface has method ParseFromBoundedZeroCopyStream() which parses
a limited number of bytes from an input stream rather than parsing until
EOF.
Java
* Fixed bug where Message.mergeFrom(Message) failed to merge extensions.
* Message interface has new method toBuilder() which is equivalent to
newBuilderForType().mergeFrom(this).
* All enums now implement the ProtocolMessageEnum interface.
* Setting a field to null now throws NullPointerException.
* Fixed tendency for TextFormat's parsing to overflow the stack when
parsing large string values. The underlying problem is with Java's
regex implementation (which unfortunately uses recursive backtracking
rather than building an NFA). Worked around by making use of possesive
quantifiers.
Python
* Updated RPC interfaces to allow for blocking operation. A client may
now pass None for a callback when making an RPC, in which case the
call will block until the response is received, and the response
object will be returned directly to the caller. This interface change
cannot be used in practice until RPC implementations are updated to
implement it.
bash-only features, and /bin/sh is not a symlink to bash on all systems.
* If an input file is a Windows absolute path (e.g. "C:\foo\bar.proto") and
the import path only contains "." (or contains "." but does not contain
the file), protoc incorrectly thought that the file was under ".", because
it thought that the path was relative (since it didn't start with a slash).
This has been fixed.
