* Optimized Java proto serialization gencode for protos having many extension ranges with few fields in between.
* More thoroughly annotate public generated code in Java lite protocol buffers.
* Fixed Bug in proto3 java lite repeated enum fields. Failed to call copyOnWrite before modifying previously built message. Causes modification to already "built" messages that should be immutable.
* Refactoring java full runtime to reuse sub-message builders and prepare to migrate parsing logic from parse constructor to builder.
* Fix Java reflection serialization of empty packed fields.
* Refactoring java full runtime to reuse sub-message builders and prepare to
migrate parsing logic from parse constructor to builder.
* Move proto wireformat parsing functionality from the private "parsing
constructor" to the Builder class.
* Change the Lite runtime to prefer merging from the wireformat into mutable
messages rather than building up a new immutable object before merging. This
way results in fewer allocations and copy operations.
* Make message-type extensions merge from wire-format instead of building up instances and merging afterwards. This has much better performance.
Python
* Changes ordering of printed fields in .pyi files from lexicographic to the same ordering found in the proto descriptor.