Rationale: it's easy to implement the callback wrong. Doing so introduces
io errors when unknown fields are present in the input. If code is not
tested with unknown fields, these bugs can remain hidden for long time.
Added a special case for the memory buffer stream, where it gives a small
speed benefit.
Added testcase for skipping fields with test_decode2 implementation.
Update issue 37
Status: FixedInGit
The size of non-callback bytes-fields was miscalculated, which
caused all following fields in a message to contain garbage.
Previous commit contains a testcase for this.
This fix changes the generated message description. If your protocol uses
bytes-fields, you should regenerate *.pb.c.
