anchor.diff:              Rest;
           length_delimited ->
               {Len, Rest} = decode_varint(Bin),
  -            <<_:Len/binary, Rest2>> = Rest,
  +            <<_:Len/binary, Rest2/binary>> = Rest,
               Rest2;
           bits32 ->
               <<_:32, Rest/binary>> = Bin,
  
positive.code:     case lists:keyfind(FieldNum, #field.fnum, MsgDef) of
          false ->
              Rest2 = skip_field(Rest, WireType),
              decode_field(MsgDef, MsgDefs, Rest2, Msg);
          #field{type = FieldType, rnum=RNum, opts=Opts} = FieldDef ->
              case proplists:get_bool(packed, Opts) of
                  true ->
  
negative.code: 
  -record(m1,{a}).
  
  skipping_unknown_varint_field_test() ->
      #m1{a = undefined} =
          decode_msg(<<32,150,1>>, %% field number 4 (not known), wire type = 0
                     m1,
                     [{{msg,m1}, [#field{name=a, fnum=1, rnum=#m1.a, type=int32,
                                         occurrence=optional, opts=[]}]}]).
  
  skipping_unknown_length_delimited_field_test() ->
      #m1{a = undefined} =
          decode_msg(<<34,1,1>>, %% field number 4 (not known), wire type = 2
                     m1,
                     [{{msg,m1}, [#field{name=a, fnum=1, rnum=#m1.a, type=int32,
                                         occurrence=optional, opts=[]}]}]).
  
  skipping_unknown_64bit_field_test() ->
      #m1{a = undefined} =
          decode_msg(<<33,0,0,0,0,0,0,0,0>>, %% field number 4, wire type = 1
                     m1,
                     [{{msg,m1}, [#field{name=a, fnum=1, rnum=#m1.a, type=int32,
                                         occurrence=optional, opts=[]}]}]).
  skipping_unknown_32bit_field_test() ->
      #m1{a = undefined} =
          decode_msg(<<37,0,0,0,0>>, %% field number 4, wire type = 5
                     m1,
                     [{{msg,m1}, [#field{name=a, fnum=1, rnum=#m1.a, type=int32,
                                         occurrence=optional, opts=[]}]}]).
  
  decode_msg_simple_occurrence_test() ->
      #m1{a = undefined} =
          decode_msg(<<>>,
  