anchor.diff:       f("    <<PackedBytes:Len/binary, Rest2/binary>> = Rest,~n"),
        f("    NewSeq = ~p(PackedBytes~sAccSeq),~n",
          [mk_fn(d_packed_field_, MsgName, FName),
  -        case mk_field_decoder_vi_params(FieldDef) of
  +        case mk_field_decoder_vi_params(FieldDef#field{is_packed=false}) of
               ""     -> [", "];
               Params -> [", ", Params, ", "]
           end]),
  
positive.code:                   end]))
       || #field{fnum=FNum, name=FName}=FieldDef <- MsgDef].
  
  mk_field_decoder_vi_params(#field{type=Type}) ->
      case Type of
          sint32   -> "0, 0"; %% varint-based
          sint64   -> "0, 0"; %% varint-based
  
negative.code:         string   -> "0, 0"; %% varint-based
          bytes    -> "0, 0"; %% varint-based
          {msg,_}  -> "0, 0"  %% varint-based
      end;
  mk_field_decoder_vi_params(#field{is_packed=true}) ->
      "0, 0". %% length of packed bytes is varint-based
  
  
  format_field_decoders(MsgName, MsgDef) ->
      [[format_field_decoder(MsgName, FieldDef), "\n"]
  