Proto3 repeated field not packed by default

[cygery]

Message definitions

proto3_test.proto:

syntax = "proto3";

package test;

message Test3Int32RepDefault {
    repeated int32 repeated_int32 = 1;
}

message Test3Int32RepPackedTrue {
    repeated int32 repeated_int32 = 1 [packed = true];
}

Compiled via:

$ protoc --version
libprotoc 3.0.0
$ protoc --go_out=. *.proto

Result

proto3_test.pb.go:

// ...
type Test3Int32RepDefault struct {
    RepeatedInt32 []int32 `protobuf:"varint,1,rep,name=repeated_int32,json=repeatedInt32" json:"repeated_int32,omitempty"`
}
// ...
type Test3Int32RepPackedTrue struct {
    RepeatedInt32 []int32 `protobuf:"varint,1,rep,packed,name=repeated_int32,json=repeatedInt32" json:"repeated_int32,omitempty"`
}
// ...

The repeated field with default packed setting compiles to a non-packed field although it should be packed by default.

[edgesite]

The bugs seems points to

protobuf/protoc-gen-go/generator/generator.go

Line 1554 in 545732f

if field.Options != nil && field.Options.GetPacked() {

As Proto3 specified, repeated fields of scalar numeric types use packed encoding by default. We should add some check here.

** This is an urgent bug because the official Protobuf Javascript implementation doesn't read tag to detect binary is packed or not. **

Both declared proto3 syntax.
repeated int64:

repeated int64 [packed=false]:

[cygery]

Thanks for your comment. Yeah, I've also submitted an issue regarding the JavaScript parser which was labelled as a bug.
For now I'm explicitly defining the packed option as a workaround but I hope both issues will be fixed eventually.

[edgesite]

I made a pr #203 to fix this problem. @cygery give it a try.
BTW. don't forget run go install after pull.