Error when deleting a branch or a tag

[luckjay]

Implemented a git server with go-git, everything goes well but deleting. It always returns the error empty packfile from rpSession.ReceivePack().

The server-side pseudo-code is following:

req := packp.NewReferenceUpdateRequest()
_ = req.Decode(r.Body)

session, _ := server.NewReceivePackSession(nil, nil) // transport is ignored here
defer session.Close()

status, err := session.ReceivePack(ctx, req) // <- returns error here
_ = status.Encode(w)

I have looked into this issue and the reason is:

1. It sets req.Packfile = r.Body when decoding the r.Body
2. In session.ReceivePack() function, it tries to write Packfile but fails to read HEAD, as shown below:

// plumbing/transport/server/server.go
if req.Packfile != nil {
    r := ioutil.NewContextReadCloser(ctx, req.Packfile)
    if err := s.writePackfile(r); err != nil {
        s.unpackErr = err
        s.firstErr = err
        return s.reportStatus(), err
    }
}

[luckjay]

There should be no packfile in a deleting request.