panic.go

func current_branch(git_dir string) string {
	head_bytes, err := ioutil.ReadFile(path.Join(git_dir, "HEAD"))
	head := string(head_bytes)
	if err != nil {
		log.Fatal("Cannot open HEAD from ", git_dir)
	}
	r, _ := regexp.Compile("ref: ref/heads/(.+)")
	match := r.FindStringSubmatch(head)
	branch := match[1]
	return branch
}