[ -z "$branchname" ] && die "git branch: I want a branch name"
[ -e "$GIT_DIR/refs/heads/$branchname" ] && die "$branchname already exists"
[ -z "$branchname" ] && die "git branch: I want a branch name"
[ -e "$GIT_DIR/refs/heads/$branchname" ] && die "$branchname already exists"