Re: [PATCH] checkout: allow full refnames for local branches

> "Lars Hjemli" <hjemli@gmail.com> writes:
>
> > On 5/9/07, Junio C Hamano <junkio@cox.net> wrote:
> >> Lars Hjemli <hjemli@gmail.com> writes:
> >>
> >> > This teaches git-checkout to strip the prefix 'refs/heads/' from the
> >> > supplied <branch> argument
> >>
> >> Why is this necessary, may I ask?
> >>
> >
> > I'm playing around with a gui frontend, and there I use
> > git-for-each-ref to obtain possible arguments for git-checkout. That's
> > how I discovered the 'problem', and solved it by stripping
> > 'refs/heads/' in my frontend.
>
> Pathspec-less variant of "git checkout" takes two kinds of
> parameters and has two flavours in its behaviour:
>
>  (1) an exact branch name, in which case it switches to the
>      branch; otherwise
>
>  (2) any arbitrary commit object name, in whch case it checks
>      out and detaches HEAD.
>
> A tricky part is that an exact branch name is often a perfectly
> valid commit object name, so rule (1) trumps the rule (2).  You
> just discovered a way to have a detached HEAD at a commit that
> happens to be at an existing branch -- by naming that commit
> without using its exact branch name.