Re: [PATCH] Proof-of-concept patch to remember what the detached HEAD was

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 15, 2009, 20:34 UTC
Message-ID: <7v3a5k4cri.fsf@alter.siamese.dyndns.org>
In-Reply-To: <alpine.LNX.2.00.0910151523020.32515@iabervon.org>

Daniel Barkalow <barkalow@iabervon.org> writes:

Show 10 quoted lines

>  $ git checkout origin/master
>  $ git fetch
>  $ git checkout origin/next
>  Uncommited file '...' would be overwritten.
>
> If HEAD is a symref to refs/remotes/origin/master, and you update 
> refs/remotes/origin/master, git will subsequently see that your index 
> doesn't match HEAD, and when you switch branches, it will try to apply a 
> revert to the branch you're switching to. It's the same issue as pushing 
> into a non-bare repository.

I think the idea here is to allow HEAD to point at outside refs/heads/, e.g. refs/remotes/origin/master, but forbid commit and other commands from updating HEAD and its underlying ref via update_ref() unless HEAD is detached or points at a local branch.