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

From: Björn Steinbrink <b.steinbrink@gmx.de>
Date: Oct 15, 2009, 14:11 UTC
Message-ID: <20091015141151.GA7867@atjola.homenet>
In-Reply-To: <m3bpk8g6nj.fsf@localhost.localdomain>

On 2009.10.15 05:54:52 -0700, Jakub Narebski wrote:

Show 22 quoted lines

> James Pickens <jepicken@gmail.com> writes:
> > Perhaps as an additional safety feature, Git could refuse to switch
> > away from a detached head if the head isn't reachable from any ref,
> > and require -f to override:
> > 
> > $ git checkout $sha1
> > $ git commit
> > $ git checkout master ;# complain
> > $ git checkout -f master ;# ok
> > 
> > Maybe I'm missing something and this all can't be done, but it seems simpler
> > than the other options I've seen in this thread.
> 
> I'm not sure about overloading '-f' option, unless we would require
> doubled '-f' for overriding both safety checks: checkout from detached
> HEAD, and current meaning of forcing a switch even if index or the
> working are differs from HEAD.  So you would need
> 
>   $ git checkout -f -f master
> 
> if you are on detached HEAD and have uncommitted changes (dirty tree 
> or dirty index).

A dirty index/worktree doesn't necessarily stop you from checking out a different branch head/commit. Only if you have uncommitted changes to a file that also has changes between HEAD and <other_branch>, git refuses to switch. And if you want to keep your uncommitted changes, you want to use -m (3-way merge), not -f (drop changes).

git checkout -f foo ~= git reset --hard && git checkout foo

So -f is most likely _not_ the flag one wants to overload.

Björn