Re: [PATCH] checkout: implement "-" shortcut name for last branch

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Jan 15, 2009, 14:14 UTC
Message-ID: <alpine.DEB.1.00.0901151510340.3586@pacific.mpi-cbg.de>
In-Reply-To: <200901151501.26394.trast@student.ethz.ch>

Hi,

On Thu, 15 Jan 2009, Thomas Rast wrote:

Show 15 quoted lines

> Johannes Schindelin wrote:
> > On Thu, 15 Jan 2009, Thomas Rast wrote:
> > 
> > > Let git-checkout save the old branch as a symref in LAST_HEAD, and
> > > make 'git checkout -' switch back to LAST_HEAD, like 'cd -' does in
> > > the shell.
> > 
> > Actually, what you want is in the reflog, no?  So... parsing 
> > .git/logs/HEAD for the latest occurrence of "checkout: moving from " and 
> > then using everything up until the next space should give you the branch 
> > name, right?
> 
> It just feels wrong to grab that information from there; it's a
> free-form comment field for user consumption.  And it wasn't even that
> hard to implement a LAST_HEAD.

There are a number of issues why I would like to avoid introducing LAST_HEAD:

- it does not work when you are using different Git versions on the same 
  repository,

- it does not work when you switched recently,

- you are storing redundant information,

- yes, the field is meant for user consumption, but no, it is not 
  free-form,

- AFAICT your version could never be convinced to resurrect deleted 
  branches, without resorting to reflogs anyway.

- the reflog method reflects pretty much exactly how people work around 
  the lack of "checkout -" currently, so why not just use the same proven 
  approach?

Ciao, Dscho