From: Shawn O. Pearce <spearce@spearce.org>
Date: Fri, 20 Mar 2009 00:44:50 GMT
Subject: Re: ref name troubles, was Re: [PATCH v2] Introduce %<branch> as shortcut to the tracked branch
Message-ID: <20090320004450.GY23521@spearce.org>
In-Reply-To: <20090320004029.GX23521@spearce.org>

"Shawn O. Pearce" <spearce@spearce.org> wrote:
> Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> > On Fri, 20 Mar 2009, Johannes Schindelin wrote:
> > 
> > > Just try this:
> > > 
> > > 	$ git checkout -b %helloworld
> > 
> > It gets worse.  Much worse.
> > 
> > Try this (triggered by a comment by Ilari on IRC):
> > 
> > 	$ git checkout -b '@{1}'
> > 
> > That _works_! WTH?
> 
> '@' is not reserved.  Neither is '{' or '}'.  Neither is
> the combination.

In hindsight, I wish we had reserved all of the "fun" characters
like !@#$%^&*():;~'"\ and prevented them from ever appearing in a
ref name.

Instead only what check_ref_format() in refs.c ll.694 tells is
is reserved:

 671 /*
 672  * Make sure "ref" is something reasonable to have under ".git/refs/";
 673  * We do not like it if:
 674  *
 675  * - any path component of it begins with ".", or
 676  * - it has double dots "..", or
 677  * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
 678  * - it ends with a "/".
 679  */

Heh.  At least : and SP are reserved.

Use BEL for your %helloworld hack.  It'll be fun to type.  :-)

-- 
Shawn.