[PATCH 0/5] interpret_branch_name bug potpourri

[Jeff King <peff@peff.net>]

On Wed, Jan 15, 2014 at 12:00:03AM -0500, Jeff King wrote:

>   $ git rev-parse --symbolic-full-name HEAD@{u}
>   refs/remotes/origin/master
>   $ git rev-parse --symbolic-full-name @mybranch@{u}
>   @mybranch@{u}
>   fatal: ambiguous argument '@mybranch@{u}': unknown revision or path
>   not in the working tree.
> 
> So I do think there is a bug. The interpret_branch_name parser somehow
> gets confused by the "@" in the name.

The "somehow" is because we only look for the first "@", and never
consider any possible marks after that. The series below fixes it, along
with two other bugs I found while looking at this code. Ugh. Remind me
never to look at our object name parser ever again.

I feel pretty good that this is fixing real bugs and not regressing
anything else. I would not be surprised if there are other weird things
lurking, though. See the discussion in patch 4.

  [1/5]: interpret_branch_name: factor out upstream handling
  [2/5]: interpret_branch_name: rename "cp" variable to "at"
  [3/5]: interpret_branch_name: always respect "namelen" parameter
  [4/5]: interpret_branch_name: avoid @{upstream} past colon
  [5/5]: interpret_branch_name: find all possible @-marks

-Peff