From: Jeff King <peff@peff.net>
Date: Thu, 31 Jan 2008 10:06:25 GMT
Subject: Re: git-push: forced update of tag shows unabbreviated SHA1
Message-ID: <20080131100625.GB25546@coredump.intra.peff.net>
In-Reply-To: <47A1948F.6080308@viscovery.net>

On Thu, Jan 31, 2008 at 10:27:43AM +0100, Johannes Sixt wrote:

> When a tag is changed to point to a new commit, then the tag is pushed to
> a repo that still has the old tag, it is correctly pushed, but the old
> SHA1 is reported with all 40 digits:

As Junio noted, this is because find_unique_abbrev returns NULL for
objects we don't have. Actually, it is somewhat worse -- we return an
erroneous abbreviation in the rare case that we are trying to find the
abbreviation for something we don't have, but for which we do have a
matching abbreviation. For example, if we have

  1234567890123456789012345678901234567890

then for every 12345678* that we don't have, we will claim the correct
abbreviation is 1234568.

In practice, I doubt this is a problem.

But getting back to your point: yes, I agree it is a little ugly.
Rewriting find_unique_abbrev would be necessary for fixing it, and I'm
not sure it is worth the trouble.

-Peff