Re: push fails with unexpected 'matches more than one'

From: "Shawn O. Pearce" <spearce@spearce.org>
To: Steffen Prohaska <prohaska@zib.de>
Cc: Git Mailing List <git@vger.kernel.org>
Subject: Re: push fails with unexpected 'matches more than one'
Date: Fri, 12 Oct 2007 23:21:00 -0400	[thread overview]
Message-ID: <20071013032100.GK27899@spearce.org> (raw)
In-Reply-To: <91A04390-89B2-47B8-9B61-7C7E652670AE@zib.de>

Steffen Prohaska <prohaska@zib.de> wrote:
> I read carefully through the documentation of git-send-pack and
> git-rev-parse. The current implementation of git-send-pack is in line
> with the documented behaviour, as is the implementation of git-rev- 
> parse.
> 
> So formally everything is correct.
> 
> But it is completely against my expectation that git-push <remote>  
> <head>
> can successfully resolve a <head> that git-rev-parse fails to parse. I
> understand that refs are not revs ;). But nonetheless, I'd expect that a
> local ref that cannot be parsed by git-rev-parse should also fail to be
> pushed by git-send-pack. I didn't expect that git-send-pack would locate
> <head> as someprefix/<head>.
> 
> Why is my expectation wrong?
> Or is the current specification of git-send-pack's ref parsing wrong?

I think its a bug.  But I didn't write the original code.

Meaning I think what happened here was someone wanted to enable
git-send-pack to match "master" here with "refs/heads/master" on
the remote side.  One easy way to do that was to see if any ref
ended with "/master", as that was what the ref here was called.

Way back when that code was written most Git repositories probably
only ever had that one branch anyway, or maybe two (refs/heads/master
and refs/heads/origin) so matching the trailing suffix never came
up as a bug.  Nobody ever had two refs that could possibly match.

Then the documentation got expanded to actually document the behavior
that git-send-pack implemented.  Unfortunately that codified the
bug as documented behavior.

So I agree with you Steffen, this is a bug in send-pack, and I run
up against it every once in a while.  I've specifically told my
coworkers "NEVER, EVER, EVER, create a branch called 'master' that
isn't exactly refs/heads/master OR ELSE I WILL COME BEAT YOU WITH A
CLUE STICK".  They still create "refs/heads/experiments/master".
*sigh*.

I think we should fix it.  Anyone that is relying on "git push
$url master" to resolve to "refs/heads/experimental/master" on the
remote side is already playing with fire.  But Junio is (rightfully
so) very conservative and doesn't like to break a user's scripts.
We may not be able to fix this until Git 1.6.

-- 
Shawn.