Re: [PATCH 0/4] pre-push hook support

From: Aaron Schrab <aaron@schrab.com>
Date: Dec 29, 2012, 14:50 UTC
Message-ID: <20121229145025.GA3789@pug.qqx.org>
In-Reply-To: <7v1ue9hb06.fsf@alter.siamese.dyndns.org>

At 18:01 -0800 28 Dec 2012, Junio C Hamano <gitster@pobox.com> wrote:

>One lesson we learned long time ago while doing hooks is to avoid
>unbound number of command line arguments and instead feed them from
>the standard input.  I think this should do the same.

Good point. I had been trying to keep the interface for this hook as close as possible to the ones for other client-side hooks on the theory that less development effort may go into those than for server-side hooks. But thinking on that more I certainly see that this could easily run into limits on argument length on some systems; especially when it's likely that each of those arguments is likely to be over 100 bytes long.

I'll work on an updated version which sends the variable length information over a pipe, using the command-line arguments only to pass the remote name and URL.

>How does the hook communicate its decision to the calling Git?
>
>Will it be "all-or-none", or "I'll allow these but not those"?

Currently it just uses the exit code to communicate that back, so it's all-or-none. I think I'll keep that in the updated version as well.

A future enhancement could modify the protocol to support reading from the hook's stdout the names of remote refs which are to be rejected, I think that just having the option for all-or-nothing is a good starting point.