From: Michael J Gruber <git@drmicha•warpmail.net>
To: Michael Haggerty <mhagger@alum•mit.edu>
Cc: git@vger•kernel.org, Junio C Hamano <gitster@pobox•com>
Subject: Re: [PATCH 1/3] git-merge: Honor pre-merge hook
Date: Thu, 06 Sep 2012 10:16:19 +0200 [thread overview]
Message-ID: <50485BD3.5020802@drmicha.warpmail.net> (raw)
In-Reply-To: <50476FFE.5070602@alum.mit.edu>
Michael Haggerty venit, vidit, dixit 05.09.2012 17:30:
> On 09/05/2012 03:39 PM, Michael J Gruber wrote:
>> git-merge does not honor the pre-commit hook when doing automatic merge
>> commits, and for compatibility reasons this is going to stay.
>>
>> Introduce a pre-merge hook which is called for an automatic merge commit
>> just like pre-commit is called for a non-automatic merge commit (or any
>> other commit).
>
> What exactly is an "automatic merge commit"? Is it any merge that
> doesn't have a conflict? A merge that doesn't invoke the editor? A
> merge done as part of another operation (e.g., pull)? I don't see the
> term mentioned in the git-merge or githooks man pages.
>
> I think it would be good if you would define this term in the
> documentation files that your patch touched, and perhaps in the githooks
> section about "pre-commit" as well.
"git merge" can go three ways:
F: fast forward: no commit is created, only a ref is changed
A: automatic: true merge (non-ff) without conflicts (i.e. chosen
strategy can perform the merge); a new commit is created
C: merge with conflicts: no commit is created but the index is prepared
(partially) for a merge commit
In case F, no commit hook is run (talking only about pre-commit/pre-merge).
In case A, no commit is run so far but my patch proposes pre-merge to be
run.
In case C, pre-commit (!) is run so far and after my patch.
> Secondly, though it is impossible (for backwards compatibility reasons)
> for the pre-commit hook to be invoked for automatic merges, no such
> considerations prohibit the pre-merge commit from being invoked for
> non-automatic merges. In other words, both hooks, pre-commit *and*
> pre-merge, could be invoked for non-automatic merges. Would this be
> preferable?
>
> It depends on what pre-merge scripts are likely to be used for. If they
> will tend to be used for merge-specific actions, then it might be more
> convenient for *all* merges to be vetted by them. On the other hand, if
> they tend to do the same actions as pre-commit hooks, then having
> non-automatic merge commits go through both hooks would tend to be more
> annoying than helpful. Specifically, one of the scripts would probably
> have to check whether the merge is a non-automatic merge, and if so do
> nothing (i.e., letting the other script take care of it). This would
> also require an easy way for a script to determine whether a commit is a
> non-automatic merge commit.
>
> Have you considered this?
Your second paragraph explains why I did it the way I did. One can
easily have pre-merge call pre-commit, or have them be different. One
can not easily have only pre-merge called for a non-automatic merge
commit, but that is because of backward compatibility. The way *I* would
like it is:
- call pre-merge for any non-ff merge commit (automatic or not)
- call pre-commit for any non-merge commit (#parents <=1)
But that would break compatibility.
So I hope my patch is the best approximation to the above which keeps
compatibility and is simple to handle in most situations.
Cheers
Michael
next prev parent reply other threads:[~2012-09-06 8:16 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-05 13:39 [PATCH 0/3] pre-merge-hook Michael J Gruber
2012-09-05 13:39 ` [PATCH 1/3] git-merge: Honor pre-merge hook Michael J Gruber
2012-09-05 15:30 ` Michael Haggerty
2012-09-06 8:16 ` Michael J Gruber [this message]
2012-09-06 10:48 ` Michael Haggerty
2012-09-06 14:25 ` [PATCHv2 0/4] pre-commit hook for merges Michael J Gruber
2012-09-06 14:25 ` [PATCHv2 1/4] merge: document prepare-commit-msg hook usage Michael J Gruber
2012-09-06 14:25 ` [PATCHv2 2/4] git-merge: Honor pre-commit hook based on config Michael J Gruber
2012-09-06 14:25 ` [PATCHv2 3/4] merge: --no-verify to bypass pre-commit hook Michael J Gruber
2012-09-06 14:25 ` [PATCHv2 4/4] t7503: add tests for pre-commit hook (merge) Michael J Gruber
2012-09-05 13:39 ` [PATCH 2/3] merge: --no-verify to bypass pre-merge hook Michael J Gruber
2012-09-05 13:39 ` [PATCH 3/3] t7503: add tests for pre-merge-hook Michael J Gruber
2012-09-06 5:07 ` [PATCH 0/3] pre-merge-hook Junio C Hamano
2012-09-06 8:16 ` Michael J Gruber
2012-09-06 18:34 ` Junio C Hamano
2012-09-07 10:00 ` Michael J Gruber
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=50485BD3.5020802@drmicha.warpmail.net \
--to=git@drmicha$(echo .)warpmail.net \
--cc=git@vger$(echo .)kernel.org \
--cc=gitster@pobox$(echo .)com \
--cc=mhagger@alum$(echo .)mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox