From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.9 required=3.0 tests=AWL,BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 788DD203E3 for ; Tue, 26 Jul 2016 14:54:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756220AbcGZOyW (ORCPT ); Tue, 26 Jul 2016 10:54:22 -0400 Received: from mout.gmx.net ([212.227.17.22]:58583 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753946AbcGZOyV (ORCPT ); Tue, 26 Jul 2016 10:54:21 -0400 Received: from virtualbox ([37.24.142.100]) by mail.gmx.com (mrgmx102) with ESMTPSA (Nemesis) id 0LwGDy-1bFQPv0dDy-0185x3; Tue, 26 Jul 2016 16:54:17 +0200 Date: Tue, 26 Jul 2016 16:54:06 +0200 (CEST) From: Johannes Schindelin X-X-Sender: virtualbox@virtualbox To: Orgad Shaneh cc: git Subject: Re: [PATCH] merge: Run commit-msg hook In-Reply-To: Message-ID: References: <1469519323-11420-1-git-send-email-orgad.shaneh@audiocodes.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Provags-ID: V03:K0:Ui6LeIaxH13W41oMENyQaQq9alKb9BY0pX6HwGRiow1ZgC8nkVC Pa5RBBEyvOFu1SslyOKXP7kuJ/lX8kayxXKNkbymbBCRie4/7o5bO/iDNsA5Vo+avnQXndQ jFOfYXNbGe/YZoj7uW4lXFSt5zdbtF6gn1bAi6GcoLWWdOPAA8LkYdRx6/phgb2Pb/NM/IZ J2NQr8zZH7TdxonfXB6xA== X-UI-Out-Filterresults: notjunk:1;V01:K0:8Sz6oe4/sug=:xeQiX24ig42ban9tzM6fo8 8fDCcz5mbNmP/Ws5ZfDdkcNMD61RBxY1+gU8/nzPFeh/sXPzhn601ydXbRqQq4fbx2nh3kfPU YeYSEhcOMM1aXr98kAM5ofMC8DEr3gftoWUh1LSFMtMvTCxulxlLfEUoJJgeQZi8KcDssrul+ 2lRwAndzOOVhyw7OczlcItKREBLUjM/CHpCqydifjEf6rfY75t6zscZxfRIDROXPMJ/mT//vA g3faL9byKiX3t/lvj9HnAGPjtAppNvP9Exmp+ukDyUEDr0bCL6HC+kmNLY1WEwt9A5cq/p9AC bykMRnMpK+7PFchBLckvvs+tD66upNV65Py5FEzn/hoCl+s1DwKy3SFaNC31C8TOux+gNCTn+ 67lqsulbhhlJ7m6xJ2yOP0vOidIurBhyIQt+5v9dU15vDRaZU76l2/dTlW/pcmUh+sYTfiN/4 KiQc1OEnAjZ0OmgXB5tOtNlLO6fMOhJmaPLjw6guftW7bSwUsG7je+rLE2ftklnx1dudkI2Xy +LAHW4WlLqtjgCz5RoMLERwPCs+qtTvqPFWso1Rky2m4Ip955gv5PteObiEz0Xr0c9SLy1WN5 5Iy3DaeYrZQgJ+22FKv/ccZbm82tB1BOxhMEHItBdbKzeWk5pjfeXjYwGX98QLdV3J4Er+ThN RydPpechXMyPyjUnunpZsAHYFZksVY9PVtR1VLAdB6FaBey/eQWPZKLbyE/+MhDhdw2S8nxzq LCKP5Gl80iz2USKzI/BahVY1BdHgPIDR75Wa/lVBZ87ETJgsKKiimlmxu5oDX2E2IxTsd/Zf1 a5iMQ/6 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Hi Orgad, On Tue, 26 Jul 2016, Orgad Shaneh wrote: > On Tue, Jul 26, 2016 at 4:02 PM, Johannes Schindelin > wrote: > > > > On Tue, 26 Jul 2016, Orgad Shaneh wrote: > > > >> commit-msg is needed to either validate the commit message or edit it. > >> Gerrit for instance uses this hook to append its Change-Id footer. > >> > >> This is relevant to merge commit just like any other commit. > > > > Hmm. This is not very convincing to me, as > > > > - if you call commit-msg in `git merge` now, why not `prepare-commit-msg`? > > prepare-commit-msg is already called, a few lines above this addition. Oh. That would have made a heck of a convincing argument in the commit message. Pity it was not mentioned. (Yes, please read that as a strong suggestion to fix that in the next patch iteration.) FWIW I dug out the original submission: http://thread.gmane.org/gmane.comp.version-control.git/151297/focus=151435 It seems that there was no discussion about the commit-msg. Which makes me wonder why nobody thought of this. Now, you could make a case that you want to run the commit-msg hook in the same spirit as prepare-commit-msg (and mention that apparently nobody thought of that when the patch was accepted into builtin/merge.c). But then I wonder what your argument would be for *not* running the pre-commit and the post-commit hooks in `git merge` as well? Seems like a big inconsistency to me, one that would not be helped by a piecemeal patch that does only half the job of resolving the inconsistency. There was actually a question why the post-commit hook was not run in `git merge`: http://thread.gmane.org/gmane.comp.version-control.git/168716/focus=168773 (but it seems nobody cared all that much). > > - a merge is a different beast from a simple commit. That is why we > > have two different commands for them. A hook to edit the merge message > > may need to know the *second* parent commit, too, for example to > > generate a diffstat, or to add information about changes in an "evil > > commit". > > That is correct for a post-merge hook. Why should *message validation* > differ between simple and merge commit? You yourself do not use the hook for validation. You use it to *edit* the message. My examples do the very same thing. Why should they wait for a *post-merge* hook to amend the message? Otherwise, why wouldn't you use the post-merge hook to add the Change-Id: in your use case, too... > > - if Gerrit is the intended user, would it not make more sense to > > introduce a new hook, e.g. `merge-msg` (and `prepare-merge-msg`), as you > > have to teach Gerrit a new trick anyway? > > Why is that new? Every commit in gerrit has a Change-Id footer, which is > generated by commit-msg hook. So it already works for Gerrit? Why is this patch needed, then? This is confusing. > What I currently do for merges that succeed without conflicts is > unconditional commit --amend --no-edit just to run the hook. So you do that manually? Or you taught Gerrit to do that? Please clarify. > > - if Gerrit is the intended user, why does it not simply edit the merge > > message itself? After all, it executes it, and probably crafts a merge > > message mentioning that this is an automatic merge, anyway, so why not > > add the Change-Id *then*? > > Most Gerrit setups require Change-Id in the commit message that the user > pushes. It is possible to disable this setting, and then you don't need the > Change-Id at all, but then you can't push a new patch set for the change > (unless you copy the Change-Id from gerrit to your commit message). > That's a real pain, I'm not aware of any public gerrit server that > disables this :) Forgive me, I never used Gerrit, and neither do I intend to do so. I would appreciate a self-contained commit message that explains just enough about Gerrit to understand what the patch tries to solve, and in a manner such that even developers who decided to ignore Gerrit understand. Ciao, Dscho