Re: [PATCH] commit: abort before commit-msg if empty message

[Jonathan Tan <jonathantanmy@google.com>]

> Jonathan Tan <jonathantanmy@google.com> writes:
> 
> > When a user runs "git commit" without specifying a message, an editor
> > appears with advice:
> >
> >     Please enter the commit message for your changes. Lines starting
> >     with '#' will be ignored, and an empty message aborts the commit.
> >
> > However, if the user supplies an empty message and has a commit-msg hook
> > which updates the message to be non-empty, the commit proceeds to occur,
> > despite what the advice states.
> 
> When "--no-edit" is given, and when commit-msg fills that blank, the
> command should go ahead and record the commit, I think.
>
> An automation where commit-msg is used to produce whatever
> appropriate message for the automation is entirely a reasonable
> thing to arrange.  Of course, you can move the logic to produce an
> appropriate message for the automation from commit-msg to the script
> that drives the "git commit" and use the output of that logic as the
> value for the "-m" option to achieve the same, so in that sense,
> there is an escape hatch even if you suddenly start to forbid such a
> working set-up, but it nevertheless is unnecessary busywork for those
> with such a set-up to adjust to this change.

Thanks for bringing up this workflow. Note that this patch only changes
behavior when the editor is brought up and, thus, the advice is shown -
see the check for use_editor in prepare_to_commit(). So there should be
no change if --no-edit is given, but I acknowledge that there will be a
negative change if the user brings up the editor and just immediately
quits it (which can happen in a workflow where commit-msg always
produces an appropriate message, but the user can provide additional
information if desired).

> I actually think in this partcular case, the commit-msg hook that
> adds Change-ID to an empty message is BUGGY.  If the hook looked at
> the message contents and refrains from making an otherwise empty
> message to non-empty, there is no need for any change here.
> 
> In any case, you'll have plenty of time to make your case after the
> rc freeze.  I am not so sympathetic to a patch that makes us bend
> backwards to support such a buggy hook to e honest.

That's reasonable. In any case, we'll also look at fixing the Gerrit
hook - at the very least, so that it can work with versions of Git that
do not have this patch of mine (or something similar).