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

Jonathan Tan [off-list ref] writes:

quoted

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).