bug#68691: 30.0.50; [WISHLIST] Make it easier to conform to desired commit message format

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: stefankangas@gmail.com,  iarchivedmywholelife@gmail.com,
>   68691@debbugs.gnu.org
> Date: Sun, 28 Jan 2024 17:04:30 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > It cannot.  Format could be okay, but will not describe all of the
> > changes, or describe them in a nonsensical way.
> >
> > OTOH, is the format below OK or not?
> >
> >      Merge from origin/emacs-29
> >
> >      53481cc9546 Fix description of when "\xNNN" is considered a unibyte 
> > character
> >      1ef8b90ae06 Simplify imenu setup for {cmake,dockerfile}-ts-modes
> >      7338af9c986 ; * etc/PROBLEMS: Document that GnuPG 2.4.4 solves the 
> > EasyPG
> >      5483a1df99c Improve documentation of profiler commands
> >      fb4cf0ab46d ; Fix xref under Output Overrides in Elisp manual.
> >      aa6c24da61f Fix broken links to Freedesktop notifications spec
> >      14d68221d26 Fix nasty cut'n'waste error in Tramp
> >      51ca049608c Fix image-dired-tags-db-file void variable error
> >      c450eec07ff typescript-ts-mode: Skip test if tsx grammar missing
> >      9841ced147f ; Fix typos
> >      557ed9c0463 * admin/README: Document the run-codespell script.
> >      5701f96335c * admin/README: Fix entry on coccinelle subdirectory.
> >      1805f4bfd62 Add script admin/run-codespell and supporting files
> 
> This starts with "Merge from..."

So any message that begins with "Merge from" will be okay, no matter
what follows it?

> > Or this one:
> >
> >     Revert "Fix typo in lispref 'Creating Strings' section"
> >
> >     This reverts commit b825962ea840348bbde0c834ca398458a06fbb8b
> >     which was mistakenly installed in master instead of emacs-29.
> 
> This starts with the word "Revert"

So any message that begins with "Revert" will be okay, no matter what
follows it?

> > Or this one:
> >
> >     ; Update copyright years in more files
> 
> And this starts with a semicolon.

So any message with a semicolon is okay?

And if I use the same log, but without a semicolon (for whatever
reasons), then the hook will abort the commit?

> > How do you distinguish between the above perfectly valid examples, and
> > some arbitrary text in a log message (which should be flagged as
> > nonconforming)?
> 
> The types of commit messages that don't require log messages is finite,

No, it's infinite, actually.  The 3 examples I've shown are just those
I found in a few seconds I had.