bug#67836: 29.1.90; map-y-or-n-p doesn't terminate when run in a kmacro in batch mode

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Spencer Baugh <sbaugh@janestreet.com>,  67836@debbugs.gnu.org
> Date: Fri, 15 Dec 2023 17:55:43 -0500
> 
> > Thanks, but let's please find a fix that doesn't make the tail wag the
> > dog.  I don't want to make a change in bitch_at_user, which will
> > affect every possible use of it in batch mode, something that we have
> > been doing for eons.
> 
> I suspect keyboard macros have not been used very much in batch mode
> over the last 32 years.

I actually question the wisdom of doing so.  It isn't what keyboard
macros are for.

> >> ding's docstring states that it terminates keyboard macros.  But, due
> >> to what seems to be an oversight, it does not do that while executing
> >> in batch mode.
> > As the code clearly shows, it isn't an oversight.
> 
> AFAICT the current logic of code can be traced back to:
> 
>     commit 4588ec205730239596486e8ad4d18d541917199a
>     Author: Jim Blandy <jimb@red-bean.com>
>     Date:   Wed Jul 3 12:10:07 1991 +0000
>     
>         Initial revision
>     
>     diff --git a/src/dispnew.c b/src/dispnew.c
>     --- /dev/null
>     +++ b/src/dispnew.c
>     @@ -0,0 +1813,9 @@
>     +{
>     +  if (noninteractive)
>     +    putchar (07);
>     +  else if (!INTERACTIVE)  /* Stop executing a keyboard macro. */
>     +    error ("Keyboard macro terminated by a command ringing the bell");
>     +  else
>     +    ring_bell ();
>     +  fflush (stdout);
>     +}
> 
> I'm not sure this code can be said to show clearly that it's not
> an oversight.
> I read it to say that the author did not consider the intersection of
> 
>     noninteractive
> and
>     !INTERACTIVE

Maybe so (we could ask Jim if we wanted, he is still around), but in
any case I'm not interested in changing how bitch_at_user works
30-something years after it was coded, and has worked well since then.
I'm okay with fixing this particular problem, but not via changes to
bitch_at_user or any similar low-level functionality used everywhere.
Such changes are IMO acceptable only if they fix a clear bug, which is
not the case here.

Spencer, I already noted once that many of your patches have this
problem: you take some problem which happens to you in a very
specialized use case, and propose to fix that by changes that affect
all of Emacs.  This isn't going to fly in Emacs in general, since
Emacs is a very old and stable program, where almost all of the old
low-level code was tested by decades of usage, and any significant
changes there run high risk of breaking something.  And yet you keep
coming up with changes which do precisely that.  Please try to see
things from the POV of the Emacs maintainers, and look for ways of
fixing those problems either by much more localized changes, or maybe
even just in your own code.  TIA.