> Sigh.  I guess we can install this on emacs-29 and cross the
> fingers...

I'm not insisting on it.
If you think it's risky, let's just have it on `master`.

BTW, see below the actual patch, including changes to etc/NEWS, manual,
as well as the addition of a runtime warning (without which I can't see
how we'll ever be able to get rid of the ugly backward compatibility
hack).


        Stefan