bug#56682: locked narrowing

[Eli Zaretskii]

> Cc: 56682@debbugs.gnu.org, monnier@iro.umontreal.ca, dgutov@yandex.ru
> Date: Sat, 26 Nov 2022 18:51:37 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> 
> We can add the tests after the branch is cut, I just wanted to be sure we
> will have them eventually.

Btw, one more general comment: we will need to tell in NEWS what we expect
from developers of modes to do to comply with these protocols, when they
adapt to Emacs 29 their code related to font-lock and anything else that can
run from redisplay.  The actual text for NEWS can be added later, after the
branch is cut, but maybe thinking about that aspect will affect your code
and/or the doc strings.