bug#66187: read-file-name unexpected behavior when MUSTMATCH is a function

[Eli Zaretskii]

> From: Drew Adams <drew.adams@oracle.com>
> CC: "michael_heerdegen@web.de" <michael_heerdegen@web.de>,
>         "philipk@posteo.net" <philipk@posteo.net>,
>         "66187@debbugs.gnu.org"
>       <66187@debbugs.gnu.org>,
>         Joseph Turner <joseph@breatheoutbreathe.in>
> Date: Thu, 5 Oct 2023 20:20:46 +0000
> 
> > The use of a function as `require-match` is
> > brand new in Emacs-29, so I think it's not
> > too late to fix it.  I think rather than
> > fixing the doc we should fix the behavior 
> 
> If it's not too late to fix what was introduced
> in Emacs 29

That is not yet established.

> then how about not breaking the
> behavior of REQUIRE-MATCH at all, and instead
> just add a separate argument for what a function
> value of REQUIRE-MATCH does in 29.1?

That is definitely not a change suitable for Emacs 29 at this point.