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

From: Eli Zaretskii <[email-masked]>
Date: Fri, 06 Oct 2023 07:47:58 +0300

> From: Drew Adams <[email-masked]>
> CC: "[email-masked]" <[email-masked]>,
>         "[email-masked]" <[email-masked]>,
>         "[email-masked]"
> 	<[email-masked]>,
>         Joseph Turner <[email-masked]>
> 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.