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

[Joseph Turner]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: philipk@posteo.net, 66187@debbugs.gnu.org
>> Date: Tue, 26 Sep 2023 17:55:37 -0700
>> From:  Joseph Turner via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>>
>> > Finally, I think the docstring of `read-directory-name' needs to be
>> > updated: it fails to mention that MUSTMATCH can be a function (the
>> > argument is passed directly to `read-file-name').
>>
>> How about the attached patch?
>
> This is okay, except that we do document the other arguments.  So why
> not just copy/paste the description of MUSTMATCH from read-file-name
> to read-directory-name instead?

The read-file-name docstring for MUSTMATCH is lengthy, and duplicating
it will mean that if read-file-name changes, we'll need to remember to
change the docstring of read-directory-name.