Eli Zaretskii <eliz@gnu.org> writes:

>> From: Joseph Turner <joseph@breatheoutbreathe.in>
>> Cc: michael_heerdegen@web.de, philipk@posteo.net, 66187@debbugs.gnu.org
>> Date: Tue, 03 Oct 2023 13:43:56 -0700
>>
>>
>> Eli Zaretskii <eliz@gnu.org> writes:
>>
>> > 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.
>
> That's true, but it doesn't sound like a grave problem to me.  We have
> the same duplication elsewhere, so this isn't a precedent.  Moreover,
> when a doc string is long and complicated, asking the reader to read
> part of it elsewhere is also quite a hassle.
>
> So I still think duplication is the lesser evil here.

Thanks for the explanation! See patch.

Joseph