Stefan Kangas <stefankangas@gmail.com> writes:

> Joseph Turner <joseph@breatheoutbreathe.in> writes:
>
>> Joseph Turner <joseph@breatheoutbreathe.in> writes:
>>
>>> Michael Heerdegen <michael_heerdegen@web.de> writes:
>>>
>>>> Joseph Turner via "Bug reports for GNU Emacs, the Swiss army knife of
>>>> text editors" <bug-gnu-emacs@gnu.org> writes:
>>>>
>>>>> I'm not sure what you mean. In both of the following examples, PREDICATE
>>>>> is used to narrow the completion candidates to only empty directories:
>>>>>
>>>>> (read-directory-name "Prompt: " "~/" nil t nil #'directory-empty-p)
>>>>> (read-directory-name "Prompt: " "~/" nil nil nil #'directory-empty-p)
>>>>
>>>> In the second version also non-empty directories will be accepted.
>>>
>>> Yes, PREDICATE narrows the completion candidates but doesn't determine a
>>> valid return value.
>>
>> Ping!  I'm happy to keep discussing this patch if others are interested.
>
> Could you please send the latest version of your patch?

Here you go!