Hi Stefan!

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> emacs -Q on the tip of the emacs-29 branch (after commit 77f5d4d523a), run...
>>
>> (let ((default-directory "~/"))
>>   (read-directory-name "Clone into new or empty directory: " nil nil
>>                        (lambda (dir) (or (not (file-exists-p dir))
>>                                     (directory-empty-p dir)))))
>>
>> ...then type "/tmp/" (the whole minibuffer now reads "~//tmp") then RET.
>>
>> Expected: Completion does not exit, instead saying "[No match]".
>
> Ah, that good old problem about whether PRED should apply to the
> quoted
> or to the unquoted string 🙁
>
> I think here the bug is in `read-directory-name` (and
> `read-file-name`)
> since their PRED arg is expected to apply to the (unquoted) file name
> itself (i.e. the thing that would be returned by the function), rather
> than to the quoted representation used in the minibuffer.
>
> They should wrap PRED so as to pass the arg through
> `substitute-in-file-name` (or otherwise arrange to make sure PRED is
> called with an unquoted file name).

Thank you for the clear instructions!  Does the attached patch do the
right thing?

If so, may it be applied to emacs-29?

Joseph