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

[Joseph Turner]

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

>> Ping!  I hope a fix like this can be merged into Emacs 29 still :)
>
> Duh, I can't believe I left you waiting for so long, this is awful.
> I just pushed this to `emacs-29`, thank you.
> I hope there might still be a next time, so I get a chance to do better.

It's all good!!  Life is happening :)

Thank you!!

Joseph

>
>         Stefan
>
>
>> From 609bf4964f88b01f4843e29b2cf71ee1cd2f6125 Mon Sep 17 00:00:00 2001
>> From: Joseph Turner <joseph@breatheoutbreathe.in>
>> Date: Sun, 12 Nov 2023 13:21:50 -0800
>> Subject: [PATCH] Fix completing-read functional REQUIRE-MATCH behavior
>>
>> * lisp/minibuffer.el (completion--complete-and-exit): If
>> minibuffer-completion-confirm is a function which returns nil,
>> immediately fail to complete.
>>
>> See bug#66187.
>> ---
>>  lisp/minibuffer.el | 11 +++++++----
>>  1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
>> index 3e30b68d5e9..9fad3e71fad 100644
>> --- a/lisp/minibuffer.el
>> +++ b/lisp/minibuffer.el
>> @@ -1847,10 +1847,13 @@ appear to be a match."
>>     ;; Allow user to specify null string
>>     ((= beg end) (funcall exit-function))
>>     ;; The CONFIRM argument is a predicate.
>> -   ((and (functionp minibuffer-completion-confirm)
>> -         (funcall minibuffer-completion-confirm
>> -                  (buffer-substring beg end)))
>> -    (funcall exit-function))
>> +   ((functionp minibuffer-completion-confirm)
>> +    (if (funcall minibuffer-completion-confirm
>> +                 (buffer-substring beg end))
>> +        (funcall exit-function)
>> +      (unless completion-fail-discreetly
>> +    (ding)
>> +    (completion--message "No match"))))
>>     ;; See if we have a completion from the table.
>>     ((test-completion (buffer-substring beg end)
>>                       minibuffer-completion-table