Re: [PATCH] change dired--find-possibly-alternative-file behaviour.

[Felix <felix.dick@web.de>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Felix <felix.dick@web.de>
>> Cc: emacs-devel@gnu.org
>> Date: Sun, 26 Feb 2023 07:07:10 +0100
>>
>>
>> Eli Zaretskii <eliz@gnu.org> writes:
>>
>> >> From: Felix <felix.dick@web.de>
>> >> Date: Sat, 25 Feb 2023 20:43:57 +0100
>> >>
>> >> diff --git a/lisp/dired.el b/lisp/dired.el
>> >> index 76499d0f520..620508bef4f 100644
>> >> --- a/lisp/dired.el
>> >> +++ b/lisp/dired.el
>> >> @@ -2728,7 +2728,8 @@ dired-find-file
>> >>  (defun dired--find-possibly-alternative-file (file)
>> >>    "Find FILE, but respect `dired-kill-when-opening-new-dired-buffer'."
>> >>    (if (and dired-kill-when-opening-new-dired-buffer
>> >> -           (file-directory-p file))
>> >> +           (file-directory-p file)
>> >> +           (= (length (get-buffer-window-list)) 1))
>> >>        (progn
>> >>          (set-buffer-modified-p nil)
>> >>          (dired--find-file #'find-alternate-file file))
>> >
>> > What if get-buffer-window-list returns nil?
>>
>> The optional argument BUFFER-OR-NAME of get-buffer-window-list defaults
>> to the current buffer, shouldn't that garantee that it never returns
>> nil?
>
> Only if the current buffer is displayed in some window.

If get-buffer-window-list returns nil for any case, (length nil) returns 0.
In that case the if condition is false and dired--find-file will not
kill any buffer.
Is there a possible case where the function is called from dired buffer,
and get-buffer-window-list returns nil?
In that case the buffer would stay alive!

dired--find-possibly-alternative-file is only used in 2 places
dired-find-file and in dired-up-directory.
I thought those functions are only useful inside dired buffer windows.