bug#67856: Dired navigation via directory line does not respect dired-kill-when-opening-new-dired-buffer

[Jared Finder via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

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On 2023-12-21 05:18, Eli Zaretskii wrote:
>> Date: Sat, 16 Dec 2023 12:35:10 -0800
>> From:  Jared Finder via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> 
>> The option dired-kill-when-opening-new-dired-buffer is not respected
>> when clicking on parent directories in the directory line at the top
>> of dired buffers.  This can be fixed by calling
>> dired--find-possibly-alternate-file instead of dired in the
>> callback, as my attached patch does.
>> 
>> I believe changing to dired--find-possibly-alternate-file is safe
>> because from playing around with dired, the directory being clicked
>> on must be a directory and can not contain wildcards at this point.
>> Therefore, at this point it is known that the directory is just a
>> plain directory (no wildcards) and so going through find-file
>> machinery will have the intended result.
> 
> If we want to install this on the emacs-29 release branch, I'd prefer
> a safer variant, which actually verified that we don't call
> dired--find-possibly-alternate-file with a wildcard.  That's because
> we have quite a few features that place buffers in Dired mode, and we
> could easily miss one that does have wildcards there.
> 
> So would you mind modifying the patch a little so that it checks
> whether current-dir includes wildcards, and if so, calls 'dired'
> instead of dired--find-possibly-alternate-file?

Done, new patch attached.  Luckily, there already is a function that 
does exactly the right check.

Feel free to alter the comment explaining why this third code path 
exists.  I wasn't sure the right style to indicate this type of 
defensive code path that I am not certain is needed.

   -- MJF

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From 30ad2b8acef36a3ab14f045bca94d7987ecd96e8 Mon Sep 17 00:00:00 2001
From: Jared Finder <jared@finder.org>
Date: Sat, 16 Dec 2023 12:10:03 -0800
Subject: [PATCH] Clicks on directory line kill prev buffer if option is set

The option dired-kill-when-opening-new-dired-buffer should be checked
in this code path as well.

* lisp/dired.el (dired--make-directory-clickable): Call
dired--find-possibly-alternative-file instead of dired in click
callback.
---
 lisp/dired.el | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/lisp/dired.el b/lisp/dired.el
index 33e38ed2c1c..fc91b58ecad 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -2010,9 +2010,18 @@ dired--make-directory-clickable
               keymap ,(let* ((current-dir dir)
                              (click (lambda ()
                                       (interactive)
-                                      (if (assoc current-dir dired-subdir-alist)
-                                          (dired-goto-subdir current-dir)
-                                        (dired current-dir)))))
+                                      (cond
+                                       ((assoc current-dir dired-subdir-alist)
+                                        (dired-goto-subdir current-dir))
+                                       ;; If there is a wildcard character in the directory, don't
+                                       ;; use the alternate file machinery which tries to keep only
+                                       ;; one dired buffer open at once.
+                                       ;;
+                                       ;; FIXME: Is this code path reachable?
+                                       ((insert-directory-wildcard-in-dir-p current-dir)
+                                        (dired current-dir))
+                                       (t
+                                        (dired--find-possibly-alternative-file current-dir))))))
                         (define-keymap
                           "<mouse-2>" click
                           "<follow-link>" 'mouse-face
-- 
2.39.2