bug#52491: 28.0.90; Regression in window deletion with minibuffer

[Juri Linkov]

>> > And the patch you proposed earlier doesn't fix this other problem?
>> 
>> Unfortunately, it doesn't fix this, since 28.0.90 uses mru,
>> but 27.2 didn't.
>
> FWIW, I don't see any catastrophe here: whoever plays such games with
> switching windows during completion should know what they are doing,
> and how to switch back to the minibuffer.

Anyway, here is the patch for the release branch
that fixes the previous regression:

diff --git a/lisp/window.el b/lisp/window.el
index 0f17bb28b4..0a422b4305 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -2531,14 +2531,15 @@ get-lru-window
            (setq best-window window)))))
     (or best-window second-best-window)))
 
-(defun get-mru-window (&optional all-frames dedicated not-selected no-other)
+(defun get-mru-window (&optional all-frames dedicated not-selected no-other 
minibuf)
    "Return the most recently used window on frames specified by ALL-FRAMES.
-A minibuffer window is never a candidate.  A dedicated window is
-never a candidate unless DEDICATED is non-nil, so if all windows
-are dedicated, the value is nil.  Optional argument NOT-SELECTED
-non-nil means never return the selected window.  Optional
+A dedicated window is never a candidate unless DEDICATED is non-nil,
+so if all windows are dedicated, the value is nil.  Optional argument
+NOT-SELECTED non-nil means never return the selected window.  Optional
 argument NO-OTHER non-nil means to never return a window whose
-'no-other-window' parameter is non-nil.
+'no-other-window' parameter is non-nil.  A minibuffer window is never
+a candidate when MINIBUF is nil or omitted.  MINIBUF t means consider
+the minibuffer window only if the minibuffer is active.
 
 The following non-nil values of the optional argument ALL-FRAMES
 have special meanings:
@@ -2556,7 +2557,7 @@ get-mru-window
 Any other value of ALL-FRAMES means consider all windows on the
 selected frame and no others."
    (let (best-window best-time time)
-    (dolist (window (window-list-1 nil 'nomini all-frames))
+    (dolist (window (window-list-1 nil (unless minibuf 'nomini) all-frames))
       (setq time (window-use-time window))
       (when (and (or dedicated (not (window-dedicated-p window)))
                 (or (not not-selected) (not (eq window (selected-window))))
@@ -4205,6 +4206,7 @@ delete-window
   (let* ((frame (window-frame window))
         (function (window-parameter window 'delete-window))
         (parent (window-parent window))
+        (choose-selected delete-window-choose-selected)
         atom-root)
     (window--check frame)
     (catch 'done
@@ -4255,7 +4257,7 @@ delete-window
          ;; Can't do without resizing fixed-size windows.
          (window--resize-siblings window (- size) horizontal t)))
 
-        (when (eq delete-window-choose-selected 'pos)
+        (when (eq choose-selected 'pos)
           ;; Remember edges and position of point of the selected window
           ;; of WINDOW'S frame.
           (setq frame-selected-window-edges
@@ -4289,9 +4291,9 @@ delete-window
                       ;; Select window at WINDOW's position at point.
                      (set-frame-selected-window
                        frame new-frame-selected-window)))))
-         ((and (eq delete-window-choose-selected 'mru)
+         ((and (eq choose-selected 'mru)
                ;; Try to use the most recently used window.
-               (let ((mru-window (get-mru-window frame nil nil t)))
+               (let ((mru-window (get-mru-window frame nil nil t t)))
                  (and mru-window
                      (set-frame-selected-window frame mru-window)))))
          ((and (window-parameter
diff --git a/lisp/simple.el b/lisp/simple.el
index 84928caa31..73c5840e02 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -9252,6 +9278,7 @@ completion-setup-function
         (setq-local completion-base-position base-position)
         (setq-local completion-list-insert-choice-function insert-fun))
       (setq-local completion-reference-buffer mainbuf)
+      (setq-local delete-window-choose-selected 'mru)
       (if base-dir (setq default-directory base-dir))
       (when completion-tab-width
         (setq tab-width completion-tab-width))