Subject: Re: bug#67882: 29.1.90; Registers' preview can delete existing window when finishing

From: Thierry Volpiatto <[email-masked]>
Date: Mon, 08 Jan 2024 14:36:37 +0000

Hello Dmitry,

is the attached patch fix this issue for you?

Thanks.

Dmitry Gutov <[email-masked]> writes:

> Set up:
>
> (defun split-window-prefer-side-by-side (&optional window)
>   (let ((split-height-threshold (and (< (window-width window)
>                                         split-width-threshold)
>                                      split-height-threshold)))
>     (split-window-sensibly window)))
>
> (setq split-window-preferred-function 'split-window-prefer-side-by-side)
>
> Split the frame, e.g. 'C-x 3'.
>
> Then create some register (e.g. using 'C-x r C-@') and then invoke
> another command reading it. E.g. 'C-x r j'.
>
> Wait the necessary 1 second for the preview to appear - it will use one
> of the existing windows to show the list of registers.
>
> Then, whether you choose the register, or C-g out of the choice, the
> window used to display the list will be deleted.
>
> Previously mentioned in bug#66394.
>
> Not a regression on master, just reproduced it in 29.
>
>
>
>

-- 
Thierry
>From b39ffa6e1db2577ecf3b265ccdcc50b102ee13b7 Mon Sep 17 00:00:00 2001
From: Thierry Volpiatto <[email-masked]>
Date: Tue, 26 Dec 2023 17:49:34 +0100
Subject: [PATCH 1/2] Fix window setting in register preview (bug#67882)

and allow configuring it if needed.

* lisp/register.el (register-preview-display-buffer-alist): New user
  var.
(register-preview,register-preview-1): Use it.
---
 lisp/register.el | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/lisp/register.el b/lisp/register.el
index baad2c2a05d..f5b0365dec2 100644
--- a/lisp/register.el
+++ b/lisp/register.el
@@ -386,18 +386,21 @@ Format of each entry is controlled by the variable `register-preview-function'."
     (setq register-preview-function (register--preview-function
                                      register--read-with-preview-function)))
   (when (or show-empty (consp register-alist))
-    (with-current-buffer-window
-     buffer
-     (cons 'display-buffer-below-selected
-	   '((window-height . fit-window-to-buffer)
-	     (preserve-size . (nil . t))))
-     nil
-     (with-current-buffer standard-output
-       (setq cursor-in-non-selected-windows nil)
-       (mapc (lambda (elem)
-               (when (get-register (car elem))
-                 (insert (funcall register-preview-function elem))))
-             register-alist)))))
+    (with-current-buffer-window buffer
+        register-preview-display-buffer-alist
+        nil
+      (with-current-buffer standard-output
+        (setq cursor-in-non-selected-windows nil)
+        (mapc (lambda (elem)
+                (when (get-register (car elem))
+                  (insert (funcall register-preview-function elem))))
+              register-alist)))))
+
+(defcustom register-preview-display-buffer-alist '(display-buffer-at-bottom
+                                                   (window-height . fit-window-to-buffer)
+	                                           (preserve-size . (nil . t)))
+  "Window configuration for the register preview buffer."
+  :type display-buffer--action-custom-type)
 
 (defun register-preview-1 (buffer &optional show-empty types)
   "Pop up a window showing the preview of registers in BUFFER.
@@ -415,9 +418,7 @@ Format of each entry is controlled by the variable `register-preview-function'."
     (when (or show-empty (consp registers))
       (with-current-buffer-window
         buffer
-        (cons 'display-buffer-below-selected
-	      '((window-height . fit-window-to-buffer)
-	        (preserve-size . (nil . t))))
+        register-preview-display-buffer-alist
         nil
         (with-current-buffer standard-output
           (setq cursor-in-non-selected-windows nil)
-- 
2.34.1