Subject: 29.4; display-buffer-reuse-mode-window does not respect dedicated flag

From: Trevor Murphy <[email-masked]>
Date: Tue, 11 Feb 2025 17:52:30 -0800

Hey, all.  Per the subject line, I noticed that this display action
function isn't respecting when I mark a window dedicated to its buffer.

Here's a minimal example you can step through in the scratch buffer:

```
(setq *w* (split-window-horizontally)
      *one* (get-buffer-create "one")
      *two* (get-buffer-create "two"))

(display-buffer-use-some-window *one* '((inhibit-same-window . t)))
;;; should see "one" appear in the *w* window

(set-window-dedicated-p *w* t)
(display-buffer-use-some-window *two* '((inhibit-same-window . t)))
;;; should not see any changes, the function returns nil
(display-buffer-reuse-mode-window *two* '((inhibit-same-window . t)))
;;; bug -- should see "two" appear in the *w* window
```

I think this is a bug in -reuse-mode-window, and so I've attached a
patch that would fix the issue.  Though maybe I'm wrong?  Is
this intended behavior?

In GNU Emacs 29.4 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.48,
cairo version 1.18.2)
Repository revision: 324f7b692ab0768891a26fe1c1431f4b555018be
Repository branch: main
System Description: Arch Linux

Configured using:
 'configure --with-pgtk --with-native-compilation=aot --sysconfdir=/etc
 --prefix=/usr --libexecdir=/usr/lib --with-tree-sitter
 --localstatedir=/var --with-cairo --disable-build-details
 --with-harfbuzz --with-libsystemd --with-modules 'CFLAGS=-march=x86-64
 -mtune=generic -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=3
 -Wformat -Werror=format-security -fstack-clash-protection
 -fcf-protection -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -g
 -ffile-prefix-map=/home/trevor/pkgbuilds/abs/emacs/src=/usr/src/debug/emacs
 -flto=auto' 'LDFLAGS=-Wl,-O1 -Wl,--sort-common -Wl,--as-needed
 -Wl,-z,relro -Wl,-z,now -Wl,-z,pack-relative-relocs -flto=auto'
 'CXXFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions
 -Wp,-D_FORTIFY_SOURCE=3 -Wformat -Werror=format-security
 -fstack-clash-protection -fcf-protection -fno-omit-frame-pointer
 -mno-omit-leaf-frame-pointer -Wp,-D_GLIBCXX_ASSERTIONS -g
 -ffile-prefix-map=/home/trevor/pkgbuilds/abs/emacs/src=/usr/src/debug/emacs
 -flto=auto''

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY
PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XIM GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search time-date mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs
comp comp-cstr warnings icons subr-x rx cl-seq cl-macs gv cl-extra
help-mode bytecomp byte-compile cl-lib sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils rmc iso-transl tooltip cconv
eldoc paren electric uniquify ediff-hook vc-hooks lisp-float-type
elisp-mode mwheel term/pgtk-win pgtk-win term/common-win pgtk-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list replace
newcomment text-mode lisp-mode prog-mode register page tab-bar menu-bar
rfn-eshadow isearch easymenu timer select scroll-bar mouse jit-lock
font-lock syntax font-core term/tty-colors frame minibuffer nadvice seq
simple cl-generic indonesian philippine cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms
cp51932 hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese composite emoji-zwj charscript charprop case-table
epa-hook jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button
loaddefs theme-loaddefs faces cus-face macroexp files window
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget keymap hashtable-print-readable backquote threads dbusbind
inotify dynamic-setting system-font-setting font-render-setting cairo
gtk pgtk lcms2 multi-tty make-network-process native-compile emacs)

Memory information:
((conses 16 76993 6931)
 (symbols 48 7111 0)
 (strings 32 19553 2302)
 (string-bytes 1 592363)
 (vectors 16 15757)
 (vector-slots 8 327500 14961)
 (floats 8 37 46)
 (intervals 56 267 0)
 (buffers 984 11))
From ba34ccbb8b4a9f2cfb57572ebd124eee98e1a654 Mon Sep 17 00:00:00 2001
From: Trevor Murphy <[email-masked]>
Date: Tue, 11 Feb 2025 17:26:55 -0800
Subject: [PATCH] Ignore dedicated windows in
 'display-buffer-reuse-mode-window'.

Unless the dedicated window is already displaying the
buffer-to-be-displayed.  In that case the window may be reused,
according to the setting of inhibit-same-window.

* lisp/window.el (display-buffer-reuse-mode-window): Check
window-dedicated-p before pushing the candidate window onto the stack.
---
 lisp/window.el | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lisp/window.el b/lisp/window.el
index 13fe1feba10..018bb35f943 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -7984,6 +7984,8 @@ display-buffer-reuse-mode-window
                        ((apply #'derived-mode-p allowed-modes)
                         'derived)))))
           (when (and mode?
+                     (or (not (window-dedicated-p window))
+                         (eq buffer (window-buffer window)))
                      (not (and inhibit-same-window-p
                                (eq window curwin))))
             (push window (if (eq curframe (window-frame window))
-- 
2.48.1