Subject: bug#63312: 29.0.90; set-frame-parameter sometimes called with dead frame when quitting ediff

From: Tobias Bading <[email-masked]>
Date: Fri, 5 May 2023 19:02:10 +0200

1. emacs -Q

2. Open a file under version control, e.g. lisp/vc/ediff-util.el

3. Selecting some text with the mouse seems to increase the chance of the
   error occurring, maybe even select some text in another application

4. M-x ediff-revision RET RET RET RET

5. q RET

Sometimes this results in error

set-frame-parameter: Wrong type argument: frame-live-p, #<dead frame Ediff 0x560ee1b46200>

With

(trace-function-background 'set-frame-parameter)
(trace-function-background 'x-dnd-after-move-frame)
(trace-function-background 'handle-move-frame)

prior to quitting ediff, the error is logged as

1 -> (handle-move-frame (move-frame (#<dead frame Ediff 0x5643a7425888>)))
| 2 -> (x-dnd-after-move-frame #<dead frame Ediff 0x5643a7425888>)
| | 3 -> (set-frame-parameter #<dead frame Ediff 0x5643a7425888> dnd-root-window-position nil)
| | 3 <- set-frame-parameter: !non-local\ exit!
| 2 <- x-dnd-after-move-frame: !non-local\ exit!
1 <- handle-move-frame: !non-local\ exit!

---

In GNU Emacs 29.0.90 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.20, cairo version 1.16.0) of 2023-05-05 built on omega
Repository revision: 21ec6c1d5cc7b6e1858f21de62a593e25d205383
Repository branch: emacs-29
Windowing system distributor 'The X.Org Foundation', version 11.0.12013000
System Description: Ubuntu 20.04.6 LTS

Configured using:
 'configure --with-modules --with-imagemagick --without-tree-sitter'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ
IMAGEMAGICK JPEG JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2
M17N_FLT MODULES NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3
THREADS TIFF TOOLKIT_SCROLL_BARS WEBP X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB

Important settings:
  value of $LC_COLLATE: C.UTF-8
  value of $LC_MONETARY: de_DE.UTF-8
  value of $LC_NUMERIC: de_DE.UTF-8
  value of $LC_TIME: de_DE.UTF-8
  value of $LANG: C.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Messages

Minor modes in effect:
  tooltip-mode: t
  global-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
  buffer-read-only: 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 mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils time-date subr-x vc
ediff-vers ediff ediff-merg ediff-mult ediff-wind ediff-diff ediff-help
ediff-init ediff-util vc-git diff-mode easy-mmode cl-loaddefs cl-lib
vc-dispatcher vc-svn bug-reference byte-opt gv bytecomp byte-compile rmc
iso-transl tooltip cconv eldoc paren electric uniquify ediff-hook
vc-hooks lisp-float-type elisp-mode mwheel term/x-win x-win
term/common-win x-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 lcms2 dynamic-setting system-font-setting
font-render-setting cairo move-toolbar gtk x-toolkit xinput2 x multi-tty
make-network-process emacs)

Memory information:
((conses 16 58114 7770)
 (symbols 48 7445 0)
 (strings 32 20878 2062)
 (string-bytes 1 638147)
 (vectors 16 14015)
 (vector-slots 8 199200 12038)
 (floats 8 45 80)
 (intervals 56 467 0)
 (buffers 976 13))