bug#57320: 29.0.50; Lucid menus can't be operated with the mouse

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

Menus stopped working recently when operated with the mouse.
What works:

- I can click on the menu bar, and that brings down the corresponding
  menu.
- I can use the arrow keys and the RET key to move in the menus and
  select a particular entry.
- I can move the mouse to select another menu.

What doesn't:

- The menu entries are not highlighted as I move the mouse over
  them, and submenus don't popup as I move the mouse over them.
- If I mouse-click on an entry in a menu, the menu is not removed and
  the corresponding command is not run.  Instead I get my window
  manager's "root menu" (i.e. the menu I get when I click in the
  background) popup on top of the Lucid menu.
  Same happens if I click on a menu entry which is a submenu.

The behavior is basically the same for popup menus, except that in popup
menus the submenus do popup as I move the mouse over them and if I click
on an entry which is a submenu the menu is popped down.


        Stefan



In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo version 1.16.0, Xaw3d scroll bars)
 of 2022-08-20 built on pastel
Repository revision: 07c04da01016cd81e064a06b2449892eff7c8da0
Repository branch: main
Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
System Description: Debian GNU/Linux 11 (bullseye)

Configured using:
 'configure -C --enable-checking --enable-check-lisp-object-type
 --with-modules --with-cairo --with-tiff=ifavailable
 --with-native-compilation 'CFLAGS=-Wall -g3 -Og -Wno-pointer-sign'
 PKG_CONFIG_PATH=/home/monnier/lib/pkgconfig'

Configured features:
CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
LIBSELINUX LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG
SECCOMP SOUND THREADS TOOLKIT_SCROLL_BARS X11 XAW3D XDBE XIM XINPUT2 XPM
LUCID ZLIB

Important settings:
  value of $LANG: fr_CH.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 sendmail
rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils comp comp-cstr
warnings icons subr-x rx cl-seq cl-macs gv cl-extra help-mode
cl-loaddefs cl-lib bytecomp byte-compile cconv rmc iso-transl tooltip
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
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 x-toolkit
xinput2 x multi-tty make-network-process native-compile emacs)

Memory information:
((conses 16 70864 9520)
 (symbols 48 7085 0)
 (strings 32 22150 3115)
 (string-bytes 1 729575)
 (vectors 16 17487)
 (vector-slots 8 252019 14476)
 (floats 8 31 35)
 (intervals 56 239 0)
 (buffers 992 11))