bug#57264: 29.0.50; Wrong xcursor colour when over an Emacs frame

[Visuwesh]

When the mouse pointer is over an Emacs frame, the xcursor has the wrong
colour; this is not observed with other Xorg apps like okular,
libreoffice, ungoogled-chromium.

Emacs has no problem with the default Xorg cursor theme---it is black as
expected---but this happens when I use the xcursor theme from below.

To reproduce,

    1. Download and install the cursor theme from
       https://π.duncano.de/files/xcursor-plan9-0.2.tar.xz
    2. Launch emacs -Q as `XCURSOR_THEME=plan9 emacs -Q'.
    3. Move the cursor over the Emacs frame into a void area and observe
       the left pointer colour.  It is white here.
    4. Now repeat the same but for another application, the left pointer
       colour is black as expected.

Changing the mouse face's :background does not help.  It changes the
border colour.  If it gives any clue, I also see this problem with st.

Thanks.


In GNU Emacs 29.0.50 (build 2, x86_64-pc-linux-gnu, X toolkit, Xaw scroll bars)
 of 2022-08-15 built on astatine
Repository revision: d5ee49c25c8f59ab17c40eebdf38a769c2f5588b
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101003
System Description: Debian GNU/Linux bookworm/sid

Configured using:
 'configure --with-sound=alsa --with-x-toolkit=lucid --with-json
 --without-xaw3d --without-gconf --without-libsystemd --without-cairo'
Configured features:
ACL DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG JSON
LIBOTF LIBSELINUX LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG RSVG
SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS WEBP X11 XDBE XFT
XIM XINPUT2 XPM LUCID ZLIB
Important settings:
  value of $LC_MONETARY: ta_IN.UTF-8
  value of $LC_NUMERIC: ta_IN.UTF-8
  value of $LANG: en_GB.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  shell-dirtrack-mode: t
  paredit-mode: t
  eros-mode: t
  flymake-mode: t
  pdf-occur-global-minor-mode: t
  minibuffer-depth-indicate-mode: t
  repeat-mode: t
  display-time-mode: t
  display-battery-mode: t
  winner-mode: t
  acme-tag-minor-mode: t
  delete-selection-mode: t
  straight-use-package-mode: t
  straight-package-neutering-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  use-hard-newlines: t
  tab-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  undelete-frame-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  abbrev-mode: t

Load-path shadows:
/home/viz/lib/emacs/straight/build/faceup/faceup hides 
/home/viz/lib/ports/emacs/lisp/emacs-lisp/faceup

Features:
(shadow sort flyspell ispell ecomplete mail-extr emacsbug message
yank-media puny rfc822 mml mml-sec epa epg rfc6068 epg-config gnus-util
mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils
mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr
mail-utils sh-script smie executable rfc2104 cursor-sensor tramp-cache
time-stamp tramp-sh tramp tramp-loaddefs trampver tramp-integration
cus-start files-x tramp-compat shell pcomplete parse-time iso8601
ls-lisp face-remap server paredit edmacro kmacro eros time-date checkdoc
lisp-mnt flymake-proc flymake project warnings wordel-autoloads
sokoban-autoloads ement-autoloads svg-lib-autoloads
taxy-magit-section-autoloads magit-section-autoloads dash-autoloads
taxy-autoloads plz-autoloads nov-autoloads esxml-autoloads kv-autoloads
transmission-autoloads lua-mode-autoloads nix-mode-autoloads
racket-mode-autoloads pos-tip-autoloads faceup-autoloads eros-autoloads
flymake-shellcheck-autoloads writegood-mode-autoloads
siege-mode-autoloads paredit-autoloads puni-autoloads
expand-region-autoloads filladapt-autoloads compose quail
scroll-other-window org-pdftools-autoloads org-noter-autoloads
change-env-autoloads math-delimiters-autoloads doct-autoloads
ob-async-autoloads async-autoloads emacs-ob-racket-autoloads
valign-autoloads cdlatex-autoloads auctex-autoloads tex-site pdf-occur
ibuf-ext ibuffer ibuffer-loaddefs tablist advice tablist-filter
semantic/wisent/comp semantic/wisent semantic/wisent/wisent
semantic/util-modes semantic/util semantic semantic/tag semantic/lex
semantic/fw mode-local cedet pdf-isearch let-alist pdf-misc imenu
pdf-tools package browse-url url url-proxy url-privacy url-expand
url-methods url-history url-cookie generate-lisp-file url-domsuf
url-util mailcap url-handlers url-parse auth-source eieio eieio-core
json map byte-opt url-vars compile comint ansi-color cus-edit edebug
debug backtrace find-func icons wid-edit pdf-view password-cache
jka-compr pdf-cache pdf-info tq pdf-util pdf-macs image-mode dired-x
dired dired-loaddefs exif pdf-tools-autoloads tablist-autoloads mb-depth
repeat visual-fill-autoloads olivetti-autoloads time format-spec battery
dbus filenotify xml dom disp-table lacarte-autoloads winner ring
acme-tag shell-command+ thingatpt diff acme-tag-autoloads
shell-command-plus-autoloads delsel cus-load easy-mmode avy-autoloads
finder-inf vc-backup-autoloads compat-autoloads icalendar diary-lib
diary-loaddefs cal-menu calendar cal-loaddefs rx filecache
imenu-xref-autoloads derived chemtable-autoloads molar-mass-autoloads
saveplace-pdf-view saveplace bookmark text-property-search pp
saveplace-pdf-view-autoloads pcase inspector-autoloads xr-autoloads
straight-autoloads cl-seq info cl-extra help-mode straight subr-x
cl-macs gv cl-loaddefs cl-lib bytecomp byte-compile cconv vz-nh-theme
vz-options-theme 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
x-toolkit xinput2 x multi-tty make-network-process emacs)

Memory information:
((conses 16 259854 135375) (symbols ?0 21282 3) (strings 32 102062 4733) 
(string-bytes 1 5042599) (vectors 16 38577) (vector-slots 8 476859 93215)
 (floats 8
         168 498) (intervals ?8 605 151) (buffers 992 22))