bug#53960: 29.0.50; describe-face: cannot use the mouse to select candidate from *Completions* buffer

[Visuwesh]

There are two problems:

    1. The candidate does not have the mouse-face, it is the "SAMPLE" text
    that does.
    2. Pressing mouse-1 when the SAMPLE is highlighted inserts "SAMPLE"
    in the minibuffer instead of the face name.

Steps to reproduce:

    1. emacs -Q
    2. M-x describe-face RET
    3. TAB
    4. Hover the mouse over the face-name, notice that it is not
    highlighted.
    5. Hover the mouse over the "SAMPLE" text, notice that it is
    highlighted but pressing mouse-1 prepends "SAMPLE" to the minibuffer
    instead.


In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo version 
1.16.0, Xaw scroll bars)
Repository revision: 58bb9eb4005599155a8fce8d5c5beb531a72c534
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12013000
System Description: NixOS 21.11 (Porcupine)

Configured using:
 'configure
 --prefix=/nix/store/0m0yw7b3zly74ljs3qmkblb780xg03id-emacs-git-20220130.0
 --disable-build-details --with-modules --with-x-toolkit=lucid
 --with-xft --with-cairo --with-native-compilation'

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

Important settings:
  value of $EMACSLOADPATH: 
  value of $EMACSNATIVELOADPATH: 
/nix/store/07cbjwzil3jfhyifj15h60k7yvixzqxs-emacs-packages-deps/share/emacs/native-lisp::
  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: Group

Minor modes in effect:
  gnus-undo-mode: t
  recentf-mode: t
  eros-mode: t
  pdf-occur-global-minor-mode: t
  minibuffer-depth-indicate-mode: t
  repeat-mode: t
  display-time-mode: t
  display-battery-mode: t
  straight-use-package-mode: t
  straight-package-neutering-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tab-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  indent-tabs-mode: t
  transient-mark-mode: t

Load-path shadows:
/home/viz/.nix-profile/share/emacs/site-lisp/site-start hides 
/nix/store/07cbjwzil3jfhyifj15h60k7yvixzqxs-emacs-packages-deps/share/emacs/site-lisp/site-start
/home/viz/lib/emacs/straight/build/map/map hides 
/nix/store/0m0yw7b3zly74ljs3qmkblb780xg03id-emacs-git-20220130.0/share/emacs/29.0.50/lisp/emacs-lisp/map
/home/viz/lib/emacs/straight/build/let-alist/let-alist hides 
/nix/store/0m0yw7b3zly74ljs3qmkblb780xg03id-emacs-git-20220130.0/share/emacs/29.0.50/lisp/emacs-lisp/let-alist

Features:
(shadow sort gnus-cite flyspell ispell goto-addr ecomplete mail-extr
emacsbug sendmail network-stream nsm nndraft nnmh nnmaildir nnagent nnml
nnnil gnus-agent gnus-srvr gnus-score score-mode nnvirtual gnus-msg
gnus-art mm-uu mml2015 mm-view mml-smime smime dig nntp gnus-cache
gnus-sum shr pixel-fill kinsoku svg dom gnus-group gnus-undo gnus-start
gnus-dbus gnus-cloud nnimap nnmail mail-source utf7 netrc nnoo
parse-time iso8601 gnus-spec gnus-int gnus-range message yank-media rmc
puny rfc822 mml mml-sec epa epg rfc6068 epg-config mm-decode mm-bodies
mm-encode mailabbrev gmm-utils mailheader gnus-win gnus nnheader
gnus-util mail-utils range misearch multi-isearch reveal noutline
outline recentf tree-widget vc-git diff-mode vc-dispatcher icomplete crm
help-fns radix-tree server paredit edmacro kmacro eros time-date
checkdoc lisp-mnt mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums
mail-prsvr flymake-proc flymake project warnings thingatpt hl-todo
writegood-mode-autoloads wordel-autoloads sokoban-autoloads
ement-autoloads ts-autoloads map-autoloads plz-autoloads nov-autoloads
esxml-autoloads kv-autoloads transmission-autoloads lua-mode-autoloads
nix-mode-autoloads magit-section-autoloads dash-autoloads
racket-mode-autoloads eros-autoloads flymake-shellcheck-autoloads avy
avy-autoloads siege-mode-autoloads paredit-autoloads puni-autoloads
expand-region-autoloads filladapt-autoloads compose quail
scroll-other-window org-pdftools-autoloads org-noter-autoloads
math-delimiters-autoloads doct-autoloads ob-async-autoloads
async-autoloads emacs-ob-racket-autoloads valign-autoloads
org-starless-autoloads cdlatex-autoloads auctex-autoloads tex-site
easy-mmode 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 find-func cedet
pdf-isearch let-alist pdf-misc imenu pdf-tools package browse-url url
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url-domsuf url-util mailcap url-handlers url-parse auth-source eieio
eieio-core eieio-loaddefs json map url-vars compile comint ansi-color
ring cus-edit 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 let-alist-autoloads tablist-autoloads derived
mb-depth cus-load repeat visual-fill-autoloads olivetti-autoloads
hl-todo-autoloads time format-spec battery dbus filenotify xml
disp-table lacarte-autoloads shell-command-plus-autoloads rx icalendar
diary-lib diary-loaddefs cal-menu calendar cal-loaddefs
flymake-grammarly-autoloads grammarly-autoloads websocket-autoloads
finder-inf request-autoloads s-autoloads chemtable-autoloads
molar-mass-autoloads saveplace-pdf-view saveplace bookmark
text-property-search pp saveplace-pdf-view-autoloads pcase
straight-autoloads info cl-seq cl-extra help-mode straight cl-macs
cl-loaddefs cl-lib vz-nh-theme seq gv subr-x byte-opt bytecomp
byte-compile cconv 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 cl-generic 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 simple abbrev obarray cl-preloaded nadvice 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
x multi-tty make-network-process native-compile emacs)

Memory information:
((conses 16 339759 20945)
 (symbols 48 25454 4)
 (strings 32 91195 10981)
 (string-bytes 1 3405287)
 (vectors 16 55133)
 (vector-slots 8 1609310 74026)
 (floats 8 376 41)
 (intervals 56 2869 46)
 (buffers 992 27))