bug#43147: 27.1; Widget text seems to disappear when building with Cairo and Xaw

[Pouar Dragon]

widgets when building with Xaw and Cairo seem to have missing text,
looking like this

ss.png
Description: screenshot

problem seems to go away when 5f4e8e2e088de9fb76cb631077c6eddd3219f594
is reverted


In GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo version 
1.17.3, Xaw3d scroll bars)
 of 2020-08-31 built on PouarArch
Repository revision: 86d8d76aa36037184db0b2897c434cdaab1a9ae8
Repository branch: makepkg
Windowing system distributor 'The X.Org Foundation', version 11.0.12008000
System Description: Arch Linux

Recent messages:
Checking 87 files in /usr/share/emacs/27.1/lisp/calc...
Checking 113 files in /usr/share/emacs/27.1/lisp/obsolete...
Checking for load-path shadows...done
You can run the command ‘report-emacs-bug’ with M-x r-em RET
Checking for load-path shadows...done
Mark set
Beginning of buffer
Undo [3 times]
C-? is undefined [3 times]
Redo [2 times]

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --with-x-toolkit=lucid --with-xft --with-modules
 --with-imagemagick --with-mailutils --with-cairo --with-rsvg'

Configured features:
XAW3D XPM JPEG TIFF GIF PNG RSVG CAIRO IMAGEMAGICK SOUND GPM DBUS
GSETTINGS GLIB NOTIFY INOTIFY ACL GNUTLS LIBXML2 FREETYPE HARFBUZZ
M17N_FLT LIBOTF ZLIB TOOLKIT_SCROLL_BARS LUCID X11 XDBE XIM MODULES
THREADS LIBSYSTEMD JSON PDUMPER LCMS2 GMP

Important settings:
  value of $LC_COLLATE: C
  value of $LC_MONETARY: en_US.UTF-8
  value of $LC_NUMERIC: en_US.UTF-8
  value of $LC_TIME: en_US.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=fcitx
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-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
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(help-mode pp shadow sort mail-extr emacsbug message rmc puny dired
dired-loaddefs format-spec rfc822 mml easymenu mml-sec password-cache
epa derived epg epg-config gnus-util rmail rmail-loaddefs
text-property-search seq byte-opt gv bytecomp byte-compile cconv
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 cl-loaddefs cl-lib tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type 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 elisp-mode lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu 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 charscript charprop case-table epa-hook
jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads dbusbind inotify lcms2 dynamic-setting
system-font-setting font-render-setting cairo x-toolkit x multi-tty
make-network-process emacs)

Memory information:
((conses 16 50575 12154)
 (symbols 48 6210 1)
 (strings 32 16997 2285)
 (string-bytes 1 537126)
 (vectors 16 11058)
 (vector-slots 8 141008 18188)
 (floats 8 25 34)
 (intervals 56 309 88)
 (buffers 1000 14))