bug#52709: 29.0.50; Font-lock trying to use keywords before setting them up

[martin rudalics]

When trying to ediff a C file or find occurrences in it on master I
frequently get this error.  A typical backtrace looks like


Debugger entered--Lisp error: (error "Font-lock trying to use keywords before 
setting them up")
  signal(error ("Font-lock trying to use keywords before setting them up"))
  error("Font-lock trying to use keywords before setting them up")
  font-lock-compile-keywords(nil)
  font-lock-fontify-keywords-region(1 112 nil)
  font-lock-default-fontify-region(1523 1532 nil)
  c-font-lock-fontify-region(1523 1532)
  c-force-redisplay(1523 1532)
  apply(c-force-redisplay (1523 1532))
  timer-event-handler([t 25023 28385 699506 nil c-force-redisplay (1523 1532) 
nil 18000 nil])


I don't know what C mode is trying to do here but I just want to turn
this timer off.  Apparently, this is not possible without substantial
surgery in the cc-files so for the moment I simply use the Emacs 28
version of these files.  Doing normal work with C files is currently
impossible with master here.

martin


In GNU Emacs 29.0.50 (build 6, x86_64-pc-linux-gnu, GTK+ Version 3.24.5, cairo 
version 1.16.0)
 of 2021-12-19 built on restno
Repository revision: 8f82a83caec9ad48a6d4abc4dc26bed67f0e89e3
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
System Description: Debian GNU/Linux 10 (buster)

Configured using:
 'configure --with-gif=ifavailable --with-tiff=ifavailable
 --with-gnutls=no --without-pop 'CFLAGS=-O3 -no-pie''

Configured features:
CAIRO DBUS FREETYPE GIF GLIB GSETTINGS HARFBUZZ JPEG LIBSELINUX MODULES
NOTIFY INOTIFY PDUMPER PNG SECCOMP SOUND THREADS TOOLKIT_SCROLL_BARS X11
XDBE XIM XPM GTK3 ZLIB

Important settings:
  value of $LANG: de_AT.utf8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Text

Minor modes in effect:
  pop-up-mini-mode: t
  shell-dirtrack-mode: t
  scroll-restore-mode: t
  tooltip-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  context-menu-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  minibuffer-regexp-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  temp-buffer-resize-mode: t
  column-number-mode: t
  line-number-mode: t
  auto-fill-function: do-auto-fill
  indent-tabs-mode: t
  transient-mark-mode: t

Load-path shadows:
/home/martin/emacs-git/trunk/lisp/emacs-lisp/eieio-compat hides 
/home/martin/emacs-git/trunk/lisp/obsolete/eieio-compat

Features:
(shadow mail-extr warnings emacsbug message mailcap yank-media rmc puny
rfc822 mml mml-sec password-cache epa derived 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 time-date thingatpt speck pop-up-mini vc cc-mode
cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars
cc-defs vc-git vc-dispatcher bug-reference elp vc-hg diff-mode
ediff-vers ediff ediff-merg ediff-mult ediff-wind ediff-diff ediff-help
ediff-init ediff-util local-tags info-look find-func elinfo-support
elinfo texinfo texinfo-loaddefs info shell pcomplete comint ansi-color
ring sidebar bookmark seq subr-x byte-opt bytecomp byte-compile cconv
text-property-search sort m&d scroll-restore regexp-lock time-stamp
eldoc-tooltip pcase easy-mmode find-dired dired dired-loaddefs cus-edit
pp cus-load wid-edit cl-loaddefs cl-lib jka-compr ls-lisp gv 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 move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 335299 40229)
 (symbols 48 14392 3)
 (strings 32 42429 3606)
 (string-bytes 1 1468638)
 (vectors 16 22758)
 (vector-slots 8 305409 30979)
 (floats 8 115 273)
 (intervals 56 33754 1489)
 (buffers 992 40))