Subject: bug#41124: 26.3; highlight regexp not working properly - not updating as you type

From: jan <[email-masked]>
Date: Thu, 7 May 2020 12:32:27 +0100

Hi all,
I've reported the same thing a few years ago, it got fixed pretty fast
but looks like it reverted again.

First ensure font-lock mode is on. Prefix arg forces it on.

   C-u 1 M-x font-lock-mode

Minibuffer says font lock mode is enabled

type some text to be highlighted:

  peq
  piq

highlight regexp:

  M-s h r  p[aeiou]q

the above 2 get highlighted as expected

now type some matchable text

  paq

this does not get highlighted.
I expected it should and as I've used this functionality extensively
before, I'm pretty sure it used to work this way.

regards

jan

In GNU Emacs 26.3 (build 1, x86_64-w64-mingw32)
 of 2019-08-29 built on CIRROCUMULUS
Repository revision: 96dd0196c28bc36779584e47fffcca433c9309cd
Windowing system distributor 'Microsoft Corp.', version 6.1.7601
Recent messages:
Font-Lock mode enabled in current buffer
Quit [2 times]
byte-code: No highlighting to remove

Quit [6 times]
Auto-saving...
command-execute: Command attempted to use minibuffer while in minibuffer
Quit [2 times]
Type C-x 1 to delete the help window, C-M-v to scroll help.
Mark saved where search started
Quit [2 times]
Configured using:
 'configure --without-dbus --host=x86_64-w64-mingw32
 --without-compress-install 'CFLAGS=-O2 -static -g3''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS THREADS LCMS2

Important settings:
  value of $LANG: ENG
  locale-coding-system: cp1252

Major mode: Text

Minor modes in effect:
  hi-lock-mode: t
  diff-auto-refine-mode: t
  desktop-save-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-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
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
rfc822 mml mml-sec epa derived epg gnus-util rmail rmail-loaddefs
mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils
mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr
mail-utils eieio-opt speedbar sb-image ezimage dframe find-func help-fns
radix-tree thingatpt hi-lock two-column iso-transl misearch
multi-isearch browse-url url-util elec-pair cl-extra help-mode
autorevert filenotify vc-git diff-mode cc-mode cc-fonts cc-guess
cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars cc-defs helm-gtags
subr-x pulse which-func imenu helm-files helm-buffers helm-occur
helm-tags helm-locate helm-grep helm-regexp format-spec helm-utils
helm-help helm-types helm easy-mmode helm-source eieio-compat
helm-multi-match helm-lib async edmacro kmacro desktop frameset
cus-start cus-load finder-inf info package easymenu epg-config
url-handlers url-parse auth-source cl-seq eieio eieio-core cl-macs
eieio-loaddefs password-cache url-vars seq byte-opt gv bytecomp
byte-compile cconv cl-loaddefs cl-lib time-date mule-util tooltip eldoc
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel dos-w32
ls-lisp disp-table term/w32-win w32-win w32-vars term/common-win
tool-bar dnd fontset image regexp-opt fringe tabulated-list replace
newcomment text-mode elisp-mode lisp-mode prog-mode register page
menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock
font-lock syntax facemenu font-core term/tty-colors frame 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 minibuffer
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 w32notify w32
lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 211611 22413)
 (symbols 48 30035 1)
 (miscs 40 188 361)
 (strings 32 64898 3209)
 (string-bytes 1 1974798)
 (vectors 16 28973)
 (vector-slots 8 763801 9572)
 (floats 8 123 316)
 (intervals 56 2575 0)
 (buffers 992 21))