bug#67884: 30.0.50; fido-mode errors when case-fold-search is nil

[parlando]

Hi,

If global case-fold-search is nil, fido-mode throws errors when typing 
upper case letters or on candidates with upper case letters.

Reproduce with: emacs -Q, then:

(fido-mode 1)
(toggle-case-fold-search)

;; then execute:
;; M-x <T or t or another pattern>

Which produces messages like:
> Error in post-command-hook (icomplete-post-command-hook): (error 
"Internal error: \\`\\(.*?\\)T does not match cpp-parse-edit")
> Error in post-command-hook (icomplete-post-command-hook): (error 
"Internal error: \\`\\(.*?\\)t does not match LaTeX-mode")

Many thanks!

--
In GNU Emacs 30.0.50 (build 1, x86_64-w64-mingw32) of 2023-12-18 built
 on <hostname>
Repository revision: 14504fca8b5589c5c80a69dcab6e02681b196fa1
Repository branch: master
Windowing system distributor 'Microsoft Corp.', version 10.0.19045
System Description: Microsoft Windows 10 Pro (v10.0.2009.19045.3803)

Configured using:
 'configure --with-tree-sitter --with-native-compilation=aot 'CFLAGS=-O2
 -gdwarf-4 -g3 -fno-optimize-sibling-calls''

Configured features:
ACL DBUS GIF GMP GNUTLS HARFBUZZ JPEG JSON LCMS2 LIBXML2 MODULES
NATIVE_COMP NOTIFY W32NOTIFY PDUMPER PNG RSVG SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XPM ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: cp1252

Major mode: Messages

Minor modes in effect:
  icomplete-mode: t
  fido-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-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
  minibuffer-regexp-mode: t
  buffer-read-only: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util time-date subr-x mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils cl-print byte-opt gv
thingatpt help-fns radix-tree help-mode compile text-property-search
comint ansi-osc ansi-color ring comp-run bytecomp byte-compile
comp-common rx cus-start cus-load icomplete cl-loaddefs cl-lib rmc
iso-transl tooltip cconv eldoc paren electric uniquify ediff-hook
vc-hooks lisp-float-type elisp-mode 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 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
theme-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 w32notify dbusbind w32 lcms2
multi-tty move-toolbar make-network-process native-compile emacs)

Memory information:
((conses 16 92115 20642) (symbols 48 8077 0) (strings 32 24764 1710)
 (string-bytes 1 674338) (vectors 16 15840)
 (vector-slots 8 336906 18454) (floats 8 33 11936)
 (intervals 56 299 17) (buffers 992 14))