bug#72063: matlab-mode-for-new-mfiles not working

[Muhali via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

In matlab-mode, I have set matlab-mode-for-new-mfiles to nil, which means that when opening a .m file matlab-mode will not be automatically invoked.

This does not work, however, as .m files always open in matlab-mode.



In GNU Emacs 29.1 (build 2, x86_64-pc-linux-gnu, X toolkit, cairo
  version 1.18.0) of 2023-11-03 built on capella
Windowing system distributor 'The X.Org Foundation', version 11.0.12401000
System Description: Manjaro Linux

Configured using:
  'configure --prefix=/opt/emacs --with-native-compilation
  --without-toolkit-scroll-bars --with-x-toolkit=lucid'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSYSTEMD LIBXML2 M17N_FLT MODULES NATIVE_COMP NOTIFY
INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TREE_SITTER
WEBP X11 XDBE XIM XINPUT2 XPM LUCID ZLIB

Important settings:
   value of $LC_MONETARY: de_DE.UTF-8
   value of $LC_NUMERIC: de_DE.UTF-8
   value of $LC_TIME: de_DE.UTF-8
   value of $LANG: en_US.UTF-8
   locale-coding-system: utf-8-unix

Major mode: ELisp/d

Minor modes in effect:
   whole-line-or-region-global-mode: t
   whole-line-or-region-local-mode: t
   recentf-mode: t
   savehist-mode: t
   server-mode: t
   image-diredx-async-mode: t
   tooltip-mode: t
   show-paren-mode: t
   mouse-wheel-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   column-number-mode: 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 yank-media puny rfc822 mml
mml-sec gnus-util text-property-search mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils vc-hg vc-bzr vc-src
vc-sccs vc-svn vc-cvs vc-rcs log-view pcvs-util vc bug-reference
time-date find-func pp cl-print help-fns radix-tree misearch
multi-isearch bs vc-git diff-mode easy-mmode vc-dispatcher matlab
matlab-scan matlab-syntax matlab-compat pulse color comp comp-cstr
warnings icons rx cl-extra help-mode whole-line-or-region tab-line
cus-load ac-octave octave smie comint ansi-osc ansi-color ring
caffe-mode recentf tree-widget wid-edit savehist server epa-file epa
derived epg rfc6068 epg-config auto-complete edmacro kmacro popup
auto-complete-autoloads auto-package-update-autoloads csv-mode-autoloads
dbc-autoloads ht-autoloads image-dired+ image-dired image-dired-tags
image-dired-external image-dired-util xdg image-mode exif dired
dired-loaddefs advice list-unicode-display-autoloads magit-autoloads
pcase git-commit-autoloads magit-section-autoloads dash-autoloads
markdown-mode-autoloads matlab-mode-autoloads popup-autoloads
list-utils-autoloads transient-autoloads with-editor-autoloads info
compat-autoloads seq-autoloads package browse-url url url-proxy
url-privacy url-expand url-methods url-history url-cookie
generate-lisp-file url-domsuf url-util mailcap url-handlers url-parse
auth-source cl-seq eieio eieio-core cl-macs password-cache json subr-x
map byte-opt gv bytecomp byte-compile url-vars cl-loaddefs cl-lib rmc
iso-transl tooltip cconv 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 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 dbusbind inotify lcms2 dynamic-setting system-font-setting
font-render-setting cairo x-toolkit xinput2 x multi-tty
make-network-process native-compile emacs)

Memory information:
((conses 16 238820 10941)
  (symbols 48 15874 0)
  (strings 32 84684 3387)
  (string-bytes 1 2062703)
  (vectors 16 28494)
  (vector-slots 8 544009 15910)
  (floats 8 153 42)
  (intervals 56 5988 1042)
  (buffers 984 20))