bug#43032: 28.0.50; hs-minor-mode broken since commit a415179b56

[Pierre Téchoueyres]

Step to reproduce :
emacs -Q
type the following text into *scratch* buffer

(progn
 (hs-minor-mode 1)
 (hs-hide-all))

evaluate the s-expression (C-x C-e)

Expected result: buffer should look like bellow.
;; This buffer is for text that is not saved, and for Lisp 
  evaluation....

(progn...))

Actually the buffer doesn't change.


I've tracked the regression up to comit a415179b56:
commit a415179b56f022f50138f55d231070e3d1b00697
Author: Tobias Zawada <i_inbox@tn-home.de>

   Make hs-special-modes-alist also work for modes derived from 
   those modes
   
   * lisp/progmodes/hideshow.el (hs-grok-mode-type): Also set up
   hideshow variables based on hs-special-modes-alist in derived
   modes (bug#39354).

The interresting part is:
--- a/lisp/progmodes/hideshow.el
+++ b/lisp/progmodes/hideshow.el
@@ -225,6 +225,8 @@
;;---------------------------------------------------------------------------
;; user-configurable variables

+(require 'cl-lib)
+
(defgroup hideshow nil
  "Minor mode for hiding and showing program and comment blocks."
  :prefix "hs-"
@@ -652,7 +654,9 @@ hs-grok-mode-type
function; and adjust-block-beginning function."
  (if (and (bound-and-true-p comment-start)
           (bound-and-true-p comment-end))
-      (let* ((lookup (assoc major-mode hs-special-modes-alist))
+      (let* ((lookup (cl-assoc-if (lambda (mode)
+                                   (derived-mode-p major-mode 
mode))
+                                 hs-special-modes-alist))
             (start-elem (or (nth 1 lookup) "\\s(")))
        (if (listp start-elem)
            ;; handle (START-REGEXP MDATA-SELECT)

But for now I don't know how to fix this.


Configured using:
'configure --prefix=/usr/local --with-xwidgets --with-modules
--host=x86_64-fc32-linux-gnu --with-mailutils
host_alias=x86_64-fc32-linux-gnu'
Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS GLIB 
NOTIFY
INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT 
LIBOTF
ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS 
XWIDGETS
LIBSYSTEMD JSON PDUMPER LCMS2
Important settings:
 value of $LC_COLLATE: C
 value of $LANG: fr_FR.UTF-8
 value of $XMODIFIERS: @im=none
 locale-coding-system: utf-8-unix