bug#51855: 29.0.50; outline-cycle-buffer in describe-bindings

[Iñaki Cornejo]

outline-cycle-buffer and outline-hide-other behave unexpectedly in
describe-bindings' help buffer. Once called all headings are collapsed
into one (showing only the first letter of the first heading "K...") and
can't be expanded again through use of outline-cycle-buffer or outline-cycle.
Steps to reproduce:
emacs -Q
M-x describe-bindings in any buffer
M-x outline-cycle-buffer

The message "outline--cycle-state: Before first heading" is displayed on
the first and any subsequent calls to outline-cycle-buffer. Regardless
of where one positions point, the buffer can't be brought back to its
original state except by calling outline-show-all or disabling
outline-minor-mode entirely.

(this new default is awesome by the way, I hope it's implemented in
more help buffers eg. describe-mode)


In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.30, cairo 
version 1.17.4)
 of 2021-11-13 built on heartofgold
Repository revision: 4df334a0f74700e72bfea7817e660605c3f2a2ee
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101001
System Description: Arch Linux

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --mandir=/usr/share/man --with-gameuser=:games
 --with-sound=alsa --with-modules --without-gconf --without-gsettings
 --enable-link-time-optimization --with-native-compilation
 --with-x-toolkit=gtk3 --without-xaw3d --without-compress-install
 '--program-transform-name=s/\([ec]tags\)/\1.emacs/'
 'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions
 -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security
 -fstack-clash-protection -fcf-protection -flto -fuse-linker-plugin'
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM HARFBUZZ JPEG JSON LCMS2
LIBOTF LIBSYSTEMD LIBXML2 M17N_FLT MODULES NATIVE_COMP NOTIFY INOTIFY
PDUMPER PNG RSVG SECCOMP SOUND THREADS TIFF TOOLKIT_SCROLL_BARS WEBP X11
XDBE XIM XPM GTK3 ZLIB

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

Major mode: ELisp/l

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  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
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media rmc puny
dired dired-loaddefs rfc822 mml mml-sec epa derived epg rfc6068
epg-config gnus-util rmail rmail-loaddefs text-property-search time-date
mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils
mailheader smtpmail auth-source cl-seq eieio eieio-core cl-macs
eieio-loaddefs password-cache json map sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils misearch multi-isearch vc-git
diff-mode vc-dispatcher cl-extra seq gv subr-x byte-opt bytecomp
byte-compile cconv noutline outline easy-mmode kmacro facemenu
two-column help-mode cl-loaddefs cl-lib 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
hashtable-print-readable backquote threads dbusbind inotify lcms2
dynamic-setting font-render-setting cairo move-toolbar gtk x-toolkit x
multi-tty make-network-process native-compile emacs)

Memory information:
((conses 16 99420 8410)
 (symbols 48 7774 0)
 (strings 32 24818 2121)
 (string-bytes 1 902923)
 (vectors 16 18756)
 (vector-slots 8 579354 14718)
 (floats 8 38 37)
 (intervals 56 7094 2)
 (buffers 992 13))