bug#55159: 29.0.50; ruler mode collides with header-line-format

bug#55159: 29.0.50; ruler mode collides with header-line-format

[Jean Louis]

Following does not work as expected:

(progn
  (ruler-mode)
  (setq header-line-format "Instructions"))

And it should -- I am not sure, but I guess that it worked before,
because I have a function that always uses ruler-mode and title.

The header-line should be displayed above the ruler in my opinion. Both
combinations should work regardless if header-line-format comes first or
second. 


In GNU Emacs 29.0.50 (build 5, x86_64-pc-linux-gnu, X toolkit, cairo version 1.17.4, Xaw3d scroll bars)
 of 2022-04-09 built on protected.rcdrun.com
Repository revision: 21ecf6b24d0549a9f27bcab51dbd8c8b1a37ef86
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101003
System Description: Parabola GNU/Linux-libre

Configured using:
 'configure --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 NOTIFY INOTIFY
PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
WEBP X11 XAW3D XDBE XIM XPM LUCID ZLIB

Important settings:
  value of $LC_ALL: en_US.UTF-8
  value of $LANG: de_DE.UTF-8
  value of $XMODIFIERS: @im=exwm-xim
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  ruler-mode: t
  text-scale-mode: t
  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
  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 ispell emacsbug message mailcap yank-media rmc
puny dired dired-loaddefs rfc822 mml mml-sec password-cache epa derived
epg rfc6068 epg-config gnus-util text-property-search time-date seq gv
subr-x byte-opt bytecomp byte-compile cconv mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs
cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
ruler-mode face-remap 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 nadvice simple 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 abbrev obarray cl-preloaded button 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
x multi-tty make-network-process emacs)

Memory information:
((conses 16 51343 7972)
 (symbols 48 6540 1)
 (strings 32 19200 3151)
 (string-bytes 1 592871)
 (vectors 16 11735)
 (vector-slots 8 166865 15012)
 (floats 8 27 33)
 (intervals 56 300 5)
 (buffers 992 12))

-- 
Thanks,
Jean Louis

Take action in Free Software Foundation campaigns:
https://www.fsf.org/campaigns

bug#55159: 29.0.50; ruler mode collides with header-line-format

[Eli Zaretskii]

> From: Jean Louis <bugs@gnu.support>
> Date: Thu, 28 Apr 2022 07:56:48 +0300
> 
> 
> Following does not work as expected:
> 
> (progn
>   (ruler-mode)
>   (setq header-line-format "Instructions"))
> 
> And it should -- I am not sure, but I guess that it worked before,
> because I have a function that always uses ruler-mode and title.

In what version of Emacs was that?

> The header-line should be displayed above the ruler in my opinion. Both
> combinations should work regardless if header-line-format comes first or
> second. 

ruler-mode.el uses the header-line to display the ruler.  It always
did.  So by overwriting header-line-format in a buffer under
ruler-mode you shoot yourself in the foot; don't do that.

I very much doubt that it ever worked for you as you describe, because
ruler-mode.el used header-line since it was first introduced in Emacs
22.1.  From NEWS.22:

  ** The ruler-mode.el library provides a minor mode for displaying an
  "active" ruler in the header line.  You can use the mouse to visually
  change the `fill-column', `window-margins' and `tab-stop-list'
  settings.

So I see no bug here, but a cockpit error.

bug#55159: 29.0.50; ruler mode collides with header-line-format

[Lars Ingebrigtsen]

Eli Zaretskii <eliz@gnu.org> writes:

> So I see no bug here, but a cockpit error.

Same here; so I'm closing this bug report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no