bug#18992: 24.4; describe-mode

[Andreas Röhler]

M-x describe-mode RET should report the major-mode.
Currently it tells the value of "mode-name".

Several issues with this:

- Value of mode-name is displayed in current-buffers mode-line allready
- mode-name often will be a quit shortened, as space in mode-line is precious
- don't see a usage of mode-name beyond mode-line
- user will be interested in value of major-mode, which isn't told

See for example from inside a M-x shell RET

M-x describe-mode says: "Shell mode"
while the real major-mode is sh-mode

Thanks all,

Andreas Röhler

In GNU Emacs 24.4.1 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2014-10-24
Windowing system distributor `The X.Org Foundation', version 11.0.11204000
System Description:     Debian GNU/Linux 7.7 (wheezy)

Important settings:
  value of $LANG: de_DE.utf8
  locale-coding-system: utf-8-unix

Major mode: Shell-script

Minor modes in effect:
  sh-electric-here-document-mode: t
  shell-dirtrack-mode: t
  tooltip-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
  transient-mark-mode: t

Recent input:
<help-echo> C-h f d e s c r i b e - m o d e <return>
C-x o C-x 1 <down> <left> <left> <left> <left> <left>
<return> C-x 1 <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<menu-bar> <options> <menu-set-font> C-s m o d e -
n a m e <left> M-x s h e l l <return> C-h v m a j p
r - <backspace> <backspace> <backspace> o r - m o <tab>
<return> C-x C-f <M-backspace> <M-backspace> <M-backspace>
<M-backspace> e i n . s h <return> C-h f <up> <return>
C-d C-g C-h v m a j o r - m o d e <return> s h - m
o d e C-x C-w <return> M-x d e s c r i b e - m o d
e <return> C-x o <down> <down> <down> <down> <down>
<down> <down> <down> <down> <down> C-SPC C-e M-w C-x
o M-x r e p o r t - e m a c s - b u g <return>

Recent messages:
(New file)
Setting up indent for shell type sh
Indentation variables are now local.
Indentation setup for shell type sh
Quit

You can run the command `describe-mode' with C-h m

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils sh-script smie executable pp shell pcomplete
comint ansi-color ring misearch multi-isearch find-func help-mode
easymenu help-fns time-date tooltip electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image
regexp-opt fringe tabulated-list newcomment lisp-mode prog-mode register
page menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock
font-lock syntax facemenu font-core frame cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese hebrew
greek romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process inotify
dynamic-setting x-toolkit x multi-tty emacs)

Memory information:
((conses 8 122385 5181)
 (symbols 24 36505 0)
 (miscs 20 123 292)
 (strings 16 50339 4912)
 (string-bytes 1 680645)
 (vectors 8 11520)
 (vector-slots 4 437709 3282)
 (floats 8 67 468)
 (intervals 28 565 16)
 (buffers 512 16)
 (heap 1024 30852 417))