bug#6311: 23.1; tabs in many texinfo files

[emacs18]

Many texinfo files in emacs bzr repository have tab characters in them.
Texinfo manual cautions users not to use tabs anywere in any texinfo
file several times.  For example following can be found:

     Caution: Do not use tabs in the lines of an example!  (Or anywhere
     else in Texinfo, except in verbatim environments.)  TeX treats
     tabs as single spaces, and that is not what they look like.  In
     Emacs, you can use `M-x untabify' to convert tabs in a region to
     multiple spaces.

Another section has similar warnings:

   * *Caution:* Last, do not use tab characters in a Texinfo file
     (except in verbatim modes)!  TeX uses variable-width fonts, which
     means that it is impractical at best to define a tab to work in all
     circumstances.  Consequently, TeX treats tabs like single spaces,
     and that is not what they look like in the source.  Furthermore,
     `makeinfo' does nothing special with tabs, and thus a tab
     character in your input file will usually appear differently in the
     output.

     To avoid this problem, Texinfo mode in GNU Emacs inserts multiple
     spaces when you press the <TAB> key.  Also, you can run `untabify'
     in Emacs to convert tabs in a region to multiple spaces, or use
     the `unexpand' command from the shell.

However emacs itself has tab character in many files as can be seen by
the following 'find' command output whee the character between the
single quote is a tab character.  Shouldn't someone do `M-x untabify'
on all these files?

$ find . -name '*.texi' -exec grep -l ' ' {} \;
./doc/emacs/mule.texi
./doc/emacs/text.texi
./doc/emacs/emacs.texi
./doc/emacs/dired.texi
./doc/emacs/emerge-xtra.texi
./doc/emacs/vc1-xtra.texi
./doc/emacs/display.texi
./doc/emacs/sending.texi
./doc/emacs/fortran-xtra.texi
./doc/emacs/custom.texi
./doc/emacs/buffers.texi
./doc/emacs/basic.texi
./doc/emacs/building.texi
./doc/emacs/msdog.texi
./doc/emacs/help.texi
./doc/emacs/rmail.texi
./doc/emacs/calendar.texi
./doc/emacs/xresources.texi
./doc/emacs/programs.texi
./doc/emacs/search.texi
./doc/emacs/frames.texi
./doc/emacs/misc.texi
./doc/emacs/files.texi
./doc/emacs/trouble.texi
./doc/emacs/mark.texi
./doc/emacs/killing.texi
./doc/emacs/maintaining.texi
./doc/emacs/screen.texi
./doc/emacs/mini.texi
./doc/emacs/abbrevs.texi
./doc/lispref/text.texi
./doc/lispref/vol1.texi
./doc/lispref/display.texi
./doc/lispref/os.texi
./doc/lispref/elisp.texi
./doc/lispref/tips.texi
./doc/lispref/loading.texi
./doc/lispref/windows.texi
./doc/lispref/debugging.texi
./doc/lispref/vol2.texi
./doc/lispref/edebug.texi
./doc/lispref/functions.texi
./doc/lispref/keymaps.texi
./doc/lispref/internals.texi
./doc/lispref/sequences.texi
./doc/lispref/compile.texi
./doc/lispref/frames.texi
./doc/lispref/numbers.texi
./doc/lispref/processes.texi
./doc/lispref/commands.texi
./doc/lispref/files.texi
./doc/lispref/minibuf.texi
./doc/lispref/eval.texi
./doc/lispref/syntax.texi
./doc/lispref/strings.texi
./doc/lispref/searching.texi
./doc/lispref/abbrevs.texi
./doc/misc/ebrowse.texi
./doc/misc/forms.texi
./doc/misc/smtpmail.texi
./doc/misc/cl.texi
./doc/misc/pgg.texi
./doc/misc/sasl.texi
./doc/misc/viper.texi
./doc/misc/dired-x.texi
./doc/misc/sem-user.texi
./doc/misc/sc.texi
./doc/misc/semantic.texi
./doc/misc/gnus-faq.texi
./doc/misc/ede.texi
./doc/misc/sieve.texi
./doc/misc/faq.texi
./doc/misc/org.texi
./doc/misc/vip.texi
./doc/misc/autotype.texi
./doc/misc/pcl-cvs.texi
./doc/misc/reftex.texi
./doc/misc/idlwave.texi
./doc/misc/speedbar.texi
./doc/misc/eieio.texi
./doc/misc/epa.texi
./doc/misc/nxml-mode.texi
./doc/misc/widget.texi
./doc/misc/flymake.texi
./doc/misc/mh-e.texi
./doc/lispintro/emacs-lisp-intro.texi



In GNU Emacs 23.1.1 (i486-pc-linux-gnu, GTK+ Version 2.18.3)
 of 2010-03-25 on palmer, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.10604000
configured using `configure  '--build=i486-linux-gnu' '--host=i486-linux-gnu' 
'--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' 
'--localstatedir=/var/lib' '--infodir=/usr/share/info' 
'--mandir=/usr/share/man' '--with-pop=yes' 
'--enable-locallisppath=/etc/emacs23:/etc/emacs:/usr/local/share/emacs/23.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.1/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.1/leim'
 '--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars' 
'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -g 
-O2' 'LDFLAGS=-g' 'CPPFLAGS=''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Mail

Minor modes in effect:
  diff-auto-refine-mode: t
  shell-dirtrack-mode: t
  which-function-mode: t
  display-time-mode: t
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
C-c c <return> f i n d SPC . SPC - n a m e SPC ' * 
. t e x i ' SPC - e x e c g <backspace> SPC g r e p 
SPC ' C-q i <backspace> C-q TAB ' SPC { } SPC \ ; <return> 
C-p ESC > C-c C-c ESC p C-a ESC C-f ESC C-f ESC C-f 
ESC C-f ESC C-f ESC C-f SPC - l <return> C-p C-p C-a 
C-f C-f ESC RET C-s TAB C-s C-s C-s C-e C-x o C-x 1 
C-u C-p C-u C-u C-u C-p C-p C-f ESC RET C-s TAB C-s 
C-s C-s C-s C-e C-x o C-n C-f ESC RET C-s C-s C-s C-s 
C-s C-v C-s C-s C-s C-s C-s C-s C-s C-s C-s C-s C-s 
C-s C-s C-s C-s C-e C-x o C-n ESC RET C-s C-s C-s C-s 
C-s C-s C-e C-x o C-x 1 ESC v C-p C-p C-p C-p ESC > 
p w d <return> C-SPC C-p C-p C-w ESC v ESC v C-l C-n 
C-n C-n C-n C-n C-n C-n C-n C-n C-n C-n C-e C-o C-n 
C-y C-p C-a C-p $ SPC C-n C-n C-e C-b C-b C-SPC C-a 
C-w C-n C-p C-k C-n C-SPC C-s $ C-b C-w C-p C-p C-p 
C-o C-n C-n C-p C-p C-n ESC > ESC w C-x m ESC > C-y 
C-x C-x C-g ESC > C-b C-b C-SPC C-a C-w C-k ESC v C-p 
C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p 
C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p 
C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p C-p 
C-p C-p ESC > ESC w ESC x r e p o r t - SPC <retur
n>

Recent messages:
$ "
Mark set [2 times]
Quit
Mark set [3 times]
Saved text from "
$ pwd
/usr/local/src/emacs-bzr/trunk

$"
Auto-saving...