bug#11264: 23.4; shell-script-mode highlighting (coloring) bugs for bash and zsh

[Vincent Lefevre]

shell-script-mode has the following highlighting (coloring) bugs
in the bash and zsh minor modes:

* In "if [[ ... ]] then", the "then" keyword is not highlighted for
  bash and zsh.

* In "[[ x == x ]]", the first x is incorrectly highlighted for zsh.

This is also reported for Debian here:

  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=335712


In GNU Emacs 23.4.1 (x86_64-pc-linux-gnu, GTK+ Version 2.24.10)
 of 2012-04-07 on trouble, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.11104000
configured using `configure  '--build' 'x86_64-linux-gnu' '--build' 
'x86_64-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/23.4/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.4/site-lisp:/usr/share/emacs/site-lisp'
 '--with-crt-dir=/usr/lib/x86_64-linux-gnu' '--with-x=yes' 
'--with-x-toolkit=gtk' '--with-toolkit-scroll-bars' 
'build_alias=x86_64-linux-gnu' 'CFLAGS=-g -O2 -fstack-protector 
--param=ssp-buffer-size=4 -Wformat -Wformat-security -Werror=format-security 
-Wall -DDEBIAN -O2' 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

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

Major mode: Lisp Interaction

Minor modes in effect:
  display-time-mode: t
  show-paren-mode: t
  tooltip-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
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<escape> x r e p o r t <tab> <return>

Recent messages:
Loading /etc/emacs/site-start.d/50latex-cjk-common.el (source)...done
Loading /etc/emacs/site-start.d/50latex-cjk-thai.el (source)...done
Loading /etc/emacs/site-start.d/50ledger.el (source)...done
Loading /etc/emacs/site-start.d/50psvn.el (source)...done
Loading /etc/emacs/site-start.d/50rnc-mode.el (source)...done
Loading /etc/emacs/site-start.d/50thailatex.el (source)...done
Loading /etc/emacs/site-start.d/50w3m-el.el (source)...done
Loading /home/vlefevre/share/emacs/site-lisp/mutteditor.el (source)...done
Loading time...done
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
/usr/share/emacs23/site-lisp/css-mode/css-mode hides 
/usr/share/emacs/site-lisp/css-mode/css-mode
/usr/share/emacs23/site-lisp/html-helper-mode/tempo hides 
/usr/share/emacs/site-lisp/html-helper-mode/tempo
/usr/share/emacs23/site-lisp/html-helper-mode/visual-basic-mode hides 
/usr/share/emacs/site-lisp/html-helper-mode/visual-basic-mode
/usr/share/emacs23/site-lisp/html-helper-mode/hhm-config hides 
/usr/share/emacs/site-lisp/html-helper-mode/hhm-config
/usr/share/emacs23/site-lisp/html-helper-mode/html-helper-mode hides 
/usr/share/emacs/site-lisp/html-helper-mode/html-helper-mode
/usr/share/emacs/23.4/site-lisp/debian-startup hides 
/usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs/23.4/site-lisp/cmake-data/cmake-mode hides 
/usr/share/emacs/site-lisp/cmake-mode
/usr/share/emacs23/site-lisp/flim/sha1 hides /usr/share/emacs/23.4/lisp/sha1
/usr/share/emacs23/site-lisp/flim/hex-util hides 
/usr/share/emacs/23.4/lisp/hex-util
/usr/share/emacs23/site-lisp/flim/md4 hides /usr/share/emacs/23.4/lisp/md4
/usr/share/emacs23/site-lisp/html-helper-mode/tempo hides 
/usr/share/emacs/23.4/lisp/tempo
/usr/share/emacs23/site-lisp/dictionaries-common/ispell hides 
/usr/share/emacs/23.4/lisp/textmodes/ispell
/usr/share/emacs23/site-lisp/dictionaries-common/flyspell hides 
/usr/share/emacs/23.4/lisp/textmodes/flyspell
/usr/share/emacs23/site-lisp/css-mode/css-mode hides 
/usr/share/emacs/23.4/lisp/textmodes/css-mode
/usr/share/emacs23/site-lisp/flim/hmac-md5 hides 
/usr/share/emacs/23.4/lisp/net/hmac-md5
/usr/share/emacs23/site-lisp/flim/sasl-ntlm hides 
/usr/share/emacs/23.4/lisp/net/sasl-ntlm
/usr/share/emacs23/site-lisp/flim/ntlm hides /usr/share/emacs/23.4/lisp/net/ntlm
/usr/share/emacs23/site-lisp/flim/sasl hides /usr/share/emacs/23.4/lisp/net/sasl
/usr/share/emacs23/site-lisp/flim/sasl-cram hides 
/usr/share/emacs/23.4/lisp/net/sasl-cram
/usr/share/emacs23/site-lisp/flim/sasl-digest hides 
/usr/share/emacs/23.4/lisp/net/sasl-digest
/usr/share/emacs23/site-lisp/flim/hmac-def hides 
/usr/share/emacs/23.4/lisp/net/hmac-def
/usr/share/emacs23/site-lisp/latex-cjk-thai/thai-word hides 
/usr/share/emacs/23.4/lisp/language/thai-word

Features:
(shadow sort mail-extr message sendmail ecomplete rfc822 mml easymenu
mml-sec password-cache mm-decode mm-bodies mm-encode mailcap mail-parse
rfc2231 rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util
netrc time-date mm-util mail-prsvr gmm-utils wid-edit mailheader canlock
sha1 sha1-el hex-util hashcash mail-utils warnings emacsbug time
cus-start cus-load paren cc-styles cc-align cc-engine cc-vars cc-defs
regexp-opt w3m-load tooltip ediff-hook vc-hooks lisp-float-type mwheel
x-win x-dnd font-setting tool-bar dnd fontset image fringe lisp-mode
register page menu-bar rfn-eshadow timer select scroll-bar mldrag 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
loaddefs button minibuffer faces cus-face files text-properties overlay
md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process dbusbind
system-font-setting font-render-setting gtk x-toolkit x multi-tty emacs)