bug#12770: 24.2.1; sh-mode parsing - bitwise leftshift misinterpreted as here-document inside arithmetic expansion $(( ))

[John Schoenick <johns@mozilla.com>]

The following, in a sh-mode buffer of shell-type bash:

echo -n $(( 5 << 2 ))

Will result in the remainder of the document being mis-interpreted as a 
here-document and mis-highlighted until a line containing a single 2 is 
encountered.

The equivalent:

let "r = 5 << 2"
echo -n $r

Is handled properly.

- John

In GNU Emacs 24.2.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.4.4)
  of 2012-08-28 on shaun
Windowing system distributor `The X.Org Foundation', version 11.0.11300000
Configured using:
  `configure '--prefix=/usr' '--sysconfdir=/etc' '--libexecdir=/usr/lib'
  '--localstatedir=/var' '--with-x-toolkit=gtk3' '--with-xft'
  'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector
  --param=ssp-buffer-size=4 -D_FORTIFY_SOURCE=2'
  'LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro''

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: Shell-script

Minor modes in effect:
   global-auto-complete-mode: t
   auto-complete-mode: t
   global-linum-mode: t
   linum-mode: t
   global-hl-line-mode: t
   shell-dirtrack-mode: t
   iswitchb-mode: t
   global-auto-revert-mode: t
   tooltip-mode: t
   mouse-wheel-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   line-number-mode: t
   transient-mark-mode: t

Features:
(shadow sort mail-extr emacsbug message idna rfc822 mml mml-sec
mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils
mailheader apropos skeleton sh-script executable help-mode view misearch
multi-isearch re-builder rect js json imenu thingatpt newcomment cc-mode
cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars
cc-defs sgml-mode vc-git server auto-complete-clang auto-complete-config
auto-complete popup multi-term warnings term disp-table ehelp electric
linum color-theme wid-edit cl sendmail rfc2047 rfc2045 ietf-drums
mail-utils reporter hl-line tramp tramp-compat auth-source eieio
byte-opt bytecomp byte-compile cconv macroexp gnus-util mm-util
mail-prsvr password-cache shell pcomplete comint ansi-color ring
format-spec advice help-fns advice-preload tramp-loaddefs regexp-opt
iswitchb fill-column-indicator easy-mmode edmacro kmacro speedbar
sb-image ezimage dframe easymenu assoc ido time-date autorevert tooltip
ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd
fontset image fringe lisp-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 loaddefs button faces cus-face files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
dbusbind dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty emacs)