bug#5108: 23.1; ps-print-buffer infinite loop on image-mode

[Kevin Ryde]

A ps-print-buffer on some image files in image-mode goes into an
infinite loop.  For example "cut.xpm" in the current emacs cvs,

    (progn
      (switch-to-buffer "x")
      (erase-buffer)
      (insert-file-contents (concat data-directory "images/cut.xpm"))
      (image-mode)
      (ps-print-buffer "/tmp/foo.ps"))

shows message

    Formatting...  0%

and then goes away apparently forever.

debug-on-quit says the loop is ps-mule-plot-string.  It seems (point)
has gone past the intended `stop' position, so "(= (point) stop)" is not
satisfied, or something like that.  Might be the forward-char under
"(looking-at ascii-or-latin-1)" going too far, maybe something to do
with the image overlay, or point movement within image mode ...

(What I actually hoped for was that it might print the image, but
perhaps it doesn't print images at all ...)



In GNU Emacs 23.1.1 (i486-pc-linux-gnu, GTK+ Version 2.16.5)
 of 2009-09-14 on raven, modified by Debian
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_AU
  value of $XMODIFIERS: nil
  locale-coding-system: iso-latin-1-unix
  default-enable-multibyte-characters: t