bug#576: 23.0.60; displaying SVG leaks memory

[Markus Triska]

The following form makes Emacs use increasingly more memory:

   (progn
     (find-file "~/emacs/etc/images/splash.svg")
     (while t
       (image-toggle-display)
       (redisplay)))

Memory use remains bounded if I instead use e.g. ".../splash8.xpm".

In GNU Emacs 23.0.60.2 (i386-apple-darwin8.11.1, GTK+ Version 2.12.9)
 of 2008-07-17 on mt-computer.local
Windowing system distributor `The XFree86 Project, Inc', version 11.0.40400000
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: nil
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default-enable-multibyte-characters: t