wrong-type-argument on mouse-set-font with xf.el

[Robert Marshall]

In GNU Emacs 21.3.50.4 (i686-pc-linux-gnu, GTK+ Version 2.2.4)
 of 2004-05-17 on jailhouse.chezmarshall.freeserve.co.uk
configured using `configure '--with-x-toolkit=gtk''

Important settings:
  value of $LC_ALL: address@hidden
  value of $LC_COLLATE: en_GB
  value of $LC_CTYPE: en_GB
  value of $LC_MESSAGES: en_GB
  value of $LC_MONETARY: en_GB
  value of $LC_NUMERIC: en_GB
  value of $LC_TIME: en_GB
  value of $LANG: en_GB
  locale-coding-system: iso-latin-9
  default-enable-multibyte-characters: t

For many years I've used the xf.el library to supplement the list of
available fonts on a mouse-set-font menu, with a recent cvs build I get
an error

: (wrong-type-argument consp nil)
  x-popup-menu((S-down-mouse-1 (#<window 8 on xf.el> 8408 
  (344 . 188) 4108313 nil 8408 (31 . 12) nil (164 . 8) (9 . 15))) 
  expanded-x-fixed-font-list-snipped )

where expanded-x-fixed-font-list-snipped is a replacement for the actual
list

emacs -q --no-init-file

(load-library "xf")
(xf-load-fonts)

(xf is at
http://groups.google.com/groups?selm=1994Oct31.153058.5119%40fuw.edu.pl&output=gplain
)

Maybe xf.el's time has passed but I thought I'd report it - and it did work
until my recent build!

Robert