bug#2180: 23.0.90; ns: M-x customize-group ns failure

Starting emacs with

nextstep/Emacs.app/Contents/MacOS/Emacs -Q

and evaluating

M-x customize-group RET ns RET

fails with the message

widget-apply: Wrong type argument: char-or-string-p, nil

and a partially-built *Customize Group: Ns* buffer.


In GNU Emacs 23.0.90.2 (i386-apple-darwin9.6.0, NS apple-appkit-949.43)
  of 2009-02-03 on nb164.iist.unu.edu
Windowing system distributor `Apple', version 10.3.949
configured using `configure  '--with-ns''

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: de_AT.UTF-8
   value of $XMODIFIERS: nil
   locale-coding-system: utf-8-unix
   default-enable-multibyte-characters: t

Major mode: Custom

Minor modes in effect:
   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
   global-auto-composition-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   line-number-mode: t
   transient-mark-mode: t

Recent input:
s-x <escape> x c u s t o m i z e - g r o u p <return>
n s <return> <escape> x r e p o r t - <tab> <retur
n>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
kill-region: The mark is not set now, so there is no region
Creating customization items...
widget-apply: Wrong type argument: char-or-string-p, nil