`set-default-font' does not function anymore

[Zhang Wei]

`set-default-font' does not function anymore, I've got the following
settings in my .emacs:

(create-fontset-from-fontset-spec
 (concat
  "-*-courier-medium-r-normal-*-14-*-*-*-*-*-fontset-courier,"
  "chinese-gb2312:-*-simsun-medium-r-*-*-14-*-*-*-c-*-gb2312*-*,"
  "mule-unicode-0100-24ff:-*-simsun-medium-r-*-*-14-*-*-*-c-*-iso10646*-*,"
  "korean-ksc5601:-*-*-medium-r-*-*-14-*-*-*-*-*-ksc5601*-*,"
  "chinese-cns11643-5:-*-simsun-medium-r-*-*-14-*-*-*-c-*-gbk*-*,"
  "chinese-cns11643-6:-*-simsun-medium-r-*-*-14-*-*-*-c-*-gbk*-*,"
  "chinese-cns11643-7:-*-simsun-medium-r-*-*-14-*-*-*-c-*-gbk*-*,"
  "sjis:-*-medium-r-normal--14-*-jisx0208*-*"))
(set-default-font "fontset-courier")

but M-x describe-fontset <RET> <RET> shows the current frame still
using `fontset-default', I don't know when does this happens, but the
setting works fine several weeks ago.

Same problem with Emacs 22 and the emacs-unicode-2 branch.