bug#5159: 23.1.50; describe-font complains define-button-type: Unknown button type `help-xref'

[Óscar Fuentes]

Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the emacs-pretest-bug@gnu.org mailing list.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug.  If you can, give
a recipe starting from `emacs -Q':

emacs -Q
M-x describe-font
define-button-type: Unknown button type `help-xref'
M-x report-emacs-bug
C-x k
M-x describe-font
  <<works fine>>

This is the error trace:

Debugger entered--Lisp error: (error "Unknown button type `help-xref'")
  signal(error ("Unknown button type `help-xref'"))
  error("Unknown button type `%s'" help-xref)
  define-button-type(list-charset-chars :supertype help-xref help-function 
list-charset-chars help-echo "mouse-2, RET: show table of characters for this 
character set")
  
byte-code("\300\301\302\303\304!\305\306\307\310&\210\300\311\312\313\314\311\302\315&\207"
 [define-button-type sort-listed-character-sets help-echo purecopy "mouse-2, 
RET: sort on this column" face bold action #[(button) "\301\302\303\"!\207" 
[button sort-listed-character-sets button-get sort-key] 4] list-charset-chars 
:supertype help-xref help-function "mouse-2, RET: show table of characters for 
this character set"] 8)
  execute-extended-command(nil)
  call-interactively(execute-extended-command nil nil)

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
For information about debugging Emacs, please read the file
/home/oscar/dev/other/emacs/etc/DEBUG.


In GNU Emacs 23.1.50.2 (x86_64-unknown-linux-gnu, X toolkit)
 of 2009-12-08 on qcore
Windowing system distributor `The X.Org Foundation', version 11.0.10604000
configured using `configure  '--without-xaw3d' '--with-x-toolkit=athena''

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

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-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:
M-x s <backspace> d e s c r i b e SPC f o n t <return> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <menu-bar> <help-menu> 
<send-emacs-bug-report>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
define-button-type: Unknown button type `help-xref'

Load-path shadows:
/home/oscar/dev/other/emacs/lisp/progmodes/sym-comp hides 
/home/oscar/dev/other/emacs/lisp/obsolete/sym-comp

Features:
(shadow mail-extr message ecomplete rfc822 mml easymenu mml-sec
password-cache mm-decode mm-bodies mm-encode mailcap mail-parse rfc2231
rfc2047 rfc2045 qp ietf-drums mailabbrev nnheader gnus-util netrc
time-date mm-util mail-prsvr gmm-utils wid-edit mailheader canlock sha1
hex-util hashcash mail-utils warnings emacsbug sendmail regexp-opt
help-fns tooltip ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd
font-setting tool-bar dnd fontset image fringe lisp-mode register page
menu-bar rfn-eshadow timer select scroll-bar mldrag mouse jit-lock
font-lock syntax facemenu font-core frame cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese hebrew
greek romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev loaddefs button
minibuffer faces cus-face text-properties overlay md5 base64 format env
code-pages mule custom widget hashtable-print-readable backquote
make-network-process font-render-setting x-toolkit x multi-tty emacs)