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':

  Start Emacs:

    $ emacs -Q

  In *scratch* buffer:

    (require 'arc-mode)

  fails with following backtrace:

Debugger entered--Lisp error: (wrong-type-argument keymapp special-mode-map)
  set-keymap-parent((keymap #^[nil nil keymap nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil nil ...]) special-mode-map)
  byte-code("..." [map global-map make-keymap set-keymap-parent special-mode-map define-key " " archive-next-line "a" archive-alternate-display "d" archive-flag-deleted "" "e" archive-extract "f" "
" "m" archive-mark "n" "" [down] "o" archive-extract-other-window "p" archive-previous-line "" [up] "r" archive-rename-entry "u" archive-unflag "\377" archive-unmark-all-files "v" archive-view "x" archive-expunge "" archive-unflag-backwards "E" "M" archive-chmod-entry "G" archive-chgrp-entry "O" archive-chown-entry [follow-link] mouse-face fboundp ...] 6)
  (defvar archive-mode-map (byte-code "..." [map global-map make-keymap set-keymap-parent special-mode-map define-key " " archive-next-line "a" archive-alternate-display "d" archive-flag-deleted "" "e" archive-extract "f" "
" "m" archive-mark "n" "" [down] "o" archive-extract-other-window "p" archive-previous-line "" [up] "r" archive-rename-entry "u" archive-unflag "\377" archive-unmark-all-files "v" archive-view "x" archive-expunge "" archive-unflag-backwards "E" "M" archive-chmod-entry "G" archive-chgrp-entry "O" archive-chown-entry [follow-link] mouse-face fboundp ...] 6) ("/usr/local/share/emacs/24.0.50/lisp/arc-mode.elc" . 7617))
  require(arc-mode)
  eval((require (quote arc-mode)))
  eval-last-sexp-1(t)
  eval-last-sexp(t)
  eval-print-last-sexp()
  call-interactively(eval-print-last-sexp nil nil)

  Please apply the attached patch.

In GNU Emacs 24.0.50.5 (i686-pc-cygwin)
 of 2011-02-03 on zeroset
configured using `configure  '--without-dbus' '--with-gconf' '--without-x''

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

Major mode: Debugger

Minor modes in effect:
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
( r e q u i r e SPC ' a r c - m o d e ) C-j ESC x r 
e p o TAB r TAB RET

Recent messages:
("emacs")
For information about GNU Emacs and the GNU system, type C-h C-a.
Entering debugger...
Making completion list...

Load-path shadows:
/usr/local/share/emacs/site-lisp/flim/sha1 hides /usr/local/share/emacs/24.0.50/lisp/sha1
/usr/local/share/emacs/site-lisp/flim/md4 hides /usr/local/share/emacs/24.0.50/lisp/md4
/usr/local/share/emacs/site-lisp/flim/hex-util hides /usr/local/share/emacs/24.0.50/lisp/hex-util
/usr/local/share/emacs/site-lisp/bitmap/po hides /usr/local/share/emacs/24.0.50/lisp/textmodes/po
/usr/local/share/emacs/site-lisp/flim/sasl hides /usr/local/share/emacs/24.0.50/lisp/net/sasl
/usr/local/share/emacs/site-lisp/flim/sasl-ntlm hides /usr/local/share/emacs/24.0.50/lisp/net/sasl-ntlm
/usr/local/share/emacs/site-lisp/flim/sasl-digest hides /usr/local/share/emacs/24.0.50/lisp/net/sasl-digest
/usr/local/share/emacs/site-lisp/flim/sasl-cram hides /usr/local/share/emacs/24.0.50/lisp/net/sasl-cram
/usr/local/share/emacs/site-lisp/flim/ntlm hides /usr/local/share/emacs/24.0.50/lisp/net/ntlm
/usr/local/share/emacs/site-lisp/flim/hmac-md5 hides /usr/local/share/emacs/24.0.50/lisp/net/hmac-md5
/usr/local/share/emacs/site-lisp/flim/hmac-def hides /usr/local/share/emacs/24.0.50/lisp/net/hmac-def
/usr/local/share/emacs/site-lisp/wl/rfc2368 hides /usr/local/share/emacs/24.0.50/lisp/mail/rfc2368
/usr/local/share/emacs/site-lisp/wl/utf7 hides /usr/local/share/emacs/24.0.50/lisp/gnus/utf7
/usr/local/share/emacs/site-lisp/semi/smime hides /usr/local/share/emacs/24.0.50/lisp/gnus/smime
/usr/local/share/emacs/site-lisp/semi/pgg hides /usr/local/share/emacs/24.0.50/lisp/obsolete/pgg
/usr/local/share/emacs/site-lisp/semi/pgg-pgp5 hides /usr/local/share/emacs/24.0.50/lisp/obsolete/pgg-pgp5
/usr/local/share/emacs/site-lisp/semi/pgg-pgp hides /usr/local/share/emacs/24.0.50/lisp/obsolete/pgg-pgp
/usr/local/share/emacs/site-lisp/semi/pgg-parse hides /usr/local/share/emacs/24.0.50/lisp/obsolete/pgg-parse
/usr/local/share/emacs/site-lisp/semi/pgg-gpg hides /usr/local/share/emacs/24.0.50/lisp/obsolete/pgg-gpg
/usr/local/share/emacs/site-lisp/semi/pgg-def hides /usr/local/share/emacs/24.0.50/lisp/obsolete/pgg-def

Features:
(shadow sort mail-extr message sendmail regexp-opt rfc822 mml mml-sec
mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045
ietf-drums mailabbrev mail-utils gmm-utils mailheader emacsbug url-util
url-parse auth-source netrc gnus-util time-date url-vars mm-util
mail-prsvr help-mode easymenu view debug japan-util ediff-hook vc-hooks
lisp-float-type lisp-mode register page menu-bar rfn-eshadow timer
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 files text-properties overlay
md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process multi-tty emacs)