bug#12992: 24.2.90.1; `C-x 8 RET RET': `Wrong type argument: characterp, nil'

[Simen Heggestøyl]

`C-x 8 RET RET' gives `Wrong type argument: characterp, nil' in Emacs
version 24.2.90.1, whereas in version 24.2.1 it produces the message
`Not a Unicode character'.


In GNU Emacs 24.2.90.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.24.10)
 of 2012-11-25 on x201
Windowing system distributor `The X.Org Foundation', version 11.0.11204000
System Description:     Debian GNU/Linux unstable (sid)

Important settings:
  value of $LANG: en_US.UTF-8
  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
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
C-x 8 <return> <return> M-x r e p o r t <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
call-interactively: Wrong type argument: characterp, nil

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils iso-transl time-date tooltip ediff-hook
vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image
regexp-opt fringe tabulated-list newcomment lisp-mode register page
menu-bar rfn-eshadow timer select scroll-bar 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 minibuffer loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process dbusbind dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty emacs)