bug#13235: 24.3.50; can't use /whois with erc

[Chep]

Start emacs: emacs -nw -q
Start erc: M-x erc
RET RET RET RET (all option by default: freenode, 6667, chep, nopasswd)
wait connection
/whois chep

Some lines are missing and i got errors:
error in process filter: format-spec: Invalid format character: `%n'
error in process filter: Invalid format character: `%n'

I got backtrace with tdoe:
Debugger entered--Lisp error: (error "Invalid format character: `%n'")
  signal(error ("Invalid format character: `%n'"))
  error("Invalid format character: `%%%c'" 110)
  format-spec("%n is/was on server %s (%c)" ((110) (115) (99 . "Sofia, BG, 
EU")))
  erc-format-message(s312 110 nil 115 nil 99 "Sofia, BG, EU")
  apply(erc-format-message s312 (110 nil 115 nil 99 "Sofia, BG, EU"))
  erc-display-message([cl-struct-erc-response ":rajaniemi.freenode.net 312 
chep` chep hitchcock.freenode.net :Sofia, BG, EU" "rajaniemi.freenode.net" 
"312" ("chep`" "chep" "hitchcock.freenode.net" "Sofia, BG, EU") "Sofia, BG, 
EU"] notice active s312 110 nil 115 nil 99 "Sofia, BG, EU")
  erc-server-312(#<process erc-irc.freenode.net-6667> [cl-struct-erc-response 
":rajaniemi.freenode.net 312 chep` chep hitchcock.freenode.net :Sofia, BG, EU" 
"rajaniemi.freenode.net" "312" ("chep`" "chep" "hitchcock.freenode.net" "Sofia, 
BG, EU") "Sofia, BG, EU"])
  run-hook-with-args-until-success(erc-server-312 #<process 
erc-irc.freenode.net-6667> [cl-struct-erc-response ":rajaniemi.freenode.net 312 
chep` chep hitchcock.freenode.net :Sofia, BG, EU" "rajaniemi.freenode.net" 
"312" ("chep`" "chep" "hitchcock.freenode.net" "Sofia, BG, EU") "Sofia, BG, 
EU"])
  erc-call-hooks(#<process erc-irc.freenode.net-6667> [cl-struct-erc-response 
":rajaniemi.freenode.net 312 chep` chep hitchcock.freenode.net :Sofia, BG, EU" 
"rajaniemi.freenode.net" "312" ("chep`" "chep" "hitchcock.freenode.net" "Sofia, 
BG, EU") "Sofia, BG, EU"])
  erc-handle-parsed-server-response(#<process erc-irc.freenode.net-6667> 
[cl-struct-erc-response ":rajaniemi.freenode.net 312 chep` chep 
hitchcock.freenode.net :Sofia, BG, EU" "rajaniemi.freenode.net" "312" ("chep`" 
"chep" "hitchcock.freenode.net" "Sofia, BG, EU") "Sofia, BG, EU"])
  erc-parse-server-response(#<process erc-irc.freenode.net-6667> 
":rajaniemi.freenode.net 312 chep` chep hitchcock.freenode.net :Sofia, BG, EU")
  erc-server-filter-function(#<process erc-irc.freenode.net-6667> 
":rajaniemi.freenode.net 312 chep` chep hitchcock.freenode.net :Sofia, BG, 
EU\n:rajaniemi.freenode.net 330 chep` chep Chep :is logged in 
as\n:rajaniemi.freenode.net 318 chep` chep :End of /WHOIS list.\n")




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
/usr/share/emacs/24.3.50/etc/DEBUG.


In GNU Emacs 24.3.50.1 (x86_64-pc-linux-gnu, GTK+ Version 3.4.2)
 of 2012-12-17 on dex, modified by Debian
 (emacs-snapshot package, version 2:20121217-1)
System Description:     Debian GNU/Linux testing (wheezy)

Configured using:
 `configure '--build' 'x86_64-linux-gnu' '--host' 'x86_64-linux-gnu'
 '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib'
 '--localstatedir=/var' '--infodir=/usr/share/info'
 '--mandir=/usr/share/man' '--with-pop=yes'
 
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/24.3.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.3.50/site-lisp:/usr/share/emacs/site-lisp'
'--without-compress-info' '--with-crt-dir=/usr/lib/x86_64-linux-gnu/'
 '--with-x=yes' '--with-x-toolkit=gtk3' '--with-imagemagick=yes'
 'build_alias=x86_64-linux-gnu' 'host_alias=x86_64-linux-gnu'
 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 'LDFLAGS=-g
 -Wl,--as-needed -znocombreloc' 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

Important settings:
  value of $LANG: fr_FR.utf8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: ERC

Minor modes in effect:
  erc-list-mode: t
  erc-menu-mode: t
  erc-autojoin-mode: t
  erc-ring-mode: t
  erc-networks-mode: t
  erc-pcomplete-mode: t
  erc-track-mode: t
  erc-track-minor-mode: t
  erc-match-mode: t
  erc-button-mode: t
  erc-fill-mode: t
  erc-stamp-mode: t
  erc-netsplit-mode: t
  erc-irccontrols-mode: t
  erc-noncommands-mode: t
  erc-move-to-prompt-mode: t
  erc-readonly-mode: t
  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
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
ESC [ > 1 ; 2 8 0 2 ; 0 c ESC x e r c RET RET RET RET
RET / w h o i s SPC c h e p RET ESC x t o o g l TAB
DEL DEL TAB TAB DEL DEL DEL DEL d e TAB b u g TAB TAB
DEL DEL DEL DEL DEL e n a TAB TAB ESC DEL C-g C-h a
d e b u g . * e r r o r RET C-c ESC O B q DEL C-x 1
ESC x t o g g l TAB d e b TAB e TAB RET ESC p RET ESC
O A C-@ ESC O B ESC O B ESC O B ESC O B ESC O B ESC
O B ESC O B ESC O B ESC O B ESC O B ESC O B ESC O B
ESC O B ESC O B ESC w q ESC O A ESC O B ESC x b u g
TAB TAB DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL DEL
DEL DEL DEL r e p o TAB TAB TAB r TAB RET

Recent messages:
error in process filter: Invalid format character: `%n'
Making completion list... [4 times]
Quit
Type C-x 1 to remove help window.
Debug on Error enabled globally
Entering debugger...
Mark set
byte-code: End of buffer
Back to top level.
Making completion list... [2 times]

Load-path shadows:
/usr/share/emacs/24.3.50/site-lisp/debian-startup hides 
/usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs/24.3.50/site-lisp/cscope/xcscope hides 
/usr/share/emacs/site-lisp/xcscope
/usr/share/emacs-snapshot/site-lisp/flim/hex-util hides 
/usr/share/emacs/24.3.50/lisp/hex-util
/usr/share/emacs-snapshot/site-lisp/flim/md4 hides 
/usr/share/emacs/24.3.50/lisp/md4
/usr/share/emacs-snapshot/site-lisp/flim/hmac-md5 hides 
/usr/share/emacs/24.3.50/lisp/net/hmac-md5
/usr/share/emacs-snapshot/site-lisp/flim/sasl hides 
/usr/share/emacs/24.3.50/lisp/net/sasl
/usr/share/emacs-snapshot/site-lisp/flim/hmac-def hides 
/usr/share/emacs/24.3.50/lisp/net/hmac-def
/usr/share/emacs-snapshot/site-lisp/flim/ntlm hides 
/usr/share/emacs/24.3.50/lisp/net/ntlm
/usr/share/emacs-snapshot/site-lisp/flim/sasl-cram hides 
/usr/share/emacs/24.3.50/lisp/net/sasl-cram
/usr/share/emacs-snapshot/site-lisp/flim/sasl-digest hides 
/usr/share/emacs/24.3.50/lisp/net/sasl-digest
/usr/share/emacs-snapshot/site-lisp/flim/sasl-ntlm hides 
/usr/share/emacs/24.3.50/lisp/net/sasl-ntlm
/usr/share/emacs-snapshot/site-lisp/wl/rfc2368 hides 
/usr/share/emacs/24.3.50/lisp/mail/rfc2368
/usr/share/emacs-snapshot/site-lisp/semi/pgg-pgp hides 
/usr/share/emacs/24.3.50/lisp/obsolete/pgg-pgp
/usr/share/emacs-snapshot/site-lisp/semi/pgg-pgp5 hides 
/usr/share/emacs/24.3.50/lisp/obsolete/pgg-pgp5
/usr/share/emacs-snapshot/site-lisp/semi/pgg hides 
/usr/share/emacs/24.3.50/lisp/obsolete/pgg
/usr/share/emacs-snapshot/site-lisp/semi/pgg-parse hides 
/usr/share/emacs/24.3.50/lisp/obsolete/pgg-parse
/usr/share/emacs-snapshot/site-lisp/semi/pgg-gpg hides 
/usr/share/emacs/24.3.50/lisp/obsolete/pgg-gpg
/usr/share/emacs-snapshot/site-lisp/semi/pgg-def hides 
/usr/share/emacs/24.3.50/lisp/obsolete/pgg-def

Features:
(shadow sort mail-extr emacsbug message rfc822 mml mml-sec mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mail-utils debug cus-start cus-load
apropos help-mode mule-util network-stream starttls tls erc-menu
easymenu erc-join erc-ring erc-networks erc-pcomplete pcomplete comint
ansi-color ring erc-track erc-match erc-button wid-edit erc-fill
erc-stamp erc-netsplit erc-goodies erc erc-backend erc-compat
format-spec auth-source eieio byte-opt bytecomp byte-compile cconv
gnus-util mm-util mail-prsvr password-cache thingatpt pp time-date
w3m-load magit-install 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 inotify dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty emacs)