bug#23047: 25.1.50; erc miscomputes the length of strings when sending utf-8 characters

[Lars Magne Ingebrigtsen]

If you send the following to an irc channel:

NOTICE: The main purpose of the Emacs tutorial is to teach you the most 
important standard Emacs commands (key bindings). Howévér, your ◆macs has b◆◆n 
customiz◆d by changing som◆ of th◆s◆ basic ◆diting commands, so it do◆sn't 
corr◆spond to th◆ tutorial. W◆ hav◆ ins◆rt◆d color◆d notic◆s wh◆r◆ th◆ alt◆r◆d 
commands hav◆ b◆◆n introduc◆d. NOTIC◆: Th◆ main purpos◆ of th◆ ◆macs tutorial 
is to t◆ach you th◆ most important standard ◆macs commands (k◆y bindings). 
How◆v◆r, your ◆macs has b◆◆n customiz◆d by changing som◆ of th◆s◆ basic ◆diting 
commands, so it do◆sn't corr◆spond to th◆ tutorial. W◆ hav◆ ins◆rt◆d color◆d 
notic◆s wh◆r◆ th◆ alt◆r◆d commands hav◆ b◆◆n introduc◆d.

then the recipient channel will receive the two lines

NOTICE: The main purpose of the Emacs tutorial is to teach you the most 
important standard Emacs commands (key bindings). Howévér, your ◆macs has b◆◆n 
customiz◆d by changing som◆ of th◆s◆ basic ◆diting commands, so it do◆sn't 
corr◆spond to th◆ tutorial. W◆ hav◆ ins◆rt◆d color◆d notic◆s wh◆r◆ th◆ alt◆r◆d 
commands hav◆ b◆◆n introduc◆d. NOTIC◆: Th◆ main purpos◆ of th◆ ◆macs tutorial i
commands (k◆y bindings). How◆v◆r, your ◆macs has b◆◆n customiz◆d by changing 
som◆ of th◆s◆ basic ◆diting commands, so it do◆sn't corr◆spond to th◆ tutorial. 
W◆ hav◆ ins◆rt◆d color◆d notic◆s wh◆r◆ th◆ alt◆r◆d commands hav◆ b◆◆n 
introduc◆d.

(Note the missing text between "tutorial i" and "commands".)

I am assuming this has something to do with miscomputing the encoded
string length, but that's just a guee.



In GNU Emacs 25.1.50.28 (x86_64-unknown-linux-gnu, GTK+ Version 3.4.2)
 of 2016-03-17 built on stories
Repository revision: 58862751bde2611d9ea99a33ecb5b0c13a7513b9
Windowing system distributor 'The X.Org Foundation', version 11.0.11204000
System Description:     Debian GNU/Linux 7.9 (wheezy)

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GSETTINGS NOTIFY GNUTLS
LIBXML2 FREETYPE LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LANG: en_US
  locale-coding-system: iso-latin-1-unix

Major mode: Group

Minor modes in effect:
  diff-auto-refine-mode: t
  shell-dirtrack-mode: t
  gnus-topic-mode: t
  gnus-undo-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-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
  buffer-read-only: t
  line-number-mode: t

Recent messages:
Reading active file via nnmh...done
nnimap read 3k from hermes.netfonds.no [3 times]
nnimap read 5k from hermes.netfonds.no
Reading active file from archive via nnfolder...done
Reading active file from archive via nnfolder...done
Reading active file via nndraft...done
Reading active file via nnmbox...done
Checking new news...done
Auto-saving...done
Making completion list...

Load-path shadows:
/home/larsi/src/clock.el/clock hides /home/larsi/lisp/clock
/home/larsi/src/cddb.el/expect hides /home/larsi/lisp/expect
/home/larsi/src/pvr.el/pvr hides /home/larsi/lisp/pvr
~/pgnus/contrib/vcard hides /home/larsi/lisp/vcard
/home/larsi/src/cddb.el/captitle hides /home/larsi/lisp/captitle
~/lisp/zenirc-2.112/src/zenirc-example hides /home/larsi/lisp/zenirc-example
/home/larsi/lisp/dom hides /home/larsi/src/emacs/trunk/lisp/dom
~/pgnus/contrib/compface hides /home/larsi/src/emacs/trunk/lisp/image/compface

Features:
(whitespace diff-mode dired-aux tramp-cache tramp tramp-compat
tramp-loaddefs trampver ucs-normalize advice shell pcomplete comint ring
jukebox humanely-sort lyric-wiki discogs json map dae musicbrainz scan
scrobble tellstick wave cddb captitle expect eieio-opt speedbar sb-image
ezimage dframe find-func ecomplete misearch multi-isearch flow-fill
shr-color color eww gnus-html help-fns url-queue url-cache mm-archive vc
vc-dispatcher copyright vc-cvs gnus-picon smiley ansi-color gnus-cite
gnus-async gnus-dup gnus-ml gmane spam-gmane dns mm-url disp-table
gnus-fun gnus-mdrtn pop3 nndoc nnmbox nndraft utf-7 gnus-topic nnmh nnml
nnfolder nnir spam-report spam spam-stat gnus-uu yenc gnus-agent
gnus-srvr gnus-score score-mode nnvirtual gnus-msg gnus-art mm-uu
mml2015 mm-view mml-smime smime dig nntp gnus-cache gnus-sum gnus-group
gnus-undo gnus-start gnus-cloud nnimap nnmail mail-source utf7 netrc
nnoo parse-time gnus-spec gnus-int gnus-range gnus-win gnus nnheader
network-stream nsm starttls mailalias smtpmail qp pp shadow sort
emacsbug message format-spec rfc822 mml mml-sec epa epg gnus-util rmail
rmail-loaddefs mailabbrev gmm-utils mailheader sendmail mail-utils movie
mkv shr svg imdb dom pvr debug debbugs-gnu easy-mmode derived debbugs
soap-client mm-decode mm-bodies mm-encode url-http tls gnutls url-auth
mail-parse rfc2231 rfc2047 rfc2045 ietf-drums url-gw puny url url-proxy
url-privacy url-expand url-methods url-history url-cookie url-domsuf
url-util mailcap warnings rng-xsd rng-dt rng-util xsd-regexp xml ido seq
flyspell ispell benchmark w3m browse-url doc-view subr-x dired
dired-loaddefs image-mode timezone w3m-hist w3m-fb w3m-ems wid-edit
w3m-ccl ccl w3m-favicon w3m-image w3m-proc w3m-util add-log mail-extr
mm-util mail-prsvr jka-compr cl finder-inf package epg-config
url-handlers url-parse auth-source cl-seq eieio byte-opt bytecomp
byte-compile cl-extra help-mode easymenu cconv eieio-core cl-macs gv
eieio-loaddefs cl-loaddefs pcase cl-lib password-cache url-vars
time-date mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar
dnd fontset image regexp-opt fringe tabulated-list newcomment elisp-mode
lisp-mode prog-mode register page menu-bar rfn-eshadow timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932
hebrew greek romanian slovak czech european ethiopic indian cyrillic
chinese charscript case-table epa-hook jka-cmpr-hook help simple abbrev
obarray minibuffer cl-preloaded nadvice loaddefs button faces cus-face
macroexp files text-properties overlay sha1 md5 base64 format env
code-pages mule custom widget hashtable-print-readable backquote inotify
dynamic-setting system-font-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 1151618 98739)
 (symbols 48 173291 183)
 (miscs 40 705 2233)
 (strings 32 251038 8990)
 (string-bytes 1 15182236)
 (vectors 16 66817)
 (vector-slots 8 2003518 84003)
 (floats 8 7860 5556)
 (intervals 56 76020 2215)
 (buffers 976 78)
 (heap 1024 125478 66151))

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no