bug#20481: 24.5; Newlines in message-box output don't work on Windows

[Adam Connor]

If I display a message using message-box, newlines seem to be ignored.
For example
    (message-box "secret\nmessage")

will show the message "secretmessage". I have also tried \r\n with the
same result.

Not a huge problem but annoying...



In GNU Emacs 24.5.1 (x86_64-w64-mingw32)
 of 2015-04-11 on KAEL
Windowing system distributor `Microsoft Corp.', version 6.3.9600
Configured using:
 `configure --prefix=/z/emacs --host=x86_64-w64-mingw32
 --target=x86_64-w64-mingw32 --build=x86_64-w64-mingw32 --with-wide-int
 --with-jpeg --with-xpm --with-png --with-tiff --with-rsvg --with-xml2
 --with-gnutls --with-sound=yes --with-file-notification=yes
 --without-dbus --without-imagemagick 'CFLAGS=-Ofast
 -fomit-frame-pointer -funroll-loops -g0 -pipe' 'LDFLAGS=-static-libgcc
 -static-libstdc++ -static -s -Wl,-s''

Important settings:
  value of $LANG: ENU
  locale-coding-system: utf-8

Major mode: Emacs-Lisp

Minor modes in effect:
  my-keys-minor-mode: t
  tabbar-mwheel-mode: t
  tabbar-mode: t
  global-nlinum-mode: t
  nlinum-mode: t
  diff-auto-refine-mode: t
  global-undo-tree-mode: t
  undo-tree-mode: t
  recentf-mode: t
  desktop-save-mode: t
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-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 messages:
Auto-saving...
Quit
Saving file c:/Users/Adam/.emacs.d/elisp/file-utils.el...
Wrote c:/Users/Adam/.emacs.d/elisp/file-utils.el
file-older-than
Quit
Saving file c:/Users/Adam/.emacs.d/elisp/file-utils.el...
Wrote c:/Users/Adam/.emacs.d/elisp/file-utils.el
file-older-than
Wrote c:/Users/Adam/.emacs.d/packages-updated.txt
nil

Load-path shadows:
~/.emacs.d/lib/tabbar-master/revive hides ~/.emacs.d/lib/revive
c:/Users/Adam/.emacs.d/elpa/dash-2.10.0/dash hides ~/.emacs.d/lib/dash
~/.emacs.d/lib/indent hides c:/dev/emacs-w64-24.5/share/emacs/24.5/lisp/indent

Features:
(shadow sort mail-extr emacsbug sendmail debug eieio-opt speedbar
sb-image ezimage dframe find-func geiser-mode geiser-xref geiser-chicken
geiser-racket geiser-guile geiser-repl geiser-image geiser-compile
geiser-debug geiser-company geiser-doc geiser-menu geiser-autodoc eldoc
info-look geiser geiser-edit etags geiser-completion geiser-eval
geiser-connection tq geiser-syntax rx geiser-log geiser-popup view
geiser-impl geiser-custom geiser-base tar-mode thingatpt cmuscheme
scheme tabify autoload misearch multi-isearch lisp-mnt help-mode
mule-util gnutls mm-archive network-stream starttls url-cache
url-handlers finder-inf vc-git tabbar revbufs fill-column-indicator
nlinum linum virtualenvwrapper dash vc-svn psvn derived log-edit message
format-spec rfc822 mml mml-sec mailabbrev mail-utils gmm-utils
mailheader pcvs-util add-log diff-mode pp elp ediff-merg ediff-wind
ediff-diff ediff-mult ediff-help ediff-init ediff-util dired rdp-utils
web-mode flymake compile python json comint ring ansi-color util
undo-tree soap-client mm-decode mm-bodies mm-encode url-http tls
url-auth mail-parse rfc2231 rfc2047 rfc2045 ietf-drums url-gw url
url-proxy url-privacy url-expand url-methods url-history url-cookie
url-domsuf url-util url-parse auth-source eieio byte-opt bytecomp
byte-compile cl-extra cconv eieio-core gnus-util mm-util mail-prsvr
password-cache url-vars mailcap warnings xml easy-mmode virtualenv-utils
env-utils proj-utils cl-macs s cl gv ido edmacro kmacro ibuffer
framemove advice help-fns ehelp editorconfig file-utils recentf
tree-widget wid-edit desktop frameset cl-loaddefs cl-lib info easymenu
package epg-config misterioso-theme library-utils time-date tooltip
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel dos-w32
ls-lisp w32-common-fns disp-table w32-win w32-vars tool-bar dnd fontset
image regexp-opt fringe tabulated-list newcomment lisp-mode prog-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 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 make-network-process
w32notify w32 multi-tty emacs)

Memory information:
((conses 16 699525 109272)
 (symbols 56 35736 0)
 (miscs 48 3413 2679)
 (strings 32 87577 14382)
 (string-bytes 1 2273331)
 (vectors 16 37061)
 (vector-slots 8 1409654 155048)
 (floats 8 159 939)
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 (buffers 960 23))