bug#19910: 24.4; Japanese font names are decoded incorrectly in Cygwin's emacs-w32 in LANG=ja_JP.UTF-8

[Fujii Hironori <fujii.hironori@gmail.com>]

(font-family-list) returns incorrectly decoded Japanese font names.
My locale-coding-system is utf-8-unix.

If I do (setq locale-coding-system 'cp932), it returns correct font names.
But, locale-coding-system is used in other places (e.g. M-x term and M-x man).
locale-coding-system must be utf-8 in my Emacs.



In GNU Emacs 24.4.1 (x86_64-unknown-cygwin)
 of 2015-02-13 on desktop-new
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure
 --srcdir=/home/kbrown/src/cygemacs/emacs-24.4-3.x86_64/src/emacs-24.4
 --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin
 --libexecdir=/usr/libexec --datadir=/usr/share --localstatedir=/var
 --sysconfdir=/etc --libdir=/usr/lib --datarootdir=/usr/share
 --docdir=/usr/share/doc/emacs --htmldir=/usr/share/doc/emacs/html -C
 --with-w32 'CFLAGS=-ggdb -O2 -pipe -Wimplicit-function-declaration
 -fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-24.4-3.x86_64/build=/usr/src/debug/emacs-24.4-3
 -fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-24.4-3.x86_64/src/emacs-24.4=/usr/src/debug/emacs-24.4-3'
 CPPFLAGS= LDFLAGS='

Important settings:
  value of $LANG: ja_JP.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
  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
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<language-change> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <menu-bar>
<help-menu> <send-emacs-bug-report>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
No docstring slot for setup-japanese-environment-internal

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 help-fns mail-prsvr mail-utils time-date japan-util tooltip
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
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 dbusbind
gfilenotify w32 multi-tty emacs)

Memory information:
((conses 16 76005 6531)
 (symbols 48 17442 0)
 (miscs 40 60 88)
 (strings 32 10617 5193)
 (string-bytes 1 268020)
 (vectors 16 9545)
 (vector-slots 8 454592 39464)
 (floats 8 57 94)
 (intervals 56 193 0)
 (buffers 960 12))