bug#24644: 26.0.50; Emacs 25: set-fontset-font does not take effect with some ASCII symbols

[Toshikazu Nakamura]

Hello,

I use Emacs for editing texts that contain Japanese as well as English
and other languages. In order to give characters of each language a
better appearance, I use a fontset that specifies a different font for
ASCII characters and double-width Japanese characters.

Since Emacs 25.1, however, I find that the default ASCII font is
always used for some characters that belongs to some other character
set (e.g. japanese-jisx0208) and for which another font is specified.

(set-language-environment "Japanese")
(set-face-attribute 'default nil :family "DejaVu Sans Mono" :height 96)
(set-fontset-font nil 'japanese-jisx0208
                  (font-spec :family "TakaoGothic"))
(add-to-list 'face-font-rescale-alist '(".*TakaoGothic.*" . 1.25))

When I launch Emacs with the "-Q" option and load the above settings,
the default ASCII font is used for characters like #x2026 and #x25bd,
though the result of describe-char shows that they belong to
japanese-jisx0208:

             position: 80 of 4241 (2%), column: 44
            character: … (displayed as …) (codepoint 8230, #o20046, #x2026)
    preferred charset: japanese-jisx0208 (JISX0208.1983/1990 Japanese Kanji: 
ISO-IR-87)
code point in charset: 0x2144
               script: symbol
               syntax: _        which means: symbol
             category: .:Base, >:Not at bol, c:Chinese, h:Korean, j:Japanese
             to input: type "C-x 8 RET 2026" or "C-x 8 RET HORIZONTAL ELLIPSIS"
          buffer code: #xE2 #x80 #xA6
            file code: #xE2 #x80 #xA6 (encoded by coding system utf-8-unix)
              display: by this font (glyph code)
    xft:-unknown-DejaVu Sans 
Mono-normal-normal-normal-*-13-*-*-*-m-0-iso10646-1 (#x728)

Character code properties: customize what to show
  name: HORIZONTAL ELLIPSIS
  general-category: Po (Punctuation, Other)
  decomposition: (compat 46 46 46) (compat '.' '.' '.')

Emacs 24 uses for these symbols the font specified for
japanese-jisx0208 and displays them as double-width Japanese symbols.
When displayed with the default ASCII font as in Emacs 25, these
symbols give Japanese texts a rather awkward appearance.

The same issue is discussed in the thread starting with the following
message:

http://lists.gnu.org/archive/html/help-gnu-emacs/2016-10/msg00004.html

I agree with Alex that there should be some way to override the
default ASCII font, especially because in my case it considerably
alters the appearance of the text. I would appreciate it if some
customization could be made possible.

Best regards.



In GNU Emacs 26.0.50.2 (x86_64-unknown-linux-gnu, GTK+ Version 3.14.5)
 of 2016-10-03 built on epson
Repository revision: a7e9d1cce3f935dbe9f242f0bf2dbf34f5919952
Windowing system distributor 'The X.Org Foundation', version 11.0.11604000
System Description:     Kona Linux 3.0 Mate/x86_64

Configured using:
 'configure --without-xim'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LANG: ja_JP.UTF-8
  value of $XMODIFIERS: @im=uim
  locale-coding-system: utf-8-unix

Major mode: Folder

Minor modes in effect:
  shell-dirtrack-mode: t
  global-company-mode: t
  global-smart-tab-mode: t
  recentf-mode: t
  delete-selection-mode: t
  show-paren-mode: t
  scroll-mode-line-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
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
/usr/local/share/emacs/site-lisp/flim/hex-util hides 
/usr/local/share/emacs/26.0.50/lisp/hex-util
/usr/local/share/emacs/site-lisp/flim/md4 hides 
/usr/local/share/emacs/26.0.50/lisp/md4
/usr/local/share/emacs/site-lisp/flim/hmac-def hides 
/usr/local/share/emacs/26.0.50/lisp/net/hmac-def
/usr/local/share/emacs/site-lisp/flim/sasl-cram hides 
/usr/local/share/emacs/26.0.50/lisp/net/sasl-cram
/usr/local/share/emacs/site-lisp/flim/sasl-digest hides 
/usr/local/share/emacs/26.0.50/lisp/net/sasl-digest
/usr/local/share/emacs/site-lisp/flim/ntlm hides 
/usr/local/share/emacs/26.0.50/lisp/net/ntlm
/usr/local/share/emacs/site-lisp/flim/sasl hides 
/usr/local/share/emacs/26.0.50/lisp/net/sasl
/usr/local/share/emacs/site-lisp/flim/hmac-md5 hides 
/usr/local/share/emacs/26.0.50/lisp/net/hmac-md5
/usr/local/share/emacs/site-lisp/flim/sasl-ntlm hides 
/usr/local/share/emacs/26.0.50/lisp/net/sasl-ntlm

Features:
(shadow eieio-opt speedbar sb-image ezimage dframe find-func dabbrev
hippie-exp help-fns radix-tree noutline outline rect shr-color color
thingatpt mel-q-ccl skk-cdb cdb descr-text emacsbug message rfc822 mml
mml-sec epa epg gnus-util rmail rmail-loaddefs mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
skk-annotation skk-look skk-num skk-cursor skk-sticky skk-dcomp
skk-comp skk-server skk-busyu skk-tankan skk-cus cus-edit cus-start
cus-load skk skk-emacs skk-macs skk-leim company-ispell ispell solar
cal-dst diary-lib diary-loaddefs pcmpl-x mime-shr shr svg dom
x-face-e21 wl-expire wl-score shell grep misearch multi-isearch
skk-vars network-stream puny seq nsm subr-x starttls navi2ch-thumbnail
navi2ch-p2 navi2ch-auto-modify navi2ch-localfile navi2ch-oyster
navi2ch-mona navi2ch-futaba navi2ch-machibbs navi2ch-jbbs-shitaraba
navi2ch-be2ch navi2ch-http-date navi2ch-multibbs navi2ch-jbbs-net
navi2ch-version navi2ch-splash navi2ch-e21 navi2ch-message
navi2ch-directory navi2ch-search navi2ch-history navi2ch-bookmark
navi2ch-articles navi2ch-board navi2ch-board-misc
navi2ch-popup-article navi2ch-article navi2ch-list navi2ch-net
browse-url navi2ch-util navi2ch-face navi2ch-config navi2ch-vars
navi2ch modb-legacy elmo-pop3 elmo-internal elmo-archive modb-standard
wl-mime mime-play filename mime-edit mime-setup mail-mime-setup
semi-setup mime-image wl-spam elmo-spam elsp-header elsp-generic tls
gnutls wl-demo wl-draft eword-encode wl-template sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils elmo-net elmo-cache
elmo-map elmo-dop wl-news wl-address wl-thread wl-action wl-summary
wl-refile wl-message elmo-mime mmelmo-buffer mmelmo-imap mime-view
mime-conf calist semi-def mmimap mime-parse mmbuffer mmgeneric
wl-highlight elmo-multi wl-folder wl wl-e21 wl-util elmo-flag
elmo-localdir wl-vars epg-config wl-version elmo elmo-signal
elmo-msgdb modb modb-generic modb-entity mime elmo-util emu invisible
inv-23 poem poem-e20 poem-e20_3 eword-decode mel mime-def alist
mcharset mcs-20 mcs-e20 pces pces-e20 pces-20 pcustom elmo-date
timezone elmo-vars path-util elmo-version luna std11 pccl pccl-20 ccl
broken poe pym static apel-ver product disp-table ccc company-oddmuse
company-keywords company-etags etags xref project company-gtags
company-dabbrev-code company-dabbrev company-files company-capf
company-cmake company-xcode company-clang company-semantic
company-eclim company-template company-css company-nxml company-bbdb
pcomplete migemo howm-diary howm-lang-ja howm-lang-en calfw-howm
howm-menu howm-reminder howm-date howm-misc howm-mode howm-view
howm-backend howm honest-report action-lock riffle gfunc illusion
cheat-font-lock howm-common howm-vars howm-version company calfw-cal
calfw japanese-holidays holidays hol-loaddefs cal-menu calendar
cal-loaddefs view smart-tab smart-quotes session redo+ recentf
tree-widget wid-edit minibuf-isearch jaspace whitespace
emms-player-mpv emms-info-libtag emms-librefm-stream xml
emms-librefm-scrobbler emms-playlist-limit emms-volume
emms-volume-amixer emms-i18n emms-history emms-score emms-stream-info
emms-metaplaylist-mode emms-bookmarks emms-cue emms-mode-line-icon
emms-browser sort emms-playlist-sort emms-last-played emms-player-xine
emms-player-mpd tq emms-playing-time emms-lyrics emms-url url
url-proxy url-privacy url-expand url-methods url-history url-cookie
url-domsuf url-util url-parse auth-source cl-seq eieio byte-opt
bytecomp byte-compile cl-extra cconv eieio-core eieio-loaddefs
password-cache url-vars mailcap emms-streams emms-show-all
emms-tag-editor format-spec emms-mark emms-mode-line emms-cache
emms-info-ogginfo emms-info-mp3info emms-info later-do
emms-playlist-mode emms-player-vlc emms-player-mplayer
emms-player-simple emms-source-playlist emms-source-file locate
emms-setup emms emms-compat bs browse-kill-ring bookmark+
bookmark+-key derived dired-x bookmark+-1 bookmark+-bmu help-mode
easymenu bookmark+-lit bookmark+-mac bookmark pp ack compile comint
ansi-color ring pdf-preview ps-mule ps-print ps-print-loaddefs ps-def
lpr delsel edmacro kmacro dired dired-loaddefs paren avoid cl-macs
easy-mmode cl gv cl-loaddefs pcase cl-lib scroll-mode-line-mode server
japan-util time-date mule-util advice skk-setup skk-autoloads 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
dbusbind 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 589477 145280)
 (symbols 48 58877 12)
 (miscs 40 1496 3501)
 (strings 32 173865 10926)
 (string-bytes 1 5945151)
 (vectors 16 56451)
 (vector-slots 8 1870026 203484)
 (floats 8 1230 1238)
 (intervals 56 18117 4643)
 (buffers 976 83)
 (heap 1024 91074 48247))

-- 
Toshikazu Nakamura