font used for some mathematical characters

font used for some mathematical characters

[Eduardo Ochs]

Some very recent changes in CVS Emacs have changed the the fonts that
are selected for displaying some mathematical characters, in a bad
way... The three sexps below will create a buffer with two problematic
characters (displayed with the face "highlight", for visibility), and
with several sexps that can be executed with C-x C-e to change to
frame font and to inspect the fonts used for individual characters.

--snip--snip--

(defun fontbug-propertize (c)
  (propertize (string c) 'face 'highlight))

(defun fontbug-string (c1 c2)
  (format "\
P%sQ <--| P
 |       |
 |  <->  |
 v       v
 R |--> Q%sS\n\n"
	  (fontbug-propertize c1)
	  (fontbug-propertize c2)))

(progn
  (switch-to-buffer "o")
  (delete-region 1 (point-max))
  (insert
   (string ?& 8743 10 10)
   (fontbug-string ?& ?>)
   (fontbug-string 8743 8835)  ;; problematic chars
   "(set-frame-font \"fixed\")\n"
   "(set-frame-font \"10x20\")\n"
   "(require 'descr-text)\n"
   "(describe-char-display 1 (char-after 1))\n"
   "(describe-char-display 2 (char-after 2))\n"
   ))

--snip--snip--

When I use the font "fixed", the two
"describe-char" lines return this:

  ("fixed:pixelsize=13:foundry=misc:weight=regular:slant=roman:width=semi-condensed" . "27")
  ("-Daewoo-Mincho-Medium-R-Normal--16-120-100-100-C-160-KSC5601.1987-0" . "217C")

and the "logical and" and "supset"/"implies"
chars (8743 and 8835) are taken from the "-Daewoo-..."
font and are ~ 2.5 times wider than normal chars.

When I use the font "10x20" the two
"describe-char" lines return this:

  ("fixed:pixelsize=20:foundry=misc:weight=regular:slant=roman:width=normal" . "08")
  ("fixed:pixelsize=20:foundry=misc:weight=regular:slant=roman:width=normal" . "C63")

and all the characters are the same size.

By the way, here "fixed" is the same font as "6x13"; I checked with:

  xlsfonts | grep -v \\-
  xlsfonts -l -fn fixed
  xlsfonts -l -fn 6x13

Versions: I am using a Debian 4.0 ("Etch", stable) GNU/Linux system;
and running "(emacs-version)" returns:
  => "GNU Emacs 23.0.60.2 (i686-pc-linux-gnu, GTK+ Version 2.8.20)
      of 2008-03-14 on persephone"

  Cheers,
    Eduardo Ochs
    http://angg.twu.net/
    eduardoochs@gmail.com