Re: font selection confusion

[Stephen Berman <stephen.berman@gmx.net>]

On Wed, 04 Mar 2009 14:19:38 +0900 Miles Bader <miles.bader@necel.com> wrote:

> GNU Emacs 23.0.91.8 (x86_64-unknown-linux-gnu, GTK+ Version 2.14.7) of 2009-03-04 on dhlpc061
>
> I'm kind of confused how emacs chooses alternative fonts to display
> funny characters.
>
> For instance, try this:
>
>   (1) Start "HOME=/tmp emacs -Q"
>
>   (2) Insert this string in *scratch*:  ❦⋮
>       (those two characters are \u2766, "FLORAL HEART", and \u22ee,
>       "VERTICAL ELLIPSIS")
>
>   (3) On my system, which is debian unstable, the default font used is
>       "Dejuavu Sans Mono"; using that font, the "FLORAL HEART" can be
>       displayed using the default font, and "VERTICAL ELLIPSIS" is
>       displayed using a different font,
>       "-mutt-clearlyu-medium-r-normal--17-120-100-100-p-123-iso10646-1"

There's something peculiar with \u22ee in my Emacs (GNU Emacs 23.0.91.2
(i686-pc-linux-gnu, GTK+ Version 2.14.4) of 2009-03-01 on escher), which
may be related.  I also use Dejavu Sans Mono (set in ~/.Xresources,
along with xft as FontBackend).  In the Gnus *Article* buffer in which
I'm reading Miles's post, both characters are displayed fine.  According
to `C-u C-x =', both use the default font; here is the complete
description of \u22ee:

        character: ⋮ (8942, #o21356, #x22ee)
preferred charset: unicode-bmp (Unicode Basic Multilingual Plane (U+0000..U+FFFF))
       code point: 0x22EE
           syntax: . 	which means: punctuation
         category: .:Base
      buffer code: #xE2 #x8B #xAE
        file code: #xE2 #x8B #xAE (encoded by coding system utf-8-unix)
          display: by this font (glyph code)
    xft:-unknown-DejaVu Sans-normal-normal-normal-*-12-*-*-*-*-0-iso10646-1 (#xD13)

Character code properties: customize what to show
  name: VERTICAL ELLIPSIS
  general-category: Sm (Symbol, Math)

However, in this description, the vertical ellipsis is not displayed,
but instead an empty box.  The same goes for the Message buffer into
which I yanked the post from the *Article* buffer (again, the latter
does display the vertical ellipsis).  Likewise if I just yank that
character into any other buffer, and also if I start emacs -Q and insert
it with ucs-insert or with `M-: (insert ?\u22ee)': it displays only as
an empty box (again, with the default font Dejavu Sans Mono).  When I
type `C-u C-x =' on any of these empty boxes, this is the result:

        character: ⋮ (8942, #o21356, #x22ee)
preferred charset: unicode-bmp (Unicode Basic Multilingual Plane (U+0000..U+FFFF))
       code point: 0x22EE
           syntax: . 	which means: punctuation
         category: .:Base
      buffer code: #xE2 #x8B #xAE
        file code: #xE2 #x8B #xAE (encoded by coding system utf-8-unix)
          display: no font available

Character code properties: customize what to show
  name: VERTICAL ELLIPSIS
  general-category: Sm (Symbol, Math)


--
Steve Berman