Re: `set-fontset-font' and ascii characters

[Kenichi Handa <handa@m17n.org>]

In article <87bryj8y94.fsf@ID-87814.user.dfncis.de>, Oliver Scholz <alkibiades@gmx.de> writes:
> I found a bug. Emacs crashes, if you evaluated the following code with
> my patch applied:

> (progn
>   (set-face-font 'default "fontset-default")
>   (set-fontset-font "fontset-default"
> 		    'ascii
> 		    '("helvetica" . "iso8859-1")))

> The critical fault seems to take place in `set_lface_from_font_name'
> in xfaces.c (called from `Finternal_set_lisp_face_attribute'):

>   if (fontset >= 0)
>     font_name = SDATA (fontset_ascii (fontset));

Oops.  Currently, a fontset should have a font name
(i.e. string, not cons of (FAMILY . REGISTRY)) for ascii.
So, if (FAMILY . REGISTRY) is specified, it mast be
transformed to "-FAMILY-*-REGISTRY".  If FAMILY doesn't
contain '-', "*-" must be prepended to FAMILY in advance.
If REGISTRY doesn't contain '-', "-*" must be appended to
REGISTRY in advance.

One more thing to note.  Currently all ascii characters
should have the same font in a fontset.  So, for instance,
(set-fontset-font FONTSET '(?a . ?z) FONT_NAME) must be
inhibited or treated as (set-fontset-font FONTSET 'ascii
FONT_NAME).

These are the dirty parts originating in a bad interaction
between face and fontset.  Clearing them out is in my todo
list for a long time, but I've never had time to work on it.

---
Ken'ichi HANDA
handa@m17n.org