[Fontconfig] GTK <-> fontconfig <-> XLFD font name translation

[Dmitry Karasik]

Hello all,

Do you know how do GTK font names map onto fontconfig
and/or XLFD name space? I'm confused, because
GTK font selection 'fixed 13' corresponds to the font
I identified in XLFD as -*-fixed-*-*-*-*-20-*-*-*-*-*-*-*,
and fontconfig result of 'fc-match fixed-13' is yet something
else.

The problem I'm trying to solve is to teach a particular GTK2
application to use my own koi8-r bitmap font, but it is neither
shown in GTK font selector, nor is used when I explicitly 
give the font name, that apparently should be in GTK format.

The reason I'm asking here, is that during my experiments
I added set of iso8859-1 and koi8-r bitmap fonts of the same
family, and both in GTK font dialog and the output of fc-list,
only iso8859-1 entries are present:

Such as, there are two pcf files, ibm-vio-12x30-iso8859-1.pcf
and ibm-vio-12x30-koi8-r.pcf, but only the former is shown
by fc-list:
 
 ibm\-vio\-12x30\-iso8859\-1.pcf:style=Regular

Any ideas?

Thanks,

-- 
Sincerely,
     Dmitry Karasik