Please describe the problem:
Fonts like Yanone Kaffesatz Thin, Light, Regular and Bold or DejaVu Sans
ExtraLight, Book and Bold aren't named consistantly across apps using
Pango/fontconfig.

http://dejavu.sourceforge.net/snapshots/
http://www.yanone.de/schriftgestaltung/kaffeesatz/


Steps to reproduce:
The GTK font selector and pango-view have different behaviours when previewing
these fonts.

Actual results:
In the GTK Font Selector Yanon Kaffesatz Thin, Light and Regular are previewed
and applied as only one of them (probably Light), only Bold has a different
weight. They are remembered as Regular by the application.

DejaVu Extralight, Book and Bold are previewed as they should be, with different
weights. The are preview and applied correctly.

pango-view does not render the proper font when using --font="DejaVuSans
ExtraLight" or "DejaVu Sans ExtraLight", it uses the default font. However it
uses ExtraLight when given --font="DejaVuSans Light".
Yanone Kaffesatz variants work with pango-view, except for --font="Yanone
Kaffeesatz Thin" which gives the default font.

Expected results:
Each fonts variant should be accessible in a consistant and clear manner.

Does this happen every time?
A similar problem occurs in Inkscape. Gimp has fontconfig renaming ExtraLight to
Ultra-Light.

Other information:
fc-list matches "Yanone Kaffeesatz" with:
Yanone Kaffeesatz:style=Thin,Regular
Yanone Kaffeesatz:style=Bold
Yanone Kaffeesatz:style=Light,Regular
Yanone Kaffeesatz:style=Regular

fc-list matches "DejaVu Sans" with
DejaVu Sans:style=ExtraLight
DejaVu Sans:style=BoldOblique
DejaVu Sans:style=Oblique
DejaVu Sans:style=Bold
DejaVu Sans:style=Book