Re: -urw-* font is always used

[Jan D.]

> > > If yes, is it likely/possible that it will also become an issue with 
> > > other
> > > Emacs builds in the future (say when we introduce anti-aliasing or
> > > something)?
>
> > It can be an issue.  Emacs can get in the same problem as KDE in the
> > case above.
>
> Sorry, I wasn't clear: I have no idea what is FontConfig and what 
> piece of
> code uses it.  So my questions were: is only the Gtk port of Emacs
> using FontConfig?  If so, what kind of future changes to Emacs could
> cause it use FontConfig for non-Gtk builds?

Fontconfig is a font naming/discovery library.  It enables software to
call up a font by the name "serif" for example, and then it picks
the best font available based on a configuration file where the
fonts that can be used for "serif" are listed, and what
fonts are actually available on your system.  It then caches this
information for faster lookup next time.  It is this cache that gets
corrupted somehow when different versions of FontConfig is used.
It also notices if fonts has been added to a directory and automatically
makes the new fonts available for applications.

Fontconfig is used together with Xft and Xrender for antialiased fonts.
Currently only Emacs-Gtk uses Fontconfig, i.e. Gtk uses Fontconfig for
the Gtk widgets.
A future Emacs version with support for anti-aliased fonts may use
Fontconfig, I think (but am not sure) that Xft uses it internally.
The anti-aliased patch posted previously used Xft.

        Jan D.