[Fontconfig] Font installation strangeness

[John Coppens]

Hello all.

After updating quite a few packages, at some point I noticed that some
of my fonts had disappeared. This wasn't too bad till I had to update a
movie title, and the font I needed had disappeared too.
(Note: When I say 'appear' I mean become available in the GIMP font
dialog, or in Inkscape).

After a lot of experimenting, I found that renaming the fonts made the
appear again. (and renaming the back, mad them disappear again!)

I went to /var/cache/fontconfig, and found several cache files ending
on -x86, while my system is 64, so I deleted _all_ of files there,
and regenerated them with fc-cache. Same thing - only renaming caused
the fonts to be included.

I straced fc-cache, and find the new fonts _are_ opened, and the
following mmap, makes me suspect they are accepted too (by fc-cache).
Also tried to run mkfontscale/mkfontdir between updates.

I first detected the renaming issue by changing the extension from .TTF
to .ttf, but it seems more general than that - just changing any letter
in the name works. And no, 'fc-cache --force' doesn't solve the problem
either.

Can someone please indicate me where to look?

fc-cache is version 2.6.0, distro is Slackware 13.1.

John