[Fontconfig] Status about fontconfig CVS regarding cache handling

[Frederic Crozat]

Le jeudi 16 février 2006 à 10:18 -0500, Patrick Lam a écrit :
> Frederic Crozat wrote:
> > Well, I've just tested here with today CVS snapshot
> > and /usr/share/fonts/ttf/big5/fonts.cache-2 is never removed, when
> > running fc-cache or fc-cache -f :( (and /usr is not read-only).
> 
> But if there's a valid cache, then fontconfig shouldn't be generating a 
> new cache?  I'm confused about how this bug arises.  This situation 
> results in cache removal:
> 
> 1. rm /var/cache/fontconfig/*
> 2. fc-cache
> 3. touch /usr/share/fonts/truetype/ttf-bitstream-vera/fonts.cache-2
> 4. fc-cache
> 
> If in step 3 instead you copy the appropriate file from /var/cache to 
> /usr/share/fonts/truetype/ttf-bitstream-vera/fonts.cache-2, then it also 
> deletes the cache in 
> /usr/share/fonts/truetype/ttf-bitstream-vera/fonts.cache-2.

On my test case, cache was created with fontconfig 2.3.92 (ie before the
switch to /var/cache/fontconfig). Since fonts didn't change, cache
"might" look valid but I doubt it does since cache format has changed
since 2.3.92 ..

> > I think we should try to really nail that bug, otherwise people will end
> > with unstable cache behaviour. Maybe adding a "--remove-obsolete-cache"
> > option to fc-cache to remove fonts.cache-2 outside /var/cache/fontconfig
> > would be a solution (and it could remove fonts.cache-1 too if we want ;)
> 
> I'll add --really-force which will remove all existing cache-2 files.  I 
> don't see a reason to remove fonts.cache-1 files, though.

Thanks. I was thinking removing fonts.cache-1 might be a good idea for
people who will migrate to 2.4.0 (when it is released) so old cache
don't stay on harddrive. But it might be a problem if directories are
used with programs using fontconfig 2.2.x and 2.4.x at the same time.
-- 
Frederic Crozat <fcrozat at mandriva.com>
Mandriva