[Fontconfig] Status about fontconfig CVS regarding cache handling

[Patrick Lam]

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.

> 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.

pat