[Fontconfig] mmap-ed caches + patch

[Patrick Lam]

Lubos Lunak wrote:
>  Any cache file I'd say (and yes, I ran fc-cache as root). AFAIK if you 
> truncate a file that's mmap-ed, any access to the no longer existing part of 
> the file results in bad things. I don't know the structure of the cache file, 
> it seems to me it can be built in several steps for different architectures, 
> but I'd expect that the code can't cope with the data simply changing under 
> its hands, and unless the format specifically prevents that I'd expect that 
> to happen. Would there be any problem if you simply unlinked the old file 
> before writing the new one?

I now use FcAtomic to write to these cache files.  Try the latest CVS
version.

pat