[Fontconfig] Fontconfig cache file update fails on Windows (also Cygwin)

[Werner LEMBERG]

>>> But, most Windows applications have their own fontconfig cache
>>> directories unlike linux applicatons.  In this case, there is no
>>> conflict with other applications even if without locking.
>>
>> Actually, that's a problem -- I wouldn't rely on that behavior
>> staying that way.  It can take several minutes to generate a large
>> font cache -- and doing that for each program would make things
>> even worse.

But this behaviour is unavoidable for any application on Windows using
fontconfig that doesn't get installed within a package framework like
`mxe'.  I guess that 99% of Windows users don't use such a framework –
they simply want to download and use an `app'.  The same is true for
Mac OS.

>>> fontconfig 2.11.1 does not lock the cache while updating it.  It
>>> works fine on Windows.
>>
>> Yeah... just because it works right in isolation doesn't mean it
>> will work right when multiple apps are trying to update it.

How will you enforce a common fontconfig infrastructure for arbitrary
applications?

> It is better that there is a possibility of success rather than a
> way that does not succeed at all, in my humble opinion.

Exactly.


    Werner