[Tuxmath-devel] PNG cache stored in user data dir now

[Wenyuan G. <guo...@gm...>]

Hi all,

I have fixed the code to store PNG cache files under user's tuxmath
data dir, e.g. /username/.tuxmath/caches. The git repository is
updated.

Moreover, if for any reason the cache file is not created, the program
just gives up caching, instead of generating a segfault :=). Any
feedbacks are welcome!

Cheers
Wenyuan