7.8 alpha 2

[Jonas Walld�n @ Pike developers forum]

I've now tracked down and fixed the bug. Ironically it's Mirar that
caused it (granted a long time ago) by "#define unsigned int size_t"
which isn't valid on a 64-bit machine. I believe it could have caused
overwriting of as much memory as the resulting JPEG image occupied
outside of the initial buffer size.