Here's another little tyrutils patch: in qbsp, I believe the
calculation of the "disksize" field of the miptex lumps when using
WAD3 textures is missing the size of the dmiptex_t struct (40 bytes),
causing the resulting bsp file to be slightly truncated.
I noticed this because one of Tronyn's levels (jam2_tronyn.bsp) was
crashing Quakespasm for me; it turned out the engine was trying to
read 40 bytes past the end of the file when loading the last texture
in the bsp. I got him to send over his map source, wads, and compiler;
he was using tyrutils 0.15 and wad3 format textures, and I confirmed
that this patch fixes the engine crash.
Signed-off-by: Kevin Shanahan <kmshanah@disenchant.net>