ATSU direct layout occasionally/unpredictably giving callback a null line; deal with it.
ATSU direct layout occasionally/unpredictably giving callback a null line;
deal with it.

adamlwgriffiths/Pyglet,niklaskorz/pyglet,adamlwgriffiths/Pyglet,seeminglee/pyglet64,niklaskorz/pyglet,seeminglee/pyglet64,seeminglee/pyglet64,adamlwgriffiths/Pyglet,adamlwgriffiths/Pyglet,niklaskorz/pyglet,niklaskorz/pyglet