Blender Git Commit Log

#bugfix #3659

Zero-sized bones in an Armature didn't result in a stable rest position.
This caused bones to rotate to random positions on each editmode exit.

This commit will automatically remove such bones on exit editmode now, and
adds a warning print for it. I've tried to code exception handling for
zero-sized bones, but this is just too hard to get stable. Better to define
by default that Bones always should have a length.

Typically zero-sized bones only get added by accident, for example while
ctrl+clicking new bones.