Blender Git Loki

adaptive_cloth: fix: Mesh: collapse edge: n2 not updated for v1

A simple solution that is extremely difficult to debug. This
particular part of the collapse edge function is run rarely and to
make this particular bug even harder to find is that only a subsequent
operation will show any signs of a problem.

One way to trigger this bug is to static remesh Suzanne (Blender
monkey) at 0.005 or lower minimum size. This leads to a crash due to a
bad optional access of a node.

The vert refers to the node but the node doesn't refer to the vert. So
once this sort of situation is created, when that vert's nodes need to
be used, it leads to a bad optional access.

Such a simple fix :)