--- /dev/null
+DESCRIPTION OF PROBLEM:
+=======================
+
+The 4-sided brush in the middle of the room (brush 0) has a duplicate plane.
+The last side (side 4) is a duplicate of the third side (side 2) with the
+vertexes re-arranged.
+
+I wanted to make sure that ChopWindingInPlaceAccu() is doing the right thing
+by setting a winding to NULL when all its points lie on the plane that the
+winding is being chopped with. This seems to be the case. My concern was
+that both windings for that duplicate plane will be NULL'ed out.
+
+Seems that some other code might be fixing duplicate planes. That's OK.