Comment 0 for bug 1797562

pcb crashes under certain conditions when a polygon, or a segment of a polygon has zero area. For example, creating a polygon with the following six points:

 1 ______ 6
  | |
  | |
 3| |
  |\ |
  | \ |
  | \___|
 2 4 5

If you then attempt to move point 2, pcb will die. Obviously this is not a shape that people are frequently interested in, but, a simpler case could happen accidentally quite easily:

1,3 ----------- 2

While debugging something else, I stumbled on this. In a debug build, there is failed assertion in polygon1.c:

Assertion failed: (poly_Valid (np)), function original_poly, file ../../src/polygon.c, line 329.

This appears to check the number of points in a polygon against the number of items found in an r_search.