Document expected behavior for degenerate polygons

[HansBrende]

I can't find any documentation on what the expected behavior is for degenerate polygons (i.e., polygons formed by only 1 or 2 vertexes).

Use-case: I am trying to prevent a user from drawing polygons in certain restricted areas on a map. But to draw a polygon, you first start off with only 1, then 2 points defining the polygon (each time the user clicks the map, a new vertex is added). So, do I need to use a different library to determine if the first point, then first line segment overlaps the restricted areas, before switching to this library when the 3rd vertex is added? I'm using intersection to determine if there is any intersection.

From my own testing, it seems like intersection does not work for degenerate polygons... but it would have been nice if this were documented. Even nicer: if intersection would simply work for degenerate polygons.

[z3dev]

See the definition of Polygon