Creating a Polygon with the topbar can deform the Polygon

[linusha]

I am not 100% sure if categorizing this as a bug is correct, but when instantiating a Polygon with the topbar, it can easily happen that the polygon deforms into a straight line. This can also be done when just creating a polygon and then decreasing its width/height enough so that it becomes a line and then increasing the widht/height again.

There is a certain logic to this behavior, but I would think that this is nearly never what one expects when doing such an operation. I am not sure yet about a good way to fix this...

Here's a video illustrating what I mean:

polygon_mayhem.mp4

Note, that the polygons itself are all okay and activating the control points on a line generated in such a manner will yield 10 control points as one would expect from the star.