Ugly case

[liberostelios]

This line is getting this ugly shape after trim. The reason is that we don't build a straight segment between the intersection of the two lines and the end point, but we try to maintain the original curvature of the line.

We can fix that by checking if something peculiar happens (e.g., in this case the length gets almost twice as long as the original) in which case we fall back to constructing a straight segment.