Trim at curve crossing

 From:  pressure (PEER)
11423.1 
I'm looking for a way to trim a first curve with a second cutter curve, but only where the first curve actually crosses the cutter and not where it just grazes it.

Like for a line tangent to a circle with the circle as the cutter the line shouldn't get cut at all.

But if the line passes through the center of the circle cutter then I expect the line to get cut into 3 pieces.

- Peer