Hi,
would it be an option for you to do
newcircleA := circleA cutbefore P1 cutafter P2 -- cycle ;
In that case you avoid extra points.
You are right, in this simple case, your solution avoid the problem, and is applicable in some of my cases (I have to rethink the code). Thanks for the proposition !
But in others cases this is not possible (I think). Imagine I wish to do a « partial moon » from the two circles in my minimal example (see bottom right of the attached pdf):