Sometimes start point of the intersection line is in the surface boundary strictly. I.e. the parameter of this point in the surface can be equal to both 0 or 2*PI equivalently. It is important to chose correct parameter value.
The algorithm of prediction is based on monotonicity property (see CylCylMonotonicity(...) function in IntPatch_ImpImpIntersection_4.gxx). Now, this function is used wrongly. The fix improves this situation.
Small optimization in the code.
Creation of test cases .
The logic of returning value by the method BoundariesComputing() has been corrected.