does the test suite clear the previous data? I get troubles in my computer if I do not clear previous polygons before testing last one.

please consider breaking the testsuite into multiple tests to avoid the "clear F" issue (and to make debugging simpler)

The problem's figure is missing. We can imagine one line segment crossing several simple polygons, which can intersect on edges or vertices. The order that we must return is the order in which each polygon is entered. If the same polygon is entered twice, it must appear two times at the output.