Things like "CGAL_assertion(denominator != 0)" produced assertion failures for no gain.
So now, the assertion is triggered only if the condition is certain, using CGAL::certainly().
That is, change the following in all assertion files :
((EX)?(static_cast<void>(0)): ::CGAL::assertion_fail( # EX , __FILE__, __LINE__))
to :
(CGAL::certainly(EX)?(static_cast<void>(0)): ::CGAL::assertion_fail( # EX , __FILE__, __LINE__))