i erroneously tried to calculate the intersection of a line with itself.
it caused a segfault.
(clear)
(define l (build-line 2))
(with-primitive l
(pdata-set "p" 0 (vector 0 -5 0))
(pdata-set "p" 1 (vector 3 5 0))
(line-intersect (pdata-ref "p" 0) (pdata-ref "p" 1)))
best,
gabor