Intersection of cylinder and cone produces open curve

For co-linear surfaces, GeomAPI_IntSS produces one closed and one open curve. The latter has a gap of ~ 1.07mm, which is small relative to its size, yet is a big absolute number and thus is considered wrong.

restore surface1_draw s1
restore surface2_draw s2
intersect r s1 s2
#r_1 is closed
cvalue r_2 0 x y z
vertex v0 x y z
cvalue r_2 1 x y z
vertex v1 x y z
distmin d v0 v1
dump d_val


*********** Dump of d_val *************
1.07637238643976