Prevent dereferencing of a null pointer

[ahoenselaar]

In lines 2078 and 2085, intersect_line_with_segment is intentionally called with 0 as the fifth argument.

[stevengj]

Good catch; it looks like we pass NULL here:

libctl/utils/geom.c

Line 2085 in 2636a59

int status = intersect_line_with_segment(q0, startPoint, endPoint, xAxis, 0);