Re: Line intersection point is wrong

> ... also, a quick review of all the LINE-related code in geo_ops.c
> says that it's just *full* of bugs. Aside from the issues already
> mentioned:
>
> line_recv fails to reject A=B=0
> line_perp can get division by zero
> silly coding in line_eq (A and B can't both be zero, no need to look at C)
> line_distance ignores l1->A, suspicious
> close_pl busted in same way as line_interpt_internal

I have tried to fix them. Patch attached.

> close_ps ignores tmp->B, suspicious

I think we better throw this one away, and implement another one using
close_pl().