Vlib: fix segments_x_ray(), Vect_point_in_poly() and Vect_point_in_area_outer_ring() must return the same result

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@64201 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/vector/Vlib/poly.c

@@ -633,7 +633,7 @@ static int segments_x_ray(double X, double Y, const struct line_pnts *Points)
 	    x_inter = dig_x_intersect(x1, x2, y1, y2, Y);
 	    G_debug(3, "x_inter = %f", x_inter);
 	    if (x_inter == X)
-		return 1;	/* point on segment, but assume inside ? */
+		return -1;	/* point on segment, do not assume inside/outside */
 	    else if (x_inter > X)
 		n_intersects++;