[postgis-tickets] r17166 - Attempt to catch point-on-edge case before more subtle tests

[Paul Ramsey]

Author: pramsey
Date: 2019-01-17 13:49:22 -0800 (Thu, 17 Jan 2019)
New Revision: 17166

Modified:
   trunk/liblwgeom/lwgeodetic.c
Log:
Attempt to catch point-on-edge case before more subtle tests
References #4298


Modified: trunk/liblwgeom/lwgeodetic.c
===================================================================
--- trunk/liblwgeom/lwgeodetic.c	2019-01-17 21:09:36 UTC (rev 17165)
+++ trunk/liblwgeom/lwgeodetic.c	2019-01-17 21:49:22 UTC (rev 17166)
@@ -36,6 +36,15 @@
 int gbox_geocentric_slow = LW_FALSE;
 
 /**
+* Utility function for ptarray_contains_point_sphere()
+*/
+static int
+point3d_equals(const POINT3D *p1, const POINT3D *p2)
+{
+	return FP_EQUALS(p1->x, p2->x) && FP_EQUALS(p1->y, p2->y) && FP_EQUALS(p1->z, p2->z);
+}
+
+/**
 * Convert a longitude to the range of -PI,PI
 */
 double longitude_radians_normalize(double lon)
@@ -3373,6 +3382,10 @@
 	POINT3D AC; /* Center point of A1/A2 */
 	double min_similarity, similarity;
 
+	/* Boundary case */
+	if (point3d_equals(A1, P) || point3d_equals(A2, P))
+		return LW_TRUE;
+
 	/* The normalized sum bisects the angle between start and end. */
 	vector_sum(A1, A2, &AC);
 	normalize(&AC);
@@ -3381,7 +3394,7 @@
 	min_similarity = dot_product(A1, &AC);
 
 	/* If the edge is sufficiently curved, use the dot product test */
-	if (fabs(1.0 - min_similarity) > 1e-10 )
+	if (fabs(1.0 - min_similarity) > 1e-10)
 	{
 		/* The projection of candidate p onto the center */
 		similarity = dot_product(P, &AC);
@@ -3390,7 +3403,7 @@
 		/* the projection of the start point, the candidate */
 		/* must be closer to the center than the start, so */
 		/* therefor inside the cone */
-		if ( similarity > min_similarity )
+		if (similarity > min_similarity)
 		{
 			return LW_TRUE;
 		}
@@ -3425,14 +3438,6 @@
 }
 
 
-/**
-* Utility function for ptarray_contains_point_sphere()
-*/
-static int
-point3d_equals(const POINT3D *p1, const POINT3D *p2)
-{
-	return FP_EQUALS(p1->x, p2->x) && FP_EQUALS(p1->y, p2->y) && FP_EQUALS(p1->z, p2->z);
-}
 
 /**
 * Utility function for edge_intersects(), signum with a tolerance