From: Paul Ramsey <pramsey@cleverelephant.ca>
Date: Fri, 12 Jun 2015 19:09:27 +0000 (+0000)
Subject: #3164, ST_ClipByBox2D a little less brittle
X-Git-Tag: 2.2.0rc1~358
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0ec9d8bdd967e86917dae59f043facf05c1b401e;p=postgis

#3164, ST_ClipByBox2D a little less brittle


git-svn-id: http://svn.osgeo.org/postgis/trunk@13669 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/liblwgeom/lwgeom.c b/liblwgeom/lwgeom.c
index 0823f3d1f..017f1c612 100644
--- a/liblwgeom/lwgeom.c
+++ b/liblwgeom/lwgeom.c
@@ -2042,7 +2042,7 @@ lwgeom_subdivide_recursive(const LWGEOM *geom, int maxvertices, int depth, LWCOL
 					/* efficient way to do this? */
 					LWGEOM *clipped = lwgeom_clip_by_rect(geom, clip->xmin, clip->ymin, clip->xmax, clip->ymax);
 					/* Hm, clipping left nothing behind, skip it */
-					if ( lwgeom_is_empty(clipped) )
+					if ( (!clipped) || lwgeom_is_empty(clipped) )
 					{
 						return 0;
 					}
@@ -2077,7 +2077,7 @@ lwgeom_subdivide_recursive(const LWGEOM *geom, int maxvertices, int depth, LWCOL
 			{
 				LWGEOM *clipped = lwgeom_clip_by_rect(geom, clip->xmin, clip->ymin, clip->xmax, clip->ymax);
 				/* Hm, clipping left nothing behind, skip it */
-				if ( lwgeom_is_empty(clipped) )
+				if ( (!clipped) || lwgeom_is_empty(clipped) )
 				{
 					return 0;
 				}
diff --git a/liblwgeom/lwgeom_geos.c b/liblwgeom/lwgeom_geos.c
index 71ff1ca9e..893c8d32c 100644
--- a/liblwgeom/lwgeom_geos.c
+++ b/liblwgeom/lwgeom_geos.c
@@ -841,9 +841,8 @@ lwgeom_clip_by_rect(const LWGEOM *geom1, double x0, double y0, double x1, double
 
 	if (g3 == NULL)
 	{
-	  lwerror("Error performing rectangular clipping: %s",
-	          lwgeom_geos_errmsg);
-		return NULL; /* never get here */
+		lwnotice("Error performing rectangular clipping: %s", lwgeom_geos_errmsg);
+		return NULL;
 	}
 
 	LWDEBUGF(3, "result: %s", GEOSGeomToWKT(g3) ) ;
@@ -853,8 +852,7 @@ lwgeom_clip_by_rect(const LWGEOM *geom1, double x0, double y0, double x1, double
 
 	if (result == NULL)
 	{
-    lwerror("Error performing intersection: GEOS2LWGEOM: %s",
-            lwgeom_geos_errmsg);
+		lwerror("Error performing intersection: GEOS2LWGEOM: %s", lwgeom_geos_errmsg);
 		return NULL ; /* never get here */
 	}
 
diff --git a/postgis/lwgeom_geos.c b/postgis/lwgeom_geos.c
index 779f254bd..9e5865c50 100644
--- a/postgis/lwgeom_geos.c
+++ b/postgis/lwgeom_geos.c
@@ -1634,7 +1634,7 @@ Datum ST_ClipByBox2d(PG_FUNCTION_ARGS)
 	GSERIALIZED *result;
 	LWGEOM *lwgeom1, *lwresult ;
 	const GBOX *bbox1;
-	const GBOX *bbox2;
+	GBOX *bbox2;
 
 	geom1 = PG_GETARG_GSERIALIZED_P(0);
 	lwgeom1 = lwgeom_from_gserialized(geom1) ;
@@ -1648,10 +1648,10 @@ Datum ST_ClipByBox2d(PG_FUNCTION_ARGS)
 
 	/* WARNING: this is really a BOX2DF, use only xmin and ymin fields */
 	bbox2 = (GBOX *)PG_GETARG_POINTER(1);
+	bbox2->flags = 0;
 
 	/* If bbox1 outside of bbox2, return empty */
-	if ( bbox1->xmin > bbox2->xmax || bbox1->xmax < bbox2->xmin ||
-	     bbox1->ymin > bbox2->ymax || bbox1->ymax < bbox2->ymin )
+	if ( ! gbox_overlaps_2d(bbox1, bbox2) )
 	{
 		lwresult = lwgeom_construct_empty(lwgeom1->type, lwgeom1->srid, 0, 0);
 		lwgeom_free(lwgeom1);
@@ -1662,8 +1662,7 @@ Datum ST_ClipByBox2d(PG_FUNCTION_ARGS)
 	}
 
 	/* if bbox1 is covered by bbox2, return lwgeom1 */
-	if ( bbox1->xmax <= bbox2->xmax && bbox1->xmin >= bbox2->xmin &&
-	     bbox1->ymax <= bbox2->ymax && bbox1->ymin >= bbox2->ymin )
+	if ( gbox_contains_2d(bbox2, bbox1) )
 	{
 		lwgeom_free(lwgeom1);
 		PG_RETURN_POINTER(geom1);
@@ -1671,14 +1670,17 @@ Datum ST_ClipByBox2d(PG_FUNCTION_ARGS)
 
 	lwresult = lwgeom_clip_by_rect(lwgeom1, bbox2->xmin, bbox2->ymin,
 	                               bbox2->xmax, bbox2->ymax);
-	lwgeom_free(lwgeom1) ;
-
-	result = geometry_serialize(lwresult) ;
-	lwgeom_free(lwresult) ;
 
+	lwgeom_free(lwgeom1);
 	PG_FREE_IF_COPY(geom1, 0);
 
+	if ( lwresult == NULL ) 
+		PG_RETURN_NULL();
+
+	result = geometry_serialize(lwresult) ;
+	lwgeom_free(lwresult) ;
 	PG_RETURN_POINTER(result);
+	
 #endif /* POSTGIS_GEOS_VERSION >= 35 */
 }