[postgis-tickets] r17176 - Avoid passing a NULL pointer to GEOSisEmpty

[Raul]

Author: algunenano
Date: 2019-01-18 08:06:56 -0800 (Fri, 18 Jan 2019)
New Revision: 17176

Modified:
   branches/2.4/NEWS
   branches/2.4/liblwgeom/lwgeom_geos_clean.c
   branches/2.4/liblwgeom/lwgeom_geos_cluster.c
Log:
Avoid passing a NULL pointer to GEOSisEmpty

References #4275



Modified: branches/2.4/NEWS
===================================================================
--- branches/2.4/NEWS	2019-01-18 16:06:14 UTC (rev 17175)
+++ branches/2.4/NEWS	2019-01-18 16:06:56 UTC (rev 17176)
@@ -12,6 +12,7 @@
   - #4290, More robust distance calculations in geography (Paul Ramsey)
   - #4292, ST_AsMVT: parse JSON numeric values with decimals as doubles (Raúl Marín)
   - #4289, ST_AsMVTGeom: Transform coordinates space before clipping (Raúl Marín)
+  - #4275, Avoid passing a NULL pointer to GEOSisEmpty (Raúl Marín)
 
 
 PostGIS 2.4.6

Modified: branches/2.4/liblwgeom/lwgeom_geos_clean.c
===================================================================
--- branches/2.4/liblwgeom/lwgeom_geos_clean.c	2019-01-18 16:06:14 UTC (rev 17175)
+++ branches/2.4/liblwgeom/lwgeom_geos_clean.c	2019-01-18 16:06:56 UTC (rev 17176)
@@ -698,10 +698,13 @@
 		const GEOSGeometry* g = GEOSGetGeometryN(gin, i);
 		GEOSGeometry* vg;
 		vg = LWGEOM_GEOS_makeValidLine(g);
-		if ( GEOSisEmpty(vg) )
+		/* Drop any invalid or empty geometry */
+		if (!vg)
+			continue;
+		if (GEOSisEmpty(vg))
 		{
-			/* we don't care about this one */
 			GEOSGeom_destroy(vg);
+			continue;
 		}
 		if ( GEOSGeomTypeId(vg) == GEOS_POINT )
 		{
@@ -960,7 +963,7 @@
 			pd = GEOSDifference(pi, po); /* input points - output points */
 			GEOSGeom_destroy(pi);
 			GEOSGeom_destroy(po);
-			loss = !GEOSisEmpty(pd);
+			loss = pd && !GEOSisEmpty(pd);
 			GEOSGeom_destroy(pd);
 			if ( loss )
 			{

Modified: branches/2.4/liblwgeom/lwgeom_geos_cluster.c
===================================================================
--- branches/2.4/liblwgeom/lwgeom_geos_cluster.c	2019-01-18 16:06:14 UTC (rev 17175)
+++ branches/2.4/liblwgeom/lwgeom_geos_cluster.c	2019-01-18 16:06:56 UTC (rev 17176)
@@ -178,7 +178,7 @@
 	{
 		const GEOSPreparedGeometry* prep = NULL;
 
-		if (GEOSisEmpty(geoms[p]))
+		if (!geoms[p] || GEOSisEmpty(geoms[p]))
 			continue;
 
 		cxt.num_items_found = 0;