[postgis-commits] svn - r3803 - trunk/liblwgeom

[postgis-commits at postgis.refractions.net]

Author: pramsey
Date: 2009-03-08 08:37:27 -0700 (Sun, 08 Mar 2009)
New Revision: 3803

Modified:
   trunk/liblwgeom/lwgeom_api.c
Log:
Fix for GBT #116, EMPTY hex polygon no longer causes crash.


Modified: trunk/liblwgeom/lwgeom_api.c
===================================================================
--- trunk/liblwgeom/lwgeom_api.c	2009-03-08 14:36:05 UTC (rev 3802)
+++ trunk/liblwgeom/lwgeom_api.c	2009-03-08 15:37:27 UTC (rev 3803)
@@ -1645,8 +1645,8 @@
 {
 	int type = lwgeom_getType(srl[0]);
 	int t;
-	uchar *loc;
-	uint32 ngeoms;
+	uchar *loc = srl;
+	uint32 nelems;
 	BOX3D *result;
 	BOX3D b1;
 	int sub_size;
@@ -1654,6 +1654,23 @@
 
 	LWDEBUGF(2, "compute_serialized_box3d called on type %d", type);
 
+	loc += 1; /* Move past the 'type' byte. */
+
+	if (lwgeom_hasBBOX(srl[0]))
+	{
+		loc += sizeof(BOX2DFLOAT4); /* Move past the bbox */
+	}
+
+	if (lwgeom_hasSRID(srl[0]) )
+	{
+		loc +=4; /* Move past the SRID */
+	}
+
+	nelems = lw_get_uint32(loc);
+
+	/* No elements? This is an EMPTY geometry. */
+	if ( nelems == 0 ) return NULL;
+
 	if (type == POINTTYPE)
 	{
 		LWPOINT *pt = lwpoint_deserialize(srl);
@@ -1700,24 +1717,11 @@
 		return NULL;
 	}
 
-	loc = srl+1;
-
-	if (lwgeom_hasBBOX(srl[0]))
-	{
-		loc += sizeof(BOX2DFLOAT4);
-	}
-
-	if (lwgeom_hasSRID(srl[0]) )
-	{
-		loc +=4;
-	}
-
-	ngeoms = lw_get_uint32(loc);
 	loc += 4;
 
 	/* each sub-type */
 	result = NULL;
-	for (t=0; t<ngeoms; t++)
+	for (t=0; t<nelems; t++)
 	{
 		if ( compute_serialized_box3d_p(loc, &b1) ) 
 		{