From: Sandro Santilli <strk@keybit.net>
Date: Wed, 1 Jun 2011 12:31:58 +0000 (+0000)
Subject: The box2d of an empty geometry is NULL, not a point. Closes ticket #938 and regress... 
X-Git-Tag: 2.0.0alpha1~1507
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5c758a4fa9dd1edc585324f7ce273cca2cdfd539;p=postgis

The box2d of an empty geometry is NULL, not a point. Closes ticket #938 and regress-tests it.

git-svn-id: http://svn.osgeo.org/postgis/trunk@7307 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/postgis/lwgeom_box2dfloat4.c b/postgis/lwgeom_box2dfloat4.c
index b330799d2..0fbca2808 100644
--- a/postgis/lwgeom_box2dfloat4.c
+++ b/postgis/lwgeom_box2dfloat4.c
@@ -143,6 +143,10 @@ Datum LWGEOM_to_BOX2DFLOAT4(PG_FUNCTION_ARGS)
 	PG_LWGEOM *lwgeom = (PG_LWGEOM *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
 	BOX2DFLOAT4 *result;
 
+	/* Cannot box empty! */
+	if ( pglwgeom_is_empty(lwgeom) )
+		PG_RETURN_NULL(); 
+
 	result = palloc(sizeof(BOX2DFLOAT4));
 	if ( ! pglwgeom_getbox2d_p(lwgeom, result) )
 	{
diff --git a/regress/tickets.sql b/regress/tickets.sql
index adc228e4d..cade7fcb8 100644
--- a/regress/tickets.sql
+++ b/regress/tickets.sql
@@ -380,6 +380,8 @@ select '#884', id, ST_Within(
 ST_GeomFromText('POINT (-113.4 35.6)', -1), the_geom
 ) from foo;
 
+select '#938', 'POLYGON EMPTY'::geometry::box2d;
+
 DROP TABLE foo;
 
 -- Clean up
diff --git a/regress/tickets_expected b/regress/tickets_expected
index 59b2c86c3..607563d8c 100644
--- a/regress/tickets_expected
+++ b/regress/tickets_expected
@@ -110,3 +110,4 @@ ERROR:  First argument must be a LINESTRING
 #834|GEOMETRYCOLLECTION(POINT(0 0 5),LINESTRING(10 10 5,10 0 5))
 #884|1|f
 #884|2|t
+#938|