From: Sandro Santilli <strk@keybit.net>
Date: Thu, 2 Oct 2014 08:03:25 +0000 (+0000)
Subject: Fix memory error in ST_ClipByBox2D (#2950)
X-Git-Tag: 2.2.0rc1~816
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6a26a66ebd196815ec17e1b593e6c4f013e81773;p=postgis

Fix memory error in ST_ClipByBox2D (#2950)

git-svn-id: http://svn.osgeo.org/postgis/trunk@13028 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/liblwgeom/cunit/cu_clip_by_rect.c b/liblwgeom/cunit/cu_clip_by_rect.c
index f681eb413..e962e3253 100644
--- a/liblwgeom/cunit/cu_clip_by_rect.c
+++ b/liblwgeom/cunit/cu_clip_by_rect.c
@@ -42,6 +42,14 @@ static void test_lwgeom_clip_by_rect(void)
 	CU_ASSERT_STRING_EQUAL(wkt, tmp)
 	lwfree(tmp); lwgeom_free(out); lwgeom_free(in);
 
+  /* Disjoint polygon */
+	wkt = "POLYGON((311017 4773762,311016 4773749,311006 4773744,310990 4773748,310980 4773758,310985 4773771,311003 4773776,311017 4773762))";
+	in = lwgeom_from_wkt(wkt, LW_PARSER_CHECK_NONE);
+	out = lwgeom_clip_by_rect(in, -80, -80, 80, 80);
+	//tmp = lwgeom_to_ewkt(out); printf("%s\n", tmp); lwfree(tmp);
+	CU_ASSERT(lwgeom_is_empty(out));
+	lwgeom_free(out); lwgeom_free(in);
+
 #endif /* POSTGIS_GEOS_VERSION >= 35 */
 }
 
diff --git a/postgis/lwgeom_geos.c b/postgis/lwgeom_geos.c
index ac559fdea..ce3a5092f 100644
--- a/postgis/lwgeom_geos.c
+++ b/postgis/lwgeom_geos.c
@@ -1671,7 +1671,7 @@ Datum ST_ClipByBox2d(PG_FUNCTION_ARGS)
 	if ( LW_FALSE == gbox_overlaps_2d(bbox1, bbox2) ) {
 		lwresult = lwgeom_construct_empty(lwgeom1->type, lwgeom1->srid, 0, 0);
 		lwgeom_free(lwgeom1);
-		PG_FREE_IF_COPY(geom1, 1);
+		PG_FREE_IF_COPY(geom1, 0);
 		result = geometry_serialize(lwresult) ;
 		lwgeom_free(lwresult) ;
 		PG_RETURN_POINTER(result);
diff --git a/regress/clipbybox2d.sql b/regress/clipbybox2d.sql
index 1f863de34..1c9a4a6f7 100644
--- a/regress/clipbybox2d.sql
+++ b/regress/clipbybox2d.sql
@@ -15,4 +15,9 @@ SELECT ST_AsText(ST_ClipByBox2d('POLYGON((0 0,5 4,5 6,0 10,10 10,5 6,5 4,10 0,0
 SELECT ST_AsText(ST_ClipByBox2d(
   '0103000000010000000400000000000000000000000000000000000000000000000000244000000000000000000000000000002440000000000000244000000000000000000000000000002440'
   , ST_MakeEnvelope(2,2,5,5)));
-
+-- Geometry disjoint from box, from a table
+-- See http://trac.osgeo.org/postgis/ticket/2950
+CREATE TEMPORARY TABLE t AS SELECT
+'SRID=3857;POLYGON((41 20,41 0,21 0,1 20,1 40,21 40,41 20))'
+::geometry g;
+SELECT ST_AsEWKT(ST_ClipByBox2d(g, ST_MakeEnvelope(-20,-20,-10,-10))) FROM t;
diff --git a/regress/clipbybox2d_expected b/regress/clipbybox2d_expected
index 299e0b6eb..8243e44fa 100644
--- a/regress/clipbybox2d_expected
+++ b/regress/clipbybox2d_expected
@@ -5,3 +5,4 @@ POINT(2 2)
 POLYGON((2 2,8 2,2 8,8 8,2 2))
 POLYGON((2.5 2,5 4,5 5,5 4,7.5 2,2.5 2))
 POLYGON((2 2,2 5,5 5,5 2,2 2))
+SRID=3857;POLYGON EMPTY