[postgis-tickets] r15643 - #3246, comment in code on the memory behavior of lwcollection_extract()

[Paul Ramsey]

Author: pramsey
Date: 2017-09-06 14:00:51 -0700 (Wed, 06 Sep 2017)
New Revision: 15643

Modified:
   trunk/liblwgeom/liblwgeom.h.in
   trunk/liblwgeom/lwcollection.c
Log:
#3246, comment in code on the memory behavior of lwcollection_extract()


Modified: trunk/liblwgeom/liblwgeom.h.in
===================================================================
--- trunk/liblwgeom/liblwgeom.h.in	2017-09-06 20:14:06 UTC (rev 15642)
+++ trunk/liblwgeom/liblwgeom.h.in	2017-09-06 21:00:51 UTC (rev 15643)
@@ -1056,6 +1056,9 @@
  ******************************************************************/
 
 LWGEOM *lwcollection_getsubgeom(LWCOLLECTION *col, int gnum);
+
+/* WARNING: the output will contain references to geometries in the input, */
+/* so the result must be carefully released, not freed. */
 LWCOLLECTION* lwcollection_extract(LWCOLLECTION *col, int type);
 
 

Modified: trunk/liblwgeom/lwcollection.c
===================================================================
--- trunk/liblwgeom/lwcollection.c	2017-09-06 20:14:06 UTC (rev 15642)
+++ trunk/liblwgeom/lwcollection.c	2017-09-06 21:00:51 UTC (rev 15643)
@@ -362,6 +362,8 @@
 /**
 * Takes a potentially heterogeneous collection and returns a homogeneous
 * collection consisting only of the specified type.
+* WARNING: the output will contain references to geometries in the input, 
+* so the result must be carefully released, not freed.
 */
 LWCOLLECTION* lwcollection_extract(LWCOLLECTION *col, int type)
 {
@@ -429,6 +431,10 @@
 				geomlist[geomlistlen] = tmpcol->geoms[j];
 				geomlistlen++;
 			}
+			if (tmpcol->geoms)
+				lwfree(tmpcol->geoms);
+			if (tmpcol->bbox)
+				lwfree(tmpcol->bbox);
 			lwfree(tmpcol);
 		}
 	}