diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index b518b1b8c71..889d4653e14 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.115 2010/01/02 16:57:58 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/mmgr/portalmem.c,v 1.116 2010/01/18 02:30:25 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -328,6 +328,13 @@ PortalReleaseCachedPlan(Portal portal)
 	{
 		ReleaseCachedPlan(portal->cplan, false);
 		portal->cplan = NULL;
+
+		/*
+		 * We must also clear portal->stmts which is now a dangling
+		 * reference to the cached plan's plan list.  This protects any
+		 * code that might try to examine the Portal later.
+		 */
+		portal->stmts = NIL;
 	}
 }
 
@@ -395,8 +402,7 @@ PortalDrop(Portal portal, bool isTopCommit)
 		(*portal->cleanup) (portal);
 
 	/* drop cached plan reference, if any */
-	if (portal->cplan)
-		PortalReleaseCachedPlan(portal);
+	PortalReleaseCachedPlan(portal);
 
 	/*
 	 * Release any resources still attached to the portal.	There are several
@@ -529,8 +535,7 @@ CommitHoldablePortals(void)
 			PersistHoldablePortal(portal);
 
 			/* drop cached plan reference, if any */
-			if (portal->cplan)
-				PortalReleaseCachedPlan(portal);
+			PortalReleaseCachedPlan(portal);
 
 			/*
 			 * Any resources belonging to the portal will be released in the
@@ -680,8 +685,7 @@ AtAbort_Portals(void)
 		}
 
 		/* drop cached plan reference, if any */
-		if (portal->cplan)
-			PortalReleaseCachedPlan(portal);
+		PortalReleaseCachedPlan(portal);
 
 		/*
 		 * Any resources belonging to the portal will be released in the
@@ -823,8 +827,7 @@ AtSubAbort_Portals(SubTransactionId mySubid,
 			}
 
 			/* drop cached plan reference, if any */
-			if (portal->cplan)
-				PortalReleaseCachedPlan(portal);
+			PortalReleaseCachedPlan(portal);
 
 			/*
 			 * Any resources belonging to the portal will be released in the