do not process workitems with NULL result

src/libimcv/imv/imv_policy_manager.c

@@ -143,7 +143,8 @@ bool policy_stop(database_t *db, int session_id)
 
 	e = db->query(db,
 			"SELECT w.rec_final, w.result, e.policy FROM workitems AS w "
-			"JOIN enforcements AS e ON w.enforcement = e.id WHERE w.session = ?",
+			"JOIN enforcements AS e ON w.enforcement = e.id "
+			"WHERE w.session = ? AND w.result IS NOT NULL",
 			 DB_INT, session_id, DB_INT, DB_TEXT, DB_INT);
 	if (e)
 	{

src/libimcv/imv/tables.sql

@@ -110,7 +110,7 @@ CREATE TABLE workitems (
   argument text NOT NULL,
   rec_fail integer NOT NULL,
   rec_noresult integer NOT NULL,
-  rec_final integer DEFAULT 3,
+  rec_final integer,
   result text
 );
 DROP INDEX IF EXISTS workitems_session;