better fix to ITS#3433

servers/slapd/backover.c

@@ -260,10 +260,9 @@ over_op_func(
 	slap_callback cb = {NULL, over_back_response, NULL, NULL};
 	int rc = SLAP_CB_CONTINUE;
 
-	if ( op->o_bd == NULL ) {
-		/* FIXME: happens for instance during abandon... */
-		return 0;
-	}
+	/* FIXME: used to happen for instance during abandon
+	 * when global overlays are used... */
+	assert( op->o_bd != NULL );
 
 	oi = op->o_bd->bd_info->bi_private;
 	on = oi->oi_list;

servers/slapd/connection.c

@@ -722,6 +722,7 @@ static void connection_abandon( Connection *c )
 		next = LDAP_STAILQ_NEXT( o, o_next );
 		op.orn_msgid = o->o_msgid;
 		o->o_abandon = 1;
+		op.o_bd = frontendDB;
 		frontendDB->be_abandon( &op, &rs );
 	}