MCOL-1734 CS now behaves similar to MDB in case of

NOT IN + correlated subquery if the subquery returns empty set.
CS now returns full outer record set.

gcc 8.2 complains about unused variable in ha_mcs_impl.cc

dbcon/mysql/ha_mcs_impl.cpp

@@ -2303,7 +2303,7 @@ int ha_mcs_impl_direct_update_delete_rows(bool execute, ha_rows *affected_rows)
         *affected_rows = ci->affectedRows;
     }
 
-    return 0;
+    return rc;
 }
 
 int ha_mcs_impl_rnd_init(TABLE* table)