Bug fix

Wrong conversion

sql/sql_tvc.cc

@@ -291,8 +291,8 @@ int table_value_constr::save_explain_data_intern(THD *thd,
   explain->select_id= select_lex->select_number;
   explain->select_type= select_lex->type;
   explain->linkage= select_lex->linkage;
-  explain->using_temporary= NULL;
-  explain->using_filesort=  NULL;
+  explain->using_temporary= false;
+  explain->using_filesort= false;
   /* Setting explain->message means that all other members are invalid */
   explain->message= message;