Hi, Sachin! On Jan 29, Sachin Setiya wrote:

commit 5bd97f22094f3b6a658d503f98022ccd9076bb19 Author: Sachin Setiya Date: Mon Jan 29 12:31:07 2018 +0530

MDEV-14849 CREATE + ALTER with user-invisible columns produce ...

Problem:- create or replace table t1 (pk int auto_increment primary key invisible, i int); alter table t1 modify pk int invisible; This last alter makes a invisible column which is not null and does not have default value.

Analysis:- This is caused because our error check for NOT_NULL_FLAG and NO_DEFAULT_VALUE_FLAG flag misses this sql_field , but this is not the fault of error check :).Actually this field come via mysql_prepare_alter_table and it does not have NO_DEFAULT_VALUE_FLAG flag turned on. (If it was create table NO_DEFAULT_VALUE_FLAG would have turned on Column_definition::check) and this would have generated error.

Solution:- I have moved the error check to kind last of mysql_prepare_create_table because upto this point we have applied NO_DEFAULT_VALUE_FLAG to required column.

ok to push! Regards, Sergei Chief Architect MariaDB and security@mariadb.org