#
# BUG#6236 - ALTER TABLE MODIFY should set implicit NOT NULL on PK columns
#
create table t1 ( a varchar(10) not null primary key ) engine=myisam;
create table t2 ( a varchar(10) not null primary key ) engine=merge union=(t1);
flush tables;
alter table t1 modify a varchar(10);
show create table t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` varchar(10) NOT NULL,
  PRIMARY KEY (`a`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci UNION=(`t1`)
flush tables;
alter table t1 modify a varchar(10) not null;
show create table t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` varchar(10) NOT NULL,
  PRIMARY KEY (`a`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci UNION=(`t1`)
drop table if exists t1, t2;
