adding tests for dropping-then-adding a column

localtests/drop-null-add-not-null/create.sql

@@ -0,0 +1,30 @@
+drop table if exists gh_ost_test;
+create table gh_ost_test (
+  id int auto_increment,
+  c1 int null,
+  c2 int not null,
+  primary key (id)
+) auto_increment=1;
+
+insert into gh_ost_test values (null, null, 17);
+insert into gh_ost_test values (null, null, 19);
+
+drop event if exists gh_ost_test;
+delimiter ;;
+create event gh_ost_test
+  on schedule every 1 second
+  starts current_timestamp
+  ends current_timestamp + interval 60 second
+  on completion not preserve
+  enable
+  do
+begin
+  insert ignore into gh_ost_test values (101, 11, 23);
+  insert ignore into gh_ost_test values (102, 13, 23);
+  insert into gh_ost_test values (null, 17, 23);
+  insert into gh_ost_test values (null, null, 29);
+  set @last_insert_id := last_insert_id();
+  -- update gh_ost_test set c2=c2+@last_insert_id where id=@last_insert_id order by id desc limit 1;
+  delete from gh_ost_test where id=1;
+  delete from gh_ost_test where c1=13; -- id=2
+end ;;

localtests/drop-null-add-not-null/extra_args

@@ -0,0 +1 @@
+--alter="drop column c1, add column c1 int not null after id"