create table t1 (a int, b int default (a+1));
insert t1 values (1,10), (2,20), (3,30);
connect  con1, localhost, root;
select a,b,default(b) from t1;
a	b	default(b)
1	10	2
2	20	3
3	30	4
set debug_sync='after_Item_default_value_calculate WAIT_FOR go';
select a,b,default(b) from t1;
connection default;
set debug_sync='ha_write_row_start SIGNAL go';
insert t1 values (100,default(b));
connection con1;
a	b	default(b)
1	10	2
2	20	3
3	30	4
connection default;
drop table t1;
set debug_sync='RESET';