When edit column default value, the initial show is not consistent with the edited value

About column default value,have the below problem
(1)create table, add column col1, the type is char(1), the default value is 1
(2)then create this table
(3)Edit this table, find the default value is 1
(4)Edit this column, popup the edit attribute dialog, then click ok
(5)Find the default value is '1',this will lead to the default value change

Other type also have this bug.