Changing login password deletes secret answer

Go to 'My Profile'. Set secret question and answer to non-empty strings and save. Then change password and save. User's secret answer is deleted (you can see this in the database).

I'm going to assume this is a bug, rather than a security feature because

• There's no warning to the user
• It inadvertently re-instates the secret question because its on the same form

I think the problem is HibernateUserDAO.updateUserPassword(..) which saves a new LoginCredentials object for the user with nulls for secret question and answer.