Is a varchar primary key case sensitive?

[Kevin Riutort]

Is this a bug or is this the way MySQL (v.3.22.22) is supposed to work:

1) CREATE TABLE test (login varchar(10) NOT NULL, PRIMARY KEY(login));

2) INSERT INTO test (login) VALUES('USERNAME');

3) INSERT INTO test (login) VALUES('username');

--> ERROR 1062: Duplicate entry 'username' for key 1

I guess I was expecting that a varchar should be case sensitive.

Thanks,

Kevin