Validator class bug

Validator class bug

       $ValidationRules = [
                'password' => 'required|min:6',
                'password2' => 'same:password'];

'password' is min 6, but if 'password2' is an empty string, the validation will be successful. Shouldn't be 'password2' same as 'password' min 6 chars long? I think this is a bug.