Fix invalid input text

Signed-off-by: Dima Kuznetsov <dkuznets@redhat.com>
Change exit to delete only upon initialization

Signed-off-by: Dima Kuznetsov <dkuznets@redhat.com>
Add fuzz tests

Signed-off-by: Dima Kuznetsov <dkuznets@redhat.com>