public class TestHHH8784 {

    @SuppressWarnings("deprecation")
    public static void main(String[] args) {
        Configuration configuration = new Configuration()
                .addAnnotatedClass(TestEntity.class)
                .setProperty(AvailableSettings.DIALECT, HibernateDialect.class.getName());

        SessionFactory sf = configuration.buildSessionFactory();

        // throws java.lang.StringIndexOutOfBoundsException: String index out of range: -2
    }

    @Entity
    public static class TestEntity implements Serializable {

        @Id
        @GeneratedValue
        private Long id;

        @Generated(GenerationTime.ALWAYS)
        private Timestamp timestamp = new Timestamp(DateTimeUtils.currentTimeMillis());
    }
}