Writes are committed immediately during a JPA/JTA transaction in EAP

Issue

• A persistence unit is configured as below

    <persistence-unit name="MyTestUnit" transaction-type="JTA">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        ...
        <properties>
            <property name="hibernate.connection.driver_class" value="..." />
            <property name="hibernate.connection.url" value="..." />
            <property name="hibernate.connection.username" value="..." />
            <property name="hibernate.connection.password" value="..." />
            <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect" />
            ...
        </properties>
    </persistence-unit>

• A transaction executes as below

    txMgr.begin();

    // Hook the entity manager into transaction events (e.g. commit) - not required in most environments
    entityManager.joinTransaction();

    // Write is not immediate on the persist() call, it is deferred until the first flush
    entityManager.persist(new Event("meeting"));

    // A committed write occurs in the process of executing the query below
    entityManager.createQuery("from Event").getResultList().size();

    // This rollback has no effect
    txMgr.rollback();

    // The assertion fails due to the write above
    Assert.assertEquals(0, entityManager.createQuery("from Event").getResultList().size());