#247 Default to non-durable topic subscr.

[Craig Demyanovich]

While deploying a message-driven bean that subscribes
to a non-durable topic, JBoss 2.4.7 indicated a
NullPointerException in
MessageDrivenMetaData.importEjbJarXml(). An
analysis of the JBoss code revealed that this exception
was thrown due to the fact that the subscr variable in
the aforementioned method was not checked for null
before calling methods on it.

The subscr variable was null because the subscription-
durability element was not present in the ejb-jar.xml
deployment descriptor for this bean. According to the
EJB 2.0 specification, section 15.4.9, a non-durable
subscription should be assumed if the subscription-
durability element is not present. The attached patch
contains a very minor fix that provides support for this
section of the specification.

[Craig Demyanovich]

Patch to enforce default of non-durable topic subscritpion