XAResourceRecord save/restore state insufficiently paranoid

The XAResourceRecord save state method writes meta-data into the objectstore before attempting to Serialize and write the actual bytes for an XAResource that it believes, on the basis of it implementing the marker interface, is Serializable. If the serialization fails at runtime, the objectstore record is left in an invalid state and can cause the recovery pass to blow up in horrible ways.

We should obtain the byte[] representing the serialized resource before writing anything to the record so that this does not occur. If serialization fails, the record will therefore be useless but at least not otherwise broken.