Usage notes
- Only messages that have a supported format can be returned by this call.
If the message has a format that is not supported, the message is discarded,
and the call completes with an appropriate reason code.
- If the message is retrieved within a unit of work (that is, with the MQGMO_SYNCPOINT
option), and the message has an unsupported format, the unit of work can be
backed out, reinstating the message on the queue. This allows the message
to be retrieved by using the MQGET call in place of the mqGetBag call.