Unexpected DLQ behaviour with non-persistent messages

[Martin Lichtin]

Can somone help me understand why a non-persistent message is "converted" into 
a persistent message on entering DLQ?
It happens in RegionBroker, around line 733:

                            if (!message.isPersistent()) {
                                message.setPersistent(true);
message.setProperty("originalDeliveryMode", "NON_PERSISTENT");
                            }

I'm puzzled as to why this would make sense.

A non-persistent message, even if configured to use DLQ, should stay 
non-persistent, i.e. not survive broker restarts.

- Martin