Once it becomes necessary to actually send a Header section for a non-persistent message, e.g. because a later priority/ttl/etc field is set, populate its durable field false explicitly since defaulting it no longer nets a strict benefit.
(The existing 0.41.0 behaviour is perfectly legal and NOT a bug, but restoring this behaviour of <=0.11.1 will help people upgrading from <=0.11.1 to a 0.20.0+ release avoid hitting
AMQ-7189 in ActiveMQ 5 releases prior to 5.15.10, which is not yet released at time of writing. More background: