Inbound client acks now route through the engine (T18/T19). On a successful
Acknowledge the T18 gate returns Good, so the SDK applies the acked state to the
AlarmConditionState node and auto-fires its own condition event (E2) -- directly
on the node, bypassing WriteAlarmCondition. The engine then re-projects that same
transition through WriteAlarmCondition, which fired again (E3): a double-emit.
Gate WriteAlarmCondition's ReportConditionEvent on a genuine delta computed
against the node's CURRENT live state (read before projecting the snapshot), not
a last-written cache (which would be stale, since the SDK-applied ack never went
through this method). For a re-projected ack the snapshot equals the node's
already-applied state -> no delta -> suppress E3. Genuine engine-driven
transitions still differ -> fire.
Compared fields (value-equality via AlarmConditionDelta record): Active, Acked,
Confirmed, Enabled, Shelving (mapped from the shelving state machine), Severity
(mapped through MapSeverity to match the bucket the node stores), Message.
Optional Confirmed/Shelving fold to the node read-back default when the child is
absent so they can't register a phantom delta.
Tests prove both: suppression of the simulated inbound ack re-projection
(EventId unchanged) and that genuine transitions fire while identical
re-projections suppress; plus a direct unit test of the ShouldFireConditionEvent
seam. 102/102 OpcUaServer.Tests green.
Joseph Doherty
004558c241