breacharbiter_test: add double handoff event

breacharbiter_test.go

@@ -1018,6 +1018,32 @@ func TestBreachHandoffSuccess(t *testing.T) {
 	// retribution information and the channel should be shown as pending
 	// force closed.
 	assertArbiterBreach(t, brar, chanPoint)
+
+	// Send another breach event. Since the handoff for this channel was
+	// already ACKed, the breach arbiter should immediately ACK and ignore
+	// this event.
+	breach = &ContractBreachEvent{
+		ChanPoint:  *chanPoint,
+		ProcessACK: make(chan error, 1),
+		BreachRetribution: &lnwallet.BreachRetribution{
+			BreachTransaction: bobClose.CloseTx,
+		},
+	}
+
+	contractBreaches <- breach
+
+	// We'll also wait to consume the ACK back from the breach arbiter.
+	select {
+	case err := <-breach.ProcessACK:
+		if err != nil {
+			t.Fatalf("handoff failed: %v", err)
+		}
+	case <-time.After(time.Second * 15):
+		t.Fatalf("breach arbiter didn't send ack back")
+	}
+
+	// State should not have changed.
+	assertArbiterBreach(t, brar, chanPoint)
 }
 
 // TestBreachHandoffFail tests that a channel's close observer properly