Merge pull request #9567 from ellemouton/graph18

itest: make sure to not hit the natural ChannelUpdate rate limit

docs/release-notes/release-notes-0.19.0.md

@@ -330,6 +330,11 @@ The underlying functionality between those two options remain the same.
 * Add a new CI-step to do some basic [backwards compatibility 
   testing](https://github.com/lightningnetwork/lnd/pull/9540) for each PR. 
 
+* [Fix](https://github.com/lightningnetwork/lnd/pull/9567) an itest flake where 
+  if a channel update is sent too quickly after the previous one, then it would 
+  be ignored due to the timestamp of the second update not being after the 
+  previous one. 
+
 ## Database
 
 * [Migrate the mission control 

itest/lnd_channel_policy_test.go

@@ -341,10 +341,10 @@ func testUpdateChannelPolicy(ht *lntest.HarnessTest) {
 	// but not the second, as she only allows two updates per day and a day
 	// has yet to elapse from the previous update.
 
-	// assertAliceAndBob is a helper closure which updates Alice's policy
-	// and asserts that both Alice and Bob have heard and updated the
+	// updateAndAssertAliceAndBob is a helper closure which updates Alice's
+	// policy and asserts that both Alice and Bob have heard and updated the
 	// policy in their graph.
-	assertAliceAndBob := func(req *lnrpc.PolicyUpdateRequest,
+	updateAndAssertAliceAndBob := func(req *lnrpc.PolicyUpdateRequest,
 		expectedPolicy *lnrpc.RoutingPolicy) {
 
 		alice.RPC.UpdateChannelPolicy(req)
@@ -377,14 +377,20 @@ func testUpdateChannelPolicy(ht *lntest.HarnessTest) {
 		)
 	}
 
+	// Channel Updates actually also have a natural rate limit of 1 update
+	// per second due to the fact that the timestamp carried in the update
+	// is only accurate to the second. So we need to ensure that the next
+	// update we send in the burst is at least 1 second after the last one.
+	time.Sleep(time.Second)
+
 	// Double the base fee and attach to the policy. Moreover, we set the
 	// inbound fee to nil and test that it does not change the propagated
 	// inbound fee.
 	baseFee1 := baseFee * 2
 	expectedPolicy.FeeBaseMsat = baseFee1
 	req.BaseFeeMsat = baseFee1
 	req.InboundFee = nil
-	assertAliceAndBob(req, expectedPolicy)
+	updateAndAssertAliceAndBob(req, expectedPolicy)
 
 	// Check that Carol has both heard the policy and updated it in her
 	// graph.
@@ -403,11 +409,17 @@ func testUpdateChannelPolicy(ht *lntest.HarnessTest) {
 		carol, alice.PubKeyStr, expectedPolicy, chanPoint3,
 	)
 
+	// Similarly to above, we again wait for the natural rate limit of the
+	// ChannelUpdate to pass so that we are really testing that Carol is
+	// _not_ getting this next update due to her rate limiting settings and
+	// not due to the natural rate limit being met.
+	time.Sleep(time.Second)
+
 	// Double the base fee and attach to the policy.
 	baseFee2 := baseFee1 * 2
 	expectedPolicy.FeeBaseMsat = baseFee2
 	req.BaseFeeMsat = baseFee2
-	assertAliceAndBob(req, expectedPolicy)
+	updateAndAssertAliceAndBob(req, expectedPolicy)
 
 	// Since Carol didn't receive the last update, she still has Alice's
 	// old policy. We validate this by checking the base fee is the older