Merge pull request #6076 from ellemouton/alwaysClampFeeFloor

lnwallet+docs: minrelayfee always above fee floor

docs/release-notes/release-notes-0.14.2.md

@@ -35,6 +35,9 @@
 
 * [Fix memory corruption in Mission Control
   Store](https://github.com/lightningnetwork/lnd/pull/6068)
+ 
+* [Ensure that the min relay fee is always clamped by our fee
+  floor](https://github.com/lightningnetwork/lnd/pull/6076)
 
 ## RPC Server
 
@@ -49,6 +52,7 @@
 
 * Andras Banki-Horvath
 * Bjarne Magnussen
+* Elle Mouton
 * Harsha Goli
 * Martin Habovštiak
 * Naveen Srinivasan

lnwallet/chainfee/minfeemanager.go

@@ -32,6 +32,12 @@ func newMinFeeManager(minUpdateInterval time.Duration,
 		return nil, err
 	}
 
+	// Ensure that the minimum fee we use is always clamped by our fee
+	// floor.
+	if minFee < FeePerKwFloor {
+		minFee = FeePerKwFloor
+	}
+
 	return &minFeeManager{
 		minFeePerKW:       minFee,
 		lastUpdatedTime:   time.Now(),

lnwallet/chainfee/minfeemanager_test.go

@@ -23,8 +23,10 @@ func (m *mockChainBackend) fetchFee() (SatPerKWeight, error) {
 func TestMinFeeManager(t *testing.T) {
 	t.Parallel()
 
+	// Initialize the mock backend and let it have a minimum fee rate
+	// below our fee floor.
 	chainBackend := &mockChainBackend{
-		minFee: SatPerKWeight(1000),
+		minFee: FeePerKwFloor - 1,
 	}
 
 	// Initialise the min fee manager. This should call the chain backend
@@ -36,11 +38,14 @@ func TestMinFeeManager(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, 1, chainBackend.callCount)
 
+	// Check that the minimum fee rate is clamped by our fee floor.
+	require.Equal(t, feeManager.minFeePerKW, FeePerKwFloor)
+
 	// If the fee is requested again, the stored fee should be returned
 	// and the chain backend should not be queried.
 	chainBackend.minFee = SatPerKWeight(2000)
 	minFee := feeManager.fetchMinFee()
-	require.Equal(t, minFee, SatPerKWeight(1000))
+	require.Equal(t, minFee, FeePerKwFloor)
 	require.Equal(t, 1, chainBackend.callCount)
 
 	// Fake the passing of time.