routing: move default cltv assignment out of router

This commit lifts default setting up to the rpc server level, in line
with other payment defaults.

lnrpc/routerrpc/router_server.go

@@ -222,7 +222,7 @@ func (s *Server) SendPayment(ctx context.Context,
 		Amount:            *payReq.MilliSat,
 		FeeLimit:          lnwire.MilliSatoshi(req.FeeLimitSat),
 		PaymentHash:       *payReq.PaymentHash,
-		FinalCLTVDelta:    &finalDelta,
+		FinalCLTVDelta:    finalDelta,
 		PayAttemptTimeout: time.Second * time.Duration(req.TimeoutSeconds),
 		RouteHints:        payReq.RouteHints,
 	}

routing/payment_session_test.go

@@ -45,7 +45,7 @@ func TestRequestRoute(t *testing.T) {
 
 	payment := &LightningPayment{
 		CltvLimit:      &cltvLimit,
-		FinalCLTVDelta: &finalCltvDelta,
+		FinalCLTVDelta: finalCltvDelta,
 	}
 
 	route, err := session.RequestRoute(payment, height, finalCltvDelta)

routing/router.go

@@ -1565,10 +1565,8 @@ type LightningPayment struct {
 
 	// FinalCLTVDelta is the CTLV expiry delta to use for the _final_ hop
 	// in the route. This means that the final hop will have a CLTV delta
-	// of at least: currentHeight + FinalCLTVDelta. If this value is
+	// of at least: currentHeight + FinalCLTVDelta.
-	// unspecified, then a default value of DefaultFinalCLTVDelta will be
+	FinalCLTVDelta uint16
-	// used.
-	FinalCLTVDelta *uint16
 
 	// PayAttemptTimeout is a timeout value that we'll use to determine
 	// when we should should abandon the payment attempt after consecutive
@@ -1732,13 +1730,6 @@ func (r *ChannelRouter) sendPayment(
 		return [32]byte{}, nil, err
 	}
 
-	var finalCLTVDelta uint16
-	if payment.FinalCLTVDelta == nil {
-		finalCLTVDelta = zpay32.DefaultFinalCLTVDelta
-	} else {
-		finalCLTVDelta = *payment.FinalCLTVDelta
-	}
-
 	var payAttemptTimeout time.Duration
 	if payment.PayAttemptTimeout == time.Duration(0) {
 		payAttemptTimeout = defaultPayAttemptTimeout
@@ -1756,7 +1747,7 @@ func (r *ChannelRouter) sendPayment(
 		paySession:     paySession,
 		timeoutChan:    timeoutChan,
 		currentHeight:  currentHeight,
-		finalCLTVDelta: finalCLTVDelta,
+		finalCLTVDelta: uint16(payment.FinalCLTVDelta),
 		attempt:        existingAttempt,
 		circuit:        nil,
 		lastError:      nil,

rpcserver.go

@@ -2998,7 +2998,11 @@ func extractPaymentIntent(rpcPayReq *rpcPaymentRequest) (rpcPaymentIntent, error
 		rpcPayReq.FeeLimit, payIntent.msat,
 	)
 
-	payIntent.cltvDelta = uint16(rpcPayReq.FinalCltvDelta)
+	if rpcPayReq.FinalCltvDelta != 0 {
+		payIntent.cltvDelta = uint16(rpcPayReq.FinalCltvDelta)
+	} else {
+		payIntent.cltvDelta = zpay32.DefaultFinalCLTVDelta
+	}
 
 	// If the user is manually specifying payment details, then the payment
 	// hash may be encoded as a string.
@@ -3069,6 +3073,7 @@ func (r *rpcServer) dispatchPaymentIntent(
 		payment := &routing.LightningPayment{
 			Target:            payIntent.dest,
 			Amount:            payIntent.msat,
+			FinalCLTVDelta:    payIntent.cltvDelta,
 			FeeLimit:          payIntent.feeLimit,
 			CltvLimit:         payIntent.cltvLimit,
 			PaymentHash:       payIntent.rHash,
@@ -3077,12 +3082,6 @@ func (r *rpcServer) dispatchPaymentIntent(
 			PaymentRequest:    payIntent.payReq,
 		}
 
-		// If the final CLTV value was specified, then we'll use that
-		// rather than the default.
-		if payIntent.cltvDelta != 0 {
-			payment.FinalCLTVDelta = &payIntent.cltvDelta
-		}
-
 		preImage, route, routerErr = r.server.chanRouter.SendPayment(
 			payment,
 		)