Fix crash on FEE_INSUFFICIENT

payment.go

@@ -109,15 +109,17 @@ func (r *regolancer) pay(ctx context.Context, amount int64, minAmount int64, max
 
 		if result.Failure.Code == lnrpc.Failure_FEE_INSUFFICIENT || result.Failure.Code == lnrpc.Failure_INCORRECT_CLTV_EXPIRY {
 			failedHop := route.Hops[result.Failure.FailureSourceIndex-1]
-			route, err = r.rebuildRoute(ctx, route, amount)
+			updatedRoute, err := r.rebuildRoute(ctx, route, amount)
-			updatedHop := route.Hops[result.Failure.FailureSourceIndex-1]
 			if err == nil {
+				updatedHop := updatedRoute.Hops[result.Failure.FailureSourceIndex-1]
 				// compare hops to make sure we do not loop endlessly
 				if !compareHops(failedHop, updatedHop) {
 					log.Printf("received channelupdate after failure, trying again with amt %s and fee %s ppm",
-						hiWhiteColor(amount), formatFeePPM(amount*1000, route.TotalFeesMsat))
+						hiWhiteColor(amount), formatFeePPM(amount*1000, updatedRoute.TotalFeesMsat))
-					return r.pay(ctx, amount, minAmount, maxFeeMsat, route, probeSteps)
+					return r.pay(ctx, amount, minAmount, maxFeeMsat, updatedRoute, probeSteps)
 				}
+			} else {
+				log.Printf("error rebuilding the route: %s", err)
 			}
 		}
 		if result.Failure.Code == lnrpc.Failure_TEMPORARY_CHANNEL_FAILURE {

routes.go

@@ -322,6 +322,9 @@ func getTarget(route *lnrpc.Route) uint64 {
 }
 
 func compareHops(hop1 *lnrpc.Hop, hop2 *lnrpc.Hop) bool {
+	if hop1 == nil || hop2 == nil {
+		return false
+	}
 	return hop1.ChanId == hop2.ChanId &&
 		hop1.FeeMsat == hop2.FeeMsat &&
 		hop1.Expiry == hop2.Expiry