From 90366b3bb73414e51254f94686d3c745497b0d6c Mon Sep 17 00:00:00 2001
From: rjl493456442 <garyrong0905@gmail.com>
Date: Mon, 30 Jul 2018 13:18:15 +0800
Subject: [PATCH] les: recover stable checkpoint if nil

---
 les/server.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/les/server.go b/les/server.go
index 3f30b85aa8..39929c6685 100644
--- a/les/server.go
+++ b/les/server.go
@@ -276,6 +276,9 @@ func (s *LesServer) checkpointLoop(checkpoint *light.TrustedCheckpoint) (err err
 			if number < light.CheckpointConfirmations+light.CheckpointFrequency {
 				continue
 			}
+			if checkpoint == nil {
+				checkpoint = s.recoverCheckpoint()
+			}
 			idx := (number-light.CheckpointConfirmations)/light.CheckpointFrequency - 1
 			if checkpoint == nil || idx > checkpoint.SectionIdx {
 				hash, ok := announcement[idx]