From 290612e9db452b92be3f93bc9cef0caeb4f7d766 Mon Sep 17 00:00:00 2001
From: Just Wonder <jianpingw@gmail.com>
Date: Sat, 9 May 2020 10:26:13 -0700
Subject: [PATCH] Fixed lock during block downloading.

---
 src/primitives/block.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/primitives/block.cpp b/src/primitives/block.cpp
index f6494be1e..260d5fe3b 100644
--- a/src/primitives/block.cpp
+++ b/src/primitives/block.cpp
@@ -21,8 +21,9 @@ static void cn_get_block_hash_by_height(uint64_t seed_height, char cnHash[32])
 {
     CBlockIndex* pblockindex = chainActive[seed_height];
     if (pblockindex == NULL) {
-        AssertLockHeld(cs_main);
-        // This will only happens during initial block download.
+        // This will happen during initial block downloading, or when we
+        // are out of sync by more than at least SEEDHASH_EPOCH_BLOCKS blocks.
+        LOCK(cs_main);
         pblockindex = mapBlockSeedHeight.find(seed_height)->second;
     }
     if (pblockindex == NULL) {