From 29bfd8abab2f4b8967315871fca2af3446a9a440 Mon Sep 17 00:00:00 2001
From: Jakub Sztandera <kubuxu@protocol.ai>
Date: Tue, 23 Jun 2020 19:16:06 +0200
Subject: [PATCH] Fix rance in GetBestMiningCandidate

Signed-off-by: Jakub Sztandera <kubuxu@protocol.ai>
---
 api/test/mining.go | 5 ++---
 miner/miner.go     | 3 +++
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/api/test/mining.go b/api/test/mining.go
index b190954501f..511aeb51aa4 100644
--- a/api/test/mining.go
+++ b/api/test/mining.go
@@ -133,11 +133,10 @@ func TestDealMining(t *testing.T, b APIBuilder, blocktime time.Duration, carExpo
 			wait := make(chan int, 2)
 			mdone := func(mined bool) {
 				go func() {
-					n := 0
 					if mined {
-						n = 1
+						wait <- 1
 					}
-					wait <- n
+					wait <- 0
 				}()
 			}
 
diff --git a/miner/miner.go b/miner/miner.go
index bdeed8ac5da..cc4aa847ccc 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -215,6 +215,9 @@ type MiningBase struct {
 }
 
 func (m *Miner) GetBestMiningCandidate(ctx context.Context) (*MiningBase, error) {
+	m.lk.Lock()
+	defer m.lk.Unlock()
+
 	bts, err := m.api.ChainHead(ctx)
 	if err != nil {
 		return nil, err