From 804debede41a5aaaae65f4f36ced1044d37cbba4 Mon Sep 17 00:00:00 2001
From: Tuna <ng.tuna@gmail.com>
Date: Wed, 9 Jan 2019 15:43:12 +0700
Subject: [PATCH] fix nil exception

---
 consensus/posv/posv.go | 2 +-
 miner/worker.go        | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/consensus/posv/posv.go b/consensus/posv/posv.go
index b86028cce0..c92371c846 100644
--- a/consensus/posv/posv.go
+++ b/consensus/posv/posv.go
@@ -774,7 +774,7 @@ func (c *Posv) Prepare(chain consensus.ChainReader, state *state.StateDB, header
 	}
 	header.Extra = header.Extra[:extraVanity]
 	masternodes := snap.GetSigners()
-	if number > 0 && number%c.config.Epoch == 0 {
+	if number >= c.config.Epoch && number%c.config.Epoch == 0 {
 		if c.HookPenalty != nil {
 			penMasternodes, err := c.HookPenalty(state, chain, number)
 			if err != nil {
diff --git a/miner/worker.go b/miner/worker.go
index 41103c87af..809a132777 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -552,7 +552,11 @@ func (self *worker) commitNewWork() {
 	if atomic.LoadInt32(&self.mining) == 1 {
 		header.Coinbase = self.coinbase
 	}
-	if err := self.engine.Prepare(self.chain, self.current.state, header); err != nil {
+	state := &state.StateDB{}
+	if self.current != nil {
+		state = self.current.state
+	}
+	if err := self.engine.Prepare(self.chain, state, header); err != nil {
 		log.Error("Failed to prepare header for new block", "err", err)
 		return
 	}