sha3Uncles is empty when uncles is empty.

libethcore/BlockInfo.cpp

@@ -78,7 +78,7 @@ void BlockInfo::populateFromHeader(RLP const& _header, bool _checkNonce)
 	try
 	{
 		parentHash = _header[field = 0].toHash<h256>();
-		sha3Uncles = _header[field = 1].toHash<h256>();
+		sha3Uncles = _header[field = 1].isEmpty() ? h256() : _header[field = 1].toHash<h256>();
 		coinbaseAddress = _header[field = 2].toHash<Address>();
 		stateRoot = _header[field = 3].toHash<h256>();
 		transactionsRoot = _header[field = 4].toHash<h256>();
@@ -148,7 +148,7 @@ void BlockInfo::verifyInternals(bytesConstRef _block) const
 	if (minGasPrice > mgp)
 		BOOST_THROW_EXCEPTION(InvalidMinGasPrice(minGasPrice, mgp));
 
-	if (sha3Uncles != sha3(root[2].data()))
+	if ((sha3Uncles && root[2].isEmpty()) || (!sha3Uncles && sha3Uncles != sha3(root[2].data())))
 		BOOST_THROW_EXCEPTION(InvalidUnclesHash());
 }
 
@@ -179,8 +179,7 @@ u256 BlockInfo::calculateDifficulty(BlockInfo const& _parent) const
 }
 
 void BlockInfo::verifyParent(BlockInfo const& _parent) const
-{
-	// Check difficulty is correct given the two timestamps.
+{	// Check difficulty is correct given the two timestamps.
 	if (difficulty != calculateDifficulty(_parent))
 		BOOST_THROW_EXCEPTION(InvalidDifficulty());
 

libethcore/CommonEth.cpp

@@ -34,7 +34,7 @@ namespace dev
 namespace eth
 {
 
-const unsigned c_protocolVersion = 35;
+const unsigned c_protocolVersion = 36;
 const unsigned c_databaseVersion = 3;
 
 static const vector<pair<u256, string>> g_units =

libethereum/State.cpp

@@ -826,7 +826,7 @@ void State::commitToMine(BlockChain const& _bc)
 	RLPStream(unclesCount).appendRaw(unclesData.out(), unclesCount).swapOut(m_currentUncles);
 
 	m_currentBlock.transactionsRoot = transactionReceipts.root();
-	m_currentBlock.sha3Uncles = sha3(m_currentUncles);
+	m_currentBlock.sha3Uncles = unclesCount ? sha3(m_currentUncles) : h256();
 
 	// Apply rewards last of all.
 	applyRewards(uncleAddresses);