remove uses of EmptyHash

core/state/state_test.go

@@ -99,7 +99,7 @@ func (s *StateSuite) TestNull(c *checker.C) {
 	s.state.SetState(address, common.Hash{}, value)
 	s.state.Commit(false)
 	value = s.state.GetState(address, common.Hash{})
-	if !common.EmptyHash(value) {
+	if value != (common.Hash{}) {
 		c.Errorf("expected empty hash. got %x", value)
 	}
 }

core/vm/gas_table.go

@@ -124,12 +124,12 @@ func gasSStore(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, m
 	// 1. From a zero-value address to a non-zero value         (NEW VALUE)
 	// 2. From a non-zero value address to a zero-value address (DELETE)
 	// 3. From a non-zero to a non-zero                         (CHANGE)
-	if common.EmptyHash(val) && !common.EmptyHash(common.BigToHash(y)) {
+	if val == (common.Hash{}) && y.Sign() != 0 {
 		// 0 => non 0
 		return params.SstoreSetGas, nil
-	} else if !common.EmptyHash(val) && common.EmptyHash(common.BigToHash(y)) {
+	} else if val != (common.Hash{}) && y.Sign() == 0 {
+		// non 0 => 0
 		evm.StateDB.AddRefund(params.SstoreRefundGas)
-
 		return params.SstoreClearGas, nil
 	} else {
 		// non 0 => non 0 (or 0 => 0)

eth/downloader/downloader.go

@@ -680,7 +680,7 @@ func (d *Downloader) findAncestor(p *peerConnection, height uint64) (uint64, err
 		}
 	}
 	// If the head fetch already found an ancestor, return
-	if !common.EmptyHash(hash) {
+	if hash != (common.Hash{}) {
 		if int64(number) <= floor {
 			p.log.Warn("Ancestor below allowance", "number", number, "hash", hash, "allowance", floor)
 			return 0, errInvalidAncestor