diff --git a/VERSION b/VERSION
index 53ed4ba51e..267637b120 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.8.9
+1.8.11
diff --git a/common/bytes.go b/common/bytes.go
index 1ef1db2407..ff309ca937 100644
--- a/common/bytes.go
+++ b/common/bytes.go
@@ -19,18 +19,22 @@ package common
 
 import (
 	"encoding/hex"
-	"fmt"
 )
 
+// ToHex returns the hex representation of b, prefixed with '0x'.
+// For empty slices, the return value is "0x0".
+//
+// Deprecated: use hexutil.Encode instead.
 func ToHex(b []byte) string {
 	hex := Bytes2Hex(b)
-	// Prefer output of "0x0" instead of "0x"
 	if len(hex) == 0 {
 		hex = "0"
 	}
 	return "0x" + hex
 }
 
+// FromHex returns the bytes represented by the hexadecimal string s.
+// s may be prefixed with "0x".
 func FromHex(s string) []byte {
 	if len(s) > 1 {
 		if s[0:2] == "0x" || s[0:2] == "0X" {
@@ -43,9 +47,7 @@ func FromHex(s string) []byte {
 	return Hex2Bytes(s)
 }
 
-// Copy bytes
-//
-// Returns an exact copy of the provided bytes
+// CopyBytes returns an exact copy of the provided bytes.
 func CopyBytes(b []byte) (copiedBytes []byte) {
 	if b == nil {
 		return nil
@@ -56,14 +58,17 @@ func CopyBytes(b []byte) (copiedBytes []byte) {
 	return
 }
 
+// hasHexPrefix validates str begins with '0x' or '0X'.
 func hasHexPrefix(str string) bool {
 	return len(str) >= 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X')
 }
 
+// isHexCharacter returns bool of c being a valid hexadecimal.
 func isHexCharacter(c byte) bool {
 	return ('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')
 }
 
+// isHex validates whether each byte is valid hexadecimal string.
 func isHex(str string) bool {
 	if len(str)%2 != 0 {
 		return false
@@ -76,19 +81,18 @@ func isHex(str string) bool {
 	return true
 }
 
+// Bytes2Hex returns the hexadecimal encoding of d.
 func Bytes2Hex(d []byte) string {
 	return hex.EncodeToString(d)
 }
 
+// Hex2Bytes returns the bytes represented by the hexadecimal string str.
 func Hex2Bytes(str string) []byte {
-	h, err := hex.DecodeString(str)
-	if err != nil {
-		panic(fmt.Sprintf("cannot hex decode the string %s, got error %v", str, err))
-	}
-
+	h, _ := hex.DecodeString(str)
 	return h
 }
 
+// Hex2BytesFixed returns bytes of a specified fixed length flen.
 func Hex2BytesFixed(str string, flen int) []byte {
 	h, _ := hex.DecodeString(str)
 	if len(h) == flen {
@@ -102,6 +106,7 @@ func Hex2BytesFixed(str string, flen int) []byte {
 	return hh
 }
 
+// RightPadBytes zero-pads slice to the right up to length l.
 func RightPadBytes(slice []byte, l int) []byte {
 	if l <= len(slice) {
 		return slice
@@ -113,6 +118,7 @@ func RightPadBytes(slice []byte, l int) []byte {
 	return padded
 }
 
+// LeftPadBytes zero-pads slice to the left up to length l.
 func LeftPadBytes(slice []byte, l int) []byte {
 	if l <= len(slice) {
 		return slice
diff --git a/common/math/big.go b/common/math/big.go
index 7872786503..dbf2770a94 100644
--- a/common/math/big.go
+++ b/common/math/big.go
@@ -78,7 +78,7 @@ func ParseBig256(s string) (*big.Int, bool) {
 	return bigint, ok
 }
 
-// MustParseBig parses s as a 256 bit big integer and panics if the string is invalid.
+// MustParseBig256 parses s as a 256 bit big integer and panics if the string is invalid.
 func MustParseBig256(s string) *big.Int {
 	v, ok := ParseBig256(s)
 	if !ok {
@@ -186,9 +186,8 @@ func U256(x *big.Int) *big.Int {
 func S256(x *big.Int) *big.Int {
 	if x.Cmp(tt255) < 0 {
 		return x
-	} else {
-		return new(big.Int).Sub(x, tt256)
 	}
+	return new(big.Int).Sub(x, tt256)
 }
 
 // Exp implements exponentiation by squaring.
diff --git a/common/number/int.go b/common/number/int.go
index 6dab2436de..5b50669703 100644
--- a/common/number/int.go
+++ b/common/number/int.go
@@ -34,13 +34,12 @@ func limitUnsigned256(x *Number) *Number {
 func limitSigned256(x *Number) *Number {
 	if x.num.Cmp(tt255) < 0 {
 		return x
-	} else {
-		x.num.Sub(x.num, tt256)
-		return x
 	}
+	x.num.Sub(x.num, tt256)
+	return x
 }
 
-// Number function
+// Initialiser is a Number function
 type Initialiser func(n int64) *Number
 
 // A Number represents a generic integer with a bounding function limiter. Limit is called after each operations
@@ -51,65 +50,65 @@ type Number struct {
 	limit func(n *Number) *Number
 }
 
-// Returns a new initialiser for a new *Number without having to expose certain fields
+// NewInitialiser returns a new initialiser for a new *Number without having to expose certain fields
 func NewInitialiser(limiter func(*Number) *Number) Initialiser {
 	return func(n int64) *Number {
 		return &Number{big.NewInt(n), limiter}
 	}
 }
 
-// Return a Number with a UNSIGNED limiter up to 256 bits
+// Uint256 returns a Number with a UNSIGNED limiter up to 256 bits
 func Uint256(n int64) *Number {
 	return &Number{big.NewInt(n), limitUnsigned256}
 }
 
-// Return a Number with a SIGNED limiter up to 256 bits
+// Int256 returns Number with a SIGNED limiter up to 256 bits
 func Int256(n int64) *Number {
 	return &Number{big.NewInt(n), limitSigned256}
 }
 
-// Returns a Number with a SIGNED unlimited size
+// Big returns a Number with a SIGNED unlimited size
 func Big(n int64) *Number {
 	return &Number{big.NewInt(n), func(x *Number) *Number { return x }}
 }
 
-// Sets i to sum of x+y
+// Add sets i to sum of x+y
 func (i *Number) Add(x, y *Number) *Number {
 	i.num.Add(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to difference of x-y
+// Sub sets i to difference of x-y
 func (i *Number) Sub(x, y *Number) *Number {
 	i.num.Sub(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to product of x*y
+// Mul sets i to product of x*y
 func (i *Number) Mul(x, y *Number) *Number {
 	i.num.Mul(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to the quotient prodject of x/y
+// Div sets i to the quotient prodject of x/y
 func (i *Number) Div(x, y *Number) *Number {
 	i.num.Div(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to x % y
+// Mod sets i to x % y
 func (i *Number) Mod(x, y *Number) *Number {
 	i.num.Mod(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to x << s
+// Lsh sets i to x << s
 func (i *Number) Lsh(x *Number, s uint) *Number {
 	i.num.Lsh(x.num, s)
 	return i.limit(i)
 }
 
-// Sets i to x^y
+// Pow sets i to x^y
 func (i *Number) Pow(x, y *Number) *Number {
 	i.num.Exp(x.num, y.num, big.NewInt(0))
 	return i.limit(i)
@@ -117,13 +116,13 @@ func (i *Number) Pow(x, y *Number) *Number {
 
 // Setters
 
-// Set x to i
+// Set sets x to i
 func (i *Number) Set(x *Number) *Number {
 	i.num.Set(x.num)
 	return i.limit(i)
 }
 
-// Set x bytes to i
+// SetBytes sets x bytes to i
 func (i *Number) SetBytes(x []byte) *Number {
 	i.num.SetBytes(x)
 	return i.limit(i)
@@ -140,12 +139,12 @@ func (i *Number) Cmp(x *Number) int {
 
 // Getters
 
-// Returns the string representation of i
+// String returns the string representation of i
 func (i *Number) String() string {
 	return i.num.String()
 }
 
-// Returns the byte representation of i
+// Bytes returns the byte representation of i
 func (i *Number) Bytes() []byte {
 	return i.num.Bytes()
 }
@@ -160,17 +159,17 @@ func (i *Number) Int64() int64 {
 	return i.num.Int64()
 }
 
-// Returns the signed version of i
+// Int256 returns the signed version of i
 func (i *Number) Int256() *Number {
 	return Int(0).Set(i)
 }
 
-// Returns the unsigned version of i
+// Uint256 returns the unsigned version of i
 func (i *Number) Uint256() *Number {
 	return Uint(0).Set(i)
 }
 
-// Returns the index of the first bit that's set to 1
+// FirstBitSet returns the index of the first bit that's set to 1
 func (i *Number) FirstBitSet() int {
 	for j := 0; j < i.num.BitLen(); j++ {
 		if i.num.Bit(j) > 0 {
diff --git a/common/path.go b/common/path.go
index bd8da86e74..69820cfe5d 100644
--- a/common/path.go
+++ b/common/path.go
@@ -30,6 +30,7 @@ func MakeName(name, version string) string {
 	return fmt.Sprintf("%s/v%s/%s/%s", name, version, runtime.GOOS, runtime.Version())
 }
 
+// FileExist checks if a file exists at filePath.
 func FileExist(filePath string) bool {
 	_, err := os.Stat(filePath)
 	if err != nil && os.IsNotExist(err) {
@@ -39,9 +40,10 @@ func FileExist(filePath string) bool {
 	return true
 }
 
-func AbsolutePath(Datadir string, filename string) string {
+// AbsolutePath returns datadir + filename, or filename if it is absolute.
+func AbsolutePath(datadir string, filename string) string {
 	if filepath.IsAbs(filename) {
 		return filename
 	}
-	return filepath.Join(Datadir, filename)
+	return filepath.Join(datadir, filename)
 }
diff --git a/common/types.go b/common/types.go
index 0b94fb2c25..12c26d94bc 100644
--- a/common/types.go
+++ b/common/types.go
@@ -42,19 +42,30 @@ var (
 // Hash represents the 32 byte Keccak256 hash of arbitrary data.
 type Hash [HashLength]byte
 
+// BytesToHash sets b to hash.
+// If b is larger than len(h), b will be cropped from the left.
 func BytesToHash(b []byte) Hash {
 	var h Hash
 	h.SetBytes(b)
 	return h
 }
+
+// BigToHash sets byte representation of b to hash.
+// If b is larger than len(h), b will be cropped from the left.
 func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }
-func HexToHash(s string) Hash   { return BytesToHash(FromHex(s)) }
 
-// Get the string representation of the underlying hash
-func (h Hash) Str() string   { return string(h[:]) }
+// HexToHash sets byte representation of s to hash.
+// If b is larger than len(h), b will be cropped from the left.
+func HexToHash(s string) Hash { return BytesToHash(FromHex(s)) }
+
+// Bytes gets the byte representation of the underlying hash.
 func (h Hash) Bytes() []byte { return h[:] }
+
+// Big converts a hash to a big integer.
 func (h Hash) Big() *big.Int { return new(big.Int).SetBytes(h[:]) }
-func (h Hash) Hex() string   { return hexutil.Encode(h[:]) }
+
+// Hex converts a hash to a hex string.
+func (h Hash) Hex() string { return hexutil.Encode(h[:]) }
 
 // TerminalString implements log.TerminalStringer, formatting a string for console
 // output during logging.
@@ -89,7 +100,8 @@ func (h Hash) MarshalText() ([]byte, error) {
 	return hexutil.Bytes(h[:]).MarshalText()
 }
 
-// Sets the hash to the value of b. If b is larger than len(h), 'b' will be cropped (from the left).
+// SetBytes sets the hash to the value of b.
+// If b is larger than len(h), b will be cropped from the left.
 func (h *Hash) SetBytes(b []byte) {
 	if len(b) > len(h) {
 		b = b[len(b)-HashLength:]
@@ -98,16 +110,6 @@ func (h *Hash) SetBytes(b []byte) {
 	copy(h[HashLength-len(b):], b)
 }
 
-// Set string `s` to h. If s is larger than len(h) s will be cropped (from left) to fit.
-func (h *Hash) SetString(s string) { h.SetBytes([]byte(s)) }
-
-// Sets h to other
-func (h *Hash) Set(other Hash) {
-	for i, v := range other {
-		h[i] = v
-	}
-}
-
 // Generate implements testing/quick.Generator.
 func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
 	m := rand.Intn(len(h))
@@ -117,10 +119,6 @@ func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
 	return reflect.ValueOf(h)
 }
 
-func EmptyHash(h Hash) bool {
-	return h == Hash{}
-}
-
 // UnprefixedHash allows marshaling a Hash without 0x prefix.
 type UnprefixedHash Hash
 
@@ -139,13 +137,21 @@ func (h UnprefixedHash) MarshalText() ([]byte, error) {
 // Address represents the 20 byte address of an Ethereum account.
 type Address [AddressLength]byte
 
+// BytesToAddress returns Address with value b.
+// If b is larger than len(h), b will be cropped from the left.
 func BytesToAddress(b []byte) Address {
 	var a Address
 	a.SetBytes(b)
 	return a
 }
+
+// BigToAddress returns Address with byte values of b.
+// If b is larger than len(h), b will be cropped from the left.
 func BigToAddress(b *big.Int) Address { return BytesToAddress(b.Bytes()) }
-func HexToAddress(s string) Address   { return BytesToAddress(FromHex(s)) }
+
+// HexToAddress returns Address with byte values of s.
+// If s is larger than len(h), s will be cropped from the left.
+func HexToAddress(s string) Address { return BytesToAddress(FromHex(s)) }
 
 // IsHexAddress verifies whether a string can represent a valid hex-encoded
 // Ethereum address or not.
@@ -156,11 +162,14 @@ func IsHexAddress(s string) bool {
 	return len(s) == 2*AddressLength && isHex(s)
 }
 
-// Get the string representation of the underlying address
-func (a Address) Str() string   { return string(a[:]) }
+// Bytes gets the string representation of the underlying address.
 func (a Address) Bytes() []byte { return a[:] }
+
+// Big converts an address to a big integer.
 func (a Address) Big() *big.Int { return new(big.Int).SetBytes(a[:]) }
-func (a Address) Hash() Hash    { return BytesToHash(a[:]) }
+
+// Hash converts an address to a hash by left-padding it with zeros.
+func (a Address) Hash() Hash { return BytesToHash(a[:]) }
 
 // Hex returns an EIP55-compliant hex string representation of the address.
 func (a Address) Hex() string {
@@ -184,7 +193,7 @@ func (a Address) Hex() string {
 	return "0x" + string(result)
 }
 
-// String implements the stringer interface and is used also by the logger.
+// String implements fmt.Stringer.
 func (a Address) String() string {
 	return a.Hex()
 }
@@ -195,7 +204,8 @@ func (a Address) Format(s fmt.State, c rune) {
 	fmt.Fprintf(s, "%"+string(c), a[:])
 }
 
-// Sets the address to the value of b. If b is larger than len(a) it will panic
+// SetBytes sets the address to the value of b.
+// If b is larger than len(a) it will panic.
 func (a *Address) SetBytes(b []byte) {
 	if len(b) > len(a) {
 		b = b[len(b)-AddressLength:]
@@ -203,16 +213,6 @@ func (a *Address) SetBytes(b []byte) {
 	copy(a[AddressLength-len(b):], b)
 }
 
-// Set string `s` to a. If s is larger than len(a) it will panic
-func (a *Address) SetString(s string) { a.SetBytes([]byte(s)) }
-
-// Sets a to other
-func (a *Address) Set(other Address) {
-	for i, v := range other {
-		a[i] = v
-	}
-}
-
 // MarshalText returns the hex representation of a.
 func (a Address) MarshalText() ([]byte, error) {
 	return hexutil.Bytes(a[:]).MarshalText()
@@ -228,7 +228,7 @@ func (a *Address) UnmarshalJSON(input []byte) error {
 	return hexutil.UnmarshalFixedJSON(addressT, input, a[:])
 }
 
-// UnprefixedHash allows marshaling an Address without 0x prefix.
+// UnprefixedAddress allows marshaling an Address without 0x prefix.
 type UnprefixedAddress Address
 
 // UnmarshalText decodes the address from hex. The 0x prefix is optional.
diff --git a/common/types_template.go b/common/types_template.go
deleted file mode 100644
index 9a8f29977b..0000000000
--- a/common/types_template.go
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2015 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-// +build none
-//sed -e 's/_N_/Hash/g' -e 's/_S_/32/g' -e '1d' types_template.go | gofmt -w hash.go
-
-package common
-
-import "math/big"
-
-type _N_ [_S_]byte
-
-func BytesTo_N_(b []byte) _N_ {
-	var h _N_
-	h.SetBytes(b)
-	return h
-}
-func StringTo_N_(s string) _N_ { return BytesTo_N_([]byte(s)) }
-func BigTo_N_(b *big.Int) _N_  { return BytesTo_N_(b.Bytes()) }
-func HexTo_N_(s string) _N_    { return BytesTo_N_(FromHex(s)) }
-
-// Don't use the default 'String' method in case we want to overwrite
-
-// Get the string representation of the underlying hash
-func (h _N_) Str() string   { return string(h[:]) }
-func (h _N_) Bytes() []byte { return h[:] }
-func (h _N_) Big() *big.Int { return new(big.Int).SetBytes(h[:]) }
-func (h _N_) Hex() string   { return "0x" + Bytes2Hex(h[:]) }
-
-// Sets the hash to the value of b. If b is larger than len(h) it will panic
-func (h *_N_) SetBytes(b []byte) {
-	// Use the right most bytes
-	if len(b) > len(h) {
-		b = b[len(b)-_S_:]
-	}
-
-	// Reverse the loop
-	for i := len(b) - 1; i >= 0; i-- {
-		h[_S_-len(b)+i] = b[i]
-	}
-}
-
-// Set string `s` to h. If s is larger than len(h) it will panic
-func (h *_N_) SetString(s string) { h.SetBytes([]byte(s)) }
-
-// Sets h to other
-func (h *_N_) Set(other _N_) {
-	for i, v := range other {
-		h[i] = v
-	}
-}
diff --git a/core/state/state_test.go b/core/state/state_test.go
index 12778f6f12..123559ea9b 100644
--- a/core/state/state_test.go
+++ b/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)
 	}
 }
diff --git a/core/state/sync.go b/core/state/sync.go
index 28fcf6ae05..c566e79073 100644
--- a/core/state/sync.go
+++ b/core/state/sync.go
@@ -25,8 +25,8 @@ import (
 )
 
 // NewStateSync create a new state trie download scheduler.
-func NewStateSync(root common.Hash, database trie.DatabaseReader) *trie.TrieSync {
-	var syncer *trie.TrieSync
+func NewStateSync(root common.Hash, database trie.DatabaseReader) *trie.Sync {
+	var syncer *trie.Sync
 	callback := func(leaf []byte, parent common.Hash) error {
 		var obj Account
 		if err := rlp.Decode(bytes.NewReader(leaf), &obj); err != nil {
@@ -36,6 +36,6 @@ func NewStateSync(root common.Hash, database trie.DatabaseReader) *trie.TrieSync
 		syncer.AddRawEntry(common.BytesToHash(obj.CodeHash), 64, parent)
 		return nil
 	}
-	syncer = trie.NewTrieSync(root, database, callback)
+	syncer = trie.NewSync(root, database, callback)
 	return syncer
 }
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 1c9516b1b7..7393c8286f 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -962,7 +962,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 	}
 	// Notify subsystem for new promoted transactions.
 	if len(promoted) > 0 {
-		pool.txFeed.Send(NewTxsEvent{promoted})
+		go pool.txFeed.Send(NewTxsEvent{promoted})
 	}
 	// If the pending limit is overflown, start equalizing allowances
 	pending := uint64(0)
diff --git a/core/types/transaction_test.go b/core/types/transaction_test.go
index d1861b14cd..b390f45c67 100644
--- a/core/types/transaction_test.go
+++ b/core/types/transaction_test.go
@@ -165,28 +165,13 @@ func TestTransactionPriceNonceSort(t *testing.T) {
 				t.Errorf("invalid nonce ordering: tx #%d (A=%x N=%v) < tx #%d (A=%x N=%v)", i, fromi[:4], txi.Nonce(), i+j, fromj[:4], txj.Nonce())
 			}
 		}
-		// Find the previous and next nonce of this account
-		prev, next := i-1, i+1
-		for j := i - 1; j >= 0; j-- {
-			if fromj, _ := Sender(signer, txs[j]); fromi == fromj {
-				prev = j
-				break
-			}
-		}
-		for j := i + 1; j < len(txs); j++ {
-			if fromj, _ := Sender(signer, txs[j]); fromi == fromj {
-				next = j
-				break
-			}
-		}
-		// Make sure that in between the neighbor nonces, the transaction is correctly positioned price wise
-		for j := prev + 1; j < next; j++ {
-			fromj, _ := Sender(signer, txs[j])
-			if j < i && txs[j].GasPrice().Cmp(txi.GasPrice()) < 0 {
-				t.Errorf("invalid gasprice ordering: tx #%d (A=%x P=%v) < tx #%d (A=%x P=%v)", j, fromj[:4], txs[j].GasPrice(), i, fromi[:4], txi.GasPrice())
-			}
-			if j > i && txs[j].GasPrice().Cmp(txi.GasPrice()) > 0 {
-				t.Errorf("invalid gasprice ordering: tx #%d (A=%x P=%v) > tx #%d (A=%x P=%v)", j, fromj[:4], txs[j].GasPrice(), i, fromi[:4], txi.GasPrice())
+
+		// If the next tx has different from account, the price must be lower than the current one
+		if i+1 < len(txs) {
+			next := txs[i+1]
+			fromNext, _ := Sender(signer, next)
+			if fromi != fromNext && txi.GasPrice().Cmp(next.GasPrice()) < 0 {
+				t.Errorf("invalid gasprice ordering: tx #%d (A=%x P=%v) < tx #%d (A=%x P=%v)", i, fromi[:4], txi.GasPrice(), i+1, fromNext[:4], next.GasPrice())
 			}
 		}
 	}
diff --git a/core/vm/gas_table.go b/core/vm/gas_table.go
index 83adba428e..0764c67a4d 100644
--- a/core/vm/gas_table.go
+++ b/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)
diff --git a/core/vm/jump_table.go b/core/vm/jump_table.go
index 3389941353..49a94d9646 100644
--- a/core/vm/jump_table.go
+++ b/core/vm/jump_table.go
@@ -33,7 +33,7 @@ type (
 var errGasUintOverflow = errors.New("gas uint64 overflow")
 
 type operation struct {
-	// op is the operation function
+	// execute is the operation function
 	execute executionFunc
 	// gasCost is the gas function and returns the gas required for execution
 	gasCost gasFunc
diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index dc23354929..51c5936015 100644
--- a/eth/downloader/downloader.go
+++ b/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
diff --git a/eth/downloader/statesync.go b/eth/downloader/statesync.go
index 5b4b9ba1b7..8d33dfec74 100644
--- a/eth/downloader/statesync.go
+++ b/eth/downloader/statesync.go
@@ -214,7 +214,7 @@ func (d *Downloader) runStateSync(s *stateSync) *stateSync {
 type stateSync struct {
 	d *Downloader // Downloader instance to access and manage current peerset
 
-	sched  *trie.TrieSync             // State trie sync scheduler defining the tasks
+	sched  *trie.Sync                 // State trie sync scheduler defining the tasks
 	keccak hash.Hash                  // Keccak256 hasher to verify deliveries with
 	tasks  map[common.Hash]*stateTask // Set of tasks currently queued for retrieval
 
diff --git a/eth/fetcher/fetcher.go b/eth/fetcher/fetcher.go
index 0c679cec3a..a2e7cdecf9 100644
--- a/eth/fetcher/fetcher.go
+++ b/eth/fetcher/fetcher.go
@@ -292,20 +292,20 @@ func (f *Fetcher) loop() {
 		height := f.chainHeight()
 		for !f.queue.Empty() {
 			op := f.queue.PopItem().(*inject)
+			hash := op.block.Hash()
 			if f.queueChangeHook != nil {
-				f.queueChangeHook(op.block.Hash(), false)
+				f.queueChangeHook(hash, false)
 			}
 			// If too high up the chain or phase, continue later
 			number := op.block.NumberU64()
 			if number > height+1 {
-				f.queue.Push(op, -float32(op.block.NumberU64()))
+				f.queue.Push(op, -float32(number))
 				if f.queueChangeHook != nil {
-					f.queueChangeHook(op.block.Hash(), true)
+					f.queueChangeHook(hash, true)
 				}
 				break
 			}
 			// Otherwise if fresh and still unknown, try and import
-			hash := op.block.Hash()
 			if number+maxUncleDist < height || f.getBlock(hash) != nil {
 				f.forgetBlock(hash)
 				continue
diff --git a/ethstats/ethstats.go b/ethstats/ethstats.go
index c116014351..a4d35044cd 100644
--- a/ethstats/ethstats.go
+++ b/ethstats/ethstats.go
@@ -362,7 +362,7 @@ type nodeInfo struct {
 
 // authMsg is the authentication infos needed to login to a monitoring server.
 type authMsg struct {
-	Id     string   `json:"id"`
+	ID     string   `json:"id"`
 	Info   nodeInfo `json:"info"`
 	Secret string   `json:"secret"`
 }
@@ -381,7 +381,7 @@ func (s *Service) login(conn *websocket.Conn) error {
 		protocol = fmt.Sprintf("les/%d", les.ClientProtocolVersions[0])
 	}
 	auth := &authMsg{
-		Id: s.node,
+		ID: s.node,
 		Info: nodeInfo{
 			Name:     s.node,
 			Node:     infos.Name,
diff --git a/interfaces.go b/interfaces.go
index 1ae1eba48a..a8b48c93d7 100644
--- a/interfaces.go
+++ b/interfaces.go
@@ -144,7 +144,7 @@ type FilterQuery struct {
 	// {} or nil          matches any topic list
 	// {{A}}              matches topic A in first position
 	// {{}, {B}}          matches any topic in first position, B in second position
-	// {{A}}, {B}}        matches topic A in first position, B in second position
+	// {{A}, {B}}         matches topic A in first position, B in second position
 	// {{A, B}}, {C, D}}  matches topic (A OR B) in first position, (C OR D) in second position
 	Topics [][]common.Hash
 }
diff --git a/p2p/discv5/metrics.go b/p2p/discv5/metrics.go
new file mode 100644
index 0000000000..cb11d7eacf
--- /dev/null
+++ b/p2p/discv5/metrics.go
@@ -0,0 +1,8 @@
+package discv5
+
+import "github.com/ethereum/go-ethereum/metrics"
+
+var (
+	ingressTrafficMeter = metrics.NewRegisteredMeter("discv5/InboundTraffic", nil)
+	egressTrafficMeter  = metrics.NewRegisteredMeter("discv5/OutboundTraffic", nil)
+)
diff --git a/p2p/discv5/udp.go b/p2p/discv5/udp.go
index 09e5f8b374..49e1cb811a 100644
--- a/p2p/discv5/udp.go
+++ b/p2p/discv5/udp.go
@@ -334,8 +334,10 @@ func (t *udp) sendPacket(toid NodeID, toaddr *net.UDPAddr, ptype byte, req inter
 		return hash, err
 	}
 	log.Trace(fmt.Sprintf(">>> %v to %x@%v", nodeEvent(ptype), toid[:8], toaddr))
-	if _, err = t.conn.WriteToUDP(packet, toaddr); err != nil {
+	if nbytes, err := t.conn.WriteToUDP(packet, toaddr); err != nil {
 		log.Trace(fmt.Sprint("UDP send failed:", err))
+	} else {
+		egressTrafficMeter.Mark(int64(nbytes))
 	}
 	//fmt.Println(err)
 	return hash, err
@@ -374,6 +376,7 @@ func (t *udp) readLoop() {
 	buf := make([]byte, 1280)
 	for {
 		nbytes, from, err := t.conn.ReadFromUDP(buf)
+		ingressTrafficMeter.Mark(int64(nbytes))
 		if netutil.IsTemporaryError(err) {
 			// Ignore temporary read errors.
 			log.Debug(fmt.Sprintf("Temporary read error: %v", err))
diff --git a/params/version.go b/params/version.go
index 1e8c43bf81..8689ccba7f 100644
--- a/params/version.go
+++ b/params/version.go
@@ -23,7 +23,7 @@ import (
 const (
 	VersionMajor = 1          // Major version component of the current release
 	VersionMinor = 8          // Minor version component of the current release
-	VersionPatch = 9          // Patch version component of the current release
+	VersionPatch = 11         // Patch version component of the current release
 	VersionMeta  = "unstable" // Version metadata to append to the version string
 )
 
diff --git a/trie/encoding.go b/trie/encoding.go
index e96a786e40..221fa6d3aa 100644
--- a/trie/encoding.go
+++ b/trie/encoding.go
@@ -83,7 +83,7 @@ func hexToKeybytes(hex []byte) []byte {
 	if len(hex)&1 != 0 {
 		panic("can't convert hex key of odd length")
 	}
-	key := make([]byte, (len(hex)+1)/2)
+	key := make([]byte, len(hex)/2)
 	decodeNibbles(hex, key)
 	return key
 }
diff --git a/trie/sync.go b/trie/sync.go
index 4ae975d042..ccec80c9e3 100644
--- a/trie/sync.go
+++ b/trie/sync.go
@@ -68,19 +68,19 @@ func newSyncMemBatch() *syncMemBatch {
 	}
 }
 
-// TrieSync is the main state trie synchronisation scheduler, which provides yet
+// Sync is the main state trie synchronisation scheduler, which provides yet
 // unknown trie hashes to retrieve, accepts node data associated with said hashes
 // and reconstructs the trie step by step until all is done.
-type TrieSync struct {
+type Sync struct {
 	database DatabaseReader           // Persistent database to check for existing entries
 	membatch *syncMemBatch            // Memory buffer to avoid frequest database writes
 	requests map[common.Hash]*request // Pending requests pertaining to a key hash
 	queue    *prque.Prque             // Priority queue with the pending requests
 }
 
-// NewTrieSync creates a new trie data download scheduler.
-func NewTrieSync(root common.Hash, database DatabaseReader, callback LeafCallback) *TrieSync {
-	ts := &TrieSync{
+// NewSync creates a new trie data download scheduler.
+func NewSync(root common.Hash, database DatabaseReader, callback LeafCallback) *Sync {
+	ts := &Sync{
 		database: database,
 		membatch: newSyncMemBatch(),
 		requests: make(map[common.Hash]*request),
@@ -91,7 +91,7 @@ func NewTrieSync(root common.Hash, database DatabaseReader, callback LeafCallbac
 }
 
 // AddSubTrie registers a new trie to the sync code, rooted at the designated parent.
-func (s *TrieSync) AddSubTrie(root common.Hash, depth int, parent common.Hash, callback LeafCallback) {
+func (s *Sync) AddSubTrie(root common.Hash, depth int, parent common.Hash, callback LeafCallback) {
 	// Short circuit if the trie is empty or already known
 	if root == emptyRoot {
 		return
@@ -126,7 +126,7 @@ func (s *TrieSync) AddSubTrie(root common.Hash, depth int, parent common.Hash, c
 // interpreted as a trie node, but rather accepted and stored into the database
 // as is. This method's goal is to support misc state metadata retrievals (e.g.
 // contract code).
-func (s *TrieSync) AddRawEntry(hash common.Hash, depth int, parent common.Hash) {
+func (s *Sync) AddRawEntry(hash common.Hash, depth int, parent common.Hash) {
 	// Short circuit if the entry is empty or already known
 	if hash == emptyState {
 		return
@@ -156,7 +156,7 @@ func (s *TrieSync) AddRawEntry(hash common.Hash, depth int, parent common.Hash)
 }
 
 // Missing retrieves the known missing nodes from the trie for retrieval.
-func (s *TrieSync) Missing(max int) []common.Hash {
+func (s *Sync) Missing(max int) []common.Hash {
 	requests := []common.Hash{}
 	for !s.queue.Empty() && (max == 0 || len(requests) < max) {
 		requests = append(requests, s.queue.PopItem().(common.Hash))
@@ -167,7 +167,7 @@ func (s *TrieSync) Missing(max int) []common.Hash {
 // Process injects a batch of retrieved trie nodes data, returning if something
 // was committed to the database and also the index of an entry if processing of
 // it failed.
-func (s *TrieSync) Process(results []SyncResult) (bool, int, error) {
+func (s *Sync) Process(results []SyncResult) (bool, int, error) {
 	committed := false
 
 	for i, item := range results {
@@ -213,7 +213,7 @@ func (s *TrieSync) Process(results []SyncResult) (bool, int, error) {
 
 // Commit flushes the data stored in the internal membatch out to persistent
 // storage, returning the number of items written and any occurred error.
-func (s *TrieSync) Commit(dbw ethdb.Putter) (int, error) {
+func (s *Sync) Commit(dbw ethdb.Putter) (int, error) {
 	// Dump the membatch into a database dbw
 	for i, key := range s.membatch.order {
 		if err := dbw.Put(key[:], s.membatch.batch[key]); err != nil {
@@ -228,14 +228,14 @@ func (s *TrieSync) Commit(dbw ethdb.Putter) (int, error) {
 }
 
 // Pending returns the number of state entries currently pending for download.
-func (s *TrieSync) Pending() int {
+func (s *Sync) Pending() int {
 	return len(s.requests)
 }
 
 // schedule inserts a new state retrieval request into the fetch queue. If there
 // is already a pending request for this node, the new request will be discarded
 // and only a parent reference added to the old one.
-func (s *TrieSync) schedule(req *request) {
+func (s *Sync) schedule(req *request) {
 	// If we're already requesting this node, add a new reference and stop
 	if old, ok := s.requests[req.hash]; ok {
 		old.parents = append(old.parents, req.parents...)
@@ -248,7 +248,7 @@ func (s *TrieSync) schedule(req *request) {
 
 // children retrieves all the missing children of a state trie entry for future
 // retrieval scheduling.
-func (s *TrieSync) children(req *request, object node) ([]*request, error) {
+func (s *Sync) children(req *request, object node) ([]*request, error) {
 	// Gather all the children of the node, irrelevant whether known or not
 	type child struct {
 		node  node
@@ -310,7 +310,7 @@ func (s *TrieSync) children(req *request, object node) ([]*request, error) {
 // commit finalizes a retrieval request and stores it into the membatch. If any
 // of the referencing parent requests complete due to this commit, they are also
 // committed themselves.
-func (s *TrieSync) commit(req *request) (err error) {
+func (s *Sync) commit(req *request) (err error) {
 	// Write the node content to the membatch
 	s.membatch.batch[req.hash] = req.data
 	s.membatch.order = append(s.membatch.order, req.hash)
diff --git a/trie/sync_test.go b/trie/sync_test.go
index 142a6f5b1a..c76779e5c7 100644
--- a/trie/sync_test.go
+++ b/trie/sync_test.go
@@ -87,14 +87,14 @@ func checkTrieConsistency(db *Database, root common.Hash) error {
 }
 
 // Tests that an empty trie is not scheduled for syncing.
-func TestEmptyTrieSync(t *testing.T) {
+func TestEmptySync(t *testing.T) {
 	dbA := NewDatabase(ethdb.NewMemDatabase())
 	dbB := NewDatabase(ethdb.NewMemDatabase())
 	emptyA, _ := New(common.Hash{}, dbA)
 	emptyB, _ := New(emptyRoot, dbB)
 
 	for i, trie := range []*Trie{emptyA, emptyB} {
-		if req := NewTrieSync(trie.Hash(), ethdb.NewMemDatabase(), nil).Missing(1); len(req) != 0 {
+		if req := NewSync(trie.Hash(), ethdb.NewMemDatabase(), nil).Missing(1); len(req) != 0 {
 			t.Errorf("test %d: content requested for empty trie: %v", i, req)
 		}
 	}
@@ -102,17 +102,17 @@ func TestEmptyTrieSync(t *testing.T) {
 
 // Tests that given a root hash, a trie can sync iteratively on a single thread,
 // requesting retrieval tasks and returning all of them in one go.
-func TestIterativeTrieSyncIndividual(t *testing.T) { testIterativeTrieSync(t, 1) }
-func TestIterativeTrieSyncBatched(t *testing.T)    { testIterativeTrieSync(t, 100) }
+func TestIterativeSyncIndividual(t *testing.T) { testIterativeSync(t, 1) }
+func TestIterativeSyncBatched(t *testing.T)    { testIterativeSync(t, 100) }
 
-func testIterativeTrieSync(t *testing.T, batch int) {
+func testIterativeSync(t *testing.T, batch int) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := append([]common.Hash{}, sched.Missing(batch)...)
 	for len(queue) > 0 {
@@ -138,14 +138,14 @@ func testIterativeTrieSync(t *testing.T, batch int) {
 
 // Tests that the trie scheduler can correctly reconstruct the state even if only
 // partial results are returned, and the others sent only later.
-func TestIterativeDelayedTrieSync(t *testing.T) {
+func TestIterativeDelayedSync(t *testing.T) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := append([]common.Hash{}, sched.Missing(10000)...)
 	for len(queue) > 0 {
@@ -173,17 +173,17 @@ func TestIterativeDelayedTrieSync(t *testing.T) {
 // Tests that given a root hash, a trie can sync iteratively on a single thread,
 // requesting retrieval tasks and returning all of them in one go, however in a
 // random order.
-func TestIterativeRandomTrieSyncIndividual(t *testing.T) { testIterativeRandomTrieSync(t, 1) }
-func TestIterativeRandomTrieSyncBatched(t *testing.T)    { testIterativeRandomTrieSync(t, 100) }
+func TestIterativeRandomSyncIndividual(t *testing.T) { testIterativeRandomSync(t, 1) }
+func TestIterativeRandomSyncBatched(t *testing.T)    { testIterativeRandomSync(t, 100) }
 
-func testIterativeRandomTrieSync(t *testing.T, batch int) {
+func testIterativeRandomSync(t *testing.T, batch int) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := make(map[common.Hash]struct{})
 	for _, hash := range sched.Missing(batch) {
@@ -217,14 +217,14 @@ func testIterativeRandomTrieSync(t *testing.T, batch int) {
 
 // Tests that the trie scheduler can correctly reconstruct the state even if only
 // partial results are returned (Even those randomly), others sent only later.
-func TestIterativeRandomDelayedTrieSync(t *testing.T) {
+func TestIterativeRandomDelayedSync(t *testing.T) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := make(map[common.Hash]struct{})
 	for _, hash := range sched.Missing(10000) {
@@ -264,14 +264,14 @@ func TestIterativeRandomDelayedTrieSync(t *testing.T) {
 
 // Tests that a trie sync will not request nodes multiple times, even if they
 // have such references.
-func TestDuplicateAvoidanceTrieSync(t *testing.T) {
+func TestDuplicateAvoidanceSync(t *testing.T) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := append([]common.Hash{}, sched.Missing(0)...)
 	requested := make(map[common.Hash]struct{})
@@ -304,14 +304,14 @@ func TestDuplicateAvoidanceTrieSync(t *testing.T) {
 
 // Tests that at any point in time during a sync, only complete sub-tries are in
 // the database.
-func TestIncompleteTrieSync(t *testing.T) {
+func TestIncompleteSync(t *testing.T) {
 	// Create a random trie to copy
 	srcDb, srcTrie, _ := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	added := []common.Hash{}
 	queue := append([]common.Hash{}, sched.Missing(1)...)
diff --git a/whisper/shhclient/client.go b/whisper/shhclient/client.go
index 8e7085a0a6..a814154e47 100644
--- a/whisper/shhclient/client.go
+++ b/whisper/shhclient/client.go
@@ -159,9 +159,9 @@ func (sc *Client) DeleteSymmetricKey(ctx context.Context, id string) error {
 }
 
 // Post a message onto the network.
-func (sc *Client) Post(ctx context.Context, message whisper.NewMessage) error {
-	var ignored bool
-	return sc.c.CallContext(ctx, &ignored, "shh_post", message)
+func (sc *Client) Post(ctx context.Context, message whisper.NewMessage) (string, error) {
+	var hash string
+	return hash, sc.c.CallContext(ctx, &hash, "shh_post", message)
 }
 
 // SubscribeMessages subscribes to messages that match the given criteria. This method