Merge branch 'master' into ui-2

2017-06-21 11:15:29 +02:00 · 2017-06-21 11:15:29 +02:00 · 97c67bc259
parent e479260e1f d152fa3e85
commit 97c67bc259
55 changed files with 407 additions and 212 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -692,7 +692,6 @@ name = "ethkey"
 version = "0.2.0"
 dependencies = [
 "byteorder 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "docopt 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "eth-secp256k1 0.5.6 (git+https://github.com/paritytech/rust-secp256k1)",
 "ethcore-bigint 0.1.3",
 "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
@ -703,10 +702,18 @@ dependencies = [
 ]

 [[package]]
-name = "ethstore"
+name = "ethkey-cli"
 version = "0.1.0"
 dependencies = [
 "docopt 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ethkey 0.2.0",
+ "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "ethstore"
+version = "0.1.0"
+dependencies = [
 "ethcore-bigint 0.1.3",
 "ethcrypto 0.1.0",
 "ethkey 0.2.0",
@ -727,6 +734,15 @@ dependencies = [
 "tiny-keccak 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

+[[package]]
+name = "ethstore-cli"
+version = "0.1.0"
+dependencies = [
+ "docopt 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ethstore 0.1.0",
+ "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "ethsync"
 version = "1.7.0"
@ -1569,7 +1585,6 @@ dependencies = [
 "ethcore-util 1.7.0",
 "ethkey 0.2.0",
 "ethsync 1.7.0",
- "evmbin 0.1.0",
 "fdlimit 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "futures 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
 "isatty 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
@ -1803,7 +1818,7 @@ dependencies = [
 [[package]]
 name = "parity-ui-precompiled"
 version = "1.4.0"
-source = "git+https://github.com/paritytech/js-precompiled.git#bebd4fc6ab48574cc976f3570357359f6e831a71"
+source = "git+https://github.com/paritytech/js-precompiled.git#259741a8ff42f0d4cd0a2c60cc7fab4f0b55aa4f"
 dependencies = [
 "parity-dapps-glue 1.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
--- a/Cargo.toml
+++ b/Cargo.toml
@ -40,7 +40,6 @@ ethcore-light = { path = "ethcore/light" }
 ethcore-logger = { path = "logger" }
 ethcore-stratum = { path = "stratum" }
 ethkey = { path = "ethkey" }
-evmbin = { path = "evmbin" }
 rlp = { path = "util/rlp" }
 rpc-cli = { path = "rpc_cli" }
 parity-hash-fetch = { path = "hash-fetch" }
@ -86,8 +85,6 @@ jit = ["ethcore/jit"]
 dev = ["clippy", "ethcore/dev", "ethcore-util/dev", "ethsync/dev", "parity-rpc/dev", "parity-dapps/dev"]
 json-tests = ["ethcore/json-tests"]
 test-heavy = ["ethcore/test-heavy"]
-ethkey-cli = ["ethcore/ethkey-cli"]
-ethstore-cli = ["ethcore/ethstore-cli"]
 evm-debug = ["ethcore/evm-debug"]
 evm-debug-tests = ["ethcore/evm-debug-tests"]
 slow-blocks = ["ethcore/slow-blocks"]
@ -104,3 +101,4 @@ lto = false
 panic = "abort"

 [workspace]
+members = ["ethstore/cli", "ethkey/cli", "evmbin"]
--- a/ethcore/Cargo.toml
+++ b/ethcore/Cargo.toml
@ -66,5 +66,3 @@ dev = ["clippy"]
 default = []
 benches = []
 ipc = []
-ethkey-cli = ["ethkey/cli"]
-ethstore-cli = ["ethstore/cli"]
--- a/ethcore/res/ethereum/classic.json
+++ b/ethcore/res/ethereum/classic.json
@ -16,6 +16,7 @@
 				"eip160Transition": 3000000,
 				"ecip1010PauseTransition": 3000000,
 				"ecip1010ContinueTransition": 5000000,
+				"ecip1017EraRounds": 5000000,

 				"eip161abcTransition": "0x7fffffffffffffff",
 				"eip161dTransition": "0x7fffffffffffffff"
--- a/ethcore/res/ethereum/frontier_like_test.json
+++ b/ethcore/res/ethereum/frontier_like_test.json
@ -12,7 +12,7 @@
 				"homesteadTransition": "0x118c30",
 				"daoHardforkTransition": "0x1d4c00",
 				"daoHardforkBeneficiary": "0xbf4ed7b27f1d666546e30d74d50d173d20bca754",
-				"daoHardforkAccounts": [  
+				"daoHardforkAccounts": [
 					"0xd4fe7bc31cedb7bfb8a345f31e668033056b2728",
 					"0xb3fb0e5aba0e20e5c49d252dfd30e102b171a425",
 					"0x2c19c7f9ae8b751e37aeb2d93a699722395ae18f",
--- a/ethcore/res/ethereum/transition_test.json
+++ b/ethcore/res/ethereum/transition_test.json
@ -12,7 +12,7 @@
 				"homesteadTransition": "0x5",
 				"daoHardforkTransition": "0x8",
 				"daoHardforkBeneficiary": "0xbf4ed7b27f1d666546e30d74d50d173d20bca754",
-				"daoHardforkAccounts": [  
+				"daoHardforkAccounts": [
 					"0xd4fe7bc31cedb7bfb8a345f31e668033056b2728",
 					"0xb3fb0e5aba0e20e5c49d252dfd30e102b171a425",
 					"0x2c19c7f9ae8b751e37aeb2d93a699722395ae18f",
--- a/ethcore/src/client/test_client.rs
+++ b/ethcore/src/client/test_client.rs
@ -55,7 +55,7 @@ pub struct TestBlockChainClient {
 	/// Blocks.
 	pub blocks: RwLock<HashMap<H256, Bytes>>,
 	/// Mapping of numbers to hashes.
- 	pub numbers: RwLock<HashMap<usize, H256>>,
+	pub numbers: RwLock<HashMap<usize, H256>>,
 	/// Genesis block hash.
 	pub genesis_hash: H256,
 	/// Last block hash.
@ -353,7 +353,7 @@ pub fn get_temp_state_db() -> GuardedTempResult<StateDB> {

 impl MiningBlockChainClient for TestBlockChainClient {
 	fn latest_schedule(&self) -> Schedule {
-		Schedule::new_post_eip150(24576, true, true, true, true)
+		Schedule::new_post_eip150(24576, true, true, true)
 	}

 	fn prepare_open_block(&self, author: Address, gas_range_target: (U256, U256), extra_data: Bytes) -> OpenBlock {
--- a/ethcore/src/engines/authority_round.rs
+++ b/ethcore/src/engines/authority_round.rs
@ -26,9 +26,8 @@ use account_provider::AccountProvider;
 use block::*;
 use spec::CommonParams;
 use engines::{Call, Engine, Seal, EngineError};
-use header::{Header, BlockNumber};
+use header::Header;
 use error::{Error, TransactionError, BlockError};
-use evm::Schedule;
 use ethjson;
 use io::{IoContext, IoHandler, TimerToken, IoService};
 use builtin::Builtin;
@ -296,11 +295,6 @@ impl Engine for AuthorityRound {
 		]
 	}

-	fn schedule(&self, block_number: BlockNumber) -> Schedule {
-		let eip86 = block_number >= self.params.eip86_transition;
-		Schedule::new_post_eip150(usize::max_value(), true, true, true, eip86)
-	}
-
 	fn populate_from_parent(&self, header: &mut Header, parent: &Header, gas_floor_target: U256, _gas_ceil_target: U256) {
 		// Chain scoring: total weight is sqrt(U256::max_value())*height - step
 		let new_difficulty = U256::from(U128::max_value()) + header_step(parent).expect("Header has been verified; qed").into() - self.step.load().into();
--- a/ethcore/src/engines/instant_seal.rs
+++ b/ethcore/src/engines/instant_seal.rs
@ -19,9 +19,7 @@ use util::{Address, HashMap};
 use builtin::Builtin;
 use engines::{Engine, Seal};
 use spec::CommonParams;
-use evm::Schedule;
 use block::ExecutedBlock;
-use header::BlockNumber;

 /// An engine which does not provide any consensus mechanism, just seals blocks internally.
 pub struct InstantSeal {
@ -58,11 +56,6 @@ impl Engine for InstantSeal {
 		&self.builtins
 	}

-	fn schedule(&self, block_number: BlockNumber) -> Schedule {
-		let eip86 = block_number >= self.params.eip86_transition;
-		Schedule::new_post_eip150(usize::max_value(), true, true, true, eip86)
-	}
-
 	fn seals_internally(&self) -> Option<bool> { Some(true) }

 	fn generate_seal(&self, _block: &ExecutedBlock) -> Seal {
--- a/ethcore/src/engines/mod.rs
+++ b/ethcore/src/engines/mod.rs
@ -147,7 +147,9 @@ pub trait Engine : Sync + Send {
 	fn params(&self) -> &CommonParams;

 	/// Get the EVM schedule for the given `block_number`.
-	fn schedule(&self, block_number: BlockNumber) -> Schedule;
+	fn schedule(&self, block_number: BlockNumber) -> Schedule {
+		Schedule::from_params(block_number, self.params())
+	}

 	/// Builtin-contracts we would like to see in the chain.
 	/// (In principle these are just hints for the engine since that has the last word on them.)
--- a/ethcore/src/engines/tendermint/mod.rs
+++ b/ethcore/src/engines/tendermint/mod.rs
@ -38,7 +38,6 @@ use account_provider::AccountProvider;
 use block::*;
 use spec::CommonParams;
 use engines::{Engine, Seal, EngineError};
-use evm::Schedule;
 use state::CleanupMode;
 use io::IoService;
 use super::signer::EngineSigner;
@ -404,11 +403,6 @@ impl Engine for Tendermint {
 		]
 	}

-	fn schedule(&self, block_number: BlockNumber) -> Schedule {
-		let eip86 = block_number >= self.params.eip86_transition;
-		Schedule::new_post_eip150(usize::max_value(), true, true, true, eip86)
-	}
-
 	fn populate_from_parent(&self, header: &mut Header, parent: &Header, gas_floor_target: U256, _gas_ceil_target: U256) {
 		// Chain scoring: total weight is sqrt(U256::max_value())*height - view
 		let new_difficulty = U256::from(U128::max_value()) + consensus_view(parent).expect("Header has been verified; qed").into() - self.view.load(AtomicOrdering::SeqCst).into();
--- a/ethcore/src/ethereum/ethash.rs
+++ b/ethcore/src/ethereum/ethash.rs
@ -86,6 +86,8 @@ pub struct EthashParams {
 	pub ecip1010_pause_transition: u64,
 	/// Number of first block where ECIP-1010 ends.
 	pub ecip1010_continue_transition: u64,
+	/// Total block number for one ECIP-1017 era.
+	pub ecip1017_era_rounds: u64,
 	/// Maximum amount of code that can be deploying into a contract.
 	pub max_code_size: u64,
 	/// Number of first block where the max gas limit becomes effective.
@ -124,6 +126,7 @@ impl From<ethjson::spec::EthashParams> for EthashParams {
 			eip161d_transition: p.eip161d_transition.map_or(u64::max_value(), Into::into),
 			ecip1010_pause_transition: p.ecip1010_pause_transition.map_or(u64::max_value(), Into::into),
 			ecip1010_continue_transition: p.ecip1010_continue_transition.map_or(u64::max_value(), Into::into),
+			ecip1017_era_rounds: p.ecip1017_era_rounds.map_or(u64::max_value(), Into::into),
 			max_code_size: p.max_code_size.map_or(u64::max_value(), Into::into),
 			max_gas_limit_transition: p.max_gas_limit_transition.map_or(u64::max_value(), Into::into),
 			max_gas_limit: p.max_gas_limit.map_or(U256::max_value(), Into::into),
@ -196,13 +199,13 @@ impl Engine for Arc<Ethash> {
 		} else if block_number < self.ethash_params.eip150_transition {
 			Schedule::new_homestead()
 		} else {
-			Schedule::new_post_eip150(
+			let mut schedule = Schedule::new_post_eip150(
 				self.ethash_params.max_code_size as usize,
 				block_number >= self.ethash_params.eip160_transition,
 				block_number >= self.ethash_params.eip161abc_transition,
-				block_number >= self.ethash_params.eip161d_transition,
-				block_number >= self.params.eip86_transition
-			)
+				block_number >= self.ethash_params.eip161d_transition);
+			schedule.apply_params(block_number, self.params());
+			schedule
 		}
 	}

@ -255,13 +258,13 @@ impl Engine for Arc<Ethash> {

 	fn on_new_block(&self, block: &mut ExecutedBlock, last_hashes: Arc<LastHashes>) -> Result<(), Error> {
 		let parent_hash = block.fields().header.parent_hash().clone();
-		try!(::engines::common::push_last_hash(block, last_hashes, self, &parent_hash));
+		::engines::common::push_last_hash(block, last_hashes, self, &parent_hash)?;
 		if block.fields().header.number() == self.ethash_params.dao_hardfork_transition {
 			let state = block.fields_mut().state;
 			for child in &self.ethash_params.dao_hardfork_accounts {
 				let beneficiary = &self.ethash_params.dao_hardfork_beneficiary;
-				try!(state.balance(child)
-					.and_then(|b| state.transfer_balance(child, beneficiary, &b, CleanupMode::NoEmpty)));
+				state.balance(child)
+					.and_then(|b| state.transfer_balance(child, beneficiary, &b, CleanupMode::NoEmpty))?;
 			}
 		}
 		Ok(())
@ -272,6 +275,8 @@ impl Engine for Arc<Ethash> {
 	fn on_close_block(&self, block: &mut ExecutedBlock) -> Result<(), Error> {
 		let reward = self.ethash_params.block_reward;
 		let fields = block.fields_mut();
+		let eras_rounds = self.ethash_params.ecip1017_era_rounds;
+		let (eras, reward) = ecip1017_eras_block_reward(eras_rounds, reward, fields.header.number());

 		// Bestow block reward
 		fields.state.add_balance(
@ -283,11 +288,19 @@ impl Engine for Arc<Ethash> {
 		// Bestow uncle rewards
 		let current_number = fields.header.number();
 		for u in fields.uncles.iter() {
-			fields.state.add_balance(
-				u.author(),
-				&(reward * U256::from(8 + u.number() - current_number) / U256::from(8)),
-				CleanupMode::NoEmpty
-			)?;
+			if eras == 0 {
+				fields.state.add_balance(
+					u.author(),
+					&(reward * U256::from(8 + u.number() - current_number) / U256::from(8)),
+					CleanupMode::NoEmpty
+				)
+			} else {
+				fields.state.add_balance(
+					u.author(),
+					&(reward / U256::from(32)),
+					CleanupMode::NoEmpty
+				)
+			}?;
 		}

 		// Commit state so that we can actually figure out the state root.
@ -413,6 +426,18 @@ fn round_block_gas_limit(gas_limit: U256, lower_limit: U256, upper_limit: U256)
 	}
 }

+fn ecip1017_eras_block_reward(era_rounds: u64, mut reward: U256, block_number:u64) -> (u64, U256){
+	let eras = if block_number != 0 && block_number % era_rounds == 0 {
+		block_number / era_rounds - 1
+	} else {
+		block_number / era_rounds
+	};
+	for _ in 0..eras {
+		reward = reward / U256::from(5) * U256::from(4);
+	}
+	(eras, reward)
+}
+
 #[cfg_attr(feature="dev", allow(wrong_self_convention))]
 impl Ethash {
 	fn calculate_difficulty(&self, header: &Header, parent: &Header) -> U256 {
@ -524,7 +549,7 @@ mod tests {
 	use error::{BlockError, Error};
 	use header::Header;
 	use super::super::{new_morden, new_homestead_test};
-	use super::{Ethash, EthashParams, PARITY_GAS_LIMIT_DETERMINANT};
+	use super::{Ethash, EthashParams, PARITY_GAS_LIMIT_DETERMINANT, ecip1017_eras_block_reward};
 	use rlp;

 	#[test]
@ -760,6 +785,42 @@ mod tests {
 		assert_eq!(U256::from_str("1fc50f118efe").unwrap(), difficulty);
 	}

+	#[test]
+	fn has_valid_ecip1017_eras_block_reward() {
+		let ethparams = EthashParams {
+			// see ethcore/res/ethereum/classic.json
+			ecip1017_era_rounds: 5000000,
+			block_reward: U256::from_str("4563918244F40000").unwrap(),
+			..get_default_ethash_params()
+		};
+		let eras_rounds = ethparams.ecip1017_era_rounds;
+		let reward = ethparams.block_reward;
+		let block_number = 0;
+		let (eras, reward) = ecip1017_eras_block_reward(eras_rounds, reward, block_number);
+		assert_eq!(0, eras);
+		assert_eq!(U256::from_str("4563918244F40000").unwrap(), reward);
+		let reward = ethparams.block_reward;
+		let block_number = 5000000;
+		let (eras, reward) = ecip1017_eras_block_reward(eras_rounds, reward, block_number);
+		assert_eq!(0, eras);
+		assert_eq!(U256::from_str("4563918244F40000").unwrap(), reward);
+		let reward = ethparams.block_reward;
+		let block_number = 10000000;
+		let (eras, reward) = ecip1017_eras_block_reward(eras_rounds, reward, block_number);
+		assert_eq!(1, eras);
+		assert_eq!(U256::from_str("3782DACE9D900000").unwrap(), reward);
+		let reward = ethparams.block_reward;
+		let block_number = 20000000;
+		let (eras, reward) = ecip1017_eras_block_reward(eras_rounds, reward, block_number);
+		assert_eq!(3, eras);
+		assert_eq!(U256::from_str("2386F26FC1000000").unwrap(), reward);
+		let reward = ethparams.block_reward;
+		let block_number = 80000000;
+		let (eras, reward) = ecip1017_eras_block_reward(eras_rounds, reward, block_number);
+		assert_eq!(15, eras);
+		assert_eq!(U256::from_str("271000000000000").unwrap(), reward);
+	}
+
 	#[test]
 	fn difficulty_classic_bomb_delay() {
 		let spec = new_homestead_test();
--- a/ethcore/src/evm/evm.rs
+++ b/ethcore/src/evm/evm.rs
@ -62,7 +62,8 @@ pub enum Error {
 	},
 	/// Built-in contract failed on given input
 	BuiltIn(&'static str),
-	/// Returned on evm internal error. Should never be ignored during development.
+	/// When execution tries to modify the state in static context
+	MutableCallInStaticContext,
 	/// Likely to cause consensus issues.
 	Internal(String),
 }
@ -90,6 +91,7 @@ impl fmt::Display for Error {
 			OutOfStack { instruction, wanted, limit } => write!(f, "Out of stack {} {}/{}", instruction, wanted, limit),
 			BuiltIn(name) => write!(f, "Built-in failed: {}", name),
 			Internal(ref msg) => write!(f, "Internal error: {}", msg),
+			MutableCallInStaticContext => write!(f, "Mutable call in static context"),
 		}
 	}
 }
--- a/ethcore/src/evm/ext.rs
+++ b/ethcore/src/evm/ext.rs
@ -53,25 +53,24 @@ pub enum CreateContractAddress {
 }

 /// Externalities interface for EVMs
-// TODO: [rob] associated error type instead of `trie::Result`. Not all EVMs are trie powered.
 pub trait Ext {
 	/// Returns a value for given key.
-	fn storage_at(&self, key: &H256) -> trie::Result<H256>;
+	fn storage_at(&self, key: &H256) -> evm::Result<H256>;

 	/// Stores a value for given key.
-	fn set_storage(&mut self, key: H256, value: H256) -> trie::Result<()>;
+	fn set_storage(&mut self, key: H256, value: H256) -> evm::Result<()>;

 	/// Determine whether an account exists.
-	fn exists(&self, address: &Address) -> trie::Result<bool>;
+	fn exists(&self, address: &Address) -> evm::Result<bool>;

 	/// Determine whether an account exists and is not null (zero balance/nonce, no code).
-	fn exists_and_not_null(&self, address: &Address) -> trie::Result<bool>;
+	fn exists_and_not_null(&self, address: &Address) -> evm::Result<bool>;

 	/// Balance of the origin account.
-	fn origin_balance(&self) -> trie::Result<U256>;
+	fn origin_balance(&self) -> evm::Result<U256>;

 	/// Returns address balance.
-	fn balance(&self, address: &Address) -> trie::Result<U256>;
+	fn balance(&self, address: &Address) -> evm::Result<U256>;

 	/// Returns the hash of one of the 256 most recent complete blocks.
 	fn blockhash(&mut self, number: &U256) -> H256;
@ -99,13 +98,13 @@ pub trait Ext {
 	) -> MessageCallResult;

 	/// Returns code at given address
-	fn extcode(&self, address: &Address) -> trie::Result<Arc<Bytes>>;
+	fn extcode(&self, address: &Address) -> evm::Result<Arc<Bytes>>;

 	/// Returns code size at given address
-	fn extcodesize(&self, address: &Address) -> trie::Result<usize>;
+	fn extcodesize(&self, address: &Address) -> evm::Result<usize>;

 	/// Creates log entry with given topics and data
-	fn log(&mut self, topics: Vec<H256>, data: &[u8]);
+	fn log(&mut self, topics: Vec<H256>, data: &[u8]) -> evm::Result<()>;

 	/// Should be called when transaction calls `RETURN` opcode.
 	/// Returns gas_left if cost of returning the data is not too high.
@ -113,7 +112,7 @@ pub trait Ext {

 	/// Should be called when contract commits suicide.
 	/// Address to which funds should be refunded.
-	fn suicide(&mut self, refund_address: &Address) -> trie::Result<()> ;
+	fn suicide(&mut self, refund_address: &Address) -> evm::Result<()> ;

 	/// Returns schedule.
 	fn schedule(&self) -> &Schedule;
--- a/ethcore/src/evm/instructions.rs
+++ b/ethcore/src/evm/instructions.rs
@ -298,6 +298,7 @@ lazy_static! {
 		arr[CALLCODE as usize] =		InstructionInfo::new("CALLCODE",		7, 1, GasPriceTier::Special);
 		arr[RETURN as usize] =			InstructionInfo::new("RETURN",			2, 0, GasPriceTier::Zero);
 		arr[DELEGATECALL as usize] =	InstructionInfo::new("DELEGATECALL",	6, 1, GasPriceTier::Special);
+		arr[STATICCALL as usize] =		InstructionInfo::new("STATICCALL",		6, 1, GasPriceTier::Special);
 		arr[SUICIDE as usize] = 		InstructionInfo::new("SUICIDE",			1, 0, GasPriceTier::Special);
 		arr[CREATE2 as usize] = 		InstructionInfo::new("CREATE2",			3, 1, GasPriceTier::Special);
 		arr[REVERT as usize] =			InstructionInfo::new("REVERT",			2, 0, GasPriceTier::Zero);
@ -584,6 +585,8 @@ pub const DELEGATECALL: Instruction = 0xf4;
 pub const CREATE2: Instruction = 0xfb;
 /// stop execution and revert state changes. Return output data.
 pub const REVERT: Instruction = 0xfd;
+/// like CALL but it does not take value, nor modify the state
+pub const STATICCALL: Instruction = 0xfa;
 /// halt execution and register account for later deletion
 pub const SUICIDE: Instruction = 0xff;

--- a/ethcore/src/evm/interpreter/gasometer.rs
+++ b/ethcore/src/evm/interpreter/gasometer.rs
@ -213,7 +213,7 @@ impl<Gas: CostType> Gasometer<Gas> {

 				Request::GasMemProvide(gas, mem, Some(requested))
 			},
-			instructions::DELEGATECALL => {
+			instructions::DELEGATECALL | instructions::STATICCALL => {
 				let gas = Gas::from(schedule.call_gas);
 				let mem = cmp::max(
 					mem_needed(stack.peek(4), stack.peek(5))?,
--- a/ethcore/src/evm/interpreter/mod.rs
+++ b/ethcore/src/evm/interpreter/mod.rs
@ -199,6 +199,7 @@ impl<Cost: CostType> Interpreter<Cost> {

 		if (instruction == instructions::DELEGATECALL && !schedule.have_delegate_call) ||
 			(instruction == instructions::CREATE2 && !schedule.have_create2) ||
+			(instruction == instructions::STATICCALL && !schedule.have_static_call) ||
 			(instruction == instructions::REVERT && !schedule.have_revert) {

 			return Err(evm::Error::BadInstruction {
@ -312,14 +313,15 @@ impl<Cost: CostType> Interpreter<Cost> {
 					}
 				};
 			},
-			instructions::CALL | instructions::CALLCODE | instructions::DELEGATECALL => {
+			instructions::CALL | instructions::CALLCODE | instructions::DELEGATECALL | instructions::STATICCALL => {
 				assert!(ext.schedule().call_value_transfer_gas > ext.schedule().call_stipend, "overflow possible");
+
 				stack.pop_back();
 				let call_gas = provided.expect("`provided` comes through Self::exec from `Gasometer::get_gas_cost_mem`; `gas_gas_mem_cost` guarantees `Some` when instruction is `CALL`/`CALLCODE`/`DELEGATECALL`/`CREATE`; this is one of `CALL`/`CALLCODE`/`DELEGATECALL`; qed");
 				let code_address = stack.pop_back();
 				let code_address = u256_to_address(&code_address);

-				let value = if instruction == instructions::DELEGATECALL {
+				let value = if instruction == instructions::DELEGATECALL || instruction == instructions::STATICCALL {
 					None
 				} else {
 					Some(stack.pop_back())
@ -347,6 +349,7 @@ impl<Cost: CostType> Interpreter<Cost> {
 						(&params.address, &params.address, has_balance, CallType::CallCode)
 					},
 					instructions::DELEGATECALL => (&params.sender, &params.address, true, CallType::DelegateCall),
+					instructions::STATICCALL => (&params.sender, &params.address, true, CallType::StaticCall),
 					_ => panic!(format!("Unexpected instruction {} in CALL branch.", instruction))
 				};

@ -405,7 +408,7 @@ impl<Cost: CostType> Interpreter<Cost> {
 					.iter()
 					.map(H256::from)
 					.collect();
-				ext.log(topics, self.mem.read_slice(offset, size));
+				ext.log(topics, self.mem.read_slice(offset, size))?;
 			},
 			instructions::PUSH1...instructions::PUSH32 => {
 				let bytes = instructions::get_push_bytes(instruction);
--- a/ethcore/src/evm/schedule.rs
+++ b/ethcore/src/evm/schedule.rs
@ -15,6 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

 //! Cost schedule and other parameterisations for the EVM.
+use spec::CommonParams;

 /// Definition of the cost schedule and other parameterisations for the EVM.
 pub struct Schedule {
@ -105,6 +106,8 @@ pub struct Schedule {
 	pub kill_empty: bool,
 	/// Blockhash instruction gas cost.
 	pub blockhash_gas: usize,
+	/// Static Call opcode enabled.
+	pub have_static_call: bool,
 }

 impl Schedule {
@ -119,12 +122,12 @@ impl Schedule {
 	}

 	/// Schedule for the post-EIP-150-era of the Ethereum main net.
-	pub fn new_post_eip150(max_code_size: usize, fix_exp: bool, no_empty: bool, kill_empty: bool, have_metropolis_instructions: bool) -> Schedule {
+	pub fn new_post_eip150(max_code_size: usize, fix_exp: bool, no_empty: bool, kill_empty: bool) -> Schedule {
 		Schedule {
 			exceptional_failed_code_deposit: true,
 			have_delegate_call: true,
-			have_create2: have_metropolis_instructions,
-			have_revert: have_metropolis_instructions,
+			have_create2: false,
+			have_revert: false,
 			stack_limit: 1024,
 			max_depth: 1024,
 			tier_step_gas: [0, 2, 3, 5, 8, 10, 20, 0],
@ -163,13 +166,36 @@ impl Schedule {
 			sub_gas_cap_divisor: Some(64),
 			no_empty: no_empty,
 			kill_empty: kill_empty,
-			blockhash_gas: if have_metropolis_instructions { 350 } else { 20 },
+			blockhash_gas: 20,
+			have_static_call: false,
+		}
+	}
+
+	/// Schedule for the Metropolis era from common spec params.
+	pub fn from_params(block_number: u64, params: &CommonParams) -> Schedule {
+		let mut schedule = Schedule::new_post_eip150(usize::max_value(), true, true, true);
+		schedule.apply_params(block_number, params);
+		schedule
+ 	}
+
+	/// Apply common spec config parameters to the schedule.
+ 	pub fn apply_params(&mut self, block_number: u64, params: &CommonParams) {
+		self.have_create2 = block_number >= params.eip86_transition;
+		self.have_revert = block_number >= params.eip140_transition;
+		self.have_static_call = block_number >= params.eip214_transition;
+		if block_number >= params.eip210_transition {
+			self.blockhash_gas = 350;
 		}
 	}

 	/// Schedule for the Metropolis of the Ethereum main net.
 	pub fn new_metropolis() -> Schedule {
-		Self::new_post_eip150(24576, true, true, true, true)
+		let mut schedule = Self::new_post_eip150(24576, true, true, true);
+		schedule.have_create2 = true;
+		schedule.have_revert = true;
+		schedule.have_static_call = true;
+		schedule.blockhash_gas = 350;
+		schedule
 	}

 	fn new(efcd: bool, hdc: bool, tcg: usize) -> Schedule {
@ -217,6 +243,7 @@ impl Schedule {
 			no_empty: false,
 			kill_empty: false,
 			blockhash_gas: 20,
+			have_static_call: false,
 		}
 	}
 }
--- a/ethcore/src/evm/tests.rs
+++ b/ethcore/src/evm/tests.rs
@ -87,28 +87,28 @@ impl Default for Schedule {
 }

 impl Ext for FakeExt {
-	fn storage_at(&self, key: &H256) -> trie::Result<H256> {
+	fn storage_at(&self, key: &H256) -> evm::Result<H256> {
 		Ok(self.store.get(key).unwrap_or(&H256::new()).clone())
 	}

-	fn set_storage(&mut self, key: H256, value: H256) -> trie::Result<()> {
+	fn set_storage(&mut self, key: H256, value: H256) -> evm::Result<()> {
 		self.store.insert(key, value);
 		Ok(())
 	}

-	fn exists(&self, address: &Address) -> trie::Result<bool> {
+	fn exists(&self, address: &Address) -> evm::Result<bool> {
 		Ok(self.balances.contains_key(address))
 	}

-	fn exists_and_not_null(&self, address: &Address) -> trie::Result<bool> {
+	fn exists_and_not_null(&self, address: &Address) -> evm::Result<bool> {
 		Ok(self.balances.get(address).map_or(false, |b| !b.is_zero()))
 	}

-	fn origin_balance(&self) -> trie::Result<U256> {
+	fn origin_balance(&self) -> evm::Result<U256> {
 		unimplemented!()
 	}

-	fn balance(&self, address: &Address) -> trie::Result<U256> {
+	fn balance(&self, address: &Address) -> evm::Result<U256> {
 		Ok(self.balances[address])
 	}

@ -152,26 +152,27 @@ impl Ext for FakeExt {
 		MessageCallResult::Success(*gas, ReturnData::empty())
 	}

-	fn extcode(&self, address: &Address) -> trie::Result<Arc<Bytes>> {
+	fn extcode(&self, address: &Address) -> evm::Result<Arc<Bytes>> {
 		Ok(self.codes.get(address).unwrap_or(&Arc::new(Bytes::new())).clone())
 	}

-	fn extcodesize(&self, address: &Address) -> trie::Result<usize> {
+	fn extcodesize(&self, address: &Address) -> evm::Result<usize> {
 		Ok(self.codes.get(address).map_or(0, |c| c.len()))
 	}

-	fn log(&mut self, topics: Vec<H256>, data: &[u8]) {
+	fn log(&mut self, topics: Vec<H256>, data: &[u8]) -> evm::Result<()> {
 		self.logs.push(FakeLogEntry {
 			topics: topics,
 			data: data.to_vec()
 		});
+		Ok(())
 	}

 	fn ret(self, _gas: &U256, _data: &ReturnData) -> evm::Result<U256> {
 		unimplemented!();
 	}

-	fn suicide(&mut self, _refund_address: &Address) -> trie::Result<()> {
+	fn suicide(&mut self, _refund_address: &Address) -> evm::Result<()> {
 		unimplemented!();
 	}

--- a/ethcore/src/executive.rs
+++ b/ethcore/src/executive.rs
@ -76,6 +76,7 @@ pub struct Executive<'a, B: 'a + StateBackend, E: 'a + Engine + ?Sized> {
 	info: &'a EnvInfo,
 	engine: &'a E,
 	depth: usize,
+	static_flag: bool,
 }

 impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
@ -86,16 +87,18 @@ impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
 			info: info,
 			engine: engine,
 			depth: 0,
+			static_flag: false,
 		}
 	}

 	/// Populates executive from parent properties. Increments executive depth.
-	pub fn from_parent(state: &'a mut State<B>, info: &'a EnvInfo, engine: &'a E, parent_depth: usize) -> Self {
+	pub fn from_parent(state: &'a mut State<B>, info: &'a EnvInfo, engine: &'a E, parent_depth: usize, static_flag: bool) -> Self {
 		Executive {
 			state: state,
 			info: info,
 			engine: engine,
 			depth: parent_depth + 1,
+			static_flag: static_flag,
 		}
 	}

@ -106,9 +109,11 @@ impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
 		substate: &'any mut Substate,
 		output: OutputPolicy<'any, 'any>,
 		tracer: &'any mut T,
-		vm_tracer: &'any mut V
+		vm_tracer: &'any mut V,
+		static_call: bool,
 	) -> Externalities<'any, T, V, B, E> where T: Tracer, V: VMTracer {
-		Externalities::new(self.state, self.info, self.engine, self.depth, origin_info, substate, output, tracer, vm_tracer)
+		let is_static = self.static_flag || static_call;
+		Externalities::new(self.state, self.info, self.engine, self.depth, origin_info, substate, output, tracer, vm_tracer, is_static)
 	}

 	/// This function should be used to execute transaction.
@ -246,11 +251,12 @@ impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
 	) -> evm::Result<FinalizationResult> where T: Tracer, V: VMTracer {

 		let depth_threshold = ::io::LOCAL_STACK_SIZE.with(|sz| sz.get() / STACK_SIZE_PER_DEPTH);
+		let static_call = params.call_type == CallType::StaticCall;

 		// Ordinary execution - keep VM in same thread
 		if (self.depth + 1) % depth_threshold != 0 {
 			let vm_factory = self.state.vm_factory();
-			let mut ext = self.as_externalities(OriginInfo::from(&params), unconfirmed_substate, output_policy, tracer, vm_tracer);
+			let mut ext = self.as_externalities(OriginInfo::from(&params), unconfirmed_substate, output_policy, tracer, vm_tracer, static_call);
 			trace!(target: "executive", "ext.schedule.have_delegate_call: {}", ext.schedule().have_delegate_call);
 			return vm_factory.create(params.gas).exec(params, &mut ext).finalize(ext);
 		}
@ -260,7 +266,7 @@ impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
 		// https://github.com/aturon/crossbeam/issues/16
 		crossbeam::scope(|scope| {
 			let vm_factory = self.state.vm_factory();
-			let mut ext = self.as_externalities(OriginInfo::from(&params), unconfirmed_substate, output_policy, tracer, vm_tracer);
+			let mut ext = self.as_externalities(OriginInfo::from(&params), unconfirmed_substate, output_policy, tracer, vm_tracer, static_call);

 			scope.spawn(move || {
 				vm_factory.create(params.gas).exec(params, &mut ext).finalize(ext)
@ -280,6 +286,15 @@ impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
 		tracer: &mut T,
 		vm_tracer: &mut V
 	) -> evm::Result<(U256, ReturnData)> where T: Tracer, V: VMTracer {
+
+		trace!("Executive::call(params={:?}) self.env_info={:?}", params, self.info);
+		if (params.call_type == CallType::StaticCall ||
+				((params.call_type == CallType::Call || params.call_type == CallType::DelegateCall) &&
+				 self.static_flag))
+			&& params.value.value() > 0.into() {
+			return Err(evm::Error::MutableCallInStaticContext);
+		}
+
 		// backup used in case of running out of gas
 		self.state.checkpoint();

@ -289,7 +304,6 @@ impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
 		if let ActionValue::Transfer(val) = params.value {
 			self.state.transfer_balance(&params.sender, &params.address, &val, substate.to_cleanup_mode(&schedule))?;
 		}
-		trace!("Executive::call(params={:?}) self.env_info={:?}", params, self.info);

 		// if destination is builtin, try to execute it
 		if let Some(builtin) = self.engine.builtin(&params.code_address, self.info.number) {
@ -403,6 +417,12 @@ impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
 			return Err(evm::Error::OutOfGas);
 		}

+		if params.call_type == CallType::StaticCall || self.static_flag {
+			let trace_info = tracer.prepare_trace_create(&params);
+			tracer.trace_failed_create(trace_info, vec![], evm::Error::MutableCallInStaticContext.into());
+			return Err(evm::Error::MutableCallInStaticContext);
+		}
+
 		// backup used in case of running out of gas
 		self.state.checkpoint();

@ -541,6 +561,7 @@ impl<'a, B: 'a + StateBackend, E: Engine + ?Sized> Executive<'a, B, E> {
 				| Err(evm::Error::StackUnderflow {..})
 				| Err(evm::Error::BuiltIn {..})
 				| Err(evm::Error::OutOfStack {..})
+				| Err(evm::Error::MutableCallInStaticContext)
 				| Ok(FinalizationResult { apply_state: false, .. }) => {
 					self.state.revert_to_checkpoint();
 			},
--- a/ethcore/src/externalities.rs
+++ b/ethcore/src/externalities.rs
@ -40,7 +40,7 @@ pub struct OriginInfo {
 	address: Address,
 	origin: Address,
 	gas_price: U256,
-	value: U256
+	value: U256,
 }

 impl OriginInfo {
@ -52,7 +52,7 @@ impl OriginInfo {
 			gas_price: params.gas_price,
 			value: match params.value {
 				ActionValue::Transfer(val) | ActionValue::Apparent(val) => val
-			}
+			},
 		}
 	}
 }
@ -71,6 +71,7 @@ pub struct Externalities<'a, T: 'a, V: 'a, B: 'a, E: 'a + Engine + ?Sized>
 	output: OutputPolicy<'a, 'a>,
 	tracer: &'a mut T,
 	vm_tracer: &'a mut V,
+	static_flag: bool,
 }

 impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Externalities<'a, T, V, B, E>
@ -87,6 +88,7 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Externalities<'a, T, V, B, E>
 		output: OutputPolicy<'a, 'a>,
 		tracer: &'a mut T,
 		vm_tracer: &'a mut V,
+		static_flag: bool,
 	) -> Self {
 		Externalities {
 			state: state,
@ -99,6 +101,7 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Externalities<'a, T, V, B, E>
 			output: output,
 			tracer: tracer,
 			vm_tracer: vm_tracer,
+			static_flag: static_flag,
 		}
 	}
 }
@ -106,26 +109,32 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Externalities<'a, T, V, B, E>
 impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Ext for Externalities<'a, T, V, B, E>
 	where T: Tracer, V: VMTracer, B: StateBackend, E: Engine + ?Sized
 {
-	fn storage_at(&self, key: &H256) -> trie::Result<H256> {
-		self.state.storage_at(&self.origin_info.address, key)
+	fn storage_at(&self, key: &H256) -> evm::Result<H256> {
+		self.state.storage_at(&self.origin_info.address, key).map_err(Into::into)
 	}

-	fn set_storage(&mut self, key: H256, value: H256) -> trie::Result<()> {
-		self.state.set_storage(&self.origin_info.address, key, value)
+	fn set_storage(&mut self, key: H256, value: H256) -> evm::Result<()> {
+		if self.static_flag {
+			Err(evm::Error::MutableCallInStaticContext)
+		} else {
+			self.state.set_storage(&self.origin_info.address, key, value).map_err(Into::into)
+		}
 	}

-	fn exists(&self, address: &Address) -> trie::Result<bool> {
-		self.state.exists(address)
+	fn exists(&self, address: &Address) -> evm::Result<bool> {
+		self.state.exists(address).map_err(Into::into)
 	}

-	fn exists_and_not_null(&self, address: &Address) -> trie::Result<bool> {
-		self.state.exists_and_not_null(address)
+	fn exists_and_not_null(&self, address: &Address) -> evm::Result<bool> {
+		self.state.exists_and_not_null(address).map_err(Into::into)
 	}

-	fn origin_balance(&self) -> trie::Result<U256> { self.balance(&self.origin_info.address) }
+	fn origin_balance(&self) -> evm::Result<U256> {
+		self.balance(&self.origin_info.address).map_err(Into::into)
+	}

-	fn balance(&self, address: &Address) -> trie::Result<U256> {
-		self.state.balance(address)
+	fn balance(&self, address: &Address) -> evm::Result<U256> {
+		self.state.balance(address).map_err(Into::into)
 	}

 	fn blockhash(&mut self, number: &U256) -> H256 {
@ -208,7 +217,7 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Ext for Externalities<'a, T, V, B, E>
 				return ContractCreateResult::Failed
 			}
 		}
-		let mut ex = Executive::from_parent(self.state, self.env_info, self.engine, self.depth);
+		let mut ex = Executive::from_parent(self.state, self.env_info, self.engine, self.depth, self.static_flag);

 		// TODO: handle internal error separately
 		match ex.create(params, self.substate, self.tracer, self.vm_tracer) {
@ -258,7 +267,7 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Ext for Externalities<'a, T, V, B, E>
 			params.value = ActionValue::Transfer(value);
 		}

-		let mut ex = Executive::from_parent(self.state, self.env_info, self.engine, self.depth);
+		let mut ex = Executive::from_parent(self.state, self.env_info, self.engine, self.depth, self.static_flag);

 		match ex.call(params, self.substate, BytesRef::Fixed(output), self.tracer, self.vm_tracer) {
 			Ok((gas_left, return_data)) => MessageCallResult::Success(gas_left, return_data),
@ -266,11 +275,11 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Ext for Externalities<'a, T, V, B, E>
 		}
 	}

-	fn extcode(&self, address: &Address) -> trie::Result<Arc<Bytes>> {
+	fn extcode(&self, address: &Address) -> evm::Result<Arc<Bytes>> {
 		Ok(self.state.code(address)?.unwrap_or_else(|| Arc::new(vec![])))
 	}

-	fn extcodesize(&self, address: &Address) -> trie::Result<usize> {
+	fn extcodesize(&self, address: &Address) -> evm::Result<usize> {
 		Ok(self.state.code_size(address)?.unwrap_or(0))
 	}

@ -312,18 +321,28 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Ext for Externalities<'a, T, V, B, E>
 		}
 	}

-	fn log(&mut self, topics: Vec<H256>, data: &[u8]) {
+	fn log(&mut self, topics: Vec<H256>, data: &[u8]) -> evm::Result<()> {
 		use log_entry::LogEntry;

+		if self.static_flag {
+			return Err(evm::Error::MutableCallInStaticContext);
+		}
+
 		let address = self.origin_info.address.clone();
 		self.substate.logs.push(LogEntry {
 			address: address,
 			topics: topics,
 			data: data.to_vec()
 		});
+
+		Ok(())
 	}

-	fn suicide(&mut self, refund_address: &Address) -> trie::Result<()> {
+	fn suicide(&mut self, refund_address: &Address) -> evm::Result<()> {
+		if self.static_flag {
+			return Err(evm::Error::MutableCallInStaticContext);
+		}
+
 		let address = self.origin_info.address.clone();
 		let balance = self.balance(&address)?;
 		if &address == refund_address {
@ -434,7 +453,7 @@ mod tests {
 		let mut tracer = NoopTracer;
 		let mut vm_tracer = NoopVMTracer;

-		let ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer);
+		let ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer, false);

 		assert_eq!(ext.env_info().number, 100);
 	}
@ -446,7 +465,7 @@ mod tests {
 		let mut tracer = NoopTracer;
 		let mut vm_tracer = NoopVMTracer;

-		let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer);
+		let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer, false);

 		let hash = ext.blockhash(&U256::from_str("0000000000000000000000000000000000000000000000000000000000120000").unwrap());

@ -470,7 +489,7 @@ mod tests {
 		let mut tracer = NoopTracer;
 		let mut vm_tracer = NoopVMTracer;

-		let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer);
+		let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer, false);

 		let hash = ext.blockhash(&U256::from_str("0000000000000000000000000000000000000000000000000000000000120000").unwrap());

@ -485,7 +504,7 @@ mod tests {
 		let mut tracer = NoopTracer;
 		let mut vm_tracer = NoopVMTracer;

-		let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer);
+		let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer, false);

 		let mut output = vec![];

@ -513,8 +532,8 @@ mod tests {
 		let mut vm_tracer = NoopVMTracer;

 		{
-			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer);
-			ext.log(log_topics, &log_data);
+			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer, false);
+			ext.log(log_topics, &log_data).unwrap();
 		}

 		assert_eq!(setup.sub_state.logs.len(), 1);
@ -530,7 +549,7 @@ mod tests {
 		let mut vm_tracer = NoopVMTracer;

 		{
-			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer);
+			let mut ext = Externalities::new(state, &setup.env_info, &*setup.engine, 0, get_test_origin(), &mut setup.sub_state, OutputPolicy::InitContract(None), &mut tracer, &mut vm_tracer, false);
 			ext.suicide(refund_account).unwrap();
 		}

--- a/ethcore/src/json_tests/executive.rs
+++ b/ethcore/src/json_tests/executive.rs
@ -75,9 +75,10 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> TestExt<'a, T, V, B, E>
 		tracer: &'a mut T,
 		vm_tracer: &'a mut V,
 	) -> trie::Result<Self> {
+		let static_call = false;
 		Ok(TestExt {
 			nonce: state.nonce(&address)?,
-			ext: Externalities::new(state, info, engine, depth, origin_info, substate, output, tracer, vm_tracer),
+			ext: Externalities::new(state, info, engine, depth, origin_info, substate, output, tracer, vm_tracer, static_call),
 			callcreates: vec![],
 			sender: address,
 		})
@ -87,27 +88,27 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> TestExt<'a, T, V, B, E>
 impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Ext for TestExt<'a, T, V, B, E>
 	where T: Tracer, V: VMTracer, B: StateBackend, E: Engine + ?Sized
 {
-	fn storage_at(&self, key: &H256) -> trie::Result<H256> {
+	fn storage_at(&self, key: &H256) -> evm::Result<H256> {
 		self.ext.storage_at(key)
 	}

-	fn set_storage(&mut self, key: H256, value: H256) -> trie::Result<()> {
+	fn set_storage(&mut self, key: H256, value: H256) -> evm::Result<()> {
 		self.ext.set_storage(key, value)
 	}

-	fn exists(&self, address: &Address) -> trie::Result<bool> {
+	fn exists(&self, address: &Address) -> evm::Result<bool> {
 		self.ext.exists(address)
 	}

-	fn exists_and_not_null(&self, address: &Address) -> trie::Result<bool> {
+	fn exists_and_not_null(&self, address: &Address) -> evm::Result<bool> {
 		self.ext.exists_and_not_null(address)
 	}

-	fn balance(&self, address: &Address) -> trie::Result<U256> {
+	fn balance(&self, address: &Address) -> evm::Result<U256> {
 		self.ext.balance(address)
 	}

-	fn origin_balance(&self) -> trie::Result<U256> {
+	fn origin_balance(&self) -> evm::Result<U256> {
 		self.ext.origin_balance()
 	}

@ -145,15 +146,15 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Ext for TestExt<'a, T, V, B, E>
 		MessageCallResult::Success(*gas, ReturnData::empty())
 	}

-	fn extcode(&self, address: &Address) -> trie::Result<Arc<Bytes>>  {
+	fn extcode(&self, address: &Address) -> evm::Result<Arc<Bytes>>  {
 		self.ext.extcode(address)
 	}

-	fn extcodesize(&self, address: &Address) -> trie::Result<usize> {
+	fn extcodesize(&self, address: &Address) -> evm::Result<usize> {
 		self.ext.extcodesize(address)
 	}

-	fn log(&mut self, topics: Vec<H256>, data: &[u8]) {
+	fn log(&mut self, topics: Vec<H256>, data: &[u8]) -> evm::Result<()> {
 		self.ext.log(topics, data)
 	}

@ -161,7 +162,7 @@ impl<'a, T: 'a, V: 'a, B: 'a, E: 'a> Ext for TestExt<'a, T, V, B, E>
 		self.ext.ret(gas, data)
 	}

-	fn suicide(&mut self, refund_address: &Address) -> trie::Result<()> {
+	fn suicide(&mut self, refund_address: &Address) -> evm::Result<()> {
 		self.ext.suicide(refund_address)
 	}

--- a/ethcore/src/spec/spec.rs
+++ b/ethcore/src/spec/spec.rs
@ -74,6 +74,8 @@ pub struct CommonParams {
 	pub eip210_contract_gas: U256,
 	/// Number of first block where EIP-211 (Metropolis: RETURNDATASIZE/RETURNDATACOPY) rules begin.
 	pub eip211_transition: BlockNumber,
+	/// Number of first block where EIP-214 rules begin.
+	pub eip214_transition: BlockNumber,
 }

 impl From<ethjson::spec::Params> for CommonParams {
@ -97,6 +99,7 @@ impl From<ethjson::spec::Params> for CommonParams {
 				Into::into),
 			eip210_contract_gas: p.eip210_contract_gas.map_or(1000000.into(), Into::into),
 			eip211_transition: p.eip211_transition.map_or(BlockNumber::max_value(), Into::into),
+			eip214_transition: p.eip214_transition.map_or(BlockNumber::max_value(), Into::into),
 		}
 	}
 }
--- a/ethcore/src/state_db.rs
+++ b/ethcore/src/state_db.rs
@ -477,7 +477,7 @@ mod tests {
 		let mut batch = DBTransaction::new();

 		// blocks  [ 3a(c) 2a(c) 2b 1b 1a(c) 0 ]
-	    // balance [ 5     5     4  3  2     2 ]
+		// balance [ 5     5     4  3  2     2 ]
 		let mut s = state_db.boxed_clone_canon(&root_parent);
 		s.add_to_account_cache(address, Some(Account::new_basic(2.into(), 0.into())), false);
 		s.journal_under(&mut batch, 0, &h0).unwrap();
--- a/ethcore/src/tests/helpers.rs
+++ b/ethcore/src/tests/helpers.rs
@ -418,6 +418,7 @@ pub fn get_default_ethash_params() -> EthashParams{
 		eip161d_transition: u64::max_value(),
 		ecip1010_pause_transition: u64::max_value(),
 		ecip1010_continue_transition: u64::max_value(),
+		ecip1017_era_rounds: u64::max_value(),
 		max_code_size: u64::max_value(),
 		max_gas_limit_transition: u64::max_value(),
 		max_gas_limit: U256::max_value(),
--- a/ethcore/src/types/executed.rs
+++ b/ethcore/src/types/executed.rs
@ -36,6 +36,8 @@ pub enum CallType {
 	CallCode,
 	/// DELEGATECALL.
 	DelegateCall,
+	/// STATICCALL
+	StaticCall,
 }

 impl Encodable for CallType {
@ -45,6 +47,7 @@ impl Encodable for CallType {
 			CallType::Call => 1,
 			CallType::CallCode => 2,
 			CallType::DelegateCall => 3,
+			CallType::StaticCall => 4,
 		};
 		Encodable::rlp_append(&v, s);
 	}
@ -57,6 +60,7 @@ impl Decodable for CallType {
 			1 => CallType::Call,
 			2 => CallType::CallCode,
 			3 => CallType::DelegateCall,
+			4 => CallType::StaticCall,
 			_ => return Err(DecoderError::Custom("Invalid value of CallType item")),
 		}))
 	}
@ -145,6 +149,8 @@ pub enum ExecutionError {
 		/// Actual balance.
 		got: U512
 	},
+	/// When execution tries to modify the state in static context
+	MutableCallInStaticContext,
 	/// Returned when internal evm error occurs.
 	Internal(String),
 	/// Returned when generic transaction occurs
@ -172,6 +178,7 @@ impl fmt::Display for ExecutionError {
 			NotEnoughCash { ref required, ref got } =>
 				format!("Cost of transaction exceeds sender balance. {} is required \
 					but the sender only has {}", required, got),
+			MutableCallInStaticContext => "Mutable Call in static context".to_owned(),
 			Internal(ref msg) => msg.clone(),
 			TransactionMalformed(ref err) => format!("Malformed transaction: {}", err),
 		};
--- a/ethcore/src/types/trace_types/error.rs
+++ b/ethcore/src/types/trace_types/error.rs
@ -40,6 +40,8 @@ pub enum Error {
 	/// Returned on evm internal error. Should never be ignored during development.
 	/// Likely to cause consensus issues.
 	Internal,
+	/// When execution tries to modify the state in static context
+	MutableCallInStaticContext,
 }

 impl<'a> From<&'a EvmError> for Error {
@ -52,6 +54,7 @@ impl<'a> From<&'a EvmError> for Error {
 			EvmError::OutOfStack { .. } => Error::OutOfStack,
 			EvmError::BuiltIn { .. } => Error::BuiltIn,
 			EvmError::Internal(_) => Error::Internal,
+			EvmError::MutableCallInStaticContext => Error::MutableCallInStaticContext,
 		}
 	}
 }
@ -73,6 +76,7 @@ impl fmt::Display for Error {
 			OutOfStack => "Out of stack",
 			BuiltIn => "Built-in failed",
 			Internal => "Internal error",
+			MutableCallInStaticContext => "Mutable Call In Static Context",
 		};
 		message.fmt(f)
 	}
@ -89,6 +93,7 @@ impl Encodable for Error {
 			OutOfStack => 4,
 			Internal => 5,
 			BuiltIn => 6,
+			MutableCallInStaticContext => 7,
 		};

 		s.append_internal(&value);
@ -107,6 +112,7 @@ impl Decodable for Error {
 			4 => Ok(OutOfStack),
 			5 => Ok(Internal),
 			6 => Ok(BuiltIn),
+			7 => Ok(MutableCallInStaticContext),
 			_ => Err(DecoderError::Custom("Invalid error type")),
 		}
 	}
--- a/ethkey/Cargo.toml
+++ b/ethkey/Cargo.toml
@ -9,16 +9,6 @@ lazy_static = "0.2"
 tiny-keccak = "1.2"
 eth-secp256k1 = { git = "https://github.com/paritytech/rust-secp256k1" }
 rustc-serialize = "0.3"
-docopt = { version = "0.7", optional = true }
 ethcore-bigint = { path = "../util/bigint" }
 rust-crypto = "0.2"
 byteorder = "1.0"
-
-[features]
-default = []
-cli = ["docopt"]
-
-[[bin]]
-name = "ethkey"
-path = "src/bin/main.rs"
-doc = false
--- a/ethkey/cli/Cargo.toml
+++ b/ethkey/cli/Cargo.toml
@ -0,0 +1,14 @@
+[package]
+name = "ethkey-cli"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+
+[dependencies]
+ethkey = { path = "../" }
+rustc-serialize = "0.3"
+docopt = "0.7"
+
+[[bin]]
+name = "ethkey"
+path = "src/main.rs"
+doc = false
--- a/ethkey/src/bin/ethkey.rs
+++ b/ethkey/src/bin/ethkey.rs
--- a/ethkey/src/bin/main.rs
+++ b/ethkey/src/bin/main.rs
@ -1,21 +0,0 @@
-// Copyright 2015-2017 Parity Technologies (UK) Ltd.
-// This file is part of Parity.
-
-// Parity is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// Parity 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 General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
-
-#[cfg(feature = "cli")]
-include!("ethkey.rs");
-
-#[cfg(not(feature = "cli"))]
-fn main() {}
--- a/ethstore/Cargo.toml
+++ b/ethstore/Cargo.toml
@ -14,7 +14,6 @@ serde_derive = "0.9"
 rustc-serialize = "0.3"
 rust-crypto = "0.2.36"
 tiny-keccak = "1.0"
-docopt = { version = "0.7", optional = true }
 time = "0.1.34"
 itertools = "0.5"
 parking_lot = "0.4"
@ -24,12 +23,4 @@ smallvec = "0.4"
 parity-wordlist = "1.0"
 tempdir = "0.3"

-[features]
-cli = ["docopt"]
-
 [lib]
-
-[[bin]]
-name = "ethstore"
-path = "src/bin/main.rs"
-doc = false
--- a/ethstore/cli/Cargo.toml
+++ b/ethstore/cli/Cargo.toml
@ -0,0 +1,14 @@
+[package]
+name = "ethstore-cli"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+
+[dependencies]
+rustc-serialize = "0.3"
+docopt = "0.7"
+ethstore = { path = "../" }
+
+[[bin]]
+name = "ethstore"
+path = "src/main.rs"
+doc = false
--- a/ethstore/src/bin/ethstore.rs
+++ b/ethstore/src/bin/ethstore.rs
--- a/ethstore/src/bin/main.rs
+++ b/ethstore/src/bin/main.rs
@ -1,21 +0,0 @@
-// Copyright 2015-2017 Parity Technologies (UK) Ltd.
-// This file is part of Parity.
-
-// Parity is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// Parity 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 General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
-
-#[cfg(feature = "cli")]
-include!("ethstore.rs");
-
-#[cfg(not(feature = "cli"))]
-fn main() {}
--- a/ethstore/src/dir/vault.rs
+++ b/ethstore/src/dir/vault.rs
@ -296,6 +296,7 @@ mod test {
 		assert!(check_vault_name("vault_with_underscores"));
 		assert!(check_vault_name("vault-with-dashes"));
 		assert!(check_vault_name("vault-with-digits-123"));
+		assert!(check_vault_name("vault中文名字"));
 	}

 	#[test]
--- a/js/package.json
+++ b/js/package.json
@ -1,6 +1,6 @@
 {
  "name": "parity.js",
-  "version": "1.7.91",
+  "version": "1.7.92",
  "main": "release/index.js",
  "jsnext:main": "src/index.js",
  "author": "Parity Team <admin@parity.io>",
--- a/js/src/api/local/accounts/accounts.js
+++ b/js/src/api/local/accounts/accounts.js
@ -129,6 +129,8 @@ export default class Accounts {

  set dappsDefaultAddress (value) {
    this._dappsDefaultAddress = value.toLowerCase();
+
+    this.persist();
  }

  get (address) {
@ -191,10 +193,16 @@ export default class Accounts {
    this.persist();
  }

-  addresses () {
+  allAddresses () {
    return Object.keys(this._store);
  }

+  accountAddresses () {
+    return Object
+      .keys(this._store)
+      .filter((address) => this._store[address].uuid);
+  }
+
  map (mapper) {
    const result = {};

--- a/js/src/api/local/localAccountsMiddleware.js
+++ b/js/src/api/local/localAccountsMiddleware.js
@ -29,7 +29,7 @@ export default class LocalAccountsMiddleware extends Middleware {
    const register = this.register.bind(this);

    register('eth_accounts', () => {
-      return accounts.addresses();
+      return accounts.accountAddresses();
    });

    register('eth_coinbase', () => {
@ -73,7 +73,7 @@ export default class LocalAccountsMiddleware extends Middleware {
    });

    register('parity_defaultAccount', () => {
-      return accounts.lastAddress;
+      return accounts.dappsDefaultAddress;
    });

    register('parity_exportAccount', ([address, password]) => {
@ -98,11 +98,11 @@ export default class LocalAccountsMiddleware extends Middleware {
    });

    register('parity_getNewDappsAddresses', () => {
-      return [];
+      return accounts.accountAddresses();
    });

    register('parity_getNewDappsDefaultAddress', () => {
-      return accounts.lastAddress;
+      return accounts.dappsDefaultAddress;
    });

    register('parity_hardwareAccountsInfo', () => {
@ -149,6 +149,8 @@ export default class LocalAccountsMiddleware extends Middleware {

    register('parity_setNewDappsDefaultAddress', ([address]) => {
      accounts.dappsDefaultAddress = address;
+
+      return true;
    });

    register('parity_postTransaction', ([tx]) => {
@ -210,6 +212,10 @@ export default class LocalAccountsMiddleware extends Middleware {
      return account.isValidPassword(password);
    });

+    register('parity_upgradeReady', () => {
+      return false;
+    });
+
    register('signer_confirmRequest', ([id, modify, password]) => {
      const {
        gasPrice,
--- a/js/src/api/subscriptions/signer.js
+++ b/js/src/api/subscriptions/signer.js
@ -57,7 +57,7 @@ export default class Signer {
        this._updateSubscriptions('signer_requestsToConfirm', null, requests);
        nextTimeout();
      })
-      .catch(nextTimeout);
+      .catch(() => nextTimeout());
  }

  _postTransaction (data) {
--- a/js/src/api/transport/http/http.js
+++ b/js/src/api/transport/http/http.js
@ -93,8 +93,8 @@ export default class Http extends JsonRpcBase {

    this
      .execute('net_listening')
-      .then(nextTimeout)
-      .catch(nextTimeout);
+      .then(() => nextTimeout())
+      .catch(() => nextTimeout());
  }

  set url (url) {
--- a/js/src/api/transport/middleware.js
+++ b/js/src/api/transport/middleware.js
@ -21,6 +21,10 @@ export default class Middleware {
  }

  register (method, handler) {
+    if (method in this._handlers) {
+      throw new Error(`${method} is already defined in the middleware!`);
+    }
+
    this._handlers[method] = handler;
  }

--- a/js/src/shell/Signer/store.js
+++ b/js/src/shell/Signer/store.js
@ -101,7 +101,7 @@ export default class SignerStore {

        this.setLocalHashes(keys);
      })
-      .then(nextTimeout)
-      .catch(nextTimeout);
+      .then(() => nextTimeout())
+      .catch(() => nextTimeout());
  }
 }
--- a/json/src/spec/ethash.rs
+++ b/json/src/spec/ethash.rs
@ -100,6 +100,10 @@ pub struct EthashParams {
 	#[serde(rename="ecip1010ContinueTransition")]
 	pub ecip1010_continue_transition: Option<Uint>,

+	/// See main EthashParams docs.
+	#[serde(rename="ecip1017EraRounds")]
+	pub ecip1017_era_rounds: Option<Uint>,
+
 	/// See main EthashParams docs.
 	#[serde(rename="maxCodeSize")]
 	pub max_code_size: Option<Uint>,
--- a/json/src/spec/params.rs
+++ b/json/src/spec/params.rs
@ -78,6 +78,9 @@ pub struct Params {
 	/// See `CommonParams` docs.
 	#[serde(rename="eip211Transition")]
 	pub eip211_transition: Option<Uint>,
+	/// See `CommonParams` docs.
+	#[serde(rename="eip214Transition")]
+	pub eip214_transition: Option<Uint>,
 }

 #[cfg(test)]
--- a/rpc/src/v1/extractors.rs
+++ b/rpc/src/v1/extractors.rs
@ -81,7 +81,7 @@ impl ws::MetaExtractor<Metadata> for WsExtractor {
 		let dapp = req.origin.as_ref().map(|origin| (&**origin).into()).unwrap_or_default();
 		metadata.origin = match self.authcodes_path {
 			Some(ref path) => {
-				let authorization = req.protocols.get(0).and_then(|p| auth_token_hash(&path, p));
+				let authorization = req.protocols.get(0).and_then(|p| auth_token_hash(&path, p, true));
 				match authorization {
 					Some(id) => Origin::Signer { session: id.into(), dapp: dapp },
 					None => Origin::Ws { session: id.into(), dapp: dapp },
@ -117,7 +117,7 @@ impl ws::RequestMiddleware for WsExtractor {
 		let protocols = req.protocols().ok().unwrap_or_else(Vec::new);
 		if let Some(ref path) = self.authcodes_path {
 			if protocols.len() == 1 {
-				let authorization = auth_token_hash(&path, protocols[0]);
+				let authorization = auth_token_hash(&path, protocols[0], false);
 				if authorization.is_none() {
 					warn!(
 						"Blocked connection from {} using invalid token.",
@ -142,7 +142,7 @@ fn add_security_headers(res: &mut ws::ws::Response) {
 	headers.push(("X-Content-Type-Options".into(), b"nosniff".to_vec()));
 }

-fn auth_token_hash(codes_path: &Path, protocol: &str) -> Option<H256> {
+fn auth_token_hash(codes_path: &Path, protocol: &str, save_file: bool) -> Option<H256> {
 	let mut split = protocol.split('_');
 	let auth = split.next().and_then(|v| v.parse().ok());
 	let time = split.next().and_then(|v| u64::from_str_radix(v, 10).ok());
@ -156,9 +156,12 @@ fn auth_token_hash(codes_path: &Path, protocol: &str) -> Option<H256> {
 				codes.clear_garbage();

 				let res = codes.is_valid(&auth, time);
-				// make sure to save back authcodes - it might have been modified
-				if codes.to_file(codes_path).is_err() {
-					warn!(target: "signer", "Couldn't save authorization codes to file.");
+
+				if save_file {
+					// make sure to save back authcodes - it might have been modified
+					if codes.to_file(codes_path).is_err() {
+						warn!(target: "signer", "Couldn't save authorization codes to file.");
+					}
 				}

 				if res {
--- a/rpc/src/v1/types/trace.rs
+++ b/rpc/src/v1/types/trace.rs
@ -251,6 +251,9 @@ pub enum CallType {
 	/// Delegate call
 	#[serde(rename="delegatecall")]
 	DelegateCall,
+	/// Static call
+	#[serde(rename="staticcall")]
+	StaticCall,
 }

 impl From<executed::CallType> for CallType {
@ -260,6 +263,7 @@ impl From<executed::CallType> for CallType {
 			executed::CallType::Call => CallType::Call,
 			executed::CallType::CallCode => CallType::CallCode,
 			executed::CallType::DelegateCall => CallType::DelegateCall,
+			executed::CallType::StaticCall => CallType::StaticCall,
 		}
 	}
 }
--- a/scripts/parity.service
+++ b/scripts/parity.service
@ -3,7 +3,7 @@ Description=Parity Daemon
 After=network.target

 [Service]
-EnvironmentFile=%h/.parity/parity.conf
+EnvironmentFile=-%h/.parity/parity.conf
 ExecStart=/usr/bin/parity $ARGS

 [Install]
--- a/secret_store/src/key_server_cluster/io/deadline.rs
+++ b/secret_store/src/key_server_cluster/io/deadline.rs
@ -24,7 +24,7 @@ type DeadlineBox<F> where F: Future = BoxFuture<DeadlineStatus<F::Item>, F::Erro
 /// Complete a passed future or fail if it is not completed within timeout.
 pub fn deadline<F, T>(duration: Duration, handle: &Handle, future: F) -> Result<Deadline<F>, io::Error>
 	where F: Future<Item = T, Error = io::Error> + Send + 'static, T: 'static {
-	let timeout = try!(Timeout::new(duration, handle)).map(|_| DeadlineStatus::Timeout).boxed();
+	let timeout = Timeout::new(duration, handle)?.map(|_| DeadlineStatus::Timeout).boxed();
 	let future = future.map(DeadlineStatus::Meet).boxed();
 	let deadline = Deadline {
 		future: timeout.select(future),
--- a/sync/src/api.rs
+++ b/sync/src/api.rs
@ -709,7 +709,7 @@ impl LightSync {
 			};

 			let mut light_proto = LightProtocol::new(params.client.clone(), light_params);
-			let sync_handler = Arc::new(try!(SyncHandler::new(params.client.clone())));
+			let sync_handler = Arc::new(SyncHandler::new(params.client.clone())?);
 			light_proto.add_handler(sync_handler.clone());

 			for handler in params.handlers {
@ -719,7 +719,7 @@ impl LightSync {
 			(sync_handler, Arc::new(light_proto))
 		};

-		let service = try!(NetworkService::new(params.network_config));
+		let service = NetworkService::new(params.network_config)?;

 		Ok(LightSync {
 			proto: light_proto,
--- a/sync/src/chain.rs
+++ b/sync/src/chain.rs
@ -521,7 +521,8 @@ impl ChainSync {
 					sn > fork_block &&
 					self.highest_block.map_or(true, |highest| highest >= sn && (highest - sn) <= SNAPSHOT_RESTORE_THRESHOLD)
 				))
-				.filter_map(|(p, peer)| peer.snapshot_hash.map(|hash| (p, hash.clone())));
+				.filter_map(|(p, peer)| peer.snapshot_hash.map(|hash| (p, hash.clone())))
+				.filter(|&(_, ref hash)| !self.snapshot.is_known_bad(hash));

 			let mut snapshot_peers = HashMap::new();
 			let mut max_peers: usize = 0;
@ -1075,10 +1076,18 @@ impl ChainSync {
 		}

 		// check service status
-		match io.snapshot_service().status() {
+		let status = io.snapshot_service().status();
+		match status {
 			RestorationStatus::Inactive | RestorationStatus::Failed => {
 				trace!(target: "sync", "{}: Snapshot restoration aborted", peer_id);
 				self.state = SyncState::WaitingPeers;
+
+				// only note bad if restoration failed.
+				if let (Some(hash), RestorationStatus::Failed) = (self.snapshot.snapshot_hash(), status) {
+					trace!(target: "sync", "Noting snapshot hash {} as bad", hash);
+					self.snapshot.note_bad(hash);
+				}
+
 				self.snapshot.clear();
 				self.continue_sync(io);
 				return Ok(());
--- a/sync/src/light_sync/mod.rs
+++ b/sync/src/light_sync/mod.rs
@ -551,7 +551,7 @@ impl<L: AsLightClient> LightSync<L> {
 			peers: RwLock::new(HashMap::new()),
 			pending_reqs: Mutex::new(HashSet::new()),
 			client: client,
-			rng: Mutex::new(try!(OsRng::new())),
+			rng: Mutex::new(OsRng::new()?),
 			state: Mutex::new(SyncState::Idle),
 		})
 	}
--- a/sync/src/light_sync/response.rs
+++ b/sync/src/light_sync/response.rs
@ -47,7 +47,7 @@ impl From<DecoderError> for BasicError {

 impl fmt::Display for BasicError {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-		try!(write!(f, "Header response verification error: "));
+		write!(f, "Header response verification error: ")?;

 		match *self {
 			BasicError::WrongSkip(ref exp, ref got)
@ -78,13 +78,13 @@ pub fn verify(headers: &[encoded::Header], request: &HeadersRequest) -> Result<V

 	let reverse = request.reverse;

-	try!(Max(request.max as usize).verify(&headers, reverse));
+	Max(request.max as usize).verify(&headers, reverse)?;
 	match request.start {
-		HashOrNumber::Number(ref num) => try!(StartsAtNumber(*num).verify(&headers, reverse)),
-		HashOrNumber::Hash(ref hash) => try!(StartsAtHash(*hash).verify(&headers, reverse)),
+		HashOrNumber::Number(ref num) => StartsAtNumber(*num).verify(&headers, reverse)?,
+		HashOrNumber::Hash(ref hash) => StartsAtHash(*hash).verify(&headers, reverse)?,
 	}

-	try!(SkipsBetween(request.skip).verify(&headers, reverse));
+	SkipsBetween(request.skip).verify(&headers, reverse)?;

 	Ok(headers)
 }
--- a/sync/src/snapshot.rs
+++ b/sync/src/snapshot.rs
@ -31,6 +31,7 @@ pub struct Snapshot {
 	downloading_chunks: HashSet<H256>,
 	completed_chunks: HashSet<H256>,
 	snapshot_hash: Option<H256>,
+	bad_hashes: HashSet<H256>,
 }

 impl Snapshot {
@ -42,6 +43,7 @@ impl Snapshot {
 			downloading_chunks: HashSet::new(),
 			completed_chunks: HashSet::new(),
 			snapshot_hash: None,
+			bad_hashes: HashSet::new(),
 		}
 	}

@ -109,6 +111,16 @@ impl Snapshot {
 		self.downloading_chunks.remove(hash);
 	}

+	// note snapshot hash as bad.
+	pub fn note_bad(&mut self, hash: H256) {
+		self.bad_hashes.insert(hash);
+	}
+
+	// whether snapshot hash is known to be bad.
+	pub fn is_known_bad(&self, hash: &H256) -> bool {
+		self.bad_hashes.contains(hash)
+	}
+
 	pub fn snapshot_hash(&self) -> Option<H256> {
 		self.snapshot_hash
 	}
@ -205,5 +217,15 @@ mod test {
 		assert_eq!(snapshot.done_chunks(), snapshot.total_chunks());
 		assert_eq!(snapshot.snapshot_hash(), Some(manifest.into_rlp().sha3()));
 	}
+
+	#[test]
+	fn tracks_known_bad() {
+		let mut snapshot = Snapshot::new();
+		let hash = H256::random();
+
+		assert_eq!(snapshot.is_known_bad(&hash), false);
+		snapshot.note_bad(hash);
+		assert_eq!(snapshot.is_known_bad(&hash), true);
+	}
 }

--- a/util/src/journaldb/archivedb.rs
+++ b/util/src/journaldb/archivedb.rs
@ -239,6 +239,21 @@ mod tests {
 		jdb.commit_batch(3, &b"3".sha3(), Some((0, b"0".sha3()))).unwrap();
 		assert!(jdb.contains(&h));
 		jdb.commit_batch(4, &b"4".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.contains(&h));
+	}
+
+	#[test]
+	#[should_panic]
+	fn multiple_owed_removal_not_allowed() {
+		let mut jdb = ArchiveDB::new_temp();
+		let h = jdb.insert(b"foo");
+		jdb.commit_batch(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.contains(&h));
+		jdb.remove(&h);
+		jdb.remove(&h);
+		// commit_batch would call journal_under(),
+		// and we don't allow multiple owned removals.
+		jdb.commit_batch(1, &b"1".sha3(), None).unwrap();
 	}

 	#[test]