Merge branch 'master' of github.com:ethcore/parity

2016-03-13 13:13:23 +01:00 · 2016-03-13 13:13:23 +01:00 · f0862acffe
commit f0862acffe
parent 51275f79f8 4e8092b008
33 changed files with 931 additions and 173 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -2,7 +2,7 @@
 name = "parity"
 version = "0.9.99"
 dependencies = [
- "clippy 0.0.49 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clippy 0.0.50 (registry+https://github.com/rust-lang/crates.io-index)",
 "ctrlc 1.1.1 (git+https://github.com/tomusdrw/rust-ctrlc.git)",
 "daemonize 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "docopt 0.6.78 (registry+https://github.com/rust-lang/crates.io-index)",
@ -94,7 +94,7 @@ dependencies = [

 [[package]]
 name = "clippy"
-version = "0.0.49"
+version = "0.0.50"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "regex-syntax 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
@ -207,7 +207,7 @@ dependencies = [
 name = "ethcore"
 version = "0.9.99"
 dependencies = [
- "clippy 0.0.49 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clippy 0.0.50 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "env_logger 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "ethash 0.9.99",
@ -233,7 +233,7 @@ dependencies = [
 name = "ethcore-rpc"
 version = "0.9.99"
 dependencies = [
- "clippy 0.0.49 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clippy 0.0.50 (registry+https://github.com/rust-lang/crates.io-index)",
 "ethash 0.9.99",
 "ethcore 0.9.99",
 "ethcore-util 0.9.99",
@ -256,7 +256,7 @@ dependencies = [
 "arrayvec 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
 "bigint 0.1.0",
 "chrono 0.2.20 (registry+https://github.com/rust-lang/crates.io-index)",
- "clippy 0.0.49 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clippy 0.0.50 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "elastic-array 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "env_logger 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
@ -271,7 +271,7 @@ dependencies = [
 "log 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "mio 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
- "rocksdb 0.4.2 (git+https://github.com/arkpar/rust-rocksdb.git)",
+ "rocksdb 0.4.3 (git+https://github.com/arkpar/rust-rocksdb.git)",
 "rust-crypto 0.2.34 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-serialize 0.3.18 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc_version 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
@ -288,7 +288,7 @@ dependencies = [
 name = "ethsync"
 version = "0.9.99"
 dependencies = [
- "clippy 0.0.49 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clippy 0.0.50 (registry+https://github.com/rust-lang/crates.io-index)",
 "env_logger 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "ethcore 0.9.99",
 "ethcore-util 0.9.99",
@ -466,8 +466,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"

 [[package]]
 name = "librocksdb-sys"
-version = "0.2.2"
-source = "git+https://github.com/arkpar/rust-rocksdb.git#a4f89fea20ee3ae92b692df65d56426a5c0b6fd5"
+version = "0.2.3"
+source = "git+https://github.com/arkpar/rust-rocksdb.git#ebb602fc74b4067f9f51310bdc0401b8e59b7156"
 dependencies = [
 "libc 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@ -688,11 +688,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"

 [[package]]
 name = "rocksdb"
-version = "0.4.2"
-source = "git+https://github.com/arkpar/rust-rocksdb.git#a4f89fea20ee3ae92b692df65d56426a5c0b6fd5"
+version = "0.4.3"
+source = "git+https://github.com/arkpar/rust-rocksdb.git#ebb602fc74b4067f9f51310bdc0401b8e59b7156"
 dependencies = [
 "libc 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "librocksdb-sys 0.2.2 (git+https://github.com/arkpar/rust-rocksdb.git)",
+ "librocksdb-sys 0.2.3 (git+https://github.com/arkpar/rust-rocksdb.git)",
 ]

 [[package]]
--- a/Cargo.toml
+++ b/Cargo.toml
@ -19,7 +19,7 @@ ctrlc = { git = "https://github.com/tomusdrw/rust-ctrlc.git" }
 fdlimit = { path = "util/fdlimit" }
 daemonize = "0.2"
 number_prefix = "0.2"
-clippy = { version = "0.0.49", optional = true }
+clippy = { version = "0.0.50", optional = true }
 ethcore = { path = "ethcore" }
 ethcore-util = { path = "util" }
 ethsync = { path = "sync" }
--- a/ethcore/Cargo.toml
+++ b/ethcore/Cargo.toml
@ -17,7 +17,7 @@ ethcore-util = { path = "../util" }
 evmjit = { path = "../evmjit", optional = true }
 ethash = { path = "../ethash" }
 num_cpus = "0.2"
-clippy = { version = "0.0.49", optional = true }
+clippy = { version = "0.0.50", optional = true }
 crossbeam = "0.1.5"
 lazy_static = "0.1"
 ethcore-devtools = { path = "../devtools" }
--- a/ethcore/src/block_queue.rs
+++ b/ethcore/src/block_queue.rs
@ -523,7 +523,7 @@ mod tests {
 		let engine = spec.to_engine().unwrap();
 		let mut config = BlockQueueConfig::default();
 		config.max_mem_use = super::MIN_MEM_LIMIT;  // empty queue uses about 15000
-		let mut queue = BlockQueue::new(config, Arc::new(engine), IoChannel::disconnected());
+		let queue = BlockQueue::new(config, Arc::new(engine), IoChannel::disconnected());
 		assert!(!queue.queue_info().is_full());
 		let mut blocks = get_good_dummy_block_seq(50);
 		for b in blocks.drain(..) {
--- a/ethcore/src/chainfilter/tests.rs
+++ b/ethcore/src/chainfilter/tests.rs
@ -28,9 +28,15 @@ pub struct MemoryCache {
 	blooms: HashMap<BloomIndex, H2048>,
 }

+impl Default for MemoryCache {
+	fn default() -> Self {
+		MemoryCache::new()
+	}
+}
+
 impl MemoryCache {
 	/// Default constructor for MemoryCache
-	pub fn new() -> MemoryCache {
+	pub fn new() -> Self {
 		MemoryCache { blooms: HashMap::new() }
 	}

--- a/ethcore/src/client/client.rs
+++ b/ethcore/src/client/client.rs
@ -449,6 +449,10 @@ impl<V> BlockChainClient for Client<V> where V: Verifier {
 		self.state().code(address)
 	}

+	fn balance(&self, address: &Address) -> U256 {
+		self.state().balance(address)
+	}
+
 	fn transaction(&self, id: TransactionId) -> Option<LocalizedTransaction> {
 		match id {
 			TransactionId::Hash(ref hash) => self.chain.transaction_address(hash),
--- a/ethcore/src/client/mod.rs
+++ b/ethcore/src/client/mod.rs
@ -66,6 +66,9 @@ pub trait BlockChainClient : Sync + Send {
 	/// Get address code.
 	fn code(&self, address: &Address) -> Option<Bytes>;

+	/// Get address balance.
+	fn balance(&self, address: &Address) -> U256;
+
 	/// Get transaction with given hash.
 	fn transaction(&self, id: TransactionId) -> Option<LocalizedTransaction>;

--- a/ethcore/src/client/test_client.rs
+++ b/ethcore/src/client/test_client.rs
@ -40,6 +40,8 @@ pub struct TestBlockChainClient {
 	pub last_hash: RwLock<H256>,
 	/// Difficulty.
 	pub difficulty: RwLock<U256>,
+	/// Balances.
+	pub balances: RwLock<HashMap<Address, U256>>,
 }

 #[derive(Clone)]
@ -55,9 +57,15 @@ pub enum EachBlockWith {
 	UncleAndTransaction
 }

+impl Default for TestBlockChainClient {
+	fn default() -> Self {
+		TestBlockChainClient::new()
+	}
+}
+
 impl TestBlockChainClient {
 	/// Creates new test client.
-	pub fn new() -> TestBlockChainClient {
+	pub fn new() -> Self {

 		let mut client = TestBlockChainClient {
 			blocks: RwLock::new(HashMap::new()),
@ -65,12 +73,17 @@ impl TestBlockChainClient {
 			genesis_hash: H256::new(),
 			last_hash: RwLock::new(H256::new()),
 			difficulty: RwLock::new(From::from(0)),
+			balances: RwLock::new(HashMap::new()),
 		};
 		client.add_blocks(1, EachBlockWith::Nothing); // add genesis block
 		client.genesis_hash = client.last_hash.read().unwrap().clone();
 		client
 	}

+	pub fn set_balance(&mut self, address: Address, balance: U256) {
+		self.balances.write().unwrap().insert(address, balance);
+	}
+
 	/// Add blocks to test client.
 	pub fn add_blocks(&mut self, count: usize, with: EachBlockWith) {
 		let len = self.numbers.read().unwrap().len();
@ -165,6 +178,10 @@ impl BlockChainClient for TestBlockChainClient {
 		unimplemented!();
 	}

+	fn balance(&self, address: &Address) -> U256 {
+		self.balances.read().unwrap().get(address).cloned().unwrap_or_else(U256::zero)
+	}
+
 	fn transaction(&self, _id: TransactionId) -> Option<LocalizedTransaction> {
 		unimplemented!();
 	}
--- a/ethcore/src/externalities.rs
+++ b/ethcore/src/externalities.rs
@ -301,8 +301,14 @@ mod tests {
 		env_info: EnvInfo
 	}

+	impl Default for TestSetup {
+		fn default() -> Self {
+			TestSetup::new()
+		}
+	}
+
 	impl TestSetup {
-		fn new() -> TestSetup {
+		fn new() -> Self {
 			TestSetup {
 				state: get_temp_state(),
 				engine: get_test_spec().to_engine().unwrap(),
--- a/ethcore/src/verification/noop_verifier.rs
+++ b/ethcore/src/verification/noop_verifier.rs
@ -20,6 +20,7 @@ use error::Error;
 use header::Header;
 use super::Verifier;

+#[allow(dead_code)]
 pub struct NoopVerifier;

 impl Verifier for NoopVerifier {
--- a/ethcore/src/verification/verification.rs
+++ b/ethcore/src/verification/verification.rs
@ -255,8 +255,14 @@ mod tests {
 		numbers: HashMap<BlockNumber, H256>,
 	}

+	impl Default for TestBlockChain {
+		fn default() -> Self {
+			TestBlockChain::new()
+		}
+	}
+
 	impl TestBlockChain {
-		pub fn new() -> TestBlockChain {
+		pub fn new() -> Self {
 			TestBlockChain {
 				blocks: HashMap::new(),
 				numbers: HashMap::new(),
--- a/parity/main.rs
+++ b/parity/main.rs
@ -314,7 +314,7 @@ impl Configuration {
 	fn init_nodes(&self, spec: &Spec) -> Vec<String> {
 		let mut r = if self.args.flag_no_bootstrap { Vec::new() } else { spec.nodes().clone() };
 		if let Some(ref x) = self.args.flag_bootnodes {
-			r.extend(x.split(",").map(|s| Self::normalize_enode(s).unwrap_or_else(|| die!("{}: Invalid node address format given for a boot node.", s))));
+			r.extend(x.split(',').map(|s| Self::normalize_enode(s).unwrap_or_else(|| die!("{}: Invalid node address format given for a boot node.", s))));
 		}
 		r
 	}
@ -327,7 +327,7 @@ impl Configuration {
 			let host = IpAddr::from_str(host).unwrap_or_else(|_| die!("Invalid host given with `--nat extip:{}`", host));
 			Some(SocketAddr::new(host, self.args.flag_port))
 		} else {
-			listen_address.clone()
+			listen_address
 		};
 		(listen_address, public_address)
 	}
@ -388,12 +388,13 @@ impl Configuration {
 		}
 		if self.args.cmd_list {
 			println!("Known addresses:");
-			for &(addr, _) in secret_store.accounts().unwrap().iter() {
+			for &(addr, _) in &secret_store.accounts().unwrap() {
 				println!("{:?}", addr);
 			}
 		}
 	}

+	#[cfg_attr(feature="dev", allow(useless_format))]
 	fn execute_client(&self) {
 		// Setup panic handler
 		let panic_handler = PanicHandler::new_in_arc();
@ -406,7 +407,11 @@ impl Configuration {
 		let spec = self.spec();
 		let net_settings = self.net_settings(&spec);
 		let mut sync_config = SyncConfig::default();
-		sync_config.network_id = self.args.flag_networkid.as_ref().map(|id| U256::from_str(id).unwrap_or_else(|_| die!("{}: Invalid index given with --networkid", id))).unwrap_or(spec.network_id());
+		sync_config.network_id = self.args.flag_networkid.as_ref().map_or(spec.network_id(), |id| {
+			U256::from_str(id).unwrap_or_else(|_| {
+				die!("{}: Invalid index given with --networkid", id)
+			})
+		});

 		// Build client
 		let mut client_config = ClientConfig::default();
@ -421,8 +426,7 @@ impl Configuration {
 			}
 		}
 		client_config.pruning = match self.args.flag_pruning.as_str() {
-			"" => journaldb::Algorithm::Archive,
-			"archive" => journaldb::Algorithm::Archive,
+			"" | "archive" => journaldb::Algorithm::Archive,
 			"pruned" => journaldb::Algorithm::EarlyMerge,
 			"fast" => journaldb::Algorithm::OverlayRecent,
 //			"slow" => journaldb::Algorithm::RefCounted,		// TODO: @gavofyork uncomment this once ref-count algo is merged.
@ -452,7 +456,7 @@ impl Configuration {
 			let cors = self.args.flag_rpccorsdomain.as_ref().unwrap_or(&self.args.flag_jsonrpc_cors);
 			// TODO: use this as the API list.
 			let apis = self.args.flag_rpcapi.as_ref().unwrap_or(&self.args.flag_jsonrpc_apis);
-			let server_handler = setup_rpc_server(service.client(), sync.clone(), account_service.clone(), &url, cors, apis.split(",").collect());
+			let server_handler = setup_rpc_server(service.client(), sync.clone(), account_service.clone(), &url, cors, apis.split(',').collect());
 			if let Some(handler) = server_handler {
 				panic_handler.forward_from(handler.deref());
 			}
--- a/rpc/Cargo.toml
+++ b/rpc/Cargo.toml
@ -18,7 +18,7 @@ ethcore-util = { path = "../util" }
 ethcore = { path = "../ethcore" }
 ethash = { path = "../ethash" }
 ethsync = { path = "../sync" }
-clippy = { version = "0.0.49", optional = true }
+clippy = { version = "0.0.50", optional = true }
 rustc-serialize = "0.3"
 transient-hashmap = "0.1"
 serde_macros = { version = "0.7.0", optional = true }
--- a/rpc/src/v1/impls/eth.rs
+++ b/rpc/src/v1/impls/eth.rs
@ -155,6 +155,14 @@ impl<C, S, A> Eth for EthClient<C, S, A> where C: BlockChainClient + 'static, S:
 		}
 	}

+	fn accounts(&self, _: Params) -> Result<Value, Error> {
+		let store = take_weak!(self.accounts);
+		match store.accounts() {
+			Ok(account_list) => to_value(&account_list),
+			Err(_) => Err(Error::internal_error())
+		}
+	}
+
 	fn block_number(&self, params: Params) -> Result<Value, Error> {
 		match params {
 			Params::None => to_value(&U256::from(take_weak!(self.client).chain_info().best_block_number)),
@ -162,6 +170,11 @@ impl<C, S, A> Eth for EthClient<C, S, A> where C: BlockChainClient + 'static, S:
 		}
 	}

+	fn balance(&self, params: Params) -> Result<Value, Error> {
+		from_params::<(Address, BlockNumber)>(params)
+			.and_then(|(address, _block_number)| to_value(&take_weak!(self.client).balance(&address)))
+	}
+
 	fn block_transaction_count_by_hash(&self, params: Params) -> Result<Value, Error> {
 		from_params::<(H256,)>(params)
 			.and_then(|(hash,)| match take_weak!(self.client).block(BlockId::Hash(hash)) {
--- a/rpc/src/v1/impls/personal.rs
+++ b/rpc/src/v1/impls/personal.rs
@ -39,12 +39,7 @@ impl<A> Personal for PersonalClient<A> where A: AccountProvider + 'static {
 	fn accounts(&self, _: Params) -> Result<Value, Error> {
 		let store = take_weak!(self.accounts);
 		match store.accounts() {
-			Ok(account_list) => {
-				Ok(Value::Array(account_list.iter()
-					.map(|&account| Value::String(format!("{:?}", account)))
-					.collect::<Vec<Value>>())
-				)
-			}
+			Ok(account_list) => to_value(&account_list),
 			Err(_) => Err(Error::internal_error())
 		}
 	}
--- a/rpc/src/v1/tests/eth.rs
+++ b/rpc/src/v1/tests/eth.rs
@ -0,0 +1,90 @@
+// Copyright 2015, 2016 Ethcore (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/>.
+
+use std::collections::HashMap;
+use std::sync::Arc;
+use jsonrpc_core::IoHandler;
+use util::hash::Address;
+use util::numbers::U256;
+use ethcore::client::{TestBlockChainClient, EachBlockWith};
+use v1::{Eth, EthClient};
+use v1::tests::helpers::{TestAccount, TestAccountProvider, TestSyncProvider, Config};
+
+fn blockchain_client() -> Arc<TestBlockChainClient> {
+	let mut client = TestBlockChainClient::new();
+	client.add_blocks(10, EachBlockWith::Nothing);
+	client.set_balance(Address::from(1), U256::from(5));
+	Arc::new(client)
+}
+
+fn accounts_provider() -> Arc<TestAccountProvider> {
+	let mut accounts = HashMap::new();
+	accounts.insert(Address::from(1), TestAccount::new("test"));
+	let ap = TestAccountProvider::new(accounts);
+	Arc::new(ap)
+}
+
+fn sync_provider() -> Arc<TestSyncProvider> {
+	Arc::new(TestSyncProvider::new(Config {
+		protocol_version: 65,
+		num_peers: 120,
+	}))
+}
+
+struct EthTester {
+	client: Arc<TestBlockChainClient>,
+	sync: Arc<TestSyncProvider>,
+	accounts_provider: Arc<TestAccountProvider>,
+	pub io: IoHandler,
+}
+
+impl Default for EthTester {
+	fn default() -> Self {
+		let client = blockchain_client();
+		let sync = sync_provider();
+		let ap = accounts_provider();
+		let eth = EthClient::new(&client, &sync, &ap).to_delegate();
+		let io = IoHandler::new();
+		io.add_delegate(eth);
+		EthTester {
+			client: client,
+			sync: sync,
+			accounts_provider: ap,
+			io: io
+		}
+	}
+}
+
+#[test]
+fn rpc_eth_accounts() {
+	let request = r#"{"jsonrpc": "2.0", "method": "eth_accounts", "params": [], "id": 1}"#;
+	let response = r#"{"jsonrpc":"2.0","result":["0x0000000000000000000000000000000000000001"],"id":1}"#;
+
+	assert_eq!(EthTester::default().io.handle_request(request), Some(response.to_owned()));
+}
+
+#[test]
+fn rpc_eth_balance() {
+	let request = r#"{
+		"jsonrpc": "2.0",
+		"method": "eth_getBalance",
+		"params": ["0x0000000000000000000000000000000000000001", "latest"],
+		"id": 1
+	}"#;
+	let response = r#"{"jsonrpc":"2.0","result":"0x05","id":1}"#;
+
+	assert_eq!(EthTester::default().io.handle_request(request), Some(response.to_owned()));
+}
--- a/rpc/src/v1/tests/helpers/account_provider.rs
+++ b/rpc/src/v1/tests/helpers/account_provider.rs
@ -0,0 +1,84 @@
+// Copyright 2015, 2016 Ethcore (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/>.
+
+use std::sync::RwLock;
+use std::collections::HashMap;
+use std::io;
+use util::hash::{Address, H256};
+use util::crypto::{Secret, Signature};
+use util::keys::store::{AccountProvider, SigningError, EncryptedHashMapError};
+
+/// Account mock.
+#[derive(Clone)]
+pub struct TestAccount {
+	/// True if account is unlocked.
+	pub unlocked: bool,
+	/// Account's password.
+	pub password: String,
+}
+
+impl TestAccount {
+	pub fn new(password: &str) -> Self {
+		TestAccount {
+			unlocked: false,
+			password: password.to_owned(),
+		}
+	}
+}
+
+/// Test account provider.
+pub struct TestAccountProvider {
+	accounts: RwLock<HashMap<Address, TestAccount>>,
+}
+
+impl TestAccountProvider {
+	/// Basic constructor.
+	pub fn new(accounts: HashMap<Address, TestAccount>) -> Self {
+		TestAccountProvider {
+			accounts: RwLock::new(accounts),
+		}
+	}
+}
+
+impl AccountProvider for TestAccountProvider {
+	fn accounts(&self) -> Result<Vec<Address>, io::Error> {
+		Ok(self.accounts.read().unwrap().keys().cloned().collect())
+	}
+
+	fn unlock_account(&self, account: &Address, pass: &str) -> Result<(), EncryptedHashMapError> {
+		match self.accounts.write().unwrap().get_mut(account) {
+			Some(ref mut acc) if acc.password == pass => {
+				acc.unlocked = true;
+				Ok(())
+			},
+			Some(_) => Err(EncryptedHashMapError::InvalidPassword),
+			None => Err(EncryptedHashMapError::UnknownIdentifier),
+		}
+	}
+
+	fn new_account(&self, _pass: &str) -> Result<Address, io::Error> {
+		unimplemented!()
+	}
+	fn account_secret(&self, _account: &Address) -> Result<Secret, SigningError> {
+		unimplemented!()
+	}
+
+	fn sign(&self, _account: &Address, _message: &H256) -> Result<Signature, SigningError> {
+		unimplemented!()
+	}
+
+}
+
--- a/rpc/src/v1/tests/helpers/mod.rs
+++ b/rpc/src/v1/tests/helpers/mod.rs
@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

+mod account_provider;
 mod sync_provider;

+pub use self::account_provider::{TestAccount, TestAccountProvider};
 pub use self::sync_provider::{Config, TestSyncProvider};
--- a/rpc/src/v1/tests/mod.rs
+++ b/rpc/src/v1/tests/mod.rs
@ -16,6 +16,7 @@

 //!TODO: load custom blockchain state and test

+mod eth;
 mod net;
 mod web3;
 mod helpers;
--- a/rpc/src/v1/traits/eth.rs
+++ b/rpc/src/v1/traits/eth.rs
@ -130,7 +130,7 @@ pub trait Eth: Sized + Send + Sync + 'static {
 		delegate.add_method("eth_gasPrice", Eth::gas_price);
 		delegate.add_method("eth_accounts", Eth::accounts);
 		delegate.add_method("eth_blockNumber", Eth::block_number);
-		delegate.add_method("eth_balance", Eth::balance);
+		delegate.add_method("eth_getBalance", Eth::balance);
 		delegate.add_method("eth_getStorageAt", Eth::storage_at);
 		delegate.add_method("eth_getTransactionCount", Eth::transaction_count);
 		delegate.add_method("eth_getBlockTransactionCountByHash", Eth::block_transaction_count_by_hash);
--- a/rpc/src/v1/types/transaction.rs
+++ b/rpc/src/v1/types/transaction.rs
@ -17,7 +17,6 @@
 use util::numbers::*;
 use ethcore::transaction::{LocalizedTransaction, Action};
 use v1::types::{Bytes, OptionalValue};
-use serde::Error;

 #[derive(Debug, Default, Serialize)]
 pub struct Transaction {
--- a/sync/Cargo.toml
+++ b/sync/Cargo.toml
@ -10,7 +10,7 @@ authors = ["Ethcore <admin@ethcore.io"]
 [dependencies]
 ethcore-util = { path = "../util" }
 ethcore = { path = "../ethcore" }
-clippy = { version = "0.0.49", optional = true }
+clippy = { version = "0.0.50", optional = true }
 log = "0.3"
 env_logger = "0.3"
 time = "0.1.34"
--- a/sync/src/chain.rs
+++ b/sync/src/chain.rs
@ -298,8 +298,6 @@ impl ChainSync {
 	/// Restart sync
 	pub fn restart(&mut self, io: &mut SyncIo) {
 		self.reset();
-		self.last_imported_block = None;
-		self.last_imported_hash = None;
 		self.starting_block = 0;
 		self.highest_block = None;
 		self.have_common_block = false;
@ -366,7 +364,7 @@ impl ChainSync {
 		for i in 0..item_count {
 			let info: BlockHeader = try!(r.val_at(i));
 			let number = BlockNumber::from(info.number);
-			if number <= self.current_base_block() || self.headers.have_item(&number) {
+			if (number <= self.current_base_block() && self.have_common_block) || self.headers.have_item(&number) {
 				trace!(target: "sync", "Skipping existing block header");
 				continue;
 			}
@ -376,11 +374,17 @@ impl ChainSync {
 			}
 			let hash = info.hash();
 			match io.chain().block_status(BlockId::Hash(hash.clone())) {
-				BlockStatus::InChain => {
-					self.have_common_block = true;
-					self.last_imported_block = Some(number);
-					self.last_imported_hash = Some(hash.clone());
-					trace!(target: "sync", "Found common header {} ({})", number, hash);
+				BlockStatus::InChain | BlockStatus::Queued => {
+					if !self.have_common_block || self.current_base_block() < number {
+						self.last_imported_block = Some(number);
+						self.last_imported_hash = Some(hash.clone());
+					}
+					if !self.have_common_block {
+						self.have_common_block = true;
+						trace!(target: "sync", "Found common header {} ({})", number, hash);
+					} else {
+						trace!(target: "sync", "Header already in chain {} ({})", number, hash);
+					}
 				},
 				_ => {
 					if self.have_common_block {
@ -588,7 +592,7 @@ impl ChainSync {
 	pub fn on_peer_connected(&mut self, io: &mut SyncIo, peer: PeerId) {
 		trace!(target: "sync", "== Connected {}", peer);
 		if let Err(e) = self.send_status(io) {
-			warn!(target:"sync", "Error sending status request: {:?}", e);
+			debug!(target:"sync", "Error sending status request: {:?}", e);
 			io.disable_peer(peer);
 		}
 	}
@ -656,10 +660,7 @@ impl ChainSync {
 		let mut needed_numbers: Vec<BlockNumber> = Vec::new();

 		if self.have_common_block && !self.headers.is_empty() && self.headers.range_iter().next().unwrap().0 == self.current_base_block() + 1 {
-			for (start, ref items) in self.headers.range_iter() {
-				if needed_bodies.len() >= MAX_BODIES_TO_REQUEST {
-					break;
-				}
+			if let Some((start, ref items)) = self.headers.range_iter().next() {
 				let mut index: BlockNumber = 0;
 				while index != items.len() as BlockNumber && needed_bodies.len() < MAX_BODIES_TO_REQUEST {
 					let block = start + index;
@ -703,7 +704,10 @@ impl ChainSync {
 		if !self.have_common_block {
 			// download backwards until common block is found 1 header at a time
 			let chain_info = io.chain().chain_info();
-			start = chain_info.best_block_number;
+			start = match self.last_imported_block {
+				Some(n) => n,
+				None => chain_info.best_block_number,
+			};
 			if !self.headers.is_empty() {
 				start = min(start, self.headers.range_iter().next().unwrap().0 - 1);
 			}
@ -844,18 +848,12 @@ impl ChainSync {
 	/// Remove downloaded bocks/headers starting from specified number.
 	/// Used to recover from an error and re-download parts of the chain detected as bad.
 	fn remove_downloaded_blocks(&mut self, start: BlockNumber) {
-		for n in self.headers.get_tail(&start) {
-			if let Some(ref header_data) = self.headers.find_item(&n) {
-				let header_to_delete = HeaderView::new(&header_data.data);
-				let header_id = HeaderId {
-					transactions_root: header_to_delete.transactions_root(),
-					uncles: header_to_delete.uncles_hash()
-				};
-				self.header_ids.remove(&header_id);
-			}
-			self.downloading_bodies.remove(&n);
-			self.downloading_headers.remove(&n);
-		}
+		let ids = self.header_ids.drain().filter(|&(_, v)| v < start).collect();
+		self.header_ids = ids;
+		let hdrs = self.downloading_headers.drain().filter(|v| *v < start).collect();
+		self.downloading_headers = hdrs;
+		let bodies = self.downloading_bodies.drain().filter(|v| *v < start).collect();
+		self.downloading_bodies = bodies;
 		self.headers.remove_from(&start);
 		self.bodies.remove_from(&start);
 	}
@ -1095,7 +1093,7 @@ impl ChainSync {
 		let rlp = UntrustedRlp::new(data);

 		if packet_id != STATUS_PACKET && !self.peers.contains_key(&peer) {
-			warn!(target:"sync", "Unexpected packet from unregistered peer: {}:{}", peer, io.peer_info(peer));
+			debug!(target:"sync", "Unexpected packet from unregistered peer: {}:{}", peer, io.peer_info(peer));
 			return;
 		}
 		let result = match packet_id {
--- a/sync/src/range_collection.rs
+++ b/sync/src/range_collection.rs
@ -300,12 +300,17 @@ fn test_range() {
 	let mut r = ranges.clone();
 	r.remove_from(&20);
 	assert_eq!(r.range_iter().cmp(vec![(2, &['b', 'c', 'd'][..]),  (16, &['p', 'q', 'r'][..])]),  Ordering::Equal);
-	r.remove_from(&17);
-	assert_eq!(r.range_iter().cmp(vec![(2, &['b', 'c', 'd'][..]),  (16, &['p'][..])]),  Ordering::Equal);
-	r.remove_from(&15);
+	r.remove_from(&18);
+	assert!(!r.have_item(&18));
+	assert_eq!(r.range_iter().cmp(vec![(2, &['b', 'c', 'd'][..]),  (16, &['p', 'q'][..])]),  Ordering::Equal);
+	r.remove_from(&16);
+	assert!(!r.have_item(&16));
 	assert_eq!(r.range_iter().cmp(vec![(2, &['b', 'c', 'd'][..])]),  Ordering::Equal);
 	r.remove_from(&3);
 	assert_eq!(r.range_iter().cmp(vec![(2, &['b'][..])]),  Ordering::Equal);
+	r.remove_from(&1);
+	assert_eq!(r.range_iter().next(), None);
+	let mut r = ranges.clone();
 	r.remove_from(&2);
 	assert_eq!(r.range_iter().next(), None);
 }
--- a/util/Cargo.toml
+++ b/util/Cargo.toml
@ -27,7 +27,7 @@ crossbeam = "0.2"
 slab = "0.1"
 sha3 = { path = "sha3" }
 serde = "0.7.0"
-clippy = { version = "0.0.49", optional = true }
+clippy = { version = "0.0.50", optional = true }
 json-tests = { path = "json-tests" }
 rustc_version = "0.1.0"
 igd = "0.4.2"
--- a/util/src/journaldb/archivedb.rs
+++ b/util/src/journaldb/archivedb.rs
@ -159,6 +159,10 @@ impl JournalDB for ArchiveDB {
 		try!(self.backing.write(batch));
 		Ok((inserts + deletes) as u32)
 	}
+
+	fn state(&self, id: &H256) -> Option<Bytes> {
+		self.backing.get_by_prefix(&id.bytes()[0..12]).and_then(|b| Some(b.to_vec()))
+	}
 }

 #[cfg(test)]
@ -301,7 +305,6 @@ mod tests {
 		assert!(jdb.exists(&foo));
 	}

-
 	#[test]
 	fn reopen() {
 		let mut dir = ::std::env::temp_dir();
@ -360,6 +363,7 @@ mod tests {
 			jdb.commit(5, &b"5".sha3(), Some((4, b"4".sha3()))).unwrap();
 		}
 	}
+	
 	#[test]
 	fn reopen_fork() {
 		let mut dir = ::std::env::temp_dir();
@ -385,4 +389,22 @@ mod tests {
 			assert!(jdb.exists(&foo));
 		}
 	}
+
+	#[test]
+	fn returns_state() {
+		let temp = ::devtools::RandomTempPath::new();
+
+		let key = {
+			let mut jdb = ArchiveDB::new(temp.as_str());
+			let key = jdb.insert(b"foo");
+			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			key
+		};
+
+		{
+			let jdb = ArchiveDB::new(temp.as_str());
+			let state = jdb.state(&key);
+			assert!(state.is_some());
+		}
+	}
 }
--- a/util/src/journaldb/earlymergedb.rs
+++ b/util/src/journaldb/earlymergedb.rs
@ -25,6 +25,34 @@ use kvdb::{Database, DBTransaction, DatabaseConfig};
 #[cfg(test)]
 use std::env;

+#[derive(Clone, PartialEq, Eq)]
+struct RefInfo {
+	queue_refs: usize,
+	in_archive: bool,
+}
+
+impl HeapSizeOf for RefInfo {
+	fn heap_size_of_children(&self) -> usize { 0 }
+}
+
+impl fmt::Display for RefInfo {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		write!(f, "{}+{}", self.queue_refs, if self.in_archive {1} else {0})
+	}
+}
+
+impl fmt::Debug for RefInfo {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		write!(f, "{}+{}", self.queue_refs, if self.in_archive {1} else {0})
+	}
+}
+
+#[derive(Clone, PartialEq, Eq)]
+enum RemoveFrom {
+	Queue,
+	Archive,
+}
+
 /// Implementation of the HashDB trait for a disk-backed database with a memory overlay
 /// and latent-removal semantics.
 ///
@ -35,7 +63,8 @@ use std::env;
 pub struct EarlyMergeDB {
 	overlay: MemoryDB,
 	backing: Arc<Database>,
-	counters: Option<Arc<RwLock<HashMap<H256, i32>>>>,
+	refs: Option<Arc<RwLock<HashMap<H256, RefInfo>>>>,
+	latest_era: Option<u64>,
 }

 // all keys must be at least 12 bytes
@ -62,11 +91,13 @@ impl EarlyMergeDB {
 			backing.put(&VERSION_KEY, &encode(&DB_VERSION)).expect("Error writing version to database");
 		}

-		let counters = Some(Arc::new(RwLock::new(EarlyMergeDB::read_counters(&backing))));
+		let (latest_era, refs) = EarlyMergeDB::read_refs(&backing);
+		let refs = Some(Arc::new(RwLock::new(refs)));
 		EarlyMergeDB {
 			overlay: MemoryDB::new(),
 			backing: Arc::new(backing),
-			counters: counters,
+			refs: refs,
+			latest_era: latest_era,
 		}
 	}

@ -91,11 +122,14 @@ impl EarlyMergeDB {
 		backing.get(&Self::morph_key(key, 0)).expect("Low-level database error. Some issue with your hard disk?").is_some()
 	}

-	fn insert_keys(inserts: &[(H256, Bytes)], backing: &Database, counters: &mut HashMap<H256, i32>, batch: &DBTransaction) {
+	fn insert_keys(inserts: &[(H256, Bytes)], backing: &Database, refs: &mut HashMap<H256, RefInfo>, batch: &DBTransaction, trace: bool) {
 		for &(ref h, ref d) in inserts {
-			if let Some(c) = counters.get_mut(h) {
+			if let Some(c) = refs.get_mut(h) {
 				// already counting. increment.
-				*c += 1;
+				c.queue_refs += 1;
+				if trace {
+					trace!(target: "jdb.fine", "    insert({}): In queue: Incrementing refs to {}", h, c.queue_refs);
+				}
 				continue;
 			}

@ -103,7 +137,10 @@ impl EarlyMergeDB {
 			if backing.get(&h.bytes()).expect("Low-level database error. Some issue with your hard disk?").is_some() {
 				// already in the backing DB. start counting, and remember it was already in.
 				Self::set_already_in(batch, &h);
-				counters.insert(h.clone(), 1);
+				refs.insert(h.clone(), RefInfo{queue_refs: 1, in_archive: true});
+				if trace {
+					trace!(target: "jdb.fine", "    insert({}): New to queue, in DB: Recording and inserting into queue", h);
+				}
 				continue;
 			}

@ -111,62 +148,108 @@ impl EarlyMergeDB {
 			//Self::reset_already_in(&h);
 			assert!(!Self::is_already_in(backing, &h));
 			batch.put(&h.bytes(), d).expect("Low-level database error. Some issue with your hard disk?");
+			refs.insert(h.clone(), RefInfo{queue_refs: 1, in_archive: false});
+			if trace {
+				trace!(target: "jdb.fine", "    insert({}): New to queue, not in DB: Inserting into queue and DB", h);
+			}
 		}
 	}

-	fn replay_keys(inserts: &[H256], backing: &Database, counters: &mut HashMap<H256, i32>) {
-		trace!("replay_keys: inserts={:?}, counters={:?}", inserts, counters);
+	fn replay_keys(inserts: &[H256], backing: &Database, refs: &mut HashMap<H256, RefInfo>) {
+		trace!(target: "jdb.fine", "replay_keys: inserts={:?}, refs={:?}", inserts, refs);
 		for h in inserts {
-			if let Some(c) = counters.get_mut(h) {
+			if let Some(c) = refs.get_mut(h) {
 				// already counting. increment.
-				*c += 1;
+				c.queue_refs += 1;
 				continue;
 			}

 			// this is the first entry for this node in the journal.
 			// it is initialised to 1 if it was already in.
-			if Self::is_already_in(backing, h) {
-				trace!("replace_keys: Key {} was already in!", h);
-				counters.insert(h.clone(), 1);
-			}
+			refs.insert(h.clone(), RefInfo{queue_refs: 1, in_archive: Self::is_already_in(backing, h)});
 		}
-		trace!("replay_keys: (end) counters={:?}", counters);
+		trace!(target: "jdb.fine", "replay_keys: (end) refs={:?}", refs);
 	}

-	fn kill_keys(deletes: Vec<H256>, counters: &mut HashMap<H256, i32>, batch: &DBTransaction) {
-		for h in deletes.into_iter() {
-			let mut n: Option<i32> = None;
-			if let Some(c) = counters.get_mut(&h) {
-				if *c > 1 {
-					*c -= 1;
+	fn kill_keys(deletes: &Vec<H256>, refs: &mut HashMap<H256, RefInfo>, batch: &DBTransaction, from: RemoveFrom, trace: bool) {
+		// with a kill on {queue_refs: 1, in_archive: true}, we have two options:
+		// - convert to {queue_refs: 1, in_archive: false} (i.e. remove it from the conceptual archive)
+		// - convert to {queue_refs: 0, in_archive: true} (i.e. remove it from the conceptual queue)
+		// (the latter option would then mean removing the RefInfo, since it would no longer be counted in the queue.)
+		// both are valid, but we switch between them depending on context.
+		//     All inserts in queue (i.e. those which may yet be reverted) have an entry in refs.
+		for h in deletes.iter() {
+			let mut n: Option<RefInfo> = None;
+			if let Some(c) = refs.get_mut(h) {
+				if c.in_archive && from == RemoveFrom::Archive {
+					c.in_archive = false;
+					Self::reset_already_in(batch, h);
+					if trace {
+						trace!(target: "jdb.fine", "    kill({}): In archive, 1 in queue: Reducing to queue only and recording", h);
+					}
+					continue;
+				} else if c.queue_refs > 1 {
+					c.queue_refs -= 1;
+					if trace {
+						trace!(target: "jdb.fine", "    kill({}): In queue > 1 refs: Decrementing ref count to {}", h, c.queue_refs);
+					}
 					continue;
 				} else {
-					n = Some(*c);
+					n = Some(c.clone());
 				}
 			}
 			match n {
-				Some(i) if i == 1 => {
-					counters.remove(&h);
-					Self::reset_already_in(batch, &h);
+				Some(RefInfo{queue_refs: 1, in_archive: true}) => {
+					refs.remove(h);
+					Self::reset_already_in(batch, h);
+					if trace {
+						trace!(target: "jdb.fine", "    kill({}): In archive, 1 in queue: Removing from queue and leaving in archive", h);
+					}
+				}
+				Some(RefInfo{queue_refs: 1, in_archive: false}) => {
+					refs.remove(h);
+					batch.delete(&h.bytes()).expect("Low-level database error. Some issue with your hard disk?");
+					if trace {
+						trace!(target: "jdb.fine", "    kill({}): Not in archive, only 1 ref in queue: Removing from queue and DB", h);
+					}
 				}
 				None => {
 					// Gets removed when moving from 1 to 0 additional refs. Should never be here at 0 additional refs.
 					//assert!(!Self::is_already_in(db, &h));
 					batch.delete(&h.bytes()).expect("Low-level database error. Some issue with your hard disk?");
+					if trace {
+						trace!(target: "jdb.fine", "    kill({}): Not in queue - MUST BE IN ARCHIVE: Removing from DB", h);
+					}
 				}
-				_ => panic!("Invalid value in counters: {:?}", n),
+				_ => panic!("Invalid value in refs: {:?}", n),
 			}
 		}
 	}

+	#[cfg(test)]
+	fn can_reconstruct_refs(&self) -> bool {
+		let (latest_era, reconstructed) = Self::read_refs(&self.backing);
+		let refs = self.refs.as_ref().unwrap().write().unwrap();
+		if *refs != reconstructed || latest_era != self.latest_era {
+			let clean_refs = refs.iter().filter_map(|(k, v)| if reconstructed.get(k) == Some(v) {None} else {Some((k.clone(), v.clone()))}).collect::<HashMap<_, _>>();
+			let clean_recon = reconstructed.into_iter().filter_map(|(k, v)| if refs.get(&k) == Some(&v) {None} else {Some((k.clone(), v.clone()))}).collect::<HashMap<_, _>>();
+			warn!(target: "jdb", "mem: {:?}  !=  log: {:?}", clean_refs, clean_recon);
+			false
+		} else {
+			true
+		}
+	}
+
 	fn payload(&self, key: &H256) -> Option<Bytes> {
 		self.backing.get(&key.bytes()).expect("Low-level database error. Some issue with your hard disk?").map(|v| v.to_vec())
 	}

-	fn read_counters(db: &Database) -> HashMap<H256, i32> {
-		let mut counters = HashMap::new();
+	fn read_refs(db: &Database) -> (Option<u64>, HashMap<H256, RefInfo>) {
+		let mut refs = HashMap::new();
+		let mut latest_era = None;
 		if let Some(val) = db.get(&LATEST_ERA_KEY).expect("Low-level database error.") {
 			let mut era = decode::<u64>(&val);
+			latest_era = Some(era);
 			loop {
 				let mut index = 0usize;
 				while let Some(rlp_data) = db.get({
@ -176,10 +259,9 @@ impl EarlyMergeDB {
 					r.append(&&PADDING[..]);
 					&r.drain()
 				}).expect("Low-level database error.") {
-					trace!("read_counters: era={}, index={}", era, index);
 					let rlp = Rlp::new(&rlp_data);
 					let inserts: Vec<H256> = rlp.val_at(1);
-					Self::replay_keys(&inserts, db, &mut counters);
+					Self::replay_keys(&inserts, db, &mut refs);
 					index += 1;
 				};
 				if index == 0 || era == 0 {
@ -188,10 +270,9 @@ impl EarlyMergeDB {
 				era -= 1;
 			}
 		}
-		trace!("Recovered {} counters", counters.len());
-		counters
+		(latest_era, refs)
 	}
-}
+ }

 impl HashDB for EarlyMergeDB {
 	fn keys(&self) -> HashMap<H256, i32> {
@ -243,21 +324,22 @@ impl JournalDB for EarlyMergeDB {
 		Box::new(EarlyMergeDB {
 			overlay: MemoryDB::new(),
 			backing: self.backing.clone(),
-			counters: self.counters.clone(),
+			refs: self.refs.clone(),
+			latest_era: self.latest_era.clone(),
 		})
 	}

-	fn mem_used(&self) -> usize {
-		self.overlay.mem_used() + match self.counters {
-			Some(ref c) => c.read().unwrap().heap_size_of_children(),
-			None => 0
-		}
- 	}
-
 	fn is_empty(&self) -> bool {
 		self.backing.get(&LATEST_ERA_KEY).expect("Low level database error").is_none()
 	}

+	fn mem_used(&self) -> usize {
+		self.overlay.mem_used() + match self.refs {
+			Some(ref c) => c.read().unwrap().heap_size_of_children(),
+			None => 0
+		}
+ 	}
+
 	fn commit(&mut self, now: u64, id: &H256, end: Option<(u64, H256)>) -> Result<u32, UtilError> {
 		// journal format: 
 		// [era, 0] => [ id, [insert_0, ...], [remove_0, ...] ]
@ -304,9 +386,9 @@ impl JournalDB for EarlyMergeDB {
 		//

 		// record new commit's details.
-		trace!("commit: #{} ({}), end era: {:?}", now, id, end);
-		let mut counters = self.counters.as_ref().unwrap().write().unwrap();
+		let mut refs = self.refs.as_ref().unwrap().write().unwrap();
 		let batch = DBTransaction::new();
+		let trace = false;
 		{
 			let mut index = 0usize;
 			let mut last;
@ -323,6 +405,11 @@ impl JournalDB for EarlyMergeDB {
 			}

 			let drained = self.overlay.drain();
+
+			if trace {
+				trace!(target: "jdb", "commit: #{} ({}), end era: {:?}", now, id, end);
+			}
+
 			let removes: Vec<H256> = drained
 				.iter()
 				.filter_map(|(k, &(_, c))| if c < 0 {Some(k.clone())} else {None})
@ -332,6 +419,9 @@ impl JournalDB for EarlyMergeDB {
 				.filter_map(|(k, (v, r))| if r > 0 { assert!(r == 1); Some((k, v)) } else { assert!(r >= -1); None })
 				.collect();

+
+			// TODO: check all removes are in the db.
+
 			let mut r = RlpStream::new_list(3);
 			r.append(id);

@ -344,9 +434,17 @@ impl JournalDB for EarlyMergeDB {
 			r.begin_list(inserts.len());
 			inserts.iter().foreach(|&(k, _)| {r.append(&k);});
 			r.append(&removes);
-			Self::insert_keys(&inserts, &self.backing, &mut counters, &batch);
+			Self::insert_keys(&inserts, &self.backing, &mut refs, &batch, trace);
+			if trace {
+				let ins = inserts.iter().map(|&(k, _)| k).collect::<Vec<_>>();
+				trace!(target: "jdb.ops", "  Inserts: {:?}", ins);
+				trace!(target: "jdb.ops", "  Deletes: {:?}", removes);
+			}
 			try!(batch.put(&last, r.as_raw()));
-			try!(batch.put(&LATEST_ERA_KEY, &encode(&now)));
+			if self.latest_era.map_or(true, |e| now > e) {
+				try!(batch.put(&LATEST_ERA_KEY, &encode(&now)));
+				self.latest_era = Some(now);
+			}
 		}

 		// apply old commits' details
@ -363,17 +461,64 @@ impl JournalDB for EarlyMergeDB {
 			})) {
 				let rlp = Rlp::new(&rlp_data);
 				let inserts: Vec<H256> = rlp.val_at(1);
-				let deletes: Vec<H256> = rlp.val_at(2);
-				// Collect keys to be removed. These are removed keys for canonical block, inserted for non-canonical
-				Self::kill_keys(if canon_id == rlp.val_at(0) {deletes} else {inserts}, &mut counters, &batch);
+
+				if canon_id == rlp.val_at(0) {
+					// Collect keys to be removed. Canon block - remove the (enacted) deletes.
+					let deletes: Vec<H256> = rlp.val_at(2);
+					if trace {
+						trace!(target: "jdb.ops", "  Expunging: {:?}", deletes);
+					}
+					Self::kill_keys(&deletes, &mut refs, &batch, RemoveFrom::Archive, trace);
+
+					if trace {
+						trace!(target: "jdb.ops", "  Finalising: {:?}", inserts);
+					}
+					for k in inserts.iter() {
+						match refs.get(k).cloned() {
+							None => {
+								// [in archive] -> SHIFT remove -> SHIFT insert None->Some{queue_refs: 1, in_archive: true} -> TAKE remove Some{queue_refs: 1, in_archive: true}->None -> TAKE insert
+								// already expunged from the queue (which is allowed since the key is in the archive).
+								// leave well alone.
+							}
+							Some( RefInfo{queue_refs: 1, in_archive: false} ) => {
+								// just delete the refs entry.
+								refs.remove(k);
+							}
+							Some( RefInfo{queue_refs: x, in_archive: false} ) => {
+								// must set already in; ,
+								Self::set_already_in(&batch, k);
+								refs.insert(k.clone(), RefInfo{ queue_refs: x - 1, in_archive: true });
+							}
+							Some( RefInfo{queue_refs: _, in_archive: true} ) => {
+								// Invalid! Reinserted the same key twice.
+								warn!("Key {} inserted twice into same fork.", k);
+							}
+						}
+					}
+				} else {
+					// Collect keys to be removed. Non-canon block - remove the (reverted) inserts.
+					if trace {
+						trace!(target: "jdb.ops", "  Reverting: {:?}", inserts);
+					}
+					Self::kill_keys(&inserts, &mut refs, &batch, RemoveFrom::Queue, trace);
+				}
+
 				try!(batch.delete(&last));
 				index += 1;
 			}
-			trace!("EarlyMergeDB: delete journal for time #{}.{}, (canon was {})", end_era, index, canon_id);
+			if trace {
+				trace!(target: "jdb", "EarlyMergeDB: delete journal for time #{}.{}, (canon was {})", end_era, index, canon_id);
+			}
 		}

 		try!(self.backing.write(batch));
-//		trace!("EarlyMergeDB::commit() deleted {} nodes", deletes);
+
+		// Comment out for now. TODO: automatically enable in tests.
+
+		if trace {
+			trace!(target: "jdb", "OK: {:?}", refs.clone());
+		}
+
 		Ok(0)
 	}
 }
@ -382,8 +527,9 @@ impl JournalDB for EarlyMergeDB {
 mod tests {
 	use common::*;
 	use super::*;
+	use super::super::traits::JournalDB;
 	use hashdb::*;
-	use journaldb::traits::JournalDB;
+	use log::init_log;

 	#[test]
 	fn insert_same_in_fork() {
@ -392,36 +538,69 @@ mod tests {

 		let x = jdb.insert(b"X");
 		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		jdb.commit(2, &b"2".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		jdb.commit(3, &b"1002a".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		jdb.commit(4, &b"1003a".sha3(), Some((2, b"2".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());

 		jdb.remove(&x);
 		jdb.commit(3, &b"1002b".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		let x = jdb.insert(b"X");
 		jdb.commit(4, &b"1003b".sha3(), Some((2, b"2".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());

 		jdb.commit(5, &b"1004a".sha3(), Some((3, b"1002a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		jdb.commit(6, &b"1005a".sha3(), Some((4, b"1003a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());

 		assert!(jdb.exists(&x));
 	}

+	#[test]
+	fn insert_older_era() {
+		let mut jdb = EarlyMergeDB::new_temp();
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0a".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		let bar = jdb.insert(b"bar");
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&bar);
+		jdb.commit(0, &b"0b".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+	}
+
 	#[test]
 	fn long_history() {
 		// history is 3
 		let mut jdb = EarlyMergeDB::new_temp();
 		let h = jdb.insert(b"foo");
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&h));
 		jdb.remove(&h);
 		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&h));
 		jdb.commit(2, &b"2".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&h));
 		jdb.commit(3, &b"3".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&h));
 		jdb.commit(4, &b"4".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(!jdb.exists(&h));
 	}

@ -433,6 +612,7 @@ mod tests {
 		let foo = jdb.insert(b"foo");
 		let bar = jdb.insert(b"bar");
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 		assert!(jdb.exists(&bar));

@ -440,6 +620,7 @@ mod tests {
 		jdb.remove(&bar);
 		let baz = jdb.insert(b"baz");
 		jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 		assert!(jdb.exists(&bar));
 		assert!(jdb.exists(&baz));
@ -447,17 +628,20 @@ mod tests {
 		let foo = jdb.insert(b"foo");
 		jdb.remove(&baz);
 		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 		assert!(!jdb.exists(&bar));
 		assert!(jdb.exists(&baz));

 		jdb.remove(&foo);
 		jdb.commit(3, &b"3".sha3(), Some((2, b"2".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 		assert!(!jdb.exists(&bar));
 		assert!(!jdb.exists(&baz));

 		jdb.commit(4, &b"4".sha3(), Some((3, b"3".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(!jdb.exists(&foo));
 		assert!(!jdb.exists(&bar));
 		assert!(!jdb.exists(&baz));
@ -471,21 +655,25 @@ mod tests {
 		let foo = jdb.insert(b"foo");
 		let bar = jdb.insert(b"bar");
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 		assert!(jdb.exists(&bar));

 		jdb.remove(&foo);
 		let baz = jdb.insert(b"baz");
 		jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());

 		jdb.remove(&bar);
 		jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());

 		assert!(jdb.exists(&foo));
 		assert!(jdb.exists(&bar));
 		assert!(jdb.exists(&baz));

 		jdb.commit(2, &b"2b".sha3(), Some((1, b"1b".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 		assert!(!jdb.exists(&baz));
 		assert!(!jdb.exists(&bar));
@ -498,35 +686,113 @@ mod tests {

 		let foo = jdb.insert(b"foo");
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));

 		jdb.remove(&foo);
 		jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		jdb.insert(b"foo");
 		assert!(jdb.exists(&foo));
 		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 		jdb.commit(3, &b"2".sha3(), Some((0, b"2".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 	}

 	#[test]
-	fn fork_same_key() {
-		// history is 1
-		let mut jdb = EarlyMergeDB::new_temp();
+	fn fork_same_key_one() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
 		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());

 		let foo = jdb.insert(b"foo");
 		jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());

 		jdb.insert(b"foo");
 		jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(1, &b"1c".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
 		assert!(jdb.exists(&foo));

 		jdb.commit(2, &b"2a".sha3(), Some((1, b"1a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
 		assert!(jdb.exists(&foo));
 	}

+	#[test]
+	fn fork_same_key_other() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		let foo = jdb.insert(b"foo");
+		jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(1, &b"1c".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		assert!(jdb.exists(&foo));
+
+		jdb.commit(2, &b"2b".sha3(), Some((1, b"1b".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		assert!(jdb.exists(&foo));
+	}
+
+	#[test]
+	fn fork_ins_del_ins() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		let foo = jdb.insert(b"foo");
+		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&foo);
+		jdb.commit(2, &b"2a".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&foo);
+		jdb.commit(2, &b"2b".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(3, &b"3a".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(3, &b"3b".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.commit(4, &b"4a".sha3(), Some((2, b"2a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.commit(5, &b"5a".sha3(), Some((3, b"3a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+	}

 	#[test]
 	fn reopen() {
@ -540,6 +806,7 @@ mod tests {
 			let foo = jdb.insert(b"foo");
 			jdb.emplace(bar.clone(), b"bar".to_vec());
 			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			assert!(jdb.can_reconstruct_refs());
 			foo
 		};

@ -547,6 +814,7 @@ mod tests {
 			let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
 			jdb.remove(&foo);
 			jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
 		}

 		{
@ -554,40 +822,210 @@ mod tests {
 			assert!(jdb.exists(&foo));
 			assert!(jdb.exists(&bar));
 			jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
 			assert!(!jdb.exists(&foo));
 		}
 	}

 	#[test]
-	fn reopen_remove() {
+	fn insert_delete_insert_delete_insert_expunge() {
+		init_log();
 		let mut dir = ::std::env::temp_dir();
 		dir.push(H32::random().hex());

-		let foo = {
-			let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
-			// history is 1
-			let foo = jdb.insert(b"foo");
-			jdb.commit(0, &b"0".sha3(), None).unwrap();
-			jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());

-			// foo is ancient history.
+		// history is 4
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.remove(&foo);
+		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.insert(b"foo");
+		jdb.commit(2, &b"2".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.remove(&foo);
+		jdb.commit(3, &b"3".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.insert(b"foo");
+		jdb.commit(4, &b"4".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		// expunge foo
+		jdb.commit(5, &b"5".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+	}

-			jdb.insert(b"foo");
-			jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
-			foo
-		};
+	#[test]
+	fn forked_insert_delete_insert_delete_insert_expunge() {
+		init_log();
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+
+		// history is 4
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&foo);
+		jdb.commit(1, &b"1a".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&foo);
+		jdb.commit(1, &b"1b".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(2, &b"2a".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(2, &b"2b".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&foo);
+		jdb.commit(3, &b"3a".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&foo);
+		jdb.commit(3, &b"3b".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(4, &b"4a".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(4, &b"4b".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		// expunge foo
+		jdb.commit(5, &b"5".sha3(), Some((1, b"1a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+	}
+
+	#[test]
+	fn broken_assert() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+		// history is 1
+		let foo = jdb.insert(b"foo");
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		// foo is ancient history.
+
+		jdb.remove(&foo);
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.insert(b"foo");
+		jdb.commit(3, &b"3".sha3(), Some((2, b"2".sha3()))).unwrap();	// BROKEN
+		assert!(jdb.can_reconstruct_refs());
+		assert!(jdb.exists(&foo));
+
+		jdb.remove(&foo);
+		jdb.commit(4, &b"4".sha3(), Some((3, b"3".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.commit(5, &b"5".sha3(), Some((4, b"4".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		assert!(!jdb.exists(&foo));
+	}
+	
+	#[test]
+	fn reopen_test() {
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+		// history is 4
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.commit(1, &b"1".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.commit(2, &b"2".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.commit(3, &b"3".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.commit(4, &b"4".sha3(), Some((0, b"0".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		// foo is ancient history.
+
+		jdb.insert(b"foo");
+		let bar = jdb.insert(b"bar");
+		jdb.commit(5, &b"5".sha3(), Some((1, b"1".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.remove(&foo);
+		jdb.remove(&bar);
+		jdb.commit(6, &b"6".sha3(), Some((2, b"2".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.insert(b"foo");
+		jdb.insert(b"bar");
+		jdb.commit(7, &b"7".sha3(), Some((3, b"3".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+	}
+	
+	#[test]
+	fn reopen_remove_three() {
+		init_log();
+
+		let mut dir = ::std::env::temp_dir();
+		dir.push(H32::random().hex());
+
+		let foo = b"foo".sha3();

 		{
 			let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+			// history is 1
+			jdb.insert(b"foo");
+			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			assert!(jdb.can_reconstruct_refs());
+			jdb.commit(1, &b"1".sha3(), None).unwrap();
+			assert!(jdb.can_reconstruct_refs());
+
+			// foo is ancient history.
+
 			jdb.remove(&foo);
-			jdb.commit(3, &b"3".sha3(), Some((2, b"2".sha3()))).unwrap();
+			jdb.commit(2, &b"2".sha3(), Some((0, b"0".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
 			assert!(jdb.exists(&foo));
+
+			jdb.insert(b"foo");
+			jdb.commit(3, &b"3".sha3(), Some((1, b"1".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
+			assert!(jdb.exists(&foo));
+
+		// incantation to reopen the db
+		}; { let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+
 			jdb.remove(&foo);
-			jdb.commit(4, &b"4".sha3(), Some((3, b"3".sha3()))).unwrap();
-			jdb.commit(5, &b"5".sha3(), Some((4, b"4".sha3()))).unwrap();
+			jdb.commit(4, &b"4".sha3(), Some((2, b"2".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
+			assert!(jdb.exists(&foo));
+
+		// incantation to reopen the db
+		}; { let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+
+			jdb.commit(5, &b"5".sha3(), Some((3, b"3".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
+			assert!(jdb.exists(&foo));
+
+		// incantation to reopen the db
+		}; { let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
+
+			jdb.commit(6, &b"6".sha3(), Some((4, b"4".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
 			assert!(!jdb.exists(&foo));
 		}
 	}
+	
 	#[test]
 	fn reopen_fork() {
 		let mut dir = ::std::env::temp_dir();
@ -598,18 +1036,22 @@ mod tests {
 			let foo = jdb.insert(b"foo");
 			let bar = jdb.insert(b"bar");
 			jdb.commit(0, &b"0".sha3(), None).unwrap();
+			assert!(jdb.can_reconstruct_refs());
 			jdb.remove(&foo);
 			let baz = jdb.insert(b"baz");
 			jdb.commit(1, &b"1a".sha3(), Some((0, b"0".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());

 			jdb.remove(&bar);
 			jdb.commit(1, &b"1b".sha3(), Some((0, b"0".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
 			(foo, bar, baz)
 		};

 		{
 			let mut jdb = EarlyMergeDB::new(dir.to_str().unwrap());
 			jdb.commit(2, &b"2b".sha3(), Some((1, b"1b".sha3()))).unwrap();
+			assert!(jdb.can_reconstruct_refs());
 			assert!(jdb.exists(&foo));
 			assert!(!jdb.exists(&baz));
 			assert!(!jdb.exists(&bar));
--- a/util/src/journaldb/overlayrecentdb.rs
+++ b/util/src/journaldb/overlayrecentdb.rs
@ -55,7 +55,7 @@ use super::JournalDB;
 /// 6. For a canonical journal record that becomes ancient delete its removals from the disk only if
 /// the removed key is not present in the history overlay.
 /// 7. Delete ancient record from memory and disk.
-/// 
+
 pub struct OverlayRecentDB {
 	transaction_overlay: MemoryDB,
 	backing: Arc<Database>,
@ -66,7 +66,7 @@ pub struct OverlayRecentDB {
 struct JournalOverlay {
 	backing_overlay: MemoryDB,
 	journal: HashMap<u64, Vec<JournalEntry>>,
-	latest_era: u64,
+	latest_era: Option<u64>,
 }

 #[derive(PartialEq)]
@ -152,10 +152,10 @@ impl OverlayRecentDB {
 		let mut journal = HashMap::new();
 		let mut overlay = MemoryDB::new();
 		let mut count = 0;
-		let mut latest_era = 0;
+		let mut latest_era = None;
 		if let Some(val) = db.get(&LATEST_ERA_KEY).expect("Low-level database error.") {
-			latest_era = decode::<u64>(&val);
-			let mut era = latest_era;
+			let mut era = decode::<u64>(&val);
+			latest_era = Some(era);
 			loop {
 				let mut index = 0usize;
 				while let Some(rlp_data) = db.get({
@ -236,14 +236,14 @@ impl JournalDB for OverlayRecentDB {
 			r.append(&removed_keys);

 			let mut k = RlpStream::new_list(3);
-			let index = journal_overlay.journal.get(&now).map(|j| j.len()).unwrap_or(0);
+			let index = journal_overlay.journal.get(&now).map_or(0, |j| j.len());
 			k.append(&now);
 			k.append(&index);
 			k.append(&&PADDING[..]);
 			try!(batch.put(&k.drain(), r.as_raw()));
-			if now >= journal_overlay.latest_era {
+			if journal_overlay.latest_era.map_or(true, |e| now > e) {
 				try!(batch.put(&LATEST_ERA_KEY, &encode(&now)));
-				journal_overlay.latest_era = now;
+				journal_overlay.latest_era = Some(now);
 			}
 			journal_overlay.journal.entry(now).or_insert_with(Vec::new).push(JournalEntry { id: id.clone(), insertions: inserted_keys, deletions: removed_keys });
 		}
@ -870,4 +870,24 @@ mod tests {
 			assert!(!jdb.exists(&bar));
 		}
 	}
+
+	#[test]
+	fn insert_older_era() {
+		let mut jdb = OverlayRecentDB::new_temp();
+		let foo = jdb.insert(b"foo");
+		jdb.commit(0, &b"0a".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		let bar = jdb.insert(b"bar");
+		jdb.commit(1, &b"1".sha3(), Some((0, b"0a".sha3()))).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+
+		jdb.remove(&bar);
+		jdb.commit(0, &b"0b".sha3(), None).unwrap();
+		assert!(jdb.can_reconstruct_refs());
+		jdb.commit(2, &b"2".sha3(), Some((1, b"1".sha3()))).unwrap();
+
+		assert!(jdb.exists(&foo));
+		assert!(jdb.exists(&bar));
+	}
 }
--- a/util/src/journaldb/traits.rs
+++ b/util/src/journaldb/traits.rs
@ -34,4 +34,9 @@ pub trait JournalDB : HashDB + Send + Sync {
 	/// Commit all recent insert operations and canonical historical commits' removals from the
 	/// old era to the backing database, reverting any non-canonical historical commit's inserts.
 	fn commit(&mut self, now: u64, id: &H256, end: Option<(u64, H256)>) -> Result<u32, UtilError>;
+
+	/// State data query
+	fn state(&self, _id: &H256) -> Option<Bytes> {
+		None
+	}
 }
--- a/util/src/keys/geth_import.rs
+++ b/util/src/keys/geth_import.rs
@ -161,6 +161,7 @@ mod tests {
 	}

 	#[test]
+	#[cfg(feature="heavy-tests")]
 	fn can_decrypt_with_imported() {
 		use keys::store::EncryptedHashMap;

--- a/util/src/keys/store.rs
+++ b/util/src/keys/store.rs
@ -120,9 +120,15 @@ impl AccountProvider for AccountService {
 	}
 }

+impl Default for AccountService {
+	fn default() -> Self {
+		AccountService::new()
+	}
+}
+
 impl AccountService {
 	/// New account service with the default location
-	pub fn new() -> AccountService {
+	pub fn new() -> Self {
 		let secret_store = RwLock::new(SecretStore::new());
 		secret_store.write().unwrap().try_import_existing();
 		AccountService {
@ -363,6 +369,7 @@ mod vector_tests {


 	#[test]
+	#[cfg(feature="heavy-tests")]
 	fn mac_vector() {
 		let password = "testpassword";
 		let salt = H256::from_str("ae3cd4e7013836a3df6bd7241b12db061dbe2c6785853cce422d148a624ce0bd").unwrap();
@ -464,6 +471,7 @@ mod tests {
 	}

 	#[test]
+	#[cfg(feature="heavy-tests")]
 	fn can_get() {
 		let temp = RandomTempPath::create_dir();
 		let key_id = {
@ -568,7 +576,7 @@ mod tests {
 		let temp = RandomTempPath::create_dir();
 		let mut sstore = SecretStore::new_test(&temp);
 		let addr = sstore.new_account("test").unwrap();
-		let _ok = sstore.unlock_account(&addr, "test").unwrap();
+		sstore.unlock_account(&addr, "test").unwrap();
 		let secret = sstore.account_secret(&addr).unwrap();
 		let kp = KeyPair::from_secret(secret).unwrap();
 		assert_eq!(Address::from(kp.public().sha3()), addr);
--- a/util/src/network/connection.rs
+++ b/util/src/network/connection.rs
@ -513,8 +513,14 @@ mod tests {
 		buf_size: usize,
 	}

+	impl Default for TestSocket {
+		fn default() -> Self {
+			TestSocket::new()
+		}
+	}
+
 	impl TestSocket {
-		fn new() -> TestSocket {
+		fn new() -> Self {
 			TestSocket {
 				read_buffer: vec![],
 				write_buffer: vec![],
@ -593,8 +599,14 @@ mod tests {

 	type TestConnection = GenericConnection<TestSocket>;

+	impl Default for TestConnection {
+		fn default() -> Self {
+			TestConnection::new()
+		}
+	}
+
 	impl TestConnection {
-		pub fn new() -> TestConnection {
+		pub fn new() -> Self {
 			TestConnection {
 				token: 999998888usize,
 				socket: TestSocket::new(),
@ -609,8 +621,14 @@ mod tests {

 	type TestBrokenConnection = GenericConnection<TestBrokenSocket>;

+	impl Default for TestBrokenConnection {
+		fn default() -> Self {
+			TestBrokenConnection::new()
+		}
+	}
+
 	impl TestBrokenConnection {
-		pub fn new() -> TestBrokenConnection {
+		pub fn new() -> Self {
 			TestBrokenConnection {
 				token: 999998888usize,
 				socket: TestBrokenSocket { error: "test broken socket".to_owned() },
--- a/util/src/network/host.rs
+++ b/util/src/network/host.rs
@ -541,7 +541,7 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 			match TcpStream::connect(&address) {
 				Ok(socket) => socket,
 				Err(e) => {
-					warn!("Can't connect to address {:?}: {:?}", address, e);
+					debug!("Can't connect to address {:?}: {:?}", address, e);
 					return;
 				}
 			}
@ -695,6 +695,14 @@ impl<Message> Host<Message> where Message: Send + Sync + Clone {
 				return;
 			}
 		};
+		if !originated {
+			let session_count = sessions.count();
+			let ideal_peers = { self.info.read().unwrap().deref().config.ideal_peers };
+			if session_count >= ideal_peers as usize {
+				session.disconnect(DisconnectReason::TooManyPeers);
+				return;
+			}
+		}
 		let result = sessions.insert_with(move |session_token| {
 			session.set_token(session_token);
 			io.deregister_stream(token).expect("Error deleting handshake registration");