Merge branch 'master' of github.com:paritytech/parity into util_error_chain

ethcore/src/client/client.rs

@@ -1446,6 +1446,10 @@ impl BlockChainClient for Client {
 		self.state_at(id).and_then(|s| s.code(address).ok()).map(|c| c.map(|c| (&*c).clone()))
 	}
 
+	fn code_hash(&self, address: &Address, id: BlockId) -> Option<H256> {
+		self.state_at(id).and_then(|s| s.code_hash(address).ok())
+	}
+
 	fn balance(&self, address: &Address, id: BlockId) -> Option<U256> {
 		self.state_at(id).and_then(|s| s.balance(address).ok())
 	}

ethcore/src/client/test_client.rs

@@ -456,6 +456,13 @@ impl BlockChainClient for TestBlockChainClient {
 		}
 	}
 
+	fn code_hash(&self, address: &Address, id: BlockId) -> Option<H256> {
+		match id {
+			BlockId::Latest | BlockId::Pending => self.code.read().get(address).map(|c| keccak(&c)),
+			_ => None,
+		}
+	}
+
 	fn balance(&self, address: &Address, id: BlockId) -> Option<U256> {
 		match id {
 			BlockId::Latest | BlockId::Pending => Some(self.balances.read().get(address).cloned().unwrap_or_else(U256::zero)),

ethcore/src/client/traits.rs

@@ -98,6 +98,9 @@ pub trait BlockChainClient : Sync + Send {
 			.expect("code will return Some if given BlockId::Latest; qed")
 	}
 
+	/// Get address code hash at given block's state.
+	fn code_hash(&self, address: &Address, id: BlockId) -> Option<H256>;
+
 	/// Get address balance at the given block's state.
 	///
 	/// May not return None if given BlockId::Latest.