Bump clippy & Fix warnings (#2109)

* Bump clippy

* Fixing warnings

ethcore/src/block.rs

@@ -417,7 +417,7 @@ impl ClosedBlock {
 	}
 
 	/// Given an engine reference, reopen the `ClosedBlock` into an `OpenBlock`.
-	pub fn reopen<'a>(self, engine: &'a Engine) -> OpenBlock<'a> {
+	pub fn reopen(self, engine: &Engine) -> OpenBlock {
 		// revert rewards (i.e. set state back at last transaction's state).
 		let mut block = self.block;
 		block.state = self.unclosed_state;

ethcore/src/blockchain/blockchain.rs

@@ -1617,7 +1617,7 @@ mod tests {
 		let mut block_header = bc.block_header(&best_hash);
 
 		while !block_header.is_none() {
-			block_header = bc.block_header(&block_header.unwrap().parent_hash());
+			block_header = bc.block_header(block_header.unwrap().parent_hash());
 		}
 		assert!(bc.cache_size().blocks > 1024 * 1024);
 

ethcore/src/ethereum/ethash.rs

@@ -160,7 +160,7 @@ impl Engine for Ethash {
 		let fields = block.fields_mut();
 
 		// Bestow block reward
-		fields.state.add_balance(&fields.header.author(), &(reward + reward / U256::from(32) * U256::from(fields.uncles.len())));
+		fields.state.add_balance(fields.header.author(), &(reward + reward / U256::from(32) * U256::from(fields.uncles.len())));
 
 		// Bestow uncle rewards
 		let current_number = fields.header.number();

ethcore/src/miner/miner.rs

@@ -246,6 +246,7 @@ impl Miner {
 		self.sealing_work.lock().queue.peek_last_ref().map(|b| b.base().clone())
 	}
 
+	#[cfg_attr(feature="dev", allow(match_same_arms))]
 	/// Prepares new block for sealing including top transactions from queue.
 	fn prepare_block(&self, chain: &MiningBlockChainClient) -> (ClosedBlock, Option<H256>) {
 		{
@@ -369,7 +370,7 @@ impl Miner {
 
 	/// Attempts to perform internal sealing (one that does not require work) to return Ok(sealed),
 	/// Err(Some(block)) returns for unsuccesful sealing while Err(None) indicates misspecified engine.
-	fn seal_block_internally(&self, block: ClosedBlock) -> Result<SealedBlock, Option<ClosedBlock>> { 
+	fn seal_block_internally(&self, block: ClosedBlock) -> Result<SealedBlock, Option<ClosedBlock>> {
 		trace!(target: "miner", "seal_block_internally: block has transaction - attempting internal seal.");
 		let s = self.engine.generate_seal(block.block(), match self.accounts {
 			Some(ref x) => Some(&**x),
@@ -672,6 +673,7 @@ impl MinerService for Miner {
 		results
 	}
 
+	#[cfg_attr(feature="dev", allow(collapsible_if))]
 	fn import_own_transaction(
 		&self,
 		chain: &MiningBlockChainClient,

ethcore/src/miner/transaction_queue.rs

@@ -949,7 +949,7 @@ mod test {
 		new_tx_pair(default_nonce(), default_gas_price(), nonce_increment, gas_price_increment)
 	}
 
-	/// Returns two transactions with identical (sender, nonce) but different gas_price/hash.
+	/// Returns two transactions with identical (sender, nonce) but different gas price/hash.
 	fn new_similar_tx_pair() -> (SignedTransaction, SignedTransaction) {
 		new_tx_pair_default(0.into(), 1.into())
 	}

ethcore/src/snapshot/tests/helpers.rs

@@ -45,6 +45,7 @@ impl StateProducer {
 		}
 	}
 
+	#[cfg_attr(feature="dev", allow(let_and_return))]
 	/// Tick the state producer. This alters the state, writing new data into
 	/// the database.
 	pub fn tick<R: Rng>(&mut self, rng: &mut R, db: &mut HashDB) {

ethcore/src/spec/spec.rs

@@ -183,7 +183,7 @@ impl Spec {
 			let r = Rlp::new(&seal);
 			(0..self.seal_fields).map(|i| r.at(i).as_raw().to_vec()).collect()
 		});
-		return header;
+		header
 	}
 
 	/// Compose the genesis block for this chain.
@@ -278,7 +278,7 @@ mod tests {
 	// https://github.com/ethcore/parity/issues/1840
 	#[test]
 	fn test_load_empty() {
-		assert!(Spec::load(&vec![] as &[u8]).is_err());
+		assert!(Spec::load(&[] as &[u8]).is_err());
 	}
 
 	#[test]

ethcore/src/state/mod.rs

@@ -1314,13 +1314,13 @@ fn storage_at_from_database() {
 	let temp = RandomTempPath::new();
 	let (root, db) = {
 		let mut state = get_temp_state_in(temp.as_path());
-		state.set_storage(&a, H256::from(&U256::from(01u64)), H256::from(&U256::from(69u64)));
+		state.set_storage(&a, H256::from(&U256::from(1u64)), H256::from(&U256::from(69u64)));
 		state.commit().unwrap();
 		state.drop()
 	};
 
 	let s = State::from_existing(db, root, U256::from(0u8), Default::default()).unwrap();
-	assert_eq!(s.storage_at(&a, &H256::from(&U256::from(01u64))), H256::from(&U256::from(69u64)));
+	assert_eq!(s.storage_at(&a, &H256::from(&U256::from(1u64))), H256::from(&U256::from(69u64)));
 }
 
 #[test]