Fix several warnings and remove some forbid(warnings) (#2874)

substrate/core/consensus/aura/src/lib.rs

@@ -889,7 +889,7 @@ mod tests {
 			.map(|_| ())
 			.map_err(|_| ());
 
-		runtime.block_on(wait_for.select(drive_to_completion).map_err(|_| ())).unwrap();
+		let _ = runtime.block_on(wait_for.select(drive_to_completion).map_err(|_| ())).unwrap();
 	}
 
 	#[test]

substrate/core/consensus/babe/src/lib.rs

@@ -24,7 +24,6 @@
 //! happen at any point.  This crate is also missing features, such as banning
 //! of malicious validators, that are essential for a production network.
 #![forbid(unsafe_code, missing_docs)]
-#![deny(warnings)]
 extern crate core;
 mod digest;
 use digest::CompatibleDigestItem;
@@ -434,7 +433,6 @@ fn find_pre_digest<B: Block>(header: &B::Header) -> Result<BabePreDigest, String
 /// This digest item will always return `Some` when used with `as_babe_pre_digest`.
 //
 // FIXME #1018 needs misbehavior types
-#[forbid(warnings)]
 fn check_header<B: Block + Sized, C: AuxStore>(
 	client: &C,
 	slot_now: u64,
@@ -950,7 +948,7 @@ mod tests {
 			.map(drop)
 			.map_err(drop);
 
-		runtime.block_on(wait_for.select(drive_to_completion).map_err(drop)).unwrap();
+		let _ = runtime.block_on(wait_for.select(drive_to_completion).map_err(drop)).unwrap();
 	}
 
 	#[test]

substrate/core/finality-grandpa/src/lib.rs

@@ -51,15 +51,11 @@
 //! number (this is num(signal) + N). When finalizing a block, we either apply
 //! or prune any signaled changes based on whether the signaling block is
 //! included in the newly-finalized chain.
-#![forbid(warnings)]
 
 use futures::prelude::*;
 use log::{debug, info, warn};
 use futures::sync::mpsc;
-use client::{
-	BlockchainEvents, CallExecutor, Client, backend::Backend,
-	error::Error as ClientError,
-};
+use client::{BlockchainEvents, CallExecutor, Client, backend::Backend, error::Error as ClientError};
 use client::blockchain::HeaderBackend;
 use parity_codec::Encode;
 use runtime_primitives::traits::{

substrate/core/finality-grandpa/src/tests.rs

@@ -534,7 +534,7 @@ fn run_to_completion_with<F>(
 		.map(|_| ())
 		.map_err(|_| ());
 
-	runtime.block_on(wait_for.select(drive_to_completion).map_err(|_| ())).unwrap();
+	let _ = runtime.block_on(wait_for.select(drive_to_completion).map_err(|_| ())).unwrap();
 
 	let highest_finalized = *highest_finalized.read();
 	highest_finalized
@@ -628,7 +628,7 @@ fn finalize_3_voters_1_full_observer() {
 		.map(|_| ())
 		.map_err(|_| ());
 
-	runtime.block_on(wait_for.select(drive_to_completion).map_err(|_| ())).unwrap();
+	let _ = runtime.block_on(wait_for.select(drive_to_completion).map_err(|_| ())).unwrap();
 }
 
 #[test]
@@ -802,7 +802,7 @@ fn transition_3_voters_twice_1_full_observer() {
 		.map(|_| ())
 		.map_err(|_| ());
 
-	runtime.block_on(wait_for.select(drive_to_completion).map_err(|_| ())).unwrap();
+	let _ = runtime.block_on(wait_for.select(drive_to_completion).map_err(|_| ())).unwrap();
 }
 
 #[test]

substrate/core/network/src/service/tests.rs

@@ -88,7 +88,7 @@ fn basic_two_nodes_connectivity() {
 	});
 
 	let combined = fut1.select(fut2).map_err(|(err, _)| err);
-	tokio::runtime::Runtime::new().unwrap().block_on_all(combined).unwrap();
+	let _ = tokio::runtime::Runtime::new().unwrap().block_on_all(combined).unwrap();
 }
 
 #[test]
@@ -141,7 +141,7 @@ fn two_nodes_transfer_lots_of_packets() {
 	});
 
 	let combined = fut1.select(fut2).map_err(|(err, _)| err);
-	tokio::runtime::Runtime::new().unwrap().block_on(combined).unwrap();
+	let _ = tokio::runtime::Runtime::new().unwrap().block_on(combined).unwrap();
 }
 
 #[test]
@@ -255,7 +255,7 @@ fn basic_two_nodes_requests_in_parallel() {
 	});
 
 	let combined = fut1.select(fut2).map_err(|(err, _)| err);
-	tokio::runtime::Runtime::new().unwrap().block_on_all(combined).unwrap();
+	let _ = tokio::runtime::Runtime::new().unwrap().block_on_all(combined).unwrap();
 }
 
 #[test]

substrate/srml/staking/src/tests.rs

@@ -1272,7 +1272,7 @@ fn on_free_balance_zero_stash_removes_validator() {
 		assert!(<Payee<Test>>::exists(&11));
 
 		// Reduce free_balance of controller to 0
-		Balances::slash(&10, u64::max_value());
+		let _ = Balances::slash(&10, u64::max_value());
 
 		// Check the balance of the stash account has not been touched
 		assert_eq!(Balances::free_balance(&11), 256000);
@@ -1287,7 +1287,7 @@ fn on_free_balance_zero_stash_removes_validator() {
 		assert!(<Payee<Test>>::exists(&11));
 
 		// Reduce free_balance of stash to 0
-		Balances::slash(&11, u64::max_value());
+		let _ = Balances::slash(&11, u64::max_value());
 		// Check total balance of stash
 		assert_eq!(Balances::total_balance(&11), 0);
 
@@ -1328,7 +1328,7 @@ fn on_free_balance_zero_stash_removes_nominator() {
 		assert!(<Payee<Test>>::exists(&11));
 
 		// Reduce free_balance of controller to 0
-		Balances::slash(&10, u64::max_value());
+		let _ = Balances::slash(&10, u64::max_value());
 		// Check total balance of account 10
 		assert_eq!(Balances::total_balance(&10), 0);
 
@@ -1344,7 +1344,7 @@ fn on_free_balance_zero_stash_removes_nominator() {
 		assert!(<Payee<Test>>::exists(&11));
 
 		// Reduce free_balance of stash to 0
-		Balances::slash(&11, u64::max_value());
+		let _ = Balances::slash(&11, u64::max_value());
 		// Check total balance of stash
 		assert_eq!(Balances::total_balance(&11), 0);