Audit review

pallet/staking/src/lib.rs

@@ -816,7 +816,10 @@ pub mod pallet {
 			// let cs_from_contract = Self::elect_from_contract(n1)?;
 			// let cs_from_pallet = Self::elect(n2)?;
 			let cs_from_contract = Self::elect_from_contract(n1).unwrap_or_default();
-			let cs_from_pallet = Self::elect(n2).unwrap_or_default();
+			let cs_from_pallet = Self::elect(n2).unwrap_or_default()
+				.into_iter()
+				.filter(|c| !cs_from_contract.contains(c))
+				.collect();
 
 			log::info!("collators from contract {cs_from_contract:?}");
 			log::info!("collators from pallet {cs_from_pallet:?}");
@@ -1356,7 +1359,8 @@ where
 	PalletId(*b"da/staki").into_account_truncating()
 }
 
-fn now<T>() -> Moment
+/// The current time in milliseconds.
+pub fn now<T>() -> Moment
 where
 	T: Config,
 {

pallet/staking/src/mock.rs

@@ -266,13 +266,15 @@ impl crate::Election<AccountId> for RingStaking {
 				.map(|i| {
 					let who = AccountId(i);
 
-					assert_ok!(Session::set_keys(
+					if Session::set_keys(
 						RuntimeOrigin::signed(who),
 						SessionKeys { uint: i.into() },
 						Vec::new()
-					));
-
-					who
+					).is_ok() {
+						who
+					} else {
+						AccountId(0)
+					}
 				})
 				.collect(),
 		)

pallet/staking/src/tests.rs

@@ -845,6 +845,24 @@ fn hybrid_election_should_work() {
 	});
 }
 
+#[test]
+fn dedup_election_should_work() {
+	ExtBuilder::default().collator_count(10).build().execute_with(|| {
+		let who = AccountId(100);
+		let _ = <pallet_balances::Pallet<Runtime>>::deposit_creating(&who, 100 as _);
+
+		assert_ok!(Staking::stake(RuntimeOrigin::signed(who), 100 as _, Vec::new()));
+		assert_ok!(Staking::collect(RuntimeOrigin::signed(who), Perbill::zero()));
+		assert_ok!(Staking::nominate(RuntimeOrigin::signed(who), who));
+
+		Timestamp::set_timestamp(30 * DAY_IN_MILLIS);
+		new_session();
+		new_session();
+
+		assert_eq!(vec![who], <pallet_session::Validators<Runtime>>::get());
+	});
+}
+
 #[test]
 fn hybrid_payout_should_work() {
 	ExtBuilder::default().collator_count(10).inflation_type(1).build().execute_with(|| {

precompile/deposit/src/lib.rs

@@ -90,15 +90,4 @@ where
 
 		Ok(true)
 	}
-
-	#[precompile::public("migrate(address)")]
-	fn migrate(handle: &mut impl PrecompileHandle, who: Address) -> EvmResult<bool> {
-		let origin: AccountIdOf<Runtime> = handle.context().caller.into();
-		RuntimeHelper::<Runtime>::try_dispatch(
-			handle,
-			Some(origin).into(),
-			darwinia_deposit::Call::<Runtime>::migrate { who: H160::from(who).into() },
-		)?;
-		Ok(true)
-	}
 }

precompile/deposit/src/tests.rs

@@ -36,7 +36,6 @@ fn selectors() {
 	assert!(PCall::lock_selectors().contains(&0x998e4242));
 	assert!(PCall::claim_selectors().contains(&0x4e71d92d));
 	assert!(PCall::claim_with_penalty_selectors().contains(&0xfa04a9bf));
-	assert!(PCall::migrate_selectors().contains(&0xce5494bb));
 }
 
 #[test]

runtime/crab/src/migration.rs

@@ -84,6 +84,8 @@ fn migrate() -> frame_support::weights::Weight {
 		<darwinia_staking::RingStakingContract<Runtime>>::put(who);
 	}
 
+	darwinia_staking::MigrationStartPoint::put(darwinia_staking::now());
+
 	// frame_support::weights::Weight::zero()
 	<Runtime as frame_system::Config>::DbWeight::get().reads_writes(7, 7)
 }

runtime/darwinia/src/migration.rs

@@ -92,6 +92,8 @@ fn migrate() -> frame_support::weights::Weight {
 		<darwinia_staking::RingStakingContract<Runtime>>::put(who);
 	}
 
+	darwinia_staking::MigrationStartPoint::put(darwinia_staking::now());
+
 	// frame_support::weights::Weight::zero()
 	<Runtime as frame_system::Config>::DbWeight::get().reads_writes(7, 107)
 }