bridges/testing/environments/rococo-westend/start_relayer.sh

@@ -7,17 +7,31 @@ source "$FRAMEWORK_PATH/utils/zombienet.sh"
 
 rococo_dir=$1
 westend_dir=$2
-__relayer_pid=$3
+__finality_relayer_pid=$3
+__parachains_relayer_pid=$4
+__messages_relayer_pid=$5
 
 logs_dir=$TEST_DIR/logs
 helper_script="${BASH_SOURCE%/*}/helper.sh"
 
-relayer_log=$logs_dir/relayer.log
-echo -e "Starting rococo-westend relayer. Logs available at: $relayer_log\n"
-start_background_process "$helper_script run-relay" $relayer_log relayer_pid
+# start finality relayer
+finality_relayer_log=$logs_dir/relayer_finality.log
+echo -e "Starting rococo-westend finality relayer. Logs available at: $finality_relayer_log\n"
+start_background_process "$helper_script run-finality-relay" $finality_relayer_log finality_relayer_pid
+
+# start parachains relayer
+parachains_relayer_log=$logs_dir/relayer_parachains.log
+echo -e "Starting rococo-westend parachains relayer. Logs available at: $parachains_relayer_log\n"
+start_background_process "$helper_script run-parachains-relay" $parachains_relayer_log parachains_relayer_pid
+
+# start messages relayer
+messages_relayer_log=$logs_dir/relayer_messages.log
+echo -e "Starting rococo-westend messages relayer. Logs available at: $messages_relayer_log\n"
+start_background_process "$helper_script run-messages-relay" $messages_relayer_log messages_relayer_pid
 
 run_zndsl ${BASH_SOURCE%/*}/rococo.zndsl $rococo_dir
 run_zndsl ${BASH_SOURCE%/*}/westend.zndsl $westend_dir
 
-eval $__relayer_pid="'$relayer_pid'"
-
+eval $__finality_relayer_pid="'$finality_relayer_pid'"
+eval $__parachains_relayer_pid="'$parachains_relayer_pid'"
+eval $__messages_relayer_pid="'$messages_relayer_pid'"

bridges/testing/framework/js-helpers/only-mandatory-headers-synced-when-idle.js → bridges/testing/framework/js-helpers/multiple-headers-synced.js

@@ -10,33 +10,23 @@ async function run(nodeName, networkInfo, args) {
 
     // start listening to new blocks
     let totalGrandpaHeaders = 0;
-    let initialParachainHeaderImported = false;
+    let totalParachainHeaders = 0;
     api.rpc.chain.subscribeNewHeads(async function (header) {
         const apiAtParent = await api.at(header.parentHash);
         const apiAtCurrent = await api.at(header.hash);
         const currentEvents = await apiAtCurrent.query.system.events();
 
-        totalGrandpaHeaders += await utils.ensureOnlyMandatoryGrandpaHeadersImported(
-            bridgedChain,
-            apiAtParent,
-            apiAtCurrent,
-            currentEvents,
-        );
-        initialParachainHeaderImported = await utils.ensureOnlyInitialParachainHeaderImported(
-            bridgedChain,
-            apiAtParent,
-            apiAtCurrent,
-            currentEvents,
-        );
+        totalGrandpaHeaders += await utils.countGrandpaHeaderImports(bridgedChain, currentEvents);
+        totalParachainHeaders += await utils.countParachainHeaderImports(bridgedChain, currentEvents);
     });
 
     // wait given time
     await new Promise(resolve => setTimeout(resolve, exitAfterSeconds * 1000));
-    // if we haven't seen any new GRANDPA or parachain headers => fail
-    if (totalGrandpaHeaders == 0) {
+    // if we haven't seen many (>1) new GRANDPA or parachain headers => fail
+    if (totalGrandpaHeaders <= 1) {
         throw new Error("No bridged relay chain headers imported");
     }
-    if (!initialParachainHeaderImported) {
+    if (totalParachainHeaders <= 1) {
         throw new Error("No bridged parachain headers imported");
     }
 }

bridges/testing/framework/js-helpers/native-asset-balance.js

+async function run(nodeName, networkInfo, args) {
+    const {wsUri, userDefinedTypes} = networkInfo.nodesByName[nodeName];
+    const api = await zombie.connect(wsUri, userDefinedTypes);
+
+    const accountAddress = args[0];
+    const accountData = await api.query.system.account(accountAddress);
+    const accountBalance = accountData.data['free'];
+    console.log("Balance of " + accountAddress + ": " + accountBalance);
+    return accountBalance;
+}
+
+module.exports = {run}

bridges/testing/tests/0001-asset-transfer/roc-reaches-westend.zndsl

@@ -3,10 +3,10 @@ Network: {{ENV_PATH}}/bridge_hub_westend_local_network.toml
 Creds: config
 
 # send 5 ROC to //Alice from Rococo AH to Westend AH
-asset-hub-westend-collator1: run {{ENV_PATH}}/helper.sh with "reserve-transfer-assets-from-asset-hub-rococo-local 5000000000000" within 120 seconds
+asset-hub-westend-collator1: run {{ENV_PATH}}/helper.sh with "auto-log reserve-transfer-assets-from-asset-hub-rococo-local 5000000000000" within 120 seconds
 
 # check that //Alice received at least 4.8 ROC on Westend AH
 asset-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/wrapped-assets-balance.js with "5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY,4800000000000,Rococo" within 600 seconds
 
-# check that the relayer //Charlie is rewarded by Westend AH
-bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/relayer-rewards.js with "5FLSigC9HGRKVhB9FiEo4Y3koPsNmBmLJbpXg2mp1hXcS59Y,0x00000002,0x6268726F,ThisChain,0" within 30 seconds
+# relayer //Ferdie is rewarded for delivering messages from Rococo BH
+bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/relayer-rewards.js with "5HGjWAeFDfFCWPsjFQdVV2Msvz2XtMktvgocEZcCj68kUMaw,0x00000002,0x6268726F,ThisChain,0" within 300 seconds

bridges/testing/tests/0001-asset-transfer/roc-relayer-balance-does-not-change.zndsl

+Description: Finality and parachain relays should have the constant balance, because their transactions are free
+Network: {{ENV_PATH}}/bridge_hub_rococo_local_network.toml
+Creds: config
+
+# local chain spec gives `1u64 << 60` tokens to every endowed account: if it'll ever
+# change, it'd need to be fixed here as well
+
+# //Charlie only submits free and mandatory relay chain headers, so the balance should stay the same
+bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5FLSigC9HGRKVhB9FiEo4Y3koPsNmBmLJbpXg2mp1hXcS59Y" return is 1152921504606846976 within 30 seconds
+# //Dave only submits free parachain headers, so the balance should stay the same
+bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5DAAnrj7VHTznn2AWBemMuyBwZWs6FNFjdyVXUeYum3PTXFy" return is 1152921504606846976 within 30 seconds

bridges/testing/tests/0001-asset-transfer/run.sh

@@ -18,8 +18,14 @@ ensure_process_file $env_pid $TEST_DIR/westend.env 300
 westend_dir=`cat $TEST_DIR/westend.env`
 echo
 
+run_zndsl ${BASH_SOURCE%/*}/roc-relayer-balance-does-not-change.zndsl $rococo_dir
+run_zndsl ${BASH_SOURCE%/*}/wnd-relayer-balance-does-not-change.zndsl $westend_dir
+
 run_zndsl ${BASH_SOURCE%/*}/roc-reaches-westend.zndsl $westend_dir
 run_zndsl ${BASH_SOURCE%/*}/wnd-reaches-rococo.zndsl $rococo_dir
 
 run_zndsl ${BASH_SOURCE%/*}/wroc-reaches-rococo.zndsl $rococo_dir
 run_zndsl ${BASH_SOURCE%/*}/wwnd-reaches-westend.zndsl $westend_dir
+
+run_zndsl ${BASH_SOURCE%/*}/roc-relayer-balance-does-not-change.zndsl $rococo_dir
+run_zndsl ${BASH_SOURCE%/*}/wnd-relayer-balance-does-not-change.zndsl $westend_dir

bridges/testing/tests/0001-asset-transfer/wnd-reaches-rococo.zndsl

@@ -3,10 +3,10 @@ Network: {{ENV_PATH}}/bridge_hub_rococo_local_network.toml
 Creds: config
 
 # send 5 WND to //Alice from Westend AH to Rococo AH
-asset-hub-rococo-collator1: run {{ENV_PATH}}/helper.sh with "reserve-transfer-assets-from-asset-hub-westend-local 5000000000000" within 120 seconds
+asset-hub-rococo-collator1: run {{ENV_PATH}}/helper.sh with "auto-log reserve-transfer-assets-from-asset-hub-westend-local 5000000000000" within 120 seconds
 
 # check that //Alice received at least 4.8 WND on Rococo AH
 asset-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/wrapped-assets-balance.js with "5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY,4800000000000,Westend" within 600 seconds
 
-# check that the relayer //Charlie is rewarded by Rococo AH
-bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/relayer-rewards.js with "5FLSigC9HGRKVhB9FiEo4Y3koPsNmBmLJbpXg2mp1hXcS59Y,0x00000002,0x62687764,ThisChain,0" within 30 seconds
+# relayer //Eve is rewarded for delivering messages from Westend BH
+bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/relayer-rewards.js with "5CiPPseXPECbkjWCa6MnjNokrgYjMqmKndv2rSnekmSK2DjL,0x00000002,0x62687764,ThisChain,0" within 300 seconds

bridges/testing/tests/0001-asset-transfer/wnd-relayer-balance-does-not-change.zndsl

+Description: Finality and parachain relays should have the constant balance, because their transactions are free
+Network: {{ENV_PATH}}/bridge_hub_westend_local_network.toml
+Creds: config
+
+# local chain spec gives `1u64 << 60` tokens to every endowed account: if it'll ever
+# change, it'd need to be fixed here as well
+
+# //Charlie only submits free and mandatory relay chain headers, so the balance should stay the same
+bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5FLSigC9HGRKVhB9FiEo4Y3koPsNmBmLJbpXg2mp1hXcS59Y" return is 1152921504606846976 within 30 seconds
+# //Dave only submits free parachain headers, so the balance should stay the same
+bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5DAAnrj7VHTznn2AWBemMuyBwZWs6FNFjdyVXUeYum3PTXFy" return is 1152921504606846976 within 30 seconds

bridges/testing/tests/0002-free-headers-synced-while-idle/rococo-to-westend.zndsl

+Description: While relayer is idle, we only sync free Rococo (and a single Rococo BH) headers to Westend BH.
+Network: {{ENV_PATH}}/bridge_hub_westend_local_network.toml
+Creds: config
+
+# local chain spec gives `1u64 << 60` tokens to every endowed account: if it'll ever
+# change, it'd need to be fixed here as well
+
+# //Charlie only submits free and mandatory relay chain headers, so the balance should stay the same
+bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5FLSigC9HGRKVhB9FiEo4Y3koPsNmBmLJbpXg2mp1hXcS59Y" return is 1152921504606846976 within 30 seconds
+# //Dave only submits free parachain headers, so the balance should stay the same
+bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5DAAnrj7VHTznn2AWBemMuyBwZWs6FNFjdyVXUeYum3PTXFy" return is 1152921504606846976 within 30 seconds
+
+# ensure that we have synced multiple relay and parachain headers while idle. This includes both
+# headers that were generated while relay was offline and those in the next 100 seconds while script is active.
+bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/multiple-headers-synced.js with "300,rococo-at-westend" within 600 seconds
+
+# //Charlie only submits free and mandatory relay chain headers, so the balance should stay the same
+bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5FLSigC9HGRKVhB9FiEo4Y3koPsNmBmLJbpXg2mp1hXcS59Y" return is 1152921504606846976 within 30 seconds
+# //Dave only submits free parachain headers, so the balance should stay the same
+bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5DAAnrj7VHTznn2AWBemMuyBwZWs6FNFjdyVXUeYum3PTXFy" return is 1152921504606846976 within 30 seconds

bridges/testing/tests/0002-mandatory-headers-synced-while-idle/run.sh → bridges/testing/tests/0002-free-headers-synced-while-idle/run.sh

@@ -22,7 +22,7 @@ echo
 # which is expected to be 60 seconds for the test environment.
 echo -e "Sleeping 90s before starting relayer ...\n"
 sleep 90
-${BASH_SOURCE%/*}/../../environments/rococo-westend/start_relayer.sh $rococo_dir $westend_dir relayer_pid
+${BASH_SOURCE%/*}/../../environments/rococo-westend/start_relayer.sh $rococo_dir $westend_dir finality_relayer_pid parachains_relayer_pid messages_relayer_pid
 
 run_zndsl ${BASH_SOURCE%/*}/rococo-to-westend.zndsl $westend_dir
 run_zndsl ${BASH_SOURCE%/*}/westend-to-rococo.zndsl $rococo_dir

bridges/testing/tests/0002-free-headers-synced-while-idle/westend-to-rococo.zndsl

+Description: While relayer is idle, we only sync free Westend (and a single Westend BH) headers to Rococo BH.
+Network: {{ENV_PATH}}/bridge_hub_rococo_local_network.toml
+Creds: config
+
+# local chain spec gives `1u64 << 60` tokens to every endowed account: if it'll ever
+# change, it'd need to be fixed here as well
+
+# //Charlie has inital balance
+bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5FLSigC9HGRKVhB9FiEo4Y3koPsNmBmLJbpXg2mp1hXcS59Y" return is 1152921504606846976 within 30 seconds
+# //Dave has inital balance
+bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5DAAnrj7VHTznn2AWBemMuyBwZWs6FNFjdyVXUeYum3PTXFy" return is 1152921504606846976 within 30 seconds
+
+# ensure that we have synced multiple relay and parachain headers while idle. This includes both
+# headers that were generated while relay was offline and those in the next 100 seconds while script is active.
+bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/multiple-headers-synced.js with "300,westend-at-rococo" within 600 seconds
+
+# //Charlie only submits free and mandatory relay chain headers, so the balance should stay the same
+bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5FLSigC9HGRKVhB9FiEo4Y3koPsNmBmLJbpXg2mp1hXcS59Y" return is 1152921504606846976 within 30 seconds
+# //Dave only submits free parachain headers, so the balance should stay the same
+bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/native-asset-balance.js with "5DAAnrj7VHTznn2AWBemMuyBwZWs6FNFjdyVXUeYum3PTXFy" return is 1152921504606846976 within 30 seconds

bridges/testing/tests/0002-mandatory-headers-synced-while-idle/rococo-to-westend.zndsl

-Description: While relayer is idle, we only sync mandatory Rococo (and a single Rococo BH) headers to Westend BH.
-Network: {{ENV_PATH}}/bridge_hub_westend_local_network.toml
-Creds: config
-
-# ensure that relayer is only syncing mandatory headers while idle. This includes both headers that were
-# generated while relay was offline and those in the next 100 seconds while script is active.
-bridge-hub-westend-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/only-mandatory-headers-synced-when-idle.js with "300,rococo-at-westend" within 600 seconds
-

bridges/testing/tests/0002-mandatory-headers-synced-while-idle/westend-to-rococo.zndsl

-Description: While relayer is idle, we only sync mandatory Westend (and a single Westend BH) headers to Rococo BH.
-Network: {{ENV_PATH}}/bridge_hub_rococo_local_network.toml
-Creds: config
-
-# ensure that relayer is only syncing mandatory headers while idle. This includes both headers that were
-# generated while relay was offline and those in the next 100 seconds while script is active.
-bridge-hub-rococo-collator1: js-script {{FRAMEWORK_PATH}}/js-helpers/only-mandatory-headers-synced-when-idle.js with "300,westend-at-rococo" within 600 seconds

cumulus/client/relay-chain-inprocess-interface/src/lib.rs

@@ -312,6 +312,9 @@ fn build_polkadot_full_node(
 			overseer_message_channel_capacity_override: None,
 			malus_finality_delay: None,
 			hwbench,
+			execute_workers_max_num: None,
+			prepare_workers_hard_max_num: None,
+			prepare_workers_soft_max_num: None,
 		},
 	)?;
 

cumulus/pallets/collator-selection/Cargo.toml

@@ -27,6 +27,7 @@ sp-staking = { path = "../../../substrate/primitives/staking", default-features
 frame-support = { path = "../../../substrate/frame/support", default-features = false }
 frame-system = { path = "../../../substrate/frame/system", default-features = false }
 pallet-authorship = { path = "../../../substrate/frame/authorship", default-features = false }
+pallet-balances = { path = "../../../substrate/frame/balances", default-features = false }
 pallet-session = { path = "../../../substrate/frame/session", default-features = false }
 
 frame-benchmarking = { path = "../../../substrate/frame/benchmarking", default-features = false, optional = true }
@@ -38,7 +39,6 @@ sp-tracing = { path = "../../../substrate/primitives/tracing" }
 sp-runtime = { path = "../../../substrate/primitives/runtime" }
 pallet-timestamp = { path = "../../../substrate/frame/timestamp" }
 sp-consensus-aura = { path = "../../../substrate/primitives/consensus/aura" }
-pallet-balances = { path = "../../../substrate/frame/balances" }
 pallet-aura = { path = "../../../substrate/frame/aura" }
 
 [features]
@@ -59,6 +59,7 @@ std = [
 	"frame-system/std",
 	"log/std",
 	"pallet-authorship/std",
+	"pallet-balances/std",
 	"pallet-session/std",
 	"rand/std",
 	"scale-info/std",

cumulus/pallets/collator-selection/src/lib.rs

@@ -121,7 +121,7 @@ pub mod pallet {
 	use sp_std::vec::Vec;
 
 	/// The in-code storage version.
-	const STORAGE_VERSION: StorageVersion = StorageVersion::new(1);
+	const STORAGE_VERSION: StorageVersion = StorageVersion::new(2);
 
 	type BalanceOf<T> =
 		<<T as Config>::Currency as Currency<<T as SystemConfig>::AccountId>>::Balance;

cumulus/pallets/collator-selection/src/migration.rs

@@ -17,9 +17,107 @@
 //! A module that is responsible for migration of storage for Collator Selection.
 
 use super::*;
-use frame_support::traits::OnRuntimeUpgrade;
+use frame_support::traits::{OnRuntimeUpgrade, UncheckedOnRuntimeUpgrade};
 use log;
 
+/// Migrate to v2. Should have been part of <https://github.com/paritytech/polkadot-sdk/pull/1340>.
+pub mod v2 {
+	use super::*;
+	use frame_support::{
+		pallet_prelude::*,
+		storage_alias,
+		traits::{Currency, ReservableCurrency},
+	};
+	use sp_runtime::traits::{Saturating, Zero};
+	#[cfg(feature = "try-runtime")]
+	use sp_std::vec::Vec;
+
+	/// [`UncheckedMigrationToV2`] wrapped in a
+	/// [`VersionedMigration`](frame_support::migrations::VersionedMigration), ensuring the
+	/// migration is only performed when on-chain version is 1.
+	pub type MigrationToV2<T> = frame_support::migrations::VersionedMigration<
+		1,
+		2,
+		UncheckedMigrationToV2<T>,
+		Pallet<T>,
+		<T as frame_system::Config>::DbWeight,
+	>;
+
+	#[storage_alias]
+	pub type Candidates<T: Config> = StorageValue<
+		Pallet<T>,
+		BoundedVec<CandidateInfo<<T as frame_system::Config>::AccountId, <<T as Config>::Currency as Currency<<T as frame_system::Config>::AccountId>>::Balance>, <T as Config>::MaxCandidates>,
+		ValueQuery,
+	>;
+
+	/// Migrate to V2.
+	pub struct UncheckedMigrationToV2<T>(sp_std::marker::PhantomData<T>);
+	impl<T: Config + pallet_balances::Config> UncheckedOnRuntimeUpgrade for UncheckedMigrationToV2<T> {
+		fn on_runtime_upgrade() -> Weight {
+			let mut weight = Weight::zero();
+			let mut count: u64 = 0;
+			// candidates who exist under the old `Candidates` key
+			let candidates = Candidates::<T>::take();
+
+			// New candidates who have registered since the upgrade. Under normal circumstances,
+			// this should not exist because the migration should be applied when the upgrade
+			// happens. But in Polkadot/Kusama we messed this up, and people registered under
+			// `CandidateList` while their funds were locked in `Candidates`.
+			let new_candidate_list = CandidateList::<T>::get();
+			if new_candidate_list.len().is_zero() {
+				// The new list is empty, so this is essentially being applied correctly. We just
+				// put the candidates into the new storage item.
+				CandidateList::<T>::put(&candidates);
+				// 1 write for the new list
+				weight.saturating_accrue(T::DbWeight::get().reads_writes(0, 1));
+			} else {
+				// Oops, the runtime upgraded without the migration. There are new candidates in
+				// `CandidateList`. So, let's just refund the old ones and assume they have already
+				// started participating in the new system.
+				for candidate in candidates {
+					let err = T::Currency::unreserve(&candidate.who, candidate.deposit);
+					if err > Zero::zero() {
+						log::error!(
+							target: LOG_TARGET,
+							"{:?} balance was unable to be unreserved from {:?}",
+							err, &candidate.who,
+						);
+					}
+					count.saturating_inc();
+				}
+				weight.saturating_accrue(
+					<<T as pallet_balances::Config>::WeightInfo as pallet_balances::WeightInfo>::force_unreserve().saturating_mul(count.into()),
+				);
+			}
+
+			log::info!(
+				target: LOG_TARGET,
+				"Unreserved locked bond of {} candidates, upgraded storage to version 2",
+				count,
+			);
+
+			weight.saturating_accrue(T::DbWeight::get().reads_writes(3, 2));
+			weight
+		}
+
+		#[cfg(feature = "try-runtime")]
+		fn pre_upgrade() -> Result<Vec<u8>, sp_runtime::DispatchError> {
+			let number_of_candidates = Candidates::<T>::get().to_vec().len();
+			Ok((number_of_candidates as u32).encode())
+		}
+
+		#[cfg(feature = "try-runtime")]
+		fn post_upgrade(_number_of_candidates: Vec<u8>) -> Result<(), sp_runtime::DispatchError> {
+			let new_number_of_candidates = Candidates::<T>::get().to_vec().len();
+			assert_eq!(
+				new_number_of_candidates, 0 as usize,
+				"after migration, the candidates map should be empty"
+			);
+			Ok(())
+		}
+	}
+}
+
 /// Version 1 Migration
 /// This migration ensures that any existing `Invulnerables` storage lists are sorted.
 pub mod v1 {
@@ -90,3 +188,136 @@ pub mod v1 {
 		}
 	}
 }
+
+#[cfg(all(feature = "try-runtime", test))]
+mod tests {
+	use super::*;
+	use crate::{
+		migration::v2::Candidates,
+		mock::{new_test_ext, Balances, Test},
+	};
+	use frame_support::{
+		traits::{Currency, ReservableCurrency, StorageVersion},
+		BoundedVec,
+	};
+	use sp_runtime::traits::ConstU32;
+
+	#[test]
+	fn migrate_to_v2_with_new_candidates() {
+		new_test_ext().execute_with(|| {
+			let storage_version = StorageVersion::new(1);
+			storage_version.put::<Pallet<Test>>();
+
+			let one = 1u64;
+			let two = 2u64;
+			let three = 3u64;
+			let deposit = 10u64;
+
+			// Set balance to 100
+			Balances::make_free_balance_be(&one, 100u64);
+			Balances::make_free_balance_be(&two, 100u64);
+			Balances::make_free_balance_be(&three, 100u64);
+
+			// Reservations: 10 for the "old" candidacy and 10 for the "new"
+			Balances::reserve(&one, 10u64).unwrap(); // old
+			Balances::reserve(&two, 20u64).unwrap(); // old + new
+			Balances::reserve(&three, 10u64).unwrap(); // new
+
+			// Candidate info
+			let candidate_one = CandidateInfo { who: one, deposit };
+			let candidate_two = CandidateInfo { who: two, deposit };
+			let candidate_three = CandidateInfo { who: three, deposit };
+
+			// Storage lists
+			let bounded_candidates =
+				BoundedVec::<CandidateInfo<u64, u64>, ConstU32<20>>::try_from(vec![
+					candidate_one.clone(),
+					candidate_two.clone(),
+				])
+				.expect("it works");
+			let bounded_candidate_list =
+				BoundedVec::<CandidateInfo<u64, u64>, ConstU32<20>>::try_from(vec![
+					candidate_two.clone(),
+					candidate_three.clone(),
+				])
+				.expect("it works");
+
+			// Set storage
+			Candidates::<Test>::put(bounded_candidates);
+			CandidateList::<Test>::put(bounded_candidate_list.clone());
+
+			// Sanity check
+			assert_eq!(Balances::free_balance(one), 90);
+			assert_eq!(Balances::free_balance(two), 80);
+			assert_eq!(Balances::free_balance(three), 90);
+
+			// Run migration
+			v2::MigrationToV2::<Test>::on_runtime_upgrade();
+
+			let new_storage_version = StorageVersion::get::<Pallet<Test>>();
+			assert_eq!(new_storage_version, 2);
+
+			// 10 should have been unreserved from the old candidacy
+			assert_eq!(Balances::free_balance(one), 100);
+			assert_eq!(Balances::free_balance(two), 90);
+			assert_eq!(Balances::free_balance(three), 90);
+			// The storage item should be gone
+			assert!(Candidates::<Test>::get().is_empty());
+			// The new storage item should be preserved
+			assert_eq!(CandidateList::<Test>::get(), bounded_candidate_list);
+		});
+	}
+
+	#[test]
+	fn migrate_to_v2_without_new_candidates() {
+		new_test_ext().execute_with(|| {
+			let storage_version = StorageVersion::new(1);
+			storage_version.put::<Pallet<Test>>();
+
+			let one = 1u64;
+			let two = 2u64;
+			let deposit = 10u64;
+
+			// Set balance to 100
+			Balances::make_free_balance_be(&one, 100u64);
+			Balances::make_free_balance_be(&two, 100u64);
+
+			// Reservations
+			Balances::reserve(&one, 10u64).unwrap(); // old
+			Balances::reserve(&two, 10u64).unwrap(); // old
+
+			// Candidate info
+			let candidate_one = CandidateInfo { who: one, deposit };
+			let candidate_two = CandidateInfo { who: two, deposit };
+
+			// Storage lists
+			let bounded_candidates =
+				BoundedVec::<CandidateInfo<u64, u64>, ConstU32<20>>::try_from(vec![
+					candidate_one.clone(),
+					candidate_two.clone(),
+				])
+				.expect("it works");
+
+			// Set storage
+			Candidates::<Test>::put(bounded_candidates.clone());
+
+			// Sanity check
+			assert_eq!(Balances::free_balance(one), 90);
+			assert_eq!(Balances::free_balance(two), 90);
+
+			// Run migration
+			v2::MigrationToV2::<Test>::on_runtime_upgrade();
+
+			let new_storage_version = StorageVersion::get::<Pallet<Test>>();
+			assert_eq!(new_storage_version, 2);
+
+			// Nothing changes deposit-wise
+			assert_eq!(Balances::free_balance(one), 90);
+			assert_eq!(Balances::free_balance(two), 90);
+			// The storage item should be gone
+			assert!(Candidates::<Test>::get().is_empty());
+			// The new storage item should have the info now
+			assert_eq!(CandidateList::<Test>::get(), bounded_candidates);
+		});
+	}
+}

cumulus/pallets/xcmp-queue/src/lib.rs

@@ -916,7 +916,8 @@ impl<T: Config> SendXcm for Pallet<T> {
 				let price = T::PriceForSiblingDelivery::price_for_delivery(id, &xcm);
 				let versioned_xcm = T::VersionWrapper::wrap_version(&d, xcm)
 					.map_err(|()| SendError::DestinationUnsupported)?;
-				validate_xcm_nesting(&versioned_xcm)
+				versioned_xcm
+					.validate_xcm_nesting()
 					.map_err(|()| SendError::ExceedsMaxMessageSize)?;
 
 				Ok(((id, versioned_xcm), price))
@@ -932,10 +933,6 @@ impl<T: Config> SendXcm for Pallet<T> {
 
 	fn deliver((id, xcm): (ParaId, VersionedXcm<()>)) -> Result<XcmHash, SendError> {
 		let hash = xcm.using_encoded(sp_io::hashing::blake2_256);
-		defensive_assert!(
-			validate_xcm_nesting(&xcm).is_ok(),
-			"Tickets are valid prior to delivery by trait XCM; qed"
-		);
 
 		match Self::send_fragment(id, XcmpMessageFormat::ConcatenatedVersionedXcm, xcm) {
 			Ok(_) => {
@@ -950,16 +947,6 @@ impl<T: Config> SendXcm for Pallet<T> {
 	}
 }
 
-/// Checks that the XCM is decodable with `MAX_XCM_DECODE_DEPTH`.
-///
-/// Note that this uses the limit of the sender - not the receiver. It it best effort.
-pub(crate) fn validate_xcm_nesting(xcm: &VersionedXcm<()>) -> Result<(), ()> {
-	xcm.using_encoded(|mut enc| {
-		VersionedXcm::<()>::decode_all_with_depth_limit(MAX_XCM_DECODE_DEPTH, &mut enc).map(|_| ())
-	})
-	.map_err(|_| ())
-}
-
 impl<T: Config> FeeTracker for Pallet<T> {
 	type Id = ParaId;
 

cumulus/parachains/integration-tests/emulated/chains/relays/westend/Cargo.toml

@@ -11,6 +11,7 @@ publish = false
 workspace = true
 
 [dependencies]
+
 # Substrate
 sp-core = { path = "../../../../../../../substrate/primitives/core", default-features = false }
 sp-runtime = { path = "../../../../../../../substrate/primitives/runtime", default-features = false }

cumulus/parachains/integration-tests/emulated/common/src/impls.rs

@@ -360,7 +360,7 @@ macro_rules! impl_send_transact_helpers_for_relay_chain {
 					recipient: $crate::impls::ParaId,
 					call: $crate::impls::DoubleEncoded<()>
 				) {
-					use $crate::impls::{bx, Chain, RelayChain, Encode};
+					use $crate::impls::{bx, Chain, RelayChain};
 
 					<Self as $crate::impls::TestExt>::execute_with(|| {
 						let root_origin = <Self as Chain>::RuntimeOrigin::root();
@@ -368,10 +368,10 @@ macro_rules! impl_send_transact_helpers_for_relay_chain {
 						let xcm = $crate::impls::xcm_transact_unpaid_execution(call, $crate::impls::OriginKind::Superuser);
 
 						// Send XCM `Transact`
-						$crate::impls::assert_ok!(<Self as [<$chain RelayPallet>]>::XcmPallet::send_blob(
+						$crate::impls::assert_ok!(<Self as [<$chain RelayPallet>]>::XcmPallet::send(
 							root_origin,
 							bx!(destination.into()),
-							xcm.encode().try_into().unwrap(),
+							bx!(xcm),
 						));
 						Self::assert_xcm_pallet_sent();
 					});