Dispatchable XCMs should translate to v0 (#4062)

* Dispatchable XCMs should translate to v0

* Formatting

* Update Westend's XCM WrapVersion

polkadot/runtime/kusama/src/lib.rs

@@ -1323,7 +1323,7 @@ parameter_types! {
 /// individual routers.
 pub type XcmRouter = (
 	// Only one router so far - use DMP to communicate with child parachains.
-	xcm_sender::ChildParachainRouter<Runtime, xcm::AlwaysRelease>,
+	xcm_sender::ChildParachainRouter<Runtime, XcmPallet>,
 );
 
 parameter_types! {

polkadot/runtime/rococo/src/lib.rs

@@ -636,7 +636,7 @@ parameter_types! {
 /// individual routers.
 pub type XcmRouter = (
 	// Only one router so far - use DMP to communicate with child parachains.
-	xcm_sender::ChildParachainRouter<Runtime, xcm::AlwaysRelease>,
+	xcm_sender::ChildParachainRouter<Runtime, XcmPallet>,
 );
 
 parameter_types! {

polkadot/runtime/westend/src/lib.rs

@@ -958,7 +958,7 @@ type LocalOriginConverter = (
 /// individual routers.
 pub type XcmRouter = (
 	// Only one router so far - use DMP to communicate with child parachains.
-	xcm_sender::ChildParachainRouter<Runtime, xcm::AlwaysRelease>,
+	xcm_sender::ChildParachainRouter<Runtime, XcmPallet>,
 );
 
 parameter_types! {

polkadot/xcm/pallet-xcm/src/lib.rs

@@ -526,16 +526,21 @@ pub mod pallet {
 				.map_err(|_| Error::<T>::CannotReanchor)?;
 			let max_assets = assets.len() as u32;
 			let assets = assets.into();
+			let mut remote_message = Xcm(vec![
+				BuyExecution { fees, weight_limit: Limited(0) },
+				DepositAsset { assets: Wild(All), max_assets, beneficiary },
+			]);
+			// use local weight for remote message and hope for the best.
+			let remote_weight = T::Weigher::weight(&mut remote_message)
+				.map_err(|()| Error::<T>::UnweighableMessage)?;
+			if let Some(BuyExecution { weight_limit: Limited(ref mut limit), .. }) =
+				remote_message.0.get_mut(0)
+			{
+				*limit = remote_weight;
+			}
 			let mut message = Xcm(vec![
 				WithdrawAsset(assets),
-				InitiateTeleport {
+				InitiateTeleport { assets: Wild(All), dest, xcm: remote_message.into() },
-					assets: Wild(All),
-					dest,
-					xcm: Xcm(vec![
-						BuyExecution { fees, weight_limit: Unlimited },
-						DepositAsset { assets: Wild(All), max_assets, beneficiary },
-					]),
-				},
 			]);
 			let weight =
 				T::Weigher::weight(&mut message).map_err(|()| Error::<T>::UnweighableMessage)?;
@@ -597,14 +602,20 @@ pub mod pallet {
 				.map_err(|_| Error::<T>::CannotReanchor)?;
 			let max_assets = assets.len() as u32;
 			let assets = assets.into();
-			let mut message = Xcm(vec![TransferReserveAsset {
+			let mut remote_message = Xcm(vec![
-				assets,
+				BuyExecution { fees, weight_limit: Limited(0) },
-				dest,
+				DepositAsset { assets: Wild(All), max_assets, beneficiary },
-				xcm: Xcm(vec![
+			]);
-					BuyExecution { fees, weight_limit: Unlimited },
+			// use local weight for remote message and hope for the best.
-					DepositAsset { assets: Wild(All), max_assets, beneficiary },
+			let remote_weight = T::Weigher::weight(&mut remote_message)
-				]),
+				.map_err(|()| Error::<T>::UnweighableMessage)?;
-			}]);
+			if let Some(BuyExecution { weight_limit: Limited(ref mut limit), .. }) =
+				remote_message.0.get_mut(0)
+			{
+				*limit = remote_weight;
+			}
+			let mut message =
+				Xcm(vec![TransferReserveAsset { assets, dest, xcm: remote_message.into() }]);
 			let weight =
 				T::Weigher::weight(&mut message).map_err(|()| Error::<T>::UnweighableMessage)?;
 			let outcome =

polkadot/xcm/pallet-xcm/src/mock.rs

@@ -310,6 +310,11 @@ pub(crate) fn buy_execution<C>(fees: impl Into<MultiAsset>) -> Instruction<C> {
 	BuyExecution { fees: fees.into(), weight_limit: Unlimited }
 }
 
+pub(crate) fn buy_limited_execution<C>(fees: impl Into<MultiAsset>, weight: u64) -> Instruction<C> {
+	use xcm::latest::prelude::*;
+	BuyExecution { fees: fees.into(), weight_limit: Limited(weight) }
+}
+
 pub(crate) fn new_test_ext_with_balances(
 	balances: Vec<(AccountId, Balance)>,
 ) -> sp_io::TestExternalities {

polkadot/xcm/pallet-xcm/src/tests.rs

@@ -218,14 +218,29 @@ fn teleport_assets_works() {
 	new_test_ext_with_balances(balances).execute_with(|| {
 		let weight = 2 * BaseXcmWeight::get();
 		assert_eq!(Balances::total_balance(&ALICE), INITIAL_BALANCE);
+		let dest: MultiLocation = AccountId32 { network: Any, id: BOB.into() }.into();
 		assert_ok!(XcmPallet::teleport_assets(
 			Origin::signed(ALICE),
 			Box::new(RelayLocation::get().into()),
-			Box::new(AccountId32 { network: Any, id: BOB.into() }.into().into()),
+			Box::new(dest.clone().into()),
 			Box::new((Here, SEND_AMOUNT).into()),
 			0,
 		));
 		assert_eq!(Balances::total_balance(&ALICE), INITIAL_BALANCE - SEND_AMOUNT);
+		assert_eq!(
+			sent_xcm(),
+			vec![(
+				RelayLocation::get().into(),
+				Xcm(vec![
+					ReceiveTeleportedAsset((Here, SEND_AMOUNT).into()),
+					ClearOrigin,
+					buy_limited_execution((Here, SEND_AMOUNT), 2000),
+					DepositAsset { assets: All.into(), max_assets: 1, beneficiary: dest },
+				]),
+			)]
+		);
+		let versioned_sent = VersionedXcm::from(sent_xcm().into_iter().next().unwrap().1);
+		let _check_v0_ok: xcm::v0::Xcm<()> = versioned_sent.try_into().unwrap();
 		assert_eq!(
 			last_event(),
 			Event::XcmPallet(crate::Event::Attempted(Outcome::Complete(weight)))
@@ -265,11 +280,13 @@ fn reserve_transfer_assets_works() {
 				Xcm(vec![
 					ReserveAssetDeposited((Parent, SEND_AMOUNT).into()),
 					ClearOrigin,
-					buy_execution((Parent, SEND_AMOUNT)),
+					buy_limited_execution((Parent, SEND_AMOUNT), 2000),
 					DepositAsset { assets: All.into(), max_assets: 1, beneficiary: dest },
 				]),
 			)]
 		);
+		let versioned_sent = VersionedXcm::from(sent_xcm().into_iter().next().unwrap().1);
+		let _check_v0_ok: xcm::v0::Xcm<()> = versioned_sent.try_into().unwrap();
 		assert_eq!(
 			last_event(),
 			Event::XcmPallet(crate::Event::Attempted(Outcome::Complete(weight)))