[pallet_xcm::reserve_transfer_assets] NotHoldingFees issue in case of paid XcmRouter is used

runtime/kusama/src/lib.rs

@@ -2108,6 +2108,8 @@ sp_api::impl_runtime_apis! {
 			use xcm_config::{
 				LocalCheckAccount, SovereignAccountOf, AssetHub, TokenLocation, XcmConfig,
 			};
+			use xcm_executor::FeesMode;
+			use xcm_executor::traits::FeeReason;
 
 			impl pallet_session_benchmarking::Config for Runtime {}
 			impl pallet_offences_benchmarking::Config for Runtime {}
@@ -2130,6 +2132,43 @@ sp_api::impl_runtime_apis! {
 						fun: Fungible(1_000_000 * UNITS),
 					}].into()
 				}
+				fn ensure_for_send(origin_ref: &MultiLocation, _dest: &MultiLocation, fee_reason: FeeReason) -> Option<FeesMode> {
+					use xcm_executor::traits::{FeeManager, TransactAsset};
+
+					let mut fees_mode = None;
+					if !<XcmConfig as xcm_executor::Config>::FeeManager::is_waived(Some(origin_ref), fee_reason) {
+						// if not waived, we need to set up accounts for paying and receiving fees
+
+						// mint ED to origin
+						let ed = MultiAsset {
+							id: Concrete(TokenLocation::get()),
+							fun: Fungible(EXISTENTIAL_DEPOSIT.into())
+						};
+						<XcmConfig as xcm_executor::Config>::AssetTransactor::deposit_asset(&ed, &origin_ref, None).unwrap();
+
+						// overestimate delivery fee
+						use runtime_common::xcm_sender::PriceForParachainDelivery;
+						let overestimated_xcm = vec![ClearOrigin; 128].into();
+						let overestimated_fees = runtime_common::xcm_sender::ExponentialPrice::<
+							xcm_config::FeeAssetId,
+							xcm_config::BaseDeliveryFee,
+							TransactionByteFee,
+							Dmp
+						>::price_for_parachain_delivery(
+							kusama_runtime_constants::system_parachain::ASSET_HUB_ID.into(),
+							&overestimated_xcm
+						);
+
+						// mint overestimated fee to origin
+						for fee in overestimated_fees.inner() {
+							<XcmConfig as xcm_executor::Config>::AssetTransactor::deposit_asset(&fee, &origin_ref, None).unwrap();
+						}
+
+						// expected worst case
+						fees_mode = Some(FeesMode { jit_withdraw: true });
+					}
+					fees_mode
+				}
 			}
 
 			parameter_types! {

runtime/kusama/src/xcm_config.rs

@@ -146,6 +146,9 @@ match_types! {
 	pub type OnlyParachains: impl Contains<MultiLocation> = {
 		MultiLocation { parents: 0, interior: X1(Parachain(_)) }
 	};
+	pub type HereLocation: impl Contains<MultiLocation> = {
+		MultiLocation { parents: 0, interior: Here }
+	};
 }
 
 /// The barriers one of which must be passed for an XCM message to be executed.
@@ -346,7 +349,8 @@ impl xcm_executor::Config for XcmConfig {
 	type SubscriptionService = XcmPallet;
 	type PalletInstancesInfo = AllPalletsWithSystem;
 	type MaxAssetsIntoHolding = MaxAssetsIntoHolding;
-	type FeeManager = XcmFeesToAccount<Self, SystemParachains, AccountId, TreasuryAccount>;
+	type FeeManager =
+		XcmFeesToAccount<Self, (SystemParachains, HereLocation), AccountId, TreasuryAccount>;
 	// No bridges yet...
 	type MessageExporter = ();
 	type UniversalAliases = Nothing;

runtime/polkadot/src/lib.rs

@@ -2085,6 +2085,8 @@ sp_api::impl_runtime_apis! {
 			use frame_benchmarking::baseline::Pallet as Baseline;
 			use xcm::latest::prelude::*;
 			use xcm_config::{XcmConfig, AssetHubLocation, TokenLocation, LocalCheckAccount, SovereignAccountOf};
+			use xcm_executor::FeesMode;
+			use xcm_executor::traits::FeeReason;
 
 			impl pallet_session_benchmarking::Config for Runtime {}
 			impl pallet_offences_benchmarking::Config for Runtime {}
@@ -2108,6 +2110,43 @@ sp_api::impl_runtime_apis! {
 					// Polkadot only knows about DOT
 					vec![MultiAsset { id: Concrete(TokenLocation::get()), fun: Fungible(1_000_000 * UNITS) }].into()
 				}
+				fn ensure_for_send(origin_ref: &MultiLocation, _dest: &MultiLocation, fee_reason: FeeReason) -> Option<FeesMode> {
+					use xcm_executor::traits::{FeeManager, TransactAsset};
+
+					let mut fees_mode = None;
+					if !<XcmConfig as xcm_executor::Config>::FeeManager::is_waived(Some(origin_ref), fee_reason) {
+						// if not waived, we need to set up accounts for paying and receiving fees
+
+						// mint ED to origin
+						let ed = MultiAsset {
+							id: Concrete(TokenLocation::get()),
+							fun: Fungible(EXISTENTIAL_DEPOSIT.into())
+						};
+						<XcmConfig as xcm_executor::Config>::AssetTransactor::deposit_asset(&ed, &origin_ref, None).unwrap();
+
+						// overestimate delivery fee
+						use runtime_common::xcm_sender::PriceForParachainDelivery;
+						let overestimated_xcm = vec![ClearOrigin; 128].into();
+						let overestimated_fees = runtime_common::xcm_sender::ExponentialPrice::<
+							xcm_config::FeeAssetId,
+							xcm_config::BaseDeliveryFee,
+							TransactionByteFee,
+							Dmp
+						>::price_for_parachain_delivery(
+							polkadot_runtime_constants::system_parachain::ASSET_HUB_ID.into(),
+							&overestimated_xcm
+						);
+
+						// mint overestimated fee to origin
+						for fee in overestimated_fees.inner() {
+							<XcmConfig as xcm_executor::Config>::AssetTransactor::deposit_asset(&fee, &origin_ref, None).unwrap();
+						}
+
+						// expected worst case
+						fees_mode = Some(FeesMode { jit_withdraw: true });
+					}
+					fees_mode
+				}
 			}
 
 			parameter_types! {

runtime/polkadot/src/xcm_config.rs

@@ -157,6 +157,9 @@ match_types! {
 		MultiLocation { parents: 0, interior: X1(Parachain(COLLECTIVES_ID)) } |
 		MultiLocation { parents: 0, interior: X2(Parachain(COLLECTIVES_ID), Plurality { id: BodyId::Technical, .. }) }
 	};
+	pub type HereLocation: impl Contains<MultiLocation> = {
+		MultiLocation { parents: 0, interior: Here }
+	};
 }
 
 /// The barriers one of which must be passed for an XCM message to be executed.
@@ -347,7 +350,8 @@ impl xcm_executor::Config for XcmConfig {
 	type SubscriptionService = XcmPallet;
 	type PalletInstancesInfo = AllPalletsWithSystem;
 	type MaxAssetsIntoHolding = MaxAssetsIntoHolding;
-	type FeeManager = XcmFeesToAccount<Self, SystemParachains, AccountId, TreasuryAccount>;
+	type FeeManager =
+		XcmFeesToAccount<Self, (SystemParachains, HereLocation), AccountId, TreasuryAccount>;
 	// No bridges yet...
 	type MessageExporter = ();
 	type UniversalAliases = Nothing;

runtime/rococo/src/lib.rs

@@ -2094,6 +2094,8 @@ sp_api::impl_runtime_apis! {
 			use xcm_config::{
 				LocalCheckAccount, LocationConverter, AssetHub, TokenLocation, XcmConfig,
 			};
+			use xcm_executor::FeesMode;
+			use xcm_executor::traits::FeeReason;
 
 			impl frame_system_benchmarking::Config for Runtime {}
 			impl frame_benchmarking::baseline::Config for Runtime {}
@@ -2110,6 +2112,43 @@ sp_api::impl_runtime_apis! {
 						fun: Fungible(1_000_000 * UNITS),
 					}].into()
 				}
+				fn ensure_for_send(origin_ref: &MultiLocation, _dest: &MultiLocation, fee_reason: FeeReason) -> Option<FeesMode> {
+					use xcm_executor::traits::{FeeManager, TransactAsset};
+
+					let mut fees_mode = None;
+					if !<XcmConfig as xcm_executor::Config>::FeeManager::is_waived(Some(origin_ref), fee_reason) {
+						// if not waived, we need to set up accounts for paying and receiving fees
+
+						// mint ED to origin
+						let ed = MultiAsset {
+							id: Concrete(TokenLocation::get()),
+							fun: Fungible(EXISTENTIAL_DEPOSIT.into())
+						};
+						<XcmConfig as xcm_executor::Config>::AssetTransactor::deposit_asset(&ed, &origin_ref, None).unwrap();
+
+						// overestimate delivery fee
+						use runtime_common::xcm_sender::PriceForParachainDelivery;
+						let overestimated_xcm = vec![ClearOrigin; 128].into();
+						let overestimated_fees = runtime_common::xcm_sender::ExponentialPrice::<
+							xcm_config::FeeAssetId,
+							xcm_config::BaseDeliveryFee,
+							TransactionByteFee,
+							Dmp
+						>::price_for_parachain_delivery(
+							rococo_runtime_constants::system_parachain::ASSET_HUB_ID.into(),
+							&overestimated_xcm
+						);
+
+						// mint overestimated fee to origin
+						for fee in overestimated_fees.inner() {
+							<XcmConfig as xcm_executor::Config>::AssetTransactor::deposit_asset(&fee, &origin_ref, None).unwrap();
+						}
+
+						// expected worst case
+						fees_mode = Some(FeesMode { jit_withdraw: true });
+					}
+					fees_mode
+				}
 			}
 
 			parameter_types! {

runtime/rococo/src/xcm_config.rs

@@ -140,6 +140,9 @@ match_types! {
 	pub type OnlyParachains: impl Contains<MultiLocation> = {
 		MultiLocation { parents: 0, interior: X1(Parachain(_)) }
 	};
+	pub type HereLocation: impl Contains<MultiLocation> = {
+		MultiLocation { parents: 0, interior: Here }
+	};
 }
 
 /// The barriers one of which must be passed for an XCM message to be executed.
@@ -319,7 +322,8 @@ impl xcm_executor::Config for XcmConfig {
 	type SubscriptionService = XcmPallet;
 	type PalletInstancesInfo = AllPalletsWithSystem;
 	type MaxAssetsIntoHolding = MaxAssetsIntoHolding;
-	type FeeManager = XcmFeesToAccount<Self, SystemParachains, AccountId, TreasuryAccount>;
+	type FeeManager =
+		XcmFeesToAccount<Self, (SystemParachains, HereLocation), AccountId, TreasuryAccount>;
 	type MessageExporter = ();
 	type UniversalAliases = Nothing;
 	type CallDispatcher = WithOriginFilter<SafeCallFilter>;

runtime/westend/src/lib.rs

@@ -1858,6 +1858,8 @@ sp_api::impl_runtime_apis! {
 				MultiAsset, MultiAssets, MultiLocation, NetworkId, Response,
 			};
 			use xcm_config::{AssetHub, TokenLocation};
+			use xcm_executor::FeesMode;
+			use xcm_executor::traits::FeeReason;
 
 			impl pallet_xcm_benchmarks::Config for Runtime {
 				type XcmConfig = xcm_config::XcmConfig;
@@ -1872,6 +1874,10 @@ sp_api::impl_runtime_apis! {
 						fun: Fungible(1_000_000 * UNITS),
 					}].into()
 				}
+				fn ensure_for_send(_origin_ref: &MultiLocation, _dest: &MultiLocation, _fee_reason: FeeReason) -> Option<FeesMode> {
+					// doing nothing
+					None
+				}
 			}
 
 			parameter_types! {

xcm/pallet-xcm-benchmarks/src/fungible/benchmarking.rs

@@ -24,7 +24,7 @@ use frame_support::{
 use sp_runtime::traits::{Bounded, Zero};
 use sp_std::{prelude::*, vec};
 use xcm::latest::prelude::*;
-use xcm_executor::traits::{ConvertLocation, TransactAsset};
+use xcm_executor::traits::{ConvertLocation, FeeReason, TransactAsset};
 
 benchmarks_instance_pallet! {
 	where_clause { where
@@ -87,12 +87,19 @@ benchmarks_instance_pallet! {
 		let dest_location = T::valid_destination()?;
 		let dest_account = T::AccountIdConverter::convert_location(&dest_location).unwrap();
 
+		let expected_fees_mode = T::ensure_for_send(&sender_location, &dest_location, FeeReason::TransferReserveAsset);
+		let sender_account_balance_before = T::TransactAsset::balance(&sender_account);
+
 		let asset = T::get_multi_asset();
 		<AssetTransactorOf<T>>::deposit_asset(&asset, &sender_location, None).unwrap();
+		assert!(T::TransactAsset::balance(&sender_account) > sender_account_balance_before);
 		let assets: MultiAssets = vec![ asset ].into();
 		assert!(T::TransactAsset::balance(&dest_account).is_zero());
 
 		let mut executor = new_executor::<T>(sender_location);
+		if let Some(expected_fees_mode) = expected_fees_mode {
+			executor.set_fees_mode(expected_fees_mode);
+		}
 		let instruction = Instruction::TransferReserveAsset {
 			assets,
 			dest: dest_location,
@@ -102,7 +109,7 @@ benchmarks_instance_pallet! {
 	}: {
 		executor.bench_process(xcm)?;
 	} verify {
-		assert!(T::TransactAsset::balance(&sender_account).is_zero());
+		assert!(T::TransactAsset::balance(&sender_account) <= sender_account_balance_before);
 		assert!(!T::TransactAsset::balance(&dest_account).is_zero());
 		// TODO: Check sender queue is not empty. #4426
 	}

xcm/pallet-xcm-benchmarks/src/fungible/mock.rs

@@ -27,6 +27,7 @@ use sp_core::H256;
 use sp_runtime::traits::{BlakeTwo256, IdentityLookup};
 use xcm::latest::prelude::*;
 use xcm_builder::{AllowUnpaidExecutionFrom, MintLocation};
+use xcm_executor::{traits::FeeReason, FeesMode};
 
 type Block = frame_system::mocking::MockBlock<Test>;
 
@@ -169,6 +170,15 @@ impl crate::Config for Test {
 			<XcmConfig as xcm_executor::Config>::MaxAssetsIntoHolding::get(),
 		)
 	}
+
+	fn ensure_for_send(
+		_origin_ref: &MultiLocation,
+		_dest: &MultiLocation,
+		_fee_reason: FeeReason,
+	) -> Option<FeesMode> {
+		// doing nothing
+		None
+	}
 }
 
 pub type TrustedTeleporters = xcm_builder::Case<TeleportConcreteFungible>;

xcm/pallet-xcm-benchmarks/src/generic/mock.rs

@@ -152,6 +152,15 @@ impl crate::Config for Test {
 			<XcmConfig as xcm_executor::Config>::MaxAssetsIntoHolding::get(),
 		)
 	}
+
+	fn ensure_for_send(
+		_origin_ref: &MultiLocation,
+		_dest: &MultiLocation,
+		_fee_reason: FeeReason,
+	) -> Option<FeesMode> {
+		// doing nothing
+		None
+	}
 }
 
 impl generic::Config for Test {

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

@@ -22,7 +22,10 @@ use codec::Encode;
 use frame_benchmarking::{account, BenchmarkError};
 use sp_std::prelude::*;
 use xcm::latest::prelude::*;
-use xcm_executor::{traits::ConvertLocation, Config as XcmConfig};
+use xcm_executor::{
+	traits::{ConvertLocation, FeeReason},
+	Config as XcmConfig, FeesMode,
+};
 
 pub mod fungible;
 pub mod generic;
@@ -47,6 +50,14 @@ pub trait Config: frame_system::Config {
 
 	/// Worst case scenario for a holding account in this runtime.
 	fn worst_case_holding(depositable_count: u32) -> MultiAssets;
+
+	/// Prepare all requirements for successful `XcmSender: SendXcm` passing (accounts, balances ...).
+	/// Returns possible `FeesMode` which is expected to be set to executor.
+	fn ensure_for_send(
+		origin_ref: &MultiLocation,
+		dest: &MultiLocation,
+		fee_reason: FeeReason,
+	) -> Option<FeesMode>;
 }
 
 const SEED: u32 = 0;