Nits

polkadot/runtime/common/src/xcm_sender.rs

@@ -150,7 +150,7 @@ impl<
 		origin_ref: &MultiLocation,
 		_dest: &MultiLocation,
 		fee_reason: xcm_executor::traits::FeeReason,
-	) -> Option<xcm_executor::FeesMode> {
+	) -> (Option<xcm_executor::FeesMode>, Option<MultiAssets>) {
 		use xcm_executor::{
 			traits::{FeeManager, TransactAsset},
 			FeesMode,
@@ -180,10 +180,10 @@ impl<
 			// allow more initialization for target parachain
 			ToParachainHelper::ensure(Parachain::get());
 
-			// expected worst case
+			// expected worst case - direct withdraw
 			fees_mode = Some(FeesMode { jit_withdraw: true });
 		}
-		fees_mode
+		(fees_mode, None)
 	}
 }
 

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

@@ -88,7 +88,11 @@ benchmarks_instance_pallet! {
 		let dest_account = T::AccountIdConverter::convert_location(&dest_location).unwrap();
 
 		use crate::EnsureDelivery;
-		let expected_fees_mode = T::DeliveryHelper::ensure_successful_delivery(&sender_location, &dest_location, FeeReason::TransferReserveAsset);
+		let (expected_fees_mode, expected_assets_in_holding) = T::DeliveryHelper::ensure_successful_delivery(
+			&sender_location,
+			&dest_location,
+			FeeReason::TransferReserveAsset
+		);
 		let sender_account_balance_before = T::TransactAsset::balance(&sender_account);
 
 		let asset = T::get_multi_asset();
@@ -101,6 +105,10 @@ benchmarks_instance_pallet! {
 		if let Some(expected_fees_mode) = expected_fees_mode {
 			executor.set_fees_mode(expected_fees_mode);
 		}
+		if let Some(expected_assets_in_holding) = expected_assets_in_holding {
+			executor.set_holding(expected_assets_in_holding.into());
+		}
+
 		let instruction = Instruction::TransferReserveAsset {
 			assets,
 			dest: dest_location,

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

@@ -119,12 +119,14 @@ pub fn account_and_location<T: Config>(index: u32) -> (T::AccountId, MultiLocati
 /// layers.
 pub trait EnsureDelivery {
 	/// Prepare all requirements for successful `XcmSender: SendXcm` passing (accounts, balances,
-	/// channels ...). Returns possible `FeesMode` which is expected to be set to executor.
+	/// channels ...). Returns:
+	/// - possible `FeesMode` which is expected to be set to executor
+	/// - possible `MultiAssets` which are expected to be subsume to the Holding Register
 	fn ensure_successful_delivery(
 		origin_ref: &MultiLocation,
 		dest: &MultiLocation,
 		fee_reason: FeeReason,
-	) -> Option<FeesMode>;
+	) -> (Option<FeesMode>, Option<MultiAssets>);
 }
 
 /// `()` implementation does nothing which means no special requirements for environment.
@@ -133,8 +135,8 @@ impl EnsureDelivery for () {
 		_origin_ref: &MultiLocation,
 		_dest: &MultiLocation,
 		_fee_reason: FeeReason,
-	) -> Option<FeesMode> {
+	) -> (Option<FeesMode>, Option<MultiAssets>) {
 		// doing nothing
-		None
+		(None, None)
 	}
 }

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

@@ -546,7 +546,7 @@ fn reserve_transfer_assets_with_paid_router_works() {
 		assert_ok!(XcmPallet::reserve_transfer_assets(
 			RuntimeOrigin::signed(user_account.clone()),
 			Box::new(Parachain(paid_para_id).into()),
-			Box::new(dest.clone().into()),
+			Box::new(dest.into()),
 			Box::new((Here, SEND_AMOUNT).into()),
 			0,
 		));