diff --git a/cumulus/parachains/runtimes/assets/test-utils/src/test_cases_over_bridge.rs b/cumulus/parachains/runtimes/assets/test-utils/src/test_cases_over_bridge.rs
index 905703a9d161b324715ffe08eb6aa338c752b0b0..4a0f31c449ea61d00b04110008d9984e5e87cbd7 100644
--- a/cumulus/parachains/runtimes/assets/test-utils/src/test_cases_over_bridge.rs
+++ b/cumulus/parachains/runtimes/assets/test-utils/src/test_cases_over_bridge.rs
@@ -244,6 +244,11 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
_ => Err(ProcessMessageError::BadFormat),
})
.expect("contains BuyExecution")
+ .match_next_inst(|instr| match instr {
+ SetAppendix(_) => Ok(()),
+ _ => Err(ProcessMessageError::BadFormat),
+ })
+ .expect("contains SetAppendix")
} else {
xcm_sent
.0
diff --git a/cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases/mod.rs b/cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases/mod.rs
index 9b7d28932686b0a59b6c3103cda719bbf58ac347..8d08915bf1fac1d29726b61cb2ddae4f8dd8e739 100644
--- a/cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases/mod.rs
+++ b/cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases/mod.rs
@@ -578,6 +578,10 @@ where
fees: Asset { id: AssetId(Location::new(1, [])), fun: Fungible(34333299) },
weight_limit: Unlimited,
},
+ SetAppendix(Xcm(vec![DepositAsset {
+ assets: Wild(AllCounted(1)),
+ beneficiary: Location::new(1, [Parachain(1000)]),
+ }])),
ExportMessage {
network: Polkadot,
destination: [Parachain(1000)].into(),
@@ -614,7 +618,6 @@ where
]),
]),
},
- DepositAsset { assets: Wild(All), beneficiary: Location::new(1, [Parachain(1000)]) },
SetTopic([
36, 224, 250, 165, 82, 195, 67, 110, 160, 170, 140, 87, 217, 62, 201, 164, 42, 98, 219,
157, 124, 105, 248, 25, 131, 218, 199, 36, 109, 173, 100, 122,
diff --git a/polkadot/xcm/xcm-builder/src/tests/bridging/mod.rs b/polkadot/xcm/xcm-builder/src/tests/bridging/mod.rs
index 11f0044fbcaf1aa36eef7922c1998e09f9edef94..767575e7f2dd9efa29cc1441a8cc2bf2cdaf3d19 100644
--- a/polkadot/xcm/xcm-builder/src/tests/bridging/mod.rs
+++ b/polkadot/xcm/xcm-builder/src/tests/bridging/mod.rs
@@ -33,6 +33,7 @@ mod paid_remote_relay_relay;
mod remote_para_para;
mod remote_para_para_via_relay;
mod remote_relay_relay;
+mod universal_exports;
parameter_types! {
pub Local: NetworkId = ByGenesis([0; 32]);
diff --git a/polkadot/xcm/xcm-builder/src/tests/bridging/paid_remote_relay_relay.rs b/polkadot/xcm/xcm-builder/src/tests/bridging/paid_remote_relay_relay.rs
index 85d6524fb68ea996973edf73f30b25f5e08697bc..f9fa0c18c1f51c6682f8b49be9fe51c613e65350 100644
--- a/polkadot/xcm/xcm-builder/src/tests/bridging/paid_remote_relay_relay.rs
+++ b/polkadot/xcm/xcm-builder/src/tests/bridging/paid_remote_relay_relay.rs
@@ -24,9 +24,9 @@
use super::*;
parameter_types! {
- // 100 to use the bridge (export) and 80 for the remote execution weight (4 instructions x (10 +
+ // 100 to use the bridge (export) and 80 for the remote execution weight (5 instructions x (10 +
// 10) weight each).
- pub SendOverBridgePrice: u128 = 180u128 + if UsingTopic::get() { 20 } else { 0 };
+ pub SendOverBridgePrice: u128 = 200u128 + if UsingTopic::get() { 20 } else { 0 };
pub UniversalLocation: Junctions = [GlobalConsensus(Local::get()), Parachain(100)].into();
pub RelayUniversalLocation: Junctions = [GlobalConsensus(Local::get())].into();
pub RemoteUniversalLocation: Junctions = [GlobalConsensus(Remote::get())].into();
@@ -101,15 +101,18 @@ fn sending_to_bridged_chain_works() {
vec![
WithdrawAsset(Asset::from((Here, price)).into()),
BuyExecution { fees: (Here, price).into(), weight_limit: Unlimited },
+ SetAppendix(Xcm(vec![DepositAsset {
+ assets: Wild(AllCounted(1)),
+ beneficiary: Parachain(100).into(),
+ }])),
ExportMessage {
network: ByGenesis([1; 32]),
destination: Here,
xcm: xcm_with_topic([0; 32], vec![Trap(1)]),
},
- DepositAsset { assets: Wild(All), beneficiary: Parachain(100).into() },
],
),
- outcome: Outcome::Complete { used: test_weight(4) },
+ outcome: Outcome::Complete { used: test_weight(5) },
paid: true,
};
assert_eq!(RoutingLog::take(), vec![entry]);
@@ -175,15 +178,18 @@ fn sending_to_parachain_of_bridged_chain_works() {
vec![
WithdrawAsset(Asset::from((Here, price)).into()),
BuyExecution { fees: (Here, price).into(), weight_limit: Unlimited },
+ SetAppendix(Xcm(vec![DepositAsset {
+ assets: Wild(AllCounted(1)),
+ beneficiary: Parachain(100).into(),
+ }])),
ExportMessage {
network: ByGenesis([1; 32]),
destination: Parachain(100).into(),
xcm: xcm_with_topic([0; 32], vec![Trap(1)]),
},
- DepositAsset { assets: Wild(All), beneficiary: Parachain(100).into() },
],
),
- outcome: Outcome::Complete { used: test_weight(4) },
+ outcome: Outcome::Complete { used: test_weight(5) },
paid: true,
};
assert_eq!(RoutingLog::take(), vec![entry]);
diff --git a/polkadot/xcm/xcm-builder/src/tests/bridging/universal_exports.rs b/polkadot/xcm/xcm-builder/src/tests/bridging/universal_exports.rs
new file mode 100644
index 0000000000000000000000000000000000000000..160c6c9af50fd3b966fa70ac504e674e0fa175e9
--- /dev/null
+++ b/polkadot/xcm/xcm-builder/src/tests/bridging/universal_exports.rs
@@ -0,0 +1,108 @@
+// Copyright (C) Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot. If not, see <http://www.gnu.org/licenses/>.
+
+use super::*;
+use crate::test_utils::TrappedAssets;
+
+#[test]
+fn sovereign_paid_remote_exporter_produces_xcm_which_does_not_trap_assets() {
+ frame_support::parameter_types! {
+ pub BridgeFeeAsset: Location = Parent.into();
+ pub LocalNetwork: NetworkId = ExecutorUniversalLocation::get().global_consensus().expect("valid `NetworkId`");
+ pub LocalBridgeLocation: Location = match &ExecutorUniversalLocation::get().split_global() {
+ Ok((_, junctions)) => Location::new(1, junctions.clone()),
+ _ => panic!("unexpected location format")
+ };
+ pub RemoteNetwork: NetworkId = ByGenesis([1; 32]);
+ pub SendOverBridgePrice: u128 = 333;
+ pub BridgeTable: Vec<NetworkExportTableItem> = vec![
+ NetworkExportTableItem::new(
+ RemoteNetwork::get(),
+ None,
+ LocalBridgeLocation::get(),
+ Some((BridgeFeeAsset::get(), SendOverBridgePrice::get()).into())
+ )
+ ];
+ pub static SenderUniversalLocation: InteriorLocation = (LocalNetwork::get(), Parachain(50)).into();
+ }
+
+ // `SovereignPaidRemoteExporter` e.g. used on sibling of `ExecutorUniversalLocation`
+ type Exporter = SovereignPaidRemoteExporter<
+ NetworkExportTable<BridgeTable>,
+ TestMessageSender,
+ SenderUniversalLocation,
+ >;
+
+ // prepare message on sending chain with tested `Exporter` and translate it to the executor
+ // message type
+ let message = Exporter::validate(
+ &mut Some(Location::new(2, [GlobalConsensus(RemoteNetwork::get())])),
+ &mut Some(Xcm(vec![])),
+ )
+ .expect("valid message");
+ let message = Xcm::<TestCall>::from(message.0 .1);
+ let mut message_id = message.using_encoded(sp_io::hashing::blake2_256);
+
+ // allow origin to pass barrier
+ let origin = Location::new(1, Parachain(50));
+ AllowPaidFrom::set(vec![origin.clone()]);
+
+ // fund origin
+ add_asset(origin.clone(), (AssetId(BridgeFeeAsset::get()), SendOverBridgePrice::get() * 2));
+ WeightPrice::set((BridgeFeeAsset::get().into(), 1_000_000_000_000, 1024 * 1024));
+
+ // check before
+ assert!(TrappedAssets::get().is_empty());
+ assert_eq!(exported_xcm(), vec![]);
+
+ // execute XCM with overrides for `MessageExporter` behavior to return `Unroutable` error on
+ // validate
+ set_exporter_override(
+ |_, _, _, _, _| Err(SendError::Unroutable),
+ |_, _, _, _, _| Err(SendError::Transport("not allowed to call here")),
+ );
+ let r = XcmExecutor::<TestConfig>::prepare_and_execute(
+ origin.clone(),
+ message.clone(),
+ &mut message_id,
+ Weight::from_parts(2_000_000_000_000, 2_000_000_000_000),
+ Weight::zero(),
+ );
+ assert_eq!(
+ r,
+ Outcome::Incomplete { used: Weight::from_parts(50, 50), error: XcmError::Unroutable }
+ );
+ // check empty trapped assets
+ assert!(TrappedAssets::get().is_empty());
+ // no xcm exported
+ assert_eq!(exported_xcm(), vec![]);
+
+ // execute XCM again with clear `MessageExporter` overrides behavior to expect delivery
+ clear_exporter_override();
+ let r = XcmExecutor::<TestConfig>::prepare_and_execute(
+ origin.clone(),
+ message,
+ &mut message_id,
+ Weight::from_parts(2_000_000_000_000, 2_000_000_000_000),
+ Weight::zero(),
+ );
+ assert_eq!(r, Outcome::Complete { used: Weight::from_parts(50, 50) });
+
+ // check empty trapped assets
+ assert!(TrappedAssets::get().is_empty());
+ // xcm exported
+ assert_eq!(exported_xcm().len(), 1);
+}
diff --git a/polkadot/xcm/xcm-builder/src/universal_exports.rs b/polkadot/xcm/xcm-builder/src/universal_exports.rs
index 1d084e022c92e081c42212a69ba43d2e4e4f6d74..6e031cdbc270d73c49fcd7960430473a9bb9c9d5 100644
--- a/polkadot/xcm/xcm-builder/src/universal_exports.rs
+++ b/polkadot/xcm/xcm-builder/src/universal_exports.rs
@@ -305,8 +305,14 @@ impl<Bridges: ExporterFor, Router: SendXcm, UniversalLocation: Get<InteriorLocat
vec![
WithdrawAsset(fees.clone().into()),
BuyExecution { fees, weight_limit: Unlimited },
+ // `SetAppendix` ensures that `fees` are not trapped in any case, for example, when
+ // `ExportXcm::validate` encounters an error during the processing of
+ // `ExportMessage`.
+ SetAppendix(Xcm(vec![DepositAsset {
+ assets: AllCounted(1).into(),
+ beneficiary: local_from_bridge,
+ }])),
export_instruction,
- DepositAsset { assets: All.into(), beneficiary: local_from_bridge },
]
} else {
vec![export_instruction]