Fix for wrong core location when dest is relay

pallet-rings/src/lib.rs

@@ -117,7 +117,7 @@ pub mod pallet {
             origin_chain_asset: <<T as pallet::Config>::Chains as ChainList>::ChainAssets,
             amount: u128,
             from: <T as pallet_inv4::Config>::CoreId,
-            to: <T as frame_system::Config>::AccountId,
+            to: Option<<T as frame_system::Config>::AccountId>,
         },
 
         /// A Chain's maintenance status changed.
@@ -201,14 +201,16 @@ pub mod pallet {
 
             let fee_asset_location = fee_asset.get_asset_location();
 
-            let beneficiary: MultiLocation = MultiLocation {
+            let mut core_multilocation: MultiLocation = MultiLocation {
                 parents: 1,
                 interior: Junctions::X2(
                     Junction::Parachain(<T as pallet_inv4::Config>::ParaId::get()),
                     descend_interior,
                 ),
             };
 
+            mutate_if_relay(&mut core_multilocation, &dest);
+
             let fee_multiasset = MultiAsset {
                 id: AssetId::Concrete(fee_asset_location),
                 fun: Fungibility::Fungible(fee),
@@ -228,7 +230,7 @@ pub mod pallet {
                 Instruction::RefundSurplus,
                 Instruction::DepositAsset {
                     assets: MultiAssetFilter::Wild(WildMultiAsset::AllCounted(1)),
-                    beneficiary,
+                    beneficiary: core_multilocation,
                 },
             ]);
 
@@ -298,14 +300,16 @@ pub mod pallet {
                 }),
             };
 
-            let core_multilocation: MultiLocation = MultiLocation {
+            let mut core_multilocation: MultiLocation = MultiLocation {
                 parents: 1,
                 interior: Junctions::X2(
                     Junction::Parachain(<T as pallet_inv4::Config>::ParaId::get()),
                     descend_interior,
                 ),
             };
 
+            mutate_if_relay(&mut core_multilocation, &dest);
+
             let fee_multiasset = MultiAsset {
                 id: AssetId::Concrete(fee_asset.get_asset_location()),
                 fun: Fungibility::Fungible(fee),
@@ -367,7 +371,6 @@ pub mod pallet {
             let core = ensure_multisig::<T, OriginFor<T>>(origin)?;
 
             let core_id = core.id.into();
-            let core_account = core.to_account_id();
 
             let from_chain = asset.get_chain();
             let from_chain_location = from_chain.get_location();
@@ -421,7 +424,7 @@ pub mod pallet {
                 })
                 .map_err(|_| Error::<T>::FailedToReanchorAsset)?;
 
-            let core_multilocation: MultiLocation = MultiLocation {
+            let mut core_multilocation: MultiLocation = MultiLocation {
                 parents: 1,
                 interior: Junctions::X2(
                     Junction::Parachain(<T as pallet_inv4::Config>::ParaId::get()),
@@ -437,9 +440,17 @@ pub mod pallet {
                         id: to_inner.into(),
                     }),
                 },
-                None => core_multilocation,
+                None => {
+                    let mut dest_core_multilocation = core_multilocation;
+
+                    mutate_if_relay(&mut dest_core_multilocation, &dest);
+
+                    dest_core_multilocation
+                }
             };
 
+            mutate_if_relay(&mut core_multilocation, &dest);
+
             // If the asset originates from the destination chain, we need to reverse the reserve-transfer.
             let message = if asset_location.starts_with(&dest) {
                 Xcm(vec![
@@ -516,10 +527,16 @@ pub mod pallet {
                 origin_chain_asset: asset,
                 from: core.id,
                 amount,
-                to: to.unwrap_or(core_account),
+                to,
             });
 
             Ok(())
         }
     }
+
+    pub fn mutate_if_relay(origin: &mut MultiLocation, dest: &MultiLocation) {
+        if dest.contains_parents_only(1) {
+            origin.dec_parent();
+        }
+    }
 }

pallet-rings/src/tests/mock.rs

@@ -476,6 +476,7 @@ impl pallet::Config for Test {
 
 #[derive(Encode, Decode, Clone, Eq, PartialEq, MaxEncodedLen, Debug, TypeInfo)]
 pub enum Chains {
+    Relay,
     ChainA,
     ChainB,
 }
@@ -488,6 +489,7 @@ pub enum Assets {
 
 #[derive(Encode, Decode, Clone, Eq, PartialEq, MaxEncodedLen, Debug, TypeInfo)]
 pub enum ChainAssets {
+    Relay(Assets),
     ChainA(Assets),
     ChainB(Assets),
 }
@@ -499,6 +501,7 @@ impl ChainAssetsList for ChainAssets {
         match self {
             Self::ChainA(_) => Chains::ChainA,
             Self::ChainB(_) => Chains::ChainB,
+            Self::Relay(_) => Chains::Relay,
         }
     }
 
@@ -507,6 +510,7 @@ impl ChainAssetsList for ChainAssets {
             match self {
                 Self::ChainA(asset) => asset,
                 Self::ChainB(asset) => asset,
+                Self::Relay(asset) => asset,
             }
         } {
             Assets::AssetA => MultiLocation {
@@ -536,13 +540,18 @@ impl ChainList for Chains {
                 parents: 1,
                 interior: Junctions::X1(Junction::Parachain(2345)),
             },
+            Self::Relay => MultiLocation {
+                parents: 1,
+                interior: Junctions::Here,
+            },
         }
     }
 
     fn get_main_asset(&self) -> Self::ChainAssets {
         match self {
             Self::ChainA => ChainAssets::ChainA(Assets::AssetA),
             Self::ChainB => ChainAssets::ChainB(Assets::AssetB),
+            Self::Relay => ChainAssets::Relay(Assets::AssetA),
         }
     }
 }

pallet-rings/src/tests/mod.rs

@@ -6,7 +6,7 @@ use frame_system::RawOrigin;
 use mock::*;
 use pallet_inv4::{origin::MultisigInternalOrigin, Origin};
 use sp_std::vec;
-use xcm::latest::Weight;
+use xcm::latest::{BodyId, BodyPart, Junction, Junctions, MultiLocation, Weight};
 
 #[test]
 fn set_maintenance_status() {
@@ -239,3 +239,52 @@ fn bridge_assets_fails() {
         );
     })
 }
+
+#[test]
+fn mutate_location_if_dest_is_relay() {
+    let relay_dest = Chains::Relay.get_location();
+    let para_dest = Chains::ChainA.get_location();
+
+    let mut core_multilocation = MultiLocation {
+        parents: 1,
+        interior: Junctions::X2(
+            Junction::Parachain(2125),
+            Junction::Plurality {
+                id: BodyId::Index(0),
+                part: BodyPart::Voice,
+            },
+        ),
+    };
+
+    crate::pallet::mutate_if_relay(&mut core_multilocation, &para_dest);
+
+    assert_eq!(
+        core_multilocation,
+        MultiLocation {
+            parents: 1,
+            interior: Junctions::X2(
+                Junction::Parachain(2125),
+                Junction::Plurality {
+                    id: BodyId::Index(0),
+                    part: BodyPart::Voice,
+                }
+            )
+        }
+    );
+
+    crate::pallet::mutate_if_relay(&mut core_multilocation, &relay_dest);
+
+    assert_eq!(
+        core_multilocation,
+        MultiLocation {
+            parents: 0,
+            interior: Junctions::X2(
+                Junction::Parachain(2125),
+                Junction::Plurality {
+                    id: BodyId::Index(0),
+                    part: BodyPart::Voice,
+                }
+            )
+        }
+    );
+}