Some late fixes for XCMv3

xcm/pallet-xcm/src/lib.rs

@@ -1340,7 +1340,7 @@ impl<T: Config> Pallet<T> {
 		let responder = responder.into();
 		let destination = T::UniversalLocation::get()
 			.invert_target(&responder)
-			.map_err(|()| XcmError::MultiLocationNotInvertible)?;
+			.map_err(|()| XcmError::LocationNotInvertible)?;
 		let query_id = Self::new_query(responder, timeout, Here);
 		let response_info = QueryResponseInfo { destination, query_id, max_weight: 0 };
 		let report_error = Xcm(vec![ReportError(response_info)]);
@@ -1379,7 +1379,7 @@ impl<T: Config> Pallet<T> {
 		let responder = responder.into();
 		let destination = T::UniversalLocation::get()
 			.invert_target(&responder)
-			.map_err(|()| XcmError::MultiLocationNotInvertible)?;
+			.map_err(|()| XcmError::LocationNotInvertible)?;
 		let notify: <T as Config>::Call = notify.into();
 		let max_weight = notify.get_dispatch_info().weight;
 		let query_id = Self::new_notify_query(responder, notify, timeout, Here);

xcm/src/v2/traits.rs

@@ -120,8 +120,8 @@ impl TryFrom<NewError> for Error {
 			Unimplemented => Self::Unimplemented,
 			UntrustedReserveLocation => Self::UntrustedReserveLocation,
 			UntrustedTeleportLocation => Self::UntrustedTeleportLocation,
-			MultiLocationFull => Self::MultiLocationFull,
-			MultiLocationNotInvertible => Self::MultiLocationNotInvertible,
+			LocationFull => Self::MultiLocationFull,
+			LocationNotInvertible => Self::MultiLocationNotInvertible,
 			BadOrigin => Self::BadOrigin,
 			InvalidLocation => Self::InvalidLocation,
 			AssetNotFound => Self::AssetNotFound,

xcm/src/v3/junctions.rs

@@ -221,6 +221,36 @@ impl Junctions {
 		}
 	}
 
+	/// Extract the network ID and the interior consensus location, treating this value as a
+	/// universal location.
+	///
+	/// This will return an `Err` if the first item is not a `GlobalConsensus`, which would indicate
+	/// that this value is not a universal location.
+	pub fn split_global(self) -> Result<(NetworkId, Junctions), ()> {
+		match self.clone().split_first() {
+			(location, Some(Junction::GlobalConsensus(network))) => Ok((network, location)),
+			_ => return Err(()),
+		}
+	}
+
+	/// Treat `self` as a universal location and the context of `relative`, returning the universal
+	/// location of relative.
+	///
+	/// This will return an error if `relative` has as many (or more) parents than there are
+	/// junctions in `self`, implying that relative refers into a different global consensus.
+	pub fn within_global(mut self, relative: MultiLocation) -> Result<Self, ()> {
+		if self.len() <= relative.parents as usize {
+			return Err(())
+		}
+		for _ in 0..relative.parents {
+			self.take_last();
+		}
+		for j in relative.interior {
+			self.push(j).map_err(|_| ())?;
+		}
+		Ok(self)
+	}
+
 	/// Consumes `self` and returns how `viewer` would address it locally.
 	pub fn relative_to(mut self, viewer: &Junctions) -> MultiLocation {
 		let mut i = 0;

xcm/src/v3/traits.rs

@@ -41,10 +41,10 @@ pub enum Error {
 	UntrustedTeleportLocation,
 	/// `MultiLocation` value too large to descend further.
 	#[codec(index = 4)]
-	MultiLocationFull,
+	LocationFull,
 	/// `MultiLocation` value ascend more parents than known ancestors of local location.
 	#[codec(index = 5)]
-	MultiLocationNotInvertible,
+	LocationNotInvertible,
 	/// The Origin Register does not contain a valid value for instruction.
 	#[codec(index = 6)]
 	BadOrigin,
@@ -126,6 +126,9 @@ pub enum Error {
 	/// The state was not in a condition where the operation was valid to make.
 	#[codec(index = 32)]
 	NoPermission,
+	/// The universal location of the local consensus is improper.
+	#[codec(index = 33)]
+	Unanchored,
 
 	// Errors that happen prior to instructions being executed. These fall outside of the XCM spec.
 	/// XCM version not able to be handled.
@@ -161,8 +164,8 @@ impl TryFrom<OldError> for Error {
 			Unimplemented => Self::Unimplemented,
 			UntrustedReserveLocation => Self::UntrustedReserveLocation,
 			UntrustedTeleportLocation => Self::UntrustedTeleportLocation,
-			MultiLocationFull => Self::MultiLocationFull,
-			MultiLocationNotInvertible => Self::MultiLocationNotInvertible,
+			MultiLocationFull => Self::LocationFull,
+			MultiLocationNotInvertible => Self::LocationNotInvertible,
 			BadOrigin => Self::BadOrigin,
 			InvalidLocation => Self::InvalidLocation,
 			AssetNotFound => Self::AssetNotFound,

xcm/xcm-builder/src/tests/bridging/mod.rs

@@ -89,19 +89,21 @@ struct UnpaidExecutingRouter<Local, Remote, RemoteExporter>(
 fn price<RemoteExporter: ExportXcm>(
 	n: NetworkId,
 	c: u32,
+	s: &InteriorMultiLocation,
 	d: &InteriorMultiLocation,
 	m: &Xcm<()>,
 ) -> Result<MultiAssets, SendError> {
-	Ok(validate_export::<RemoteExporter>(n, c, d.clone(), m.clone())?.1)
+	Ok(validate_export::<RemoteExporter>(n, c, s.clone(), d.clone(), m.clone())?.1)
 }
 
 fn deliver<RemoteExporter: ExportXcm>(
 	n: NetworkId,
 	c: u32,
+	s: InteriorMultiLocation,
 	d: InteriorMultiLocation,
 	m: Xcm<()>,
 ) -> Result<XcmHash, SendError> {
-	export_xcm::<RemoteExporter>(n, c, d, m).map(|(hash, _)| hash)
+	export_xcm::<RemoteExporter>(n, c, s, d, m).map(|(hash, _)| hash)
 }
 
 impl<Local: Get<Junctions>, Remote: Get<Junctions>, RemoteExporter: ExportXcm> SendXcm

xcm/xcm-builder/src/tests/mock.rs

@@ -107,10 +107,24 @@ impl GetDispatchInfo for TestCall {
 
 thread_local! {
 	pub static SENT_XCM: RefCell<Vec<(MultiLocation, Xcm<()>, XcmHash)>> = RefCell::new(Vec::new());
-	pub static EXPORTED_XCM: RefCell<Vec<(NetworkId, u32, InteriorMultiLocation, Xcm<()>, XcmHash)>> = RefCell::new(Vec::new());
+	pub static EXPORTED_XCM: RefCell<
+		Vec<(NetworkId, u32, InteriorMultiLocation, InteriorMultiLocation, Xcm<()>, XcmHash)>
+	> = RefCell::new(Vec::new());
 	pub static EXPORTER_OVERRIDE: RefCell<Option<(
-		fn(NetworkId, u32, &InteriorMultiLocation, &Xcm<()>) -> Result<MultiAssets, SendError>,
-		fn(NetworkId, u32, InteriorMultiLocation, Xcm<()>) -> Result<XcmHash, SendError>,
+		fn(
+			NetworkId,
+			u32,
+			&InteriorMultiLocation,
+			&InteriorMultiLocation,
+			&Xcm<()>,
+		) -> Result<MultiAssets, SendError>,
+		fn(
+			NetworkId,
+			u32,
+			InteriorMultiLocation,
+			InteriorMultiLocation,
+			Xcm<()>,
+		) -> Result<XcmHash, SendError>,
 	)>> = RefCell::new(None);
 	pub static SEND_PRICE: RefCell<MultiAssets> = RefCell::new(MultiAssets::new());
 }
@@ -120,12 +134,25 @@ pub fn sent_xcm() -> Vec<(MultiLocation, opaque::Xcm, XcmHash)> {
 pub fn set_send_price(p: impl Into<MultiAsset>) {
 	SEND_PRICE.with(|l| l.replace(p.into().into()));
 }
-pub fn exported_xcm() -> Vec<(NetworkId, u32, InteriorMultiLocation, opaque::Xcm, XcmHash)> {
+pub fn exported_xcm(
+) -> Vec<(NetworkId, u32, InteriorMultiLocation, InteriorMultiLocation, opaque::Xcm, XcmHash)> {
 	EXPORTED_XCM.with(|q| (*q.borrow()).clone())
 }
 pub fn set_exporter_override(
-	price: fn(NetworkId, u32, &InteriorMultiLocation, &Xcm<()>) -> Result<MultiAssets, SendError>,
-	deliver: fn(NetworkId, u32, InteriorMultiLocation, Xcm<()>) -> Result<XcmHash, SendError>,
+	price: fn(
+		NetworkId,
+		u32,
+		&InteriorMultiLocation,
+		&InteriorMultiLocation,
+		&Xcm<()>,
+	) -> Result<MultiAssets, SendError>,
+	deliver: fn(
+		NetworkId,
+		u32,
+		InteriorMultiLocation,
+		InteriorMultiLocation,
+		Xcm<()>,
+	) -> Result<XcmHash, SendError>,
 ) {
 	EXPORTER_OVERRIDE.with(|x| x.replace(Some((price, deliver))));
 }
@@ -153,40 +180,43 @@ impl SendXcm for TestMessageSender {
 }
 pub struct TestMessageExporter;
 impl ExportXcm for TestMessageExporter {
-	type Ticket = (NetworkId, u32, InteriorMultiLocation, Xcm<()>, XcmHash);
+	type Ticket = (NetworkId, u32, InteriorMultiLocation, InteriorMultiLocation, Xcm<()>, XcmHash);
 	fn validate(
 		network: NetworkId,
 		channel: u32,
+		uni_src: &mut Option<InteriorMultiLocation>,
 		dest: &mut Option<InteriorMultiLocation>,
 		msg: &mut Option<Xcm<()>>,
-	) -> SendResult<(NetworkId, u32, InteriorMultiLocation, Xcm<()>, XcmHash)> {
-		let (d, m) = (dest.take().unwrap(), msg.take().unwrap());
+	) -> SendResult<(NetworkId, u32, InteriorMultiLocation, InteriorMultiLocation, Xcm<()>, XcmHash)>
+	{
+		let (s, d, m) = (uni_src.take().unwrap(), dest.take().unwrap(), msg.take().unwrap());
 		let r: Result<MultiAssets, SendError> = EXPORTER_OVERRIDE.with(|e| {
 			if let Some((ref f, _)) = &*e.borrow() {
-				f(network, channel, &d, &m)
+				f(network, channel, &s, &d, &m)
 			} else {
 				Ok(MultiAssets::new())
 			}
 		});
 		let h = fake_message_hash(&m);
 		match r {
-			Ok(price) => Ok(((network, channel, d, m, h), price)),
+			Ok(price) => Ok(((network, channel, s, d, m, h), price)),
 			Err(e) => {
+				*uni_src = Some(s);
 				*dest = Some(d);
 				*msg = Some(m);
 				Err(e)
 			},
 		}
 	}
 	fn deliver(
-		tuple: (NetworkId, u32, InteriorMultiLocation, Xcm<()>, XcmHash),
+		tuple: (NetworkId, u32, InteriorMultiLocation, InteriorMultiLocation, Xcm<()>, XcmHash),
 	) -> Result<XcmHash, SendError> {
 		EXPORTER_OVERRIDE.with(|e| {
 			if let Some((_, ref f)) = &*e.borrow() {
-				let (network, channel, dest, msg, _hash) = tuple;
-				f(network, channel, dest, msg)
+				let (network, channel, uni_src, dest, msg, _hash) = tuple;
+				f(network, channel, uni_src, dest, msg)
 			} else {
-				let hash = tuple.4;
+				let hash = tuple.5;
 				EXPORTED_XCM.with(|q| q.borrow_mut().push(tuple));
 				Ok(hash)
 			}

xcm/xcm-builder/src/tests/origins.rs

@@ -71,5 +71,9 @@ fn export_message_should_work() {
 	let hash = fake_message_hash(&message);
 	let r = XcmExecutor::<TestConfig>::execute_xcm(Parachain(1), message, hash, 50);
 	assert_eq!(r, Outcome::Complete(10));
-	assert_eq!(exported_xcm(), vec![(Polkadot, 403611790, Here, expected_message, expected_hash)]);
+	let uni_src = (ByGenesis([0; 32]), Parachain(42), Parachain(1)).into();
+	assert_eq!(
+		exported_xcm(),
+		vec![(Polkadot, 403611790, uni_src, Here, expected_message, expected_hash)]
+	);
 }