From ddc8eca8bca651377e724cf8cc5fb098bea2e334 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89lo=C3=AFs?= <c@elo.tf>
Date: Tue, 27 Aug 2024 13:11:56 +0200
Subject: [PATCH] fix: pallet-emergency para-xcm should not wrap
 XcmpMessageHandler (#53)

---
 pallets/emergency-para-xcm/src/lib.rs   | 27 ++++---------------------
 pallets/emergency-para-xcm/src/mock.rs  |  3 +--
 pallets/emergency-para-xcm/src/tests.rs | 19 -----------------
 3 files changed, 5 insertions(+), 44 deletions(-)

diff --git a/pallets/emergency-para-xcm/src/lib.rs b/pallets/emergency-para-xcm/src/lib.rs
index 0a113d6..7230e1b 100644
--- a/pallets/emergency-para-xcm/src/lib.rs
+++ b/pallets/emergency-para-xcm/src/lib.rs
@@ -33,7 +33,7 @@
 //! In particular:
 //! * `CheckAssociatedRelayNumber` is used to check the relay chain block diff and
 //!    enter emergency mode when appropriate.
-//! * `QueuePausedQuery` and `XcmpMessageHandler` are used to pause XCM execution
+//! * `QueuePausedQuery` is used to pause XCM execution
 
 #![allow(non_camel_case_types)]
 #![cfg_attr(not(feature = "std"), no_std)]
@@ -52,7 +52,7 @@ use frame_support::traits::{ProcessMessage, QueuePausedQuery};
 use frame_system::pallet_prelude::*;
 use frame_system::{RawOrigin, WeightInfo};
 use parity_scale_codec::{Decode, Encode};
-use polkadot_parachain_primitives::primitives::{Id, RelayChainBlockNumber, XcmpMessageHandler};
+use polkadot_parachain_primitives::primitives::RelayChainBlockNumber;
 
 #[derive(Decode, Default, Encode, PartialEq, TypeInfo)]
 /// XCM Execution mode
@@ -77,10 +77,8 @@ pub mod pallet {
 	#[pallet::config]
 	pub trait Config:
 		frame_system::Config
-		+ cumulus_pallet_parachain_system::Config<
-			CheckAssociatedRelayNumber = Pallet<Self>,
-			XcmpMessageHandler = Pallet<Self>,
-		> + pallet_message_queue::Config<QueuePausedQuery = Pallet<Self>>
+		+ cumulus_pallet_parachain_system::Config<CheckAssociatedRelayNumber = Pallet<Self>>
+		+ pallet_message_queue::Config<QueuePausedQuery = Pallet<Self>>
 	{
 		/// Overarching event type
 		type RuntimeEvent: From<Event> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
@@ -93,9 +91,6 @@ pub mod pallet {
 		/// what would be passed to `pallet_message_queue` if this pallet was not being used.
 		type QueuePausedQuery: QueuePausedQuery<<Self::MessageProcessor as ProcessMessage>::Origin>;
 
-		/// The XCMP handler to be used in normal operating mode
-		type XcmpMessageHandler: XcmpMessageHandler;
-
 		/// Maximum number of relay block to skip before trigering the Paused mode.
 		type PausedThreshold: Get<RelayChainBlockNumber>;
 
@@ -183,20 +178,6 @@ impl<T: Config> CheckAssociatedRelayNumber for Pallet<T> {
 	}
 }
 
-impl<T: Config> XcmpMessageHandler for Pallet<T> {
-	fn handle_xcmp_messages<'a, I: Iterator<Item = (Id, RelayChainBlockNumber, &'a [u8])>>(
-		iter: I,
-		limit: Weight,
-	) -> Weight {
-		match Mode::<T>::get() {
-			XcmMode::Normal => <T as Config>::XcmpMessageHandler::handle_xcmp_messages(iter, limit),
-			XcmMode::Paused => {
-				<T as Config>::XcmpMessageHandler::handle_xcmp_messages(iter, Weight::zero())
-			}
-		}
-	}
-}
-
 impl<T> QueuePausedQuery<<T::MessageProcessor as ProcessMessage>::Origin> for Pallet<T>
 where
 	T: Config,
diff --git a/pallets/emergency-para-xcm/src/mock.rs b/pallets/emergency-para-xcm/src/mock.rs
index 7c4c029..f742961 100644
--- a/pallets/emergency-para-xcm/src/mock.rs
+++ b/pallets/emergency-para-xcm/src/mock.rs
@@ -89,7 +89,7 @@ impl cumulus_pallet_parachain_system::Config for Test {
 	type SelfParaId = ParachainId;
 	type OnSystemEvent = ();
 	type OutboundXcmpMessageSource = ();
-	type XcmpMessageHandler = EmergencyParaXcm;
+	type XcmpMessageHandler = JustConsumeAllWeight;
 	type ReservedXcmpWeight = ();
 	type DmpQueue = frame_support::traits::EnqueueWithOrigin<MessageQueue, RelayOrigin>;
 	type ReservedDmpWeight = ();
@@ -124,7 +124,6 @@ impl Config for Test {
 	type RuntimeEvent = RuntimeEvent;
 	type CheckAssociatedRelayNumber = cumulus_pallet_parachain_system::AnyRelayNumber;
 	type QueuePausedQuery = ();
-	type XcmpMessageHandler = JustConsumeAllWeight;
 	type PausedThreshold = ConstU32<PAUSED_THRESHOLD>;
 	type FastAuthorizeUpgradeOrigin = EnsureRoot<AccountId>;
 	type PausedToNormalOrigin = EnsureRoot<AccountId>;
diff --git a/pallets/emergency-para-xcm/src/tests.rs b/pallets/emergency-para-xcm/src/tests.rs
index d80bbbf..d013493 100644
--- a/pallets/emergency-para-xcm/src/tests.rs
+++ b/pallets/emergency-para-xcm/src/tests.rs
@@ -106,25 +106,6 @@ fn pauses_queue_on_paused_mode() {
 	});
 }
 
-#[test]
-fn uses_all_xcmp_weight_on_normal_mode() {
-	new_test_ext().execute_with(|| {
-		let msgs = vec![(100.into(), 1, [8_u8].as_slice())];
-		let assigned_weight = EmergencyParaXcm::handle_xcmp_messages(msgs.into_iter(), Weight::MAX);
-		assert_eq!(assigned_weight, Weight::MAX);
-	});
-}
-
-#[test]
-fn uses_no_xcmp_weight_on_paused_mode() {
-	new_test_ext().execute_with(|| {
-		Mode::<Test>::set(XcmMode::Paused);
-		let msgs = vec![(100.into(), 1, [8_u8].as_slice())];
-		let assigned_weight = EmergencyParaXcm::handle_xcmp_messages(msgs.into_iter(), Weight::MAX);
-		assert_eq!(assigned_weight, Weight::zero());
-	});
-}
-
 #[test]
 fn cannot_authorize_upgrade_with_wrong_origin() {
 	new_test_ext().execute_with(|| {