feat: democracy - allow TC to remove a vote

pallets/democracy/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "pallet-democracy"
-version = "4.2.1"
+version = "4.3.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2021"
 license = "Apache-2.0"

pallets/democracy/src/lib.rs

@@ -341,6 +341,9 @@ pub mod pallet {
 		/// Hooks are actions that are executed on certain events.
 		/// Eg: on_vote
 		type DemocracyHooks: DemocracyHooks<Self::AccountId, BalanceOf<Self>>;
+
+		/// Origin for anyone able to force remove a vote.
+		type VoteRemovalOrigin: EnsureOrigin<Self::RuntimeOrigin, Success = Self::AccountId>;
 	}
 
 	/// The number of (public) proposals that have been made so far.
@@ -988,7 +991,7 @@ pub mod pallet {
 		#[pallet::weight(T::WeightInfo::remove_vote(T::MaxVotes::get()))]
 		pub fn remove_vote(origin: OriginFor<T>, index: ReferendumIndex) -> DispatchResult {
 			let who = ensure_signed(origin)?;
-			Self::try_remove_vote(&who, index, UnvoteScope::Any)
+			Self::try_remove_vote(&who, index, UnvoteScope::Any, false)
 		}
 
 		/// Remove a vote for a referendum.
@@ -1020,7 +1023,7 @@ pub mod pallet {
 			} else {
 				UnvoteScope::OnlyExpired
 			};
-			Self::try_remove_vote(&target, index, scope)?;
+			Self::try_remove_vote(&target, index, scope, false)?;
 			Ok(())
 		}
 
@@ -1165,6 +1168,38 @@ pub mod pallet {
 			}
 			Ok(())
 		}
+
+		/// Allow to force remove a vote for a referendum.
+		///
+		/// The dispatch origin of this call must be `VoteRemovalOrigin`.
+		///
+		/// Only allowed if the referendum is finished.
+		///
+		/// The dispatch origin of this call must be _Signed_.
+		///
+		/// - `target`: The account of the vote to be removed; this account must have voted for
+		///   referendum `index`.
+		/// - `index`: The index of referendum of the vote to be removed.
+		///
+		/// Weight: `O(R + log R)` where R is the number of referenda that `target` has voted on.
+		///   Weight is calculated for the maximum number of vote.
+		#[pallet::call_index(19)]
+		#[pallet::weight(T::WeightInfo::remove_other_vote(T::MaxVotes::get()))]
+		pub fn force_remove_vote(
+			origin: OriginFor<T>,
+			target: crate::AccountIdLookupOf<T>,
+			index: crate::types::ReferendumIndex,
+		) -> DispatchResult {
+			let who = T::VoteRemovalOrigin::ensure_origin(origin)?;
+			let target = T::Lookup::lookup(target)?;
+			let scope = if target == who {
+				crate::types::UnvoteScope::Any
+			} else {
+				crate::types::UnvoteScope::OnlyExpired
+			};
+			Self::try_remove_vote(&target, index, scope, true)?;
+			Ok(())
+		}
 	}
 }
 
@@ -1332,7 +1367,12 @@ impl<T: Config> Pallet<T> {
 	/// - The referendum has finished and the voter's lock period is up.
 	///
 	/// This will generally be combined with a call to `unlock`.
-	fn try_remove_vote(who: &T::AccountId, ref_index: ReferendumIndex, scope: UnvoteScope) -> DispatchResult {
+	fn try_remove_vote(
+		who: &T::AccountId,
+		ref_index: ReferendumIndex,
+		scope: UnvoteScope,
+		forced: bool,
+	) -> DispatchResult {
 		let info = ReferendumInfoOf::<T>::get(ref_index);
 		VotingOf::<T>::try_mutate(who, |voting| -> DispatchResult {
 			if let Voting::Direct {
@@ -1361,7 +1401,7 @@ impl<T: Config> Pallet<T> {
 								end.saturating_add(T::VoteLockingPeriod::get().saturating_mul(lock_periods.into()));
 							let now = frame_system::Pallet::<T>::block_number();
 							if now < unlock_at {
-								ensure!(matches!(scope, UnvoteScope::Any), Error::<T>::NoPermission);
+								ensure!(forced || matches!(scope, UnvoteScope::Any), Error::<T>::NoPermission);
 								prior.accumulate(unlock_at, balance)
 							}
 						} else {
@@ -1375,7 +1415,7 @@ impl<T: Config> Pallet<T> {
 									);
 									let now = frame_system::Pallet::<T>::block_number();
 									if now < unlock_at {
-										ensure!(matches!(scope, UnvoteScope::Any), Error::<T>::NoPermission);
+										ensure!(forced || matches!(scope, UnvoteScope::Any), Error::<T>::NoPermission);
 										prior.accumulate(unlock_at, to_lock)
 									}
 								}

pallets/democracy/src/tests.rs

@@ -170,6 +170,7 @@ ord_parameter_types! {
 	pub const Four: u64 = 4;
 	pub const Five: u64 = 5;
 	pub const Six: u64 = 6;
+	pub const Seven: u64 = 7;
 }
 pub struct OneToFive;
 impl SortedMembers<u64> for OneToFive {
@@ -211,6 +212,7 @@ impl Config for Test {
 	type MaxProposals = ConstU32<100>;
 	type Preimages = Preimage;
 	type DemocracyHooks = HooksHandler;
+	type VoteRemovalOrigin = EnsureSignedBy<Seven, u64>;
 }
 
 pub fn new_test_ext() -> sp_io::TestExternalities {

pallets/democracy/src/tests/voting.rs

@@ -194,3 +194,61 @@ fn passing_low_turnout_voting_should_work() {
 		assert_eq!(Balances::free_balance(42), 2);
 	});
 }
+
+#[test]
+fn force_remove_vote_should_work() {
+	new_test_ext().execute_with(|| {
+		System::set_block_number(0);
+		assert_ok!(propose_set_balance(1, 2, 1));
+		let r = 0;
+		assert!(Democracy::referendum_info(r).is_none());
+
+		// start of 2 => next referendum scheduled.
+		fast_forward_to(2);
+		assert_ok!(Democracy::vote(RuntimeOrigin::signed(1), r, big_aye(1)));
+
+		assert_eq!(Democracy::referendum_count(), 1);
+		assert_eq!(
+			Democracy::referendum_status(0),
+			Ok(ReferendumStatus {
+				end: 4,
+				proposal: set_balance_proposal(2),
+				threshold: VoteThreshold::SuperMajorityApprove,
+				delay: 2,
+				tally: Tally {
+					ayes: 10,
+					nays: 0,
+					turnout: 10
+				},
+			})
+		);
+
+		fast_forward_to(3);
+
+		// referendum still running
+		assert_ok!(Democracy::referendum_status(0));
+
+		// not allowed to force remove a vote when referendum is ongoing
+		assert_noop!(
+			Democracy::force_remove_vote(RuntimeOrigin::signed(7), 1, 0),
+			Error::<Test>::NoPermission
+		);
+
+		// referendum runs during 2 and 3, ends @ start of 4.
+		fast_forward_to(4);
+
+		assert_noop!(Democracy::referendum_status(0), Error::<Test>::ReferendumInvalid);
+		assert!(pallet_scheduler::Agenda::<Test>::get(6)[0].is_some());
+
+		// referendum passes and wait another two blocks for enactment.
+		fast_forward_to(6);
+
+		assert_eq!(Balances::free_balance(42), 2);
+
+		// Not allowed origin
+		assert_noop!(Democracy::force_remove_vote(RuntimeOrigin::signed(4), 1, 0), BadOrigin);
+
+		// Allowed origin
+		assert_ok!(Democracy::force_remove_vote(RuntimeOrigin::signed(7), 1, 0));
+	});
+}

runtime/hydradx/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "hydradx-runtime"
-version = "245.0.0"
+version = "246.0.0"
 authors = ["GalacticCouncil"]
 edition = "2021"
 license = "Apache 2.0"

runtime/hydradx/src/governance.rs

@@ -334,6 +334,8 @@ impl pallet_democracy::Config for Runtime {
 	type PalletsOrigin = OriginCaller;
 	type Slash = Treasury;
 	type DemocracyHooks = pallet_staking::integrations::democracy::StakingDemocracy<Runtime>;
+	// Any single technical committee member may remove a vote.
+	type VoteRemovalOrigin = frame_system::EnsureSignedBy<TechCommAccounts, AccountId>;
 }
 
 parameter_types! {

runtime/hydradx/src/lib.rs

@@ -113,7 +113,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	spec_name: create_runtime_str!("hydradx"),
 	impl_name: create_runtime_str!("hydradx"),
 	authoring_version: 1,
-	spec_version: 245,
+	spec_version: 246,
 	impl_version: 0,
 	apis: RUNTIME_API_VERSIONS,
 	transaction_version: 1,