Fix Society v2 migration

frame/society/Cargo.toml

@@ -24,7 +24,7 @@ sp-io = { version = "23.0.0", default-features = false, path = "../../primitives
 sp-arithmetic = { version = "16.0.0", default-features = false, path = "../../primitives/arithmetic" }
 sp-runtime = { version = "24.0.0", default-features = false, path = "../../primitives/runtime" }
 frame-benchmarking = { version = "4.0.0-dev", default-features = false, optional = true, path = "../benchmarking" }
-frame-support = { version = "4.0.0-dev", default-features = false, path = "../support" }
+frame-support = { version = "4.0.0-dev", default-features = false, path = "../support", features=["experimental"] }
 frame-system = { version = "4.0.0-dev", default-features = false, path = "../system" }
 
 [dev-dependencies]

frame/society/src/lib.rs

@@ -466,12 +466,12 @@ pub struct GroupParams<Balance> {
 
 pub type GroupParamsFor<T, I> = GroupParams<BalanceOf<T, I>>;
 
+pub(crate) const STORAGE_VERSION: StorageVersion = StorageVersion::new(2);
+
 #[frame_support::pallet]
 pub mod pallet {
 	use super::*;
 
-	const STORAGE_VERSION: StorageVersion = StorageVersion::new(2);
-
 	#[pallet::pallet]
 	#[pallet::storage_version(STORAGE_VERSION)]
 	#[pallet::without_storage_info]
@@ -1681,8 +1681,8 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 		bids.iter().any(|bid| bid.who == *who)
 	}
 
-	/// Add a member to the sorted members list. If the user is already a member, do nothing.
-	/// Can fail when `MaxMember` limit is reached, but in that case it has no side-effects.
+	/// Add a member to the members list. If the user is already a member, do nothing. Can fail when
+	/// `MaxMember` limit is reached, but in that case it has no side-effects.
 	///
 	/// Set the `payouts` for the member. NOTE: This *WILL NOT RESERVE THE FUNDS TO MAKE THE
 	/// PAYOUT*. Only set this to be non-empty if you already have the funds reserved in the Payouts
@@ -1703,7 +1703,7 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 		Ok(())
 	}
 
-	/// Add a member back to the sorted members list, setting their `rank` and `payouts`.
+	/// Add a member back to the members list, setting their `rank` and `payouts`.
 	///
 	/// Can fail when `MaxMember` limit is reached, but in that case it has no side-effects.
 	///
@@ -1713,8 +1713,8 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 		Self::insert_member(who, rank)
 	}
 
-	/// Add a member to the sorted members list. If the user is already a member, do nothing.
-	/// Can fail when `MaxMember` limit is reached, but in that case it has no side-effects.
+	/// Add a member to the members list. If the user is already a member, do nothing. Can fail when
+	/// `MaxMember` limit is reached, but in that case it has no side-effects.
 	fn add_new_member(who: &T::AccountId, rank: Rank) -> DispatchResult {
 		Self::insert_member(who, rank)
 	}

frame/society/src/migrations.rs

@@ -19,7 +19,10 @@
 
 use super::*;
 use codec::{Decode, Encode};
-use frame_support::traits::{Instance, OnRuntimeUpgrade};
+use frame_support::{
+	migrations::VersionedRuntimeUpgrade,
+	traits::{Instance, OnRuntimeUpgrade},
+};
 
 #[cfg(feature = "try-runtime")]
 use sp_runtime::TryRuntimeError;
@@ -28,15 +31,15 @@ use sp_runtime::TryRuntimeError;
 const TARGET: &'static str = "runtime::society::migration";
 
 /// This migration moves all the state to v2 of Society.
-pub struct MigrateToV2<T: Config<I>, I: 'static, PastPayouts>(
+pub struct VersionUncheckedMigrateToV2<T: Config<I>, I: 'static, PastPayouts>(
 	sp_std::marker::PhantomData<(T, I, PastPayouts)>,
 );
 
 impl<
 		T: Config<I>,
 		I: Instance + 'static,
 		PastPayouts: Get<Vec<(<T as frame_system::Config>::AccountId, BalanceOf<T, I>)>>,
-	> OnRuntimeUpgrade for MigrateToV2<T, I, PastPayouts>
+	> OnRuntimeUpgrade for VersionUncheckedMigrateToV2<T, I, PastPayouts>
 {
 	#[cfg(feature = "try-runtime")]
 	fn pre_upgrade() -> Result<Vec<u8>, TryRuntimeError> {
@@ -50,14 +53,20 @@ impl<
 	}
 
 	fn on_runtime_upgrade() -> Weight {
-		let current = Pallet::<T, I>::current_storage_version();
 		let onchain = Pallet::<T, I>::on_chain_storage_version();
-		if current == 2 && onchain == 0 {
-			from_original::<T, I>(&mut PastPayouts::get())
-		} else {
+		if onchain < 2 {
 			log::info!(
-				"Running migration with current storage version {:?} / onchain {:?}",
-				current,
+				target: TARGET,
+				"Running migration against onchain version {:?}",
+				onchain
+			);
+			let weight = from_original::<T, I>(&mut PastPayouts::get());
+			crate::STORAGE_VERSION.put::<Pallet<T, I>>();
+			weight
+		} else {
+			log::warn!(
+				target: TARGET,
+				"Migration is a noop. onchain version: {:?}",
 				onchain
 			);
 			T::DbWeight::get().reads(1)
@@ -95,6 +104,14 @@ impl<
 	}
 }
 
+pub type VersionCheckedMigrateToV2<Runtime, Pallet, I, PastPayouts> = VersionedRuntimeUpgrade<
+	0,
+	2,
+	VersionUncheckedMigrateToV2<Runtime, I, PastPayouts>,
+	Pallet,
+	<Runtime as frame_system::Config>::DbWeight,
+>;
+
 pub(crate) mod old {
 	use super::*;
 	use frame_support::storage_alias;
@@ -181,7 +198,7 @@ pub(crate) mod old {
 }
 
 pub fn can_migrate<T: Config<I>, I: Instance + 'static>() -> bool {
-	old::Members::<T, I>::exists()
+	Members::<T, I>::iter().next().is_none()
 }
 
 /// Will panic if there are any inconsistencies in the pallet's state or old keys remaining.
@@ -236,9 +253,9 @@ pub fn assert_internal_consistency<T: Config<I>, I: Instance + 'static>() {
 pub fn from_original<T: Config<I>, I: Instance + 'static>(
 	past_payouts: &mut [(<T as frame_system::Config>::AccountId, BalanceOf<T, I>)],
 ) -> Weight {
-	// First check that this is the original state layout. This is easy since the original layout
-	// contained the Members value, and this value no longer exists in the new layout.
-	if !old::Members::<T, I>::exists() {
+	// First check that this is the original state layout. This is easy since the new layout
+	// contains a new Members value, which did not exist in the old layout.
+	if Members::<T, I>::iter().next().is_some() {
 		log::warn!(target: TARGET, "Skipping MigrateToV2 migration since it appears unapplicable");
 		// Already migrated or no data to migrate: Bail.
 		return T::DbWeight::get().reads(1)
@@ -281,6 +298,31 @@ pub fn from_original<T: Config<I>, I: Instance + 'static>(
 		let record = MemberRecord { index: member_count, rank: 0, strikes, vouching };
 		Members::<T, I>::insert(&member, record);
 		MemberByIndex::<T, I>::insert(member_count, &member);
+
+		// The founder must be the first member in Society V2. If we find the founder not in index
+		// zero, we swap it with the first member.
+		if member == Founder::<T, I>::get().expect("founder is always set; qed") && member_count > 0
+		{
+			let member_to_swap = MemberByIndex::<T, I>::get(0)
+				.expect("member_count > 0, we must have at least 1 member; qed");
+			// Swap the founder with the first member in MemberByIndex.
+			MemberByIndex::<T, I>::swap(0, member_count);
+			// Update the indicies of the swapped member MemberRecords.
+			Members::<T, I>::mutate(&member, |m| {
+				if let Some(member) = m {
+					member.index = 0;
+				} else {
+					log::error!("Member somehow disapeared from storage after it was inserted")
+				}
+			});
+			Members::<T, I>::mutate(&member_to_swap, |m| {
+				if let Some(member) = m {
+					member.index = member_count;
+				} else {
+					log::error!("Member somehow disapeared from storage after it was queried")
+				}
+			});
+		}
 		member_count.saturating_inc();
 	}
 	MemberCount::<T, I>::put(member_count);

frame/support/src/migrations.rs

@@ -78,7 +78,7 @@ pub struct VersionedRuntimeUpgrade<const FROM: u16, const TO: u16, Inner, Pallet
 #[derive(codec::Encode, codec::Decode)]
 pub enum VersionedPostUpgradeData {
 	/// The migration ran, inner vec contains pre_upgrade data.
-	MigrationExecuted(Vec<u8>),
+	MigrationExecuted(sp_std::vec::Vec<u8>),
 	/// This migration is a noop, do not run post_upgrade checks.
 	Noop,
 }