fix bug of session rotating twice in parachain staking

pallets/parachain-staking/src/migrations.rs

@@ -3,7 +3,7 @@
 use crate::{
 	pallet::{Config, Pallet, OLD_STAKING_ID, STAKING_ID},
 	types::{AccountIdOf, Candidate, OldCandidate},
-	CandidatePool, ForceNewRound,
+	CandidatePool, ForceNewRound, Round,
 };
 use frame_support::{
 	pallet_prelude::{GetStorageVersion, StorageVersion, ValueQuery},
@@ -94,9 +94,16 @@ mod upgrade {
 					Versions::default() as u16
 				);
 
-				// force start new session
-				<ForceNewRound<T>>::put(true);
-				weight_writes += 1;
+				let round = Round::<T>::get();
+				let now = <frame_system::Pallet<T>>::block_number();
+				weight_reads += 2;
+				// Force new round if round wasn't about to be rotated anyway
+				if !round.should_update(now) {
+					// force start new session
+					<ForceNewRound<T>>::put(true);
+					weight_writes += 1;
+					log::info!("Will force new round for token economy V2.");
+				}
 
 				log::info!("V11 Migrating Done.");
 			}