[XCM] `pallet_xcm` internal data changes proposal

[bkontur]

Part of: https://github.com/paritytech/polkadot-sdk/issues/3214 Follow-up of: https://github.com/paritytech/polkadot-sdk/pull/6148

RemoteLockedFungibles

• [ ] change data structure:

actual shape:

    pallet::storage]
    pub(super) type RemoteLockedFungibles<T: Config> = StorageDoubleMap<
        _,
        (
            NMapKey<Twox64Concat, XcmVersion>,
            NMapKey<Blake2_128Concat, T::AccountId>,
            NMapKey<Blake2_128Concat, VersionedAssetId>,
        ),
        RemoteLockedFungibleRecord<T::RemoteLockConsumerIdentifier, T::MaxRemoteLockConsumers>,
        OptionQuery,
    >;

proposed shape: - we don't need XcmVersion nmapkey prefx here

    #[pallet::storage]
    pub(super) type RemoteLockedFungibles<T: Config> = StorageDoubleMap<
        _,
        Blake2_128Concat,
        T::AccountId,
        Blake2_128Concat,
        VersionedAssetId,
        RemoteLockedFungibleRecord<T::RemoteLockConsumerIdentifier, T::MaxRemoteLockConsumers>,
        OptionQuery,
    >;

• [ ] fix checks, comparing VersionedLocation does not work when comparing VersionedLocation::V4 and VersionedLocation::V5

  ensure!(self.locker == record.locker && self.owner == record.owner, UnexpectedState);
  ensure!(old.locker == record.locker && old.owner == record.owner, WouldClobber);

  • e.g. for LockedFungibles we do a correct checks e.g.: x.1.try_as::<_>() == Ok(&unlocker)

RecordedXcm change stored xcm::latest::Xcm to xcm::VersionedXcm ?

• [ ] add try_state check
• [ ] add to the latest migration

Does RecordedXcm work when adding a new XCM version? Possibly it could work, when XCM is compatible.

Bump storage version

• [ ] at least RemoteLockedFungibles requires this bump