upgrade runtime, the stored data has changed

Question

No custom data migration logic for this pallet. but the data retrieved by the chain state has changed. here is code logic.

#[derive(Copy, Clone, Encode, Decode, Eq, PartialEq, RuntimeDebug, MaxEncodedLen, TypeInfo)]
pub enum MyEnum {
    A,
    B,
    C,
    D,
}



#[derive(Clone, Encode, Decode, Eq, Copy, PartialEq, RuntimeDebug, MaxEncodedLen, TypeInfo)]
pub struct MyStruct<
    Balance: Encode + Decode + Clone + Debug + Eq + PartialEq,
    AccountId: Encode + Decode + Clone + Debug + Eq + PartialEq,
> {
    pub account: AccountId,

    pub cost: Balance,

    pub action: MyEnum,
}




#[pallet::storage]
#[pallet::getter(fn action_list)]
pub(super) type ActionListOf<T: Config> =
StorageMap<_, Blake2_128Concat, MyEnum, Vec<Option<MyStruct<BalanceOf<T>, T::AccountId>>>, ValueQuery>;

before the upgrade, the retrieved data of the chain state is as follows:

[
  [
    [
      B
    ]
    [
      {
        account: 5HgtRNQxpttSomysgAsGgYmohdMD8knPBt8HtR5EH3neLbvV
        fee: 100,000,000,000,000,0
        action: B
      }
    ]
  ]
]

After the upgrade, the retrieved data of the chain state is as follows:

[
  [
    [
      A
    ]
    [
      {
        account: 5HgtRNQxpttSomysgAsGgYmohdMD8knPBt8HtR5EH3neLbvV
        fee: 100,000,000,000,000,0
        action: B
      }
    ]
  ]
]

The key in the StorageMap has changed, how to fix this problem？

commit checklist QA:

1. no update code for this pallet
2. update system weight

Answer 1

It's hard to determine what happened without inspecting the new runtime and knowing what steps you took from pre to post upgrade.

The first thing to verify is to look at was upgraded in the runtime and make sure the upgrade didn't corrupt this StorageMap inside the pallet itself. Then, are you sure there were no dispatchables called post upgrade that could have updated the key to A ? Steps that could help understand what happened here would be:

1. Reproduce the new runtime
2. Inspect it using sr-tool and compare against the runtime that gave the unexpected storage. If they're not the same, you can look where they differ and fix your runtime code.
3. If they are the same, then update your runtime with the new blob and make no other extrinsics to the pallet (again, this could have been an issue but its hard to know based on your problem description).