Change utility::as_derivative index to u32

substrate/frame/utility/src/lib.rs

@@ -266,7 +266,7 @@ pub mod pallet {
  })]
  pub fn as_derivative(
  origin: OriginFor<T>,
- index: u16,
+ index: u32,
  call: Box<<T as Config>::RuntimeCall>,
  ) -> DispatchResultWithPostInfo {
  let mut origin = origin;
@@ -504,8 +504,13 @@ impl TypeId for IndexedUtilityPalletId {
 
 impl<T: Config> Pallet<T> {
  /// Derive a derivative account ID from the owner account and the sub-account index.
- pub fn derivative_account_id(who: T::AccountId, index: u16) -> T::AccountId {
- let entropy = (b"modlpy/utilisuba", who, index).using_encoded(blake2_256);
+ pub fn derivative_account_id(who: T::AccountId, index: u32) -> T::AccountId {
+ // Derive the same addresses as when index was u16
+ let entropy = if index <= u16::MAX as u32 {
+ (b"modlpy/utilisuba", who, index as u16).using_encoded(blake2_256)
+ } else {
+ (b"modlpy/utilisuba", who, index).using_encoded(blake2_256)
+ };
  Decode::decode(&mut TrailingZeroInput::new(entropy.as_ref()))
  .expect("infinite length input; no invalid inputs for type; qed")
  }

substrate/frame/utility/src/tests.rs

@@ -398,6 +398,15 @@ fn as_derivative_filters() {
  });
 }
 
+#[test]
+fn as_derivative_u32_compat_with_old_u16() {
+ new_test_ext().execute_with(|| {
+ let sub_1_0 = Utility::derivative_account_id(1, 0);
+ const SAME_DERIVATIVE_AS_WITH_OLD_U16_INDEX: u64 = 13950085325555297514;
+ assert_eq!(sub_1_0, SAME_DERIVATIVE_AS_WITH_OLD_U16_INDEX);
+ })
+}
+
 #[test]
 fn batch_with_root_works() {
  new_test_ext().execute_with(|| {