Fixes

frame/examples/basic/src/lib.rs

@@ -731,6 +731,16 @@ where
 		Ok(())
 	}
 
+	fn pre_dispatch(
+		self,
+		who: &Self::AccountId,
+		call: &Self::Call,
+		info: &DispatchInfoOf<Self::Call>,
+		len: usize,
+	) -> Result<Self::Pre, TransactionValidityError> {
+		Ok(self.validate(who, call, info, len).map(|_| ())?)
+	}
+
 	fn validate(
 		&self,
 		_who: &Self::AccountId,

frame/system/src/extensions/check_genesis.rs

@@ -19,7 +19,7 @@ use crate::{Config, Pallet};
 use codec::{Decode, Encode};
 use scale_info::TypeInfo;
 use sp_runtime::{
-	traits::{SignedExtension, Zero},
+	traits::{SignedExtension, Zero, DispatchInfoOf},
 	transaction_validity::TransactionValidityError,
 };
 
@@ -62,4 +62,14 @@ impl<T: Config + Send + Sync> SignedExtension for CheckGenesis<T> {
 	fn additional_signed(&self) -> Result<Self::AdditionalSigned, TransactionValidityError> {
 		Ok(<Pallet<T>>::block_hash(T::BlockNumber::zero()))
 	}
+
+	fn pre_dispatch(
+		self,
+		who: &Self::AccountId,
+		call: &Self::Call,
+		info: &DispatchInfoOf<Self::Call>,
+		len: usize,
+	) -> Result<Self::Pre, TransactionValidityError> {
+		Ok(self.validate(who, call, info, len).map(|_| ())?)
+	}
 }

frame/system/src/extensions/check_mortality.rs

@@ -85,6 +85,16 @@ impl<T: Config + Send + Sync> SignedExtension for CheckMortality<T> {
 			Ok(<Pallet<T>>::block_hash(n))
 		}
 	}
+
+	fn pre_dispatch(
+		self,
+		who: &Self::AccountId,
+		call: &Self::Call,
+		info: &DispatchInfoOf<Self::Call>,
+		len: usize,
+	) -> Result<Self::Pre, TransactionValidityError> {
+		Ok(self.validate(who, call, info, len).map(|_| ())?)
+	}
 }
 
 #[cfg(test)]

frame/system/src/extensions/check_non_zero_sender.rs

@@ -65,6 +65,16 @@ where
 		Ok(())
 	}
 
+	fn pre_dispatch(
+		self,
+		who: &Self::AccountId,
+		call: &Self::Call,
+		info: &DispatchInfoOf<Self::Call>,
+		len: usize,
+	) -> Result<Self::Pre, TransactionValidityError> {
+		Ok(self.validate(who, call, info, len).map(|_| ())?)
+	}
+
 	fn validate(
 		&self,
 		who: &Self::AccountId,

frame/system/src/extensions/check_spec_version.rs

@@ -18,7 +18,8 @@
 use crate::{Config, Pallet};
 use codec::{Decode, Encode};
 use scale_info::TypeInfo;
-use sp_runtime::{traits::SignedExtension, transaction_validity::TransactionValidityError};
+use sp_runtime::traits::{SignedExtension, DispatchInfoOf};
+use sp_runtime::transaction_validity::TransactionValidityError;
 
 /// Ensure the runtime version registered in the transaction is the same as at present.
 ///
@@ -59,4 +60,14 @@ impl<T: Config + Send + Sync> SignedExtension for CheckSpecVersion<T> {
 	fn additional_signed(&self) -> Result<Self::AdditionalSigned, TransactionValidityError> {
 		Ok(<Pallet<T>>::runtime_version().spec_version)
 	}
+
+	fn pre_dispatch(
+		self,
+		who: &Self::AccountId,
+		call: &Self::Call,
+		info: &DispatchInfoOf<Self::Call>,
+		len: usize,
+	) -> Result<Self::Pre, TransactionValidityError> {
+		Ok(self.validate(who, call, info, len).map(|_| ())?)
+	}
 }

frame/system/src/extensions/check_tx_version.rs

@@ -18,7 +18,7 @@
 use crate::{Config, Pallet};
 use codec::{Decode, Encode};
 use scale_info::TypeInfo;
-use sp_runtime::{traits::SignedExtension, transaction_validity::TransactionValidityError};
+use sp_runtime::{traits::{SignedExtension, DispatchInfoOf}, transaction_validity::TransactionValidityError};
 
 /// Ensure the transaction version registered in the transaction is the same as at present.
 ///
@@ -59,4 +59,13 @@ impl<T: Config + Send + Sync> SignedExtension for CheckTxVersion<T> {
 	fn additional_signed(&self) -> Result<Self::AdditionalSigned, TransactionValidityError> {
 		Ok(<Pallet<T>>::runtime_version().transaction_version)
 	}
+	fn pre_dispatch(
+		self,
+		who: &Self::AccountId,
+		call: &Self::Call,
+		info: &DispatchInfoOf<Self::Call>,
+		len: usize,
+	) -> Result<Self::Pre, TransactionValidityError> {
+		Ok(self.validate(who, call, info, len).map(|_| ())?)
+	}
 }

frame/system/src/extensions/check_weight.rs

@@ -223,7 +223,7 @@ where
 	}
 
 	fn post_dispatch(
-		_pre: Self::Pre,
+		_pre: Option<Self::Pre>,
 		info: &DispatchInfoOf<Self::Call>,
 		post_info: &PostDispatchInfoOf<Self::Call>,
 		_len: usize,
@@ -563,7 +563,7 @@ mod tests {
 			let pre = CheckWeight::<Test>(PhantomData).pre_dispatch(&1, CALL, &info, len).unwrap();
 			assert_eq!(BlockWeight::<Test>::get().total(), info.weight + 256);
 
-			assert_ok!(CheckWeight::<Test>::post_dispatch(pre, &info, &post_info, len, &Ok(())));
+			assert_ok!(CheckWeight::<Test>::post_dispatch(Some(pre), &info, &post_info, len, &Ok(())));
 			assert_eq!(BlockWeight::<Test>::get().total(), post_info.actual_weight.unwrap() + 256);
 		})
 	}
@@ -587,7 +587,7 @@ mod tests {
 				info.weight + 128 + block_weights().get(DispatchClass::Normal).base_extrinsic,
 			);
 
-			assert_ok!(CheckWeight::<Test>::post_dispatch(pre, &info, &post_info, len, &Ok(())));
+			assert_ok!(CheckWeight::<Test>::post_dispatch(Some(pre), &info, &post_info, len, &Ok(())));
 			assert_eq!(
 				BlockWeight::<Test>::get().total(),
 				info.weight + 128 + block_weights().get(DispatchClass::Normal).base_extrinsic,

frame/transaction-payment/asset-tx-payment/src/lib.rs

@@ -210,7 +210,7 @@ where
 		// tip
 		BalanceOf<T>,
 		// who paid the fee
-		Option<Self::AccountId>,
+		Self::AccountId,
 		// imbalance resulting from withdrawing the fee
 		InitialPayment<T>,
 	);
@@ -240,49 +240,48 @@ where
 		len: usize,
 	) -> Result<Self::Pre, TransactionValidityError> {
 		let (_fee, initial_payment) = self.withdraw_fee(who, call, info, len)?;
-		Ok((self.tip, Some(who.clone()), initial_payment))
+		Ok((self.tip, who.clone(), initial_payment))
 	}
 
 	fn post_dispatch(
-		pre: Self::Pre,
+		pre: Option<Self::Pre>,
 		info: &DispatchInfoOf<Self::Call>,
 		post_info: &PostDispatchInfoOf<Self::Call>,
 		len: usize,
 		result: &DispatchResult,
 	) -> Result<(), TransactionValidityError> {
-		let (tip, who, initial_payment) = pre;
-		match initial_payment {
-			InitialPayment::Native(already_withdrawn) => {
-				pallet_transaction_payment::ChargeTransactionPayment::<T>::post_dispatch(
-					(tip, who, already_withdrawn),
-					info,
-					post_info,
-					len,
-					result,
-				)?;
-			},
-			InitialPayment::Asset(already_withdrawn) => {
-				let actual_fee = pallet_transaction_payment::Pallet::<T>::compute_actual_fee(
-					len as u32, info, post_info, tip,
-				);
-				let who =
-					who.ok_or(TransactionValidityError::Invalid(InvalidTransaction::Custom(255)))?;
-				T::OnChargeAssetTransaction::correct_and_deposit_fee(
-					&who,
-					info,
-					post_info,
-					actual_fee.into(),
-					tip.into(),
-					already_withdrawn.into(),
-				)?;
-			},
-			InitialPayment::Nothing => {
-				// `actual_fee` should be zero here for any signed extrinsic. It would be non-zero
-				// here in case of unsigned extrinsics as they don't pay fees but
-				// `compute_actual_fee` is not aware of them. In both cases it's fine to just move
-				// ahead without adjusting the fee, though, so we do nothing.
-				debug_assert!(tip.is_zero(), "tip should be zero if initial fee was zero.");
-			},
+		if let Some((tip, who, initial_payment)) = pre {
+			match initial_payment {
+				InitialPayment::Native(already_withdrawn) => {
+					pallet_transaction_payment::ChargeTransactionPayment::<T>::post_dispatch(
+						Some((tip, who, already_withdrawn)),
+						info,
+						post_info,
+						len,
+						result,
+					)?;
+				},
+				InitialPayment::Asset(already_withdrawn) => {
+					let actual_fee = pallet_transaction_payment::Pallet::<T>::compute_actual_fee(
+						len as u32, info, post_info, tip,
+					);
+					T::OnChargeAssetTransaction::correct_and_deposit_fee(
+						&who,
+						info,
+						post_info,
+						actual_fee.into(),
+						tip.into(),
+						already_withdrawn.into(),
+					)?;
+				},
+				InitialPayment::Nothing => {
+					// `actual_fee` should be zero here for any signed extrinsic. It would be non-zero
+					// here in case of unsigned extrinsics as they don't pay fees but
+					// `compute_actual_fee` is not aware of them. In both cases it's fine to just move
+					// ahead without adjusting the fee, though, so we do nothing.
+					debug_assert!(tip.is_zero(), "tip should be zero if initial fee was zero.");
+				},
+			}
 		}
 
 		Ok(())

frame/transaction-payment/asset-tx-payment/src/tests.rs

@@ -305,7 +305,7 @@ fn transaction_payment_in_native_possible() {
 			assert_eq!(Balances::free_balance(1), initial_balance - 5 - 5 - 10);
 
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				Some(pre),
 				&info_from_weight(5),
 				&default_post_info(),
 				len,
@@ -320,7 +320,7 @@ fn transaction_payment_in_native_possible() {
 			assert_eq!(Balances::free_balance(2), initial_balance_for_2 - 5 - 10 - 100 - 5);
 
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				Some(pre),
 				&info_from_weight(100),
 				&post_info_from_weight(50),
 				len,
@@ -371,7 +371,7 @@ fn transaction_payment_in_asset_possible() {
 			assert_eq!(Assets::balance(asset_id, BLOCK_AUTHOR), 0);
 
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				Some(pre),
 				&info_from_weight(weight),
 				&default_post_info(),
 				len,
@@ -424,7 +424,7 @@ fn transaction_payment_without_fee() {
 			assert_eq!(Assets::balance(asset_id, BLOCK_AUTHOR), 0);
 
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				Some(pre),
 				&info_from_weight(weight),
 				&post_info_from_pays(Pays::No),
 				len,
@@ -476,7 +476,7 @@ fn asset_transaction_payment_with_tip_and_refund() {
 
 			let final_weight = 50;
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				Some(pre),
 				&info_from_weight(weight),
 				&post_info_from_weight(final_weight),
 				len,
@@ -529,7 +529,7 @@ fn payment_from_account_with_only_assets() {
 			assert_eq!(Assets::balance(asset_id, caller), balance - fee);
 
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				Some(pre),
 				&info_from_weight(weight),
 				&default_post_info(),
 				len,
@@ -613,7 +613,7 @@ fn converted_fee_is_never_zero_if_input_fee_is_not() {
 				assert_eq!(Assets::balance(asset_id, caller), balance);
 
 				assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-					pre,
+					Some(pre),
 					&info_from_pays(Pays::No),
 					&post_info_from_pays(Pays::No),
 					len,
@@ -628,7 +628,7 @@ fn converted_fee_is_never_zero_if_input_fee_is_not() {
 			assert_eq!(Assets::balance(asset_id, caller), balance - 1);
 
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				Some(pre),
 				&info_from_weight(weight),
 				&default_post_info(),
 				len,
@@ -685,7 +685,7 @@ fn post_dispatch_fee_is_zero_if_pre_dispatch_fee_is_zero() {
 			// `Pays::Yes` on post-dispatch does not mean we pay (we never charge more than the
 			// initial fee)
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				Some(pre),
 				&info_from_pays(Pays::No),
 				&post_info_from_pays(Pays::Yes),
 				len,
@@ -722,25 +722,18 @@ fn post_dispatch_fee_is_zero_if_unsigned_pre_dispatch_fee_is_zero() {
 			assert_eq!(Assets::balance(asset_id, caller), balance);
 			let weight = 1;
 			let len = 1;
-			let pre = ChargeAssetTxPayment::<Runtime>::pre_dispatch_unsigned(
+			ChargeAssetTxPayment::<Runtime>::pre_dispatch_unsigned(
 				CALL,
 				&info_from_weight(weight),
 				len,
-			)
-			.unwrap();
+			).unwrap();
 
 			assert_eq!(Assets::balance(asset_id, caller), balance);
-			let (_tip, _who, initial_payment) = &pre;
-			let not_paying = match initial_payment {
-				&InitialPayment::Nothing => true,
-				_ => false,
-			};
-			assert!(not_paying, "initial payment is Nothing for unsigned extrinsics");
 
 			// `Pays::Yes` on post-dispatch does not mean we pay (we never charge more than the
 			// initial fee)
 			assert_ok!(ChargeAssetTxPayment::<Runtime>::post_dispatch(
-				pre,
+				None,
 				&info_from_weight(weight),
 				&post_info_from_pays(Pays::Yes),
 				len,