Add arithmetic dispatch errors. (#8726)

* Add arithmetic dispatch errors.

* Replace custom overflow errors.

* Replace custom underflow and division by zero errors.

* Replace overflow/underflow in token error.

* Add token and arithmetic errors in dispatch error equality test.

* Trigger CI.

substrate/frame/support/src/traits/tokens/fungible/balanced.rs

@@ -20,7 +20,7 @@
 
 use super::*;
 use sp_std::marker::PhantomData;
-use sp_runtime::{TokenError, traits::{CheckedAdd, Zero}};
+use sp_runtime::{TokenError, ArithmeticError, traits::{CheckedAdd, Zero}};
 use super::super::Imbalance as ImbalanceT;
 use crate::traits::misc::{SameOrOther, TryDrop};
 use crate::dispatch::{DispatchResult, DispatchError};
@@ -221,7 +221,7 @@ pub trait Unbalanced<AccountId>: Inspect<AccountId> {
 		-> Result<Self::Balance, DispatchError>
 	{
 		let old_balance = Self::balance(who);
-		let new_balance = old_balance.checked_add(&amount).ok_or(TokenError::Overflow)?;
+		let new_balance = old_balance.checked_add(&amount).ok_or(ArithmeticError::Overflow)?;
 		if new_balance < Self::minimum_balance() {
 			Err(TokenError::BelowMinimum)?
 		}

substrate/frame/support/src/traits/tokens/fungibles/balanced.rs

@@ -20,7 +20,7 @@
 
 use super::*;
 use sp_std::marker::PhantomData;
-use sp_runtime::{TokenError, traits::{Zero, CheckedAdd}};
+use sp_runtime::{ArithmeticError, TokenError, traits::{Zero, CheckedAdd}};
 use sp_arithmetic::traits::Saturating;
 use crate::dispatch::{DispatchError, DispatchResult};
 use crate::traits::misc::{SameOrOther, TryDrop};
@@ -236,7 +236,7 @@ pub trait Unbalanced<AccountId>: Inspect<AccountId> {
 		-> Result<Self::Balance, DispatchError>
 	{
 		let old_balance = Self::balance(asset, who);
-		let new_balance = old_balance.checked_add(&amount).ok_or(TokenError::Overflow)?;
+		let new_balance = old_balance.checked_add(&amount).ok_or(ArithmeticError::Overflow)?;
 		if new_balance < Self::minimum_balance(asset) {
 			Err(TokenError::BelowMinimum)?
 		}

substrate/frame/support/src/traits/tokens/misc.rs

@@ -20,7 +20,7 @@
 use codec::{Encode, Decode, FullCodec};
 use sp_core::RuntimeDebug;
 use sp_arithmetic::traits::{Zero, AtLeast32BitUnsigned};
-use sp_runtime::TokenError;
+use sp_runtime::{DispatchError, ArithmeticError, TokenError};
 
 /// One of a number of consequences of withdrawing a fungible from an account.
 #[derive(Copy, Clone, Eq, PartialEq)]
@@ -50,17 +50,17 @@ pub enum WithdrawConsequence<Balance> {
 }
 
 impl<Balance: Zero> WithdrawConsequence<Balance> {
-	/// Convert the type into a `Result` with `TokenError` as the error or the additional `Balance`
+	/// Convert the type into a `Result` with `DispatchError` as the error or the additional `Balance`
 	/// by which the account will be reduced.
-	pub fn into_result(self) -> Result<Balance, TokenError> {
+	pub fn into_result(self) -> Result<Balance, DispatchError> {
 		use WithdrawConsequence::*;
 		match self {
-			NoFunds => Err(TokenError::NoFunds),
-			WouldDie => Err(TokenError::WouldDie),
-			UnknownAsset => Err(TokenError::UnknownAsset),
-			Underflow => Err(TokenError::Underflow),
-			Overflow => Err(TokenError::Overflow),
-			Frozen => Err(TokenError::Frozen),
+			NoFunds => Err(TokenError::NoFunds.into()),
+			WouldDie => Err(TokenError::WouldDie.into()),
+			UnknownAsset => Err(TokenError::UnknownAsset.into()),
+			Underflow => Err(ArithmeticError::Underflow.into()),
+			Overflow => Err(ArithmeticError::Overflow.into()),
+			Frozen => Err(TokenError::Frozen.into()),
 			ReducedToZero(result) => Ok(result),
 			Success => Ok(Zero::zero()),
 		}
@@ -90,13 +90,13 @@ pub enum DepositConsequence {
 
 impl DepositConsequence {
 	/// Convert the type into a `Result` with `TokenError` as the error.
-	pub fn into_result(self) -> Result<(), TokenError> {
+	pub fn into_result(self) -> Result<(), DispatchError> {
 		use DepositConsequence::*;
 		Err(match self {
-			BelowMinimum => TokenError::BelowMinimum,
-			CannotCreate => TokenError::CannotCreate,
-			UnknownAsset => TokenError::UnknownAsset,
-			Overflow => TokenError::Overflow,
+			BelowMinimum => TokenError::BelowMinimum.into(),
+			CannotCreate => TokenError::CannotCreate.into(),
+			UnknownAsset => TokenError::UnknownAsset.into(),
+			Overflow => ArithmeticError::Overflow.into(),
 			Success => return Ok(()),
 		})
 	}