add ExistenceRequirement

currencies/src/lib.rs

@@ -134,7 +134,13 @@ pub mod module {
 		) -> DispatchResult {
 			let from = ensure_signed(origin)?;
 			let to = T::Lookup::lookup(dest)?;
-			<Self as MultiCurrency<T::AccountId>>::transfer(currency_id, &from, &to, amount)
+			<Self as MultiCurrency<T::AccountId>>::transfer(
+				currency_id,
+				&from,
+				&to,
+				amount,
+				ExistenceRequirement::AllowDeath,
+			)
 		}
 
 		/// Transfer some native currency to another account.
@@ -220,14 +226,15 @@ impl<T: Config> MultiCurrency<T::AccountId> for Pallet<T> {
 		from: &T::AccountId,
 		to: &T::AccountId,
 		amount: Self::Balance,
+		existence_requirement: ExistenceRequirement,
 	) -> DispatchResult {
 		if amount.is_zero() || from == to {
 			return Ok(());
 		}
 		if currency_id == T::GetNativeCurrencyId::get() {
 			T::NativeCurrency::transfer(from, to, amount)
 		} else {
-			T::MultiCurrency::transfer(currency_id, from, to, amount)
+			T::MultiCurrency::transfer(currency_id, from, to, amount, existence_requirement)
 		}
 	}
 
@@ -242,14 +249,19 @@ impl<T: Config> MultiCurrency<T::AccountId> for Pallet<T> {
 		}
 	}
 
-	fn withdraw(currency_id: Self::CurrencyId, who: &T::AccountId, amount: Self::Balance) -> DispatchResult {
+	fn withdraw(
+		currency_id: Self::CurrencyId,
+		who: &T::AccountId,
+		amount: Self::Balance,
+		existence_requirement: ExistenceRequirement,
+	) -> DispatchResult {
 		if amount.is_zero() {
 			return Ok(());
 		}
 		if currency_id == T::GetNativeCurrencyId::get() {
 			T::NativeCurrency::withdraw(who, amount)
 		} else {
-			T::MultiCurrency::withdraw(currency_id, who, amount)
+			T::MultiCurrency::withdraw(currency_id, who, amount, existence_requirement)
 		}
 	}
 
@@ -476,15 +488,21 @@ where
 	}
 
 	fn transfer(from: &T::AccountId, to: &T::AccountId, amount: Self::Balance) -> DispatchResult {
-		<Pallet<T> as MultiCurrency<T::AccountId>>::transfer(GetCurrencyId::get(), from, to, amount)
+		<Pallet<T> as MultiCurrency<T::AccountId>>::transfer(
+			GetCurrencyId::get(),
+			from,
+			to,
+			amount,
+			ExistenceRequirement::AllowDeath,
+		)
 	}
 
 	fn deposit(who: &T::AccountId, amount: Self::Balance) -> DispatchResult {
 		<Pallet<T>>::deposit(GetCurrencyId::get(), who, amount)
 	}
 
 	fn withdraw(who: &T::AccountId, amount: Self::Balance) -> DispatchResult {
-		<Pallet<T>>::withdraw(GetCurrencyId::get(), who, amount)
+		<Pallet<T>>::withdraw(GetCurrencyId::get(), who, amount, ExistenceRequirement::AllowDeath)
 	}
 
 	fn can_slash(who: &T::AccountId, amount: Self::Balance) -> bool {

tokens/src/lib.rs

@@ -1161,9 +1161,10 @@ impl<T: Config> MultiCurrency<T::AccountId> for Pallet<T> {
 		from: &T::AccountId,
 		to: &T::AccountId,
 		amount: Self::Balance,
+		existence_requirement: ExistenceRequirement,
 	) -> DispatchResult {
 		// allow death
-		Self::do_transfer(currency_id, from, to, amount, ExistenceRequirement::AllowDeath)
+		Self::do_transfer(currency_id, from, to, amount, existence_requirement)
 	}
 
 	fn deposit(currency_id: Self::CurrencyId, who: &T::AccountId, amount: Self::Balance) -> DispatchResult {
@@ -1172,9 +1173,14 @@ impl<T: Config> MultiCurrency<T::AccountId> for Pallet<T> {
 		Ok(())
 	}
 
-	fn withdraw(currency_id: Self::CurrencyId, who: &T::AccountId, amount: Self::Balance) -> DispatchResult {
+	fn withdraw(
+		currency_id: Self::CurrencyId,
+		who: &T::AccountId,
+		amount: Self::Balance,
+		existence_requirement: ExistenceRequirement,
+	) -> DispatchResult {
 		// allow death
-		Self::do_withdraw(currency_id, who, amount, ExistenceRequirement::AllowDeath, true)
+		Self::do_withdraw(currency_id, who, amount, existence_requirement, true)
 	}
 
 	// Check if `value` amount of free balance can be slashed from `who`.
@@ -1269,7 +1275,7 @@ impl<T: Config> MultiCurrencyExtended<T::AccountId> for Pallet<T> {
 		if by_amount.is_positive() {
 			Self::deposit(currency_id, who, by_balance)
 		} else {
-			Self::withdraw(currency_id, who, by_balance).map(|_| ())
+			Self::withdraw(currency_id, who, by_balance, ExistenceRequirement::AllowDeath).map(|_| ())
 		}
 	}
 }

traits/src/currency.rs

@@ -1,5 +1,5 @@
 use crate::{arithmetic, Happened};
-use frame_support::traits::tokens::Balance;
+use frame_support::traits::{tokens::Balance, ExistenceRequirement};
 pub use frame_support::{
 	traits::{BalanceStatus, DefensiveSaturating, LockIdentifier},
 	transactional,
@@ -56,6 +56,7 @@ pub trait MultiCurrency<AccountId> {
 		from: &AccountId,
 		to: &AccountId,
 		amount: Self::Balance,
+		existence_requirement: ExistenceRequirement,
 	) -> DispatchResult;
 
 	/// Add `amount` to the balance of `who` under `currency_id` and increase
@@ -64,7 +65,12 @@ pub trait MultiCurrency<AccountId> {
 
 	/// Remove `amount` from the balance of `who` under `currency_id` and reduce
 	/// total issuance.
-	fn withdraw(currency_id: Self::CurrencyId, who: &AccountId, amount: Self::Balance) -> DispatchResult;
+	fn withdraw(
+		currency_id: Self::CurrencyId,
+		who: &AccountId,
+		amount: Self::Balance,
+		existence_requirement: ExistenceRequirement,
+	) -> DispatchResult;
 
 	/// Same result as `slash(currency_id, who, value)` (but without the
 	/// side-effects) assuming there are no balance changes in the meantime and

xcm-support/src/currency_adapter.rs

@@ -1,4 +1,4 @@
-use frame_support::traits::Get;
+use frame_support::traits::{ExistenceRequirement, Get};
 use parity_scale_codec::FullCodec;
 use sp_runtime::{
 	traits::{Convert, MaybeSerializeDeserialize, SaturatedConversion},
@@ -173,7 +173,8 @@ impl<
 			let amount: MultiCurrency::Balance = Match::matches_fungible(asset)
 				.ok_or_else(|| XcmError::from(Error::FailedToMatchFungible))?
 				.saturated_into();
-			MultiCurrency::withdraw(currency_id, &who, amount).map_err(|e| XcmError::FailedToTransactAsset(e.into()))
+			MultiCurrency::withdraw(currency_id, &who, amount, ExistenceRequirement::AllowDeath)
+				.map_err(|e| XcmError::FailedToTransactAsset(e.into()))
 		})?;
 
 		Ok(asset.clone().into())
@@ -194,8 +195,14 @@ impl<
 		let amount: MultiCurrency::Balance = Match::matches_fungible(asset)
 			.ok_or_else(|| XcmError::from(Error::FailedToMatchFungible))?
 			.saturated_into();
-		MultiCurrency::transfer(currency_id, &from_account, &to_account, amount)
-			.map_err(|e| XcmError::FailedToTransactAsset(e.into()))?;
+		MultiCurrency::transfer(
+			currency_id,
+			&from_account,
+			&to_account,
+			amount,
+			ExistenceRequirement::AllowDeath,
+		)
+		.map_err(|e| XcmError::FailedToTransactAsset(e.into()))?;
 
 		Ok(asset.clone().into())
 	}