Skip CDD check on contract's 'deposit_account', which is only used to…

… hold storage deposits.

Signed-off-by: Robert G. Jakabosky <rjakabosky+neopallium@neoawareness.com>

substrate/frame/contracts/src/lib.rs

@@ -1615,7 +1615,10 @@ impl<T: Config> Pallet<T> {
 
 	/// Return the existential deposit of [`Config::Currency`].
 	fn min_balance() -> BalanceOf<T> {
-		<T::Currency as Inspect<AccountIdOf<T>>>::minimum_balance()
+		// POLYMESH: Need to make sure the contract's account is created.
+		// So we need to return a non-zero amount here.
+		//<T::Currency as Inspect<AccountIdOf<T>>>::minimum_balance()
+		1u32.into()
 	}
 
 	/// Convert gas_limit from 1D Weight to a 2D Weight.

substrate/frame/contracts/src/storage/meter.rs

@@ -537,7 +537,9 @@ impl<T: Config> Ext<T> for ReservingExt {
 		terminated: bool,
 	) -> Result<(), DispatchError> {
 		match amount {
-			Deposit::Charge(amount) => T::Currency::transfer(
+			// POLYMESH: Use `transfer_no_cdd` instead of `transfer`, to avoid CDD check on
+			// `deposit_account`.
+			Deposit::Charge(amount) => T::Currency::transfer_no_cdd(
 				origin,
 				deposit_account,
 				*amount,

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

@@ -132,6 +132,20 @@ pub trait Currency<AccountId> {
 		existence_requirement: ExistenceRequirement,
 	) -> DispatchResult;
 
+	/// Transfer some liquid free balance to another staker.  Without CDD check on `dest`.
+	///
+	/// This is a very high-level function. It will ensure all appropriate fees are paid
+	/// and no imbalance in the system remains.
+	/// POLYMESH: Added for `pallet_contracts`.
+	fn transfer_no_cdd(
+		source: &AccountId,
+		dest: &AccountId,
+		value: Self::Balance,
+		existence_requirement: ExistenceRequirement,
+	) -> DispatchResult {
+		Self::transfer(source, dest, value, existence_requirement)
+	}
+
 	/// Deducts up to `value` from the combined balance of `who`, preferring to deduct from the
 	/// free balance. This function cannot fail.
 	///