add test locking removed when amount is zero (paritytech#14284)

* add test locking removed when amount is zero

* add test set lock with withdraw reasons empty removes lock

* fix test set lock with withdraw reasons

frame/balances/src/tests/currency_tests.rs

@@ -33,6 +33,30 @@ const ID_2: LockIdentifier = *b"2       ";
 pub const CALL: &<Test as frame_system::Config>::RuntimeCall =
 	&RuntimeCall::Balances(crate::Call::transfer_allow_death { dest: 0, value: 0 });
 
+#[test]
+fn set_lock_with_amount_zero_removes_lock() {
+	ExtBuilder::default()
+		.existential_deposit(1)
+		.monied(true)
+		.build_and_execute_with(|| {
+			Balances::set_lock(ID_1, &1, u64::MAX, WithdrawReasons::all());
+			Balances::set_lock(ID_1, &1, 0, WithdrawReasons::all());
+			assert_ok!(<Balances as Currency<_>>::transfer(&1, &2, 1, AllowDeath));
+		});
+}
+
+#[test]
+fn set_lock_with_withdraw_reasons_empty_removes_lock() {
+	ExtBuilder::default()
+		.existential_deposit(1)
+		.monied(true)
+		.build_and_execute_with(|| {
+			Balances::set_lock(ID_1, &1, u64::MAX, WithdrawReasons::all());
+			Balances::set_lock(ID_1, &1, u64::MAX, WithdrawReasons::empty());
+			assert_ok!(<Balances as Currency<_>>::transfer(&1, &2, 1, AllowDeath));
+		});
+}
+
 #[test]
 fn basic_locking_should_work() {
 	ExtBuilder::default()