Delegate call test

frame/contracts/fixtures/reentrant_count_delegated_call.wat

@@ -0,0 +1,69 @@
+(module
+	(import "seal0" "seal_input" (func $seal_input (param i32 i32)))
+	(import "seal0" "seal_set_storage" (func $seal_set_storage (param i32 i32 i32)))
+	(import "seal0" "seal_delegate_call" (func $seal_delegate_call (param i32 i32 i32 i32 i32 i32) (result i32)))
+	(import "__unstable__" "seal_reentrant_count" (func $seal_reentrant_count (result i32)))
+	(import "env" "memory" (memory 1 1))
+
+	;; [0, 32) buffer where code hash is copied
+
+	;; [32, 36) buffer for the call stack high
+
+	;; [36, 40) size of the input buffer
+	(data (i32.const 36) "\24")
+
+	(func $assert (param i32)
+		(block $ok
+			(br_if $ok
+				(get_local 0)
+			)
+			(unreachable)
+		)
+	)
+	(func (export "call")
+		(local $callstack_high i32)
+		(local $delegate_call_exit_code i32)
+
+		;; Reading input
+		(call $seal_input (i32.const 0) (i32.const 36))
+
+		;; reading passed callstack high
+		(set_local $callstack_high (i32.load (i32.const 32)))
+
+		;; incrementing callstack high
+		(i32.store (i32.const 32) (i32.add (i32.load (i32.const 32)) (i32.const 1)))
+
+		;; reentrance count stays 0
+		(call $assert
+			(i32.eq (call $seal_reentrant_count) (i32.const 0))
+		)
+
+		(i32.eq (get_local $callstack_high) (i32.const 5))
+		(if
+			(then) ;; exit recursion case
+			(else
+				;; Call to itself
+				(set_local $delegate_call_exit_code
+					(call $seal_delegate_call
+						(i32.const 0)	;; Set no call flags
+						(i32.const 0)	;; Pointer to "callee" code_hash.
+						(i32.const 0)	;; Input is ingored
+						(i32.const 36)	;; Length of the input
+						(i32.const 4294967295)	;; u32 max sentinel value: do not copy output
+						(i32.const 0)	;; Length is ignored in this case
+					)
+				)
+
+				(call $assert
+					(i32.eq (get_local $delegate_call_exit_code) (i32.const 0))
+				)
+			)
+		)
+
+		(call $assert
+			(i32.le_s (get_local $callstack_high) (i32.const 5))
+		)
+	)
+
+	(func (export "deploy"))
+)

frame/contracts/src/tests.rs

@@ -3261,6 +3261,43 @@ fn reentrant_count_works_with_call() {
 		.unwrap();
 	});
 }
+
+#[test]
+#[cfg(feature = "unstable-interface")]
+fn reentrant_count_works_with_delegated_call() {
+	let (wasm1, code_hash1) = compile_module::<Test>("reentrant_count_delegated_call").unwrap();
+	let contract_addr1 = Contracts::contract_address(&ALICE, &code_hash1, &[]);
+
+	ExtBuilder::default().existential_deposit(100).build().execute_with(|| {
+		let _ = Balances::deposit_creating(&ALICE, 1_000_000);
+
+		assert_ok!(Contracts::instantiate_with_code(
+			Origin::signed(ALICE),
+			300_000,
+			GAS_LIMIT,
+			None,
+			wasm1,
+			vec![],
+			vec![],
+		));
+
+		let mut input = AsRef::<[u8]>::as_ref(&(code_hash1.clone())).to_vec();
+		input.push(1); // adding callstack high to the input
+
+		Contracts::bare_call(
+			ALICE,
+			contract_addr1.clone(),
+			0,
+			GAS_LIMIT,
+			None,
+			input,
+			true,
+		)
+			.result
+			.unwrap();
+	});
+}
+
 #[test]
 #[cfg(feature = "unstable-interface")]
 fn account_entrance_count_works() {