From 2137e1bafd7b34d2be9ab5a7da29a6ec2fc362b3 Mon Sep 17 00:00:00 2001
From: Pavel Yaskevich <pyaskevich@apple.com>
Date: Thu, 8 Apr 2021 16:02:32 -0700
Subject: [PATCH] [TypeChecker] NFC: Add a test-case to test condition
 requirements interaction with transitive conformance checks

---
 test/Constraints/protocols.swift | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/test/Constraints/protocols.swift b/test/Constraints/protocols.swift
index eb5e22bfbac..bfca35ac6ac 100644
--- a/test/Constraints/protocols.swift
+++ b/test/Constraints/protocols.swift
@@ -454,3 +454,23 @@ func test_inference_through_implicit_conversion() {
   let _: UnsafePointer<C> = test([C()]) // Ok - argument is implicitly converted to a pointer
   let _: AnyHashable = test(C()) // Ok - argument is implicitly converted to `AnyHashable` because it's Hashable
 }
+
+// Make sure that conformances transitively checked through implicit conversions work with conditional requirements
+protocol TestCond {}
+
+extension Optional : TestCond where Wrapped == Int? {}
+
+func simple<T : TestCond>(_ x: T) -> T { x }
+
+func overloaded<T: TestCond>(_ x: T) -> T { x }
+func overloaded<T: TestCond>(_ x: String) -> T { fatalError() }
+
+func overloaded_result() -> Int { 42 }
+func overloaded_result() -> String { "" }
+
+func test_arg_conformance_with_conditional_reqs(i: Int) {
+  let _: Int?? = simple(i)
+  let _: Int?? = overloaded(i)
+  let _: Int?? = simple(overloaded_result())
+  let _: Int?? = overloaded(overloaded_result())
+}