From 76bb82a533a84b2fd2d14ff228a9a47632849f6b Mon Sep 17 00:00:00 2001
From: David Smith <david_smith@apple.com>
Date: Fri, 17 May 2024 16:28:08 -0700
Subject: [PATCH] rdar://127199021, fix compatibility with apps that
 accidentally do [[[aSwiftArray class] new] mutableCopy] to work

(cherry picked from commit 011034023ef80530cfbb901749d0f28484428760)
---
 stdlib/public/stubs/SwiftNativeNSXXXBase.mm.gyb | 13 +++++++++++++
 test/stdlib/ArrayBridge.swift.gyb               |  5 +++++
 test/stdlib/Inputs/ArrayBridge/ArrayBridge.h    |  1 +
 test/stdlib/Inputs/ArrayBridge/ArrayBridge.m    | 16 ++++++++++++++++
 4 files changed, 35 insertions(+)

diff --git a/stdlib/public/stubs/SwiftNativeNSXXXBase.mm.gyb b/stdlib/public/stubs/SwiftNativeNSXXXBase.mm.gyb
index 89e389f8ba8bc..d08792ff80228 100644
--- a/stdlib/public/stubs/SwiftNativeNSXXXBase.mm.gyb
+++ b/stdlib/public/stubs/SwiftNativeNSXXXBase.mm.gyb
@@ -103,6 +103,19 @@ swift_stdlib_connectNSBaseClasses() {
   return true;
 }
 
+@interface __SwiftNativeNSArrayBase (Compatibility)
++ (id) new;
+@end
+
+@implementation __SwiftNativeNSArrayBase (Compatibility)
+
++ (id) new {
+  // Some apps accidentally do [[[aSwiftArray class] new] mutableCopy]
+  return [objc_lookUpClass("NSArray") new];
+}
+
+@end
+
 #endif
 
 // ${'Local Variables'}:
diff --git a/test/stdlib/ArrayBridge.swift.gyb b/test/stdlib/ArrayBridge.swift.gyb
index 4d7009dea4220..004650818eab0 100644
--- a/test/stdlib/ArrayBridge.swift.gyb
+++ b/test/stdlib/ArrayBridge.swift.gyb
@@ -422,6 +422,11 @@ tests.test("testThunks") {
   testBridgeableValue(Thunks())
 }
 
+tests.test("testHKTFilter") {
+  let base = ["hello", "world"]
+  let result = testHKTFilter(base) as! NSArray as! [String]
+  expectEqual(result, ["hello"])
+}
 
 tests.test("testRoundTrip") {
   class Test : NSObject {
diff --git a/test/stdlib/Inputs/ArrayBridge/ArrayBridge.h b/test/stdlib/Inputs/ArrayBridge/ArrayBridge.h
index f026d8185bfef..44bee7687ff38 100644
--- a/test/stdlib/Inputs/ArrayBridge/ArrayBridge.h
+++ b/test/stdlib/Inputs/ArrayBridge/ArrayBridge.h
@@ -16,6 +16,7 @@ NSArray* idAsArray(id a);
 
 void testSubclass(id thunks);
 void testBridgeableValue(id thunks);
+id testHKTFilter(id array);
 
 @interface RDar27905230 : NSObject
 + (NSDictionary<NSString *, NSArray<id> *> *)mutableDictionaryOfMutableLists;
diff --git a/test/stdlib/Inputs/ArrayBridge/ArrayBridge.m b/test/stdlib/Inputs/ArrayBridge/ArrayBridge.m
index 957cf5e3f372b..22913c38761ee 100644
--- a/test/stdlib/Inputs/ArrayBridge/ArrayBridge.m
+++ b/test/stdlib/Inputs/ArrayBridge/ArrayBridge.m
@@ -67,6 +67,22 @@ void testBridgeableValue(id thunks) {
   [thunks acceptBridgeableValueArray: toSwiftArr];
 }
 
+static id filter(id<NSFastEnumeration, NSObject> container, BOOL (^predicate)(id)) {
+  id result = [[[container class] new] mutableCopy];
+  for (id object in container) {
+    if (predicate(object)) {
+      [result addObject:object];
+    }
+  }
+  return result;
+}
+
+id testHKTFilter(id array) {
+  return filter(array, ^(id obj) {
+    return [obj isEqual:@"hello"];
+  });
+}
+
 @implementation RDar27905230
 
 + (NSDictionary<NSString *, NSArray<id> *> *)mutableDictionaryOfMutableLists  {