Merge pull request #27131 from jckarter/regression-test-8789

Add regression test for SR-8789.

Author: jckarter

test/SILGen/Inputs/objc_init_iuo_override.h

@@ -0,0 +1,19 @@
+#import <Foundation/Foundation.h>
+
+
+// NB: No NS_ASSUME_NONNULL
+
+@protocol FooProtocol <NSObject>
+
+@property (nonatomic,readonly) NSString *name;
+
+@end
+
+
+@interface ParentClass : NSObject
+
+- (instancetype)initWithFoo:(id<FooProtocol>)foo;
+
+@end
+
+

test/SILGen/objc_init_iuo_override.swift

@@ -0,0 +1,18 @@
+// SR-8789
+
+// RUN: %target-swift-emit-silgen -verify -import-objc-header %S/Inputs/objc_init_iuo_override.h %s
+// REQUIRES: objc_interop
+
+class ChildClass: ParentClass {}
+
+class GrandchildClass: ChildClass {
+	// The original init is defined in objc as:
+        //   - (instancetype)initWithFoo:(id<FooProtocol>)foo;
+        // without nullability audits, meaning the signature in Swift is:
+        //   init!(foo: FooProtocol)
+        // and
+	override init(foo: FooProtocol) {
+		super.init(foo: foo)
+	}
+}
+