From 373d08e572528db4ff9312ad26b6e220dade7f62 Mon Sep 17 00:00:00 2001
From: Slava Pestov <spestov@apple.com>
Date: Tue, 13 May 2025 11:16:39 -0400
Subject: [PATCH] Add regression test for rdar://148357926

I believe this was fixed by https://github.com/swiftlang/swift/pull/81181.
---
 test/Constraints/opened_existentials.swift | 26 ++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/test/Constraints/opened_existentials.swift b/test/Constraints/opened_existentials.swift
index a8519e23d4df8..ebbcae1227f10 100644
--- a/test/Constraints/opened_existentials.swift
+++ b/test/Constraints/opened_existentials.swift
@@ -565,3 +565,29 @@ do {
     types.assertTypesAreEqual()
   }
 }
+
+struct G<A>: PP3 {}
+
+protocol PP1 {
+    associatedtype A
+}
+
+extension PP1 {
+    func f(p: any PP2<G<Self.A>>) {
+        p.g(t: self)
+    }
+}
+
+protocol PP2<B> {
+    associatedtype A
+    associatedtype B: PP3 where Self.B.A == Self.A
+}
+
+extension PP2 {
+    func g<T: PP1>(t: T) where Self.B == G<T.A> {}
+}
+
+protocol PP3 {
+    associatedtype A
+}
+