From 06d9451551f2b3b212a2889ac6ed21baad572e6d Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Mon, 10 Jul 2023 20:50:24 +0200
Subject: [PATCH] LibWeb: Don't cache property accesses on WindowProxy

Since the underlying HTML::Window can change, caching property accesses
on WindowProxy is not as simple as remembering the shape. Let's disable
caching here for now. We can come back to it in the future when we have
no low-hanging fruit left. :^)

Fixes an assertion failure on https://twinings.co.uk/
---
 .../expected/window-proxy-property-inline-cache.txt |  2 ++
 .../input/window-proxy-property-inline-cache.html   | 13 +++++++++++++
 Userland/Libraries/LibWeb/HTML/WindowProxy.cpp      |  4 ++--
 3 files changed, 17 insertions(+), 2 deletions(-)
 create mode 100644 Tests/LibWeb/Text/expected/window-proxy-property-inline-cache.txt
 create mode 100644 Tests/LibWeb/Text/input/window-proxy-property-inline-cache.html

diff --git a/Tests/LibWeb/Text/expected/window-proxy-property-inline-cache.txt b/Tests/LibWeb/Text/expected/window-proxy-property-inline-cache.txt
new file mode 100644
index 00000000000..370fd29745e
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/window-proxy-property-inline-cache.txt
@@ -0,0 +1,2 @@
+123
+undefined
diff --git a/Tests/LibWeb/Text/input/window-proxy-property-inline-cache.html b/Tests/LibWeb/Text/input/window-proxy-property-inline-cache.html
new file mode 100644
index 00000000000..af005f95615
--- /dev/null
+++ b/Tests/LibWeb/Text/input/window-proxy-property-inline-cache.html
@@ -0,0 +1,13 @@
+<script src="include.js"></script>
+<script>
+    test(() => {
+        function ic(o) {
+            return o.foo
+        }
+
+        window.foo = 123
+        println(ic(window))
+        delete window.foo
+        println(ic(window))
+    });
+</script>
diff --git a/Userland/Libraries/LibWeb/HTML/WindowProxy.cpp b/Userland/Libraries/LibWeb/HTML/WindowProxy.cpp
index 7cf010ece5e..4554c0157aa 100644
--- a/Userland/Libraries/LibWeb/HTML/WindowProxy.cpp
+++ b/Userland/Libraries/LibWeb/HTML/WindowProxy.cpp
@@ -144,7 +144,7 @@ JS::ThrowCompletionOr<bool> WindowProxy::internal_define_own_property(JS::Proper
 }
 
 // 7.4.7 [[Get]] ( P, Receiver ), https://html.spec.whatwg.org/multipage/window-object.html#windowproxy-get
-JS::ThrowCompletionOr<JS::Value> WindowProxy::internal_get(JS::PropertyKey const& property_key, JS::Value receiver, JS::CacheablePropertyMetadata* cacheable_metadata) const
+JS::ThrowCompletionOr<JS::Value> WindowProxy::internal_get(JS::PropertyKey const& property_key, JS::Value receiver, JS::CacheablePropertyMetadata*) const
 {
     auto& vm = this->vm();
 
@@ -156,7 +156,7 @@ JS::ThrowCompletionOr<JS::Value> WindowProxy::internal_get(JS::PropertyKey const
     // 3. If IsPlatformObjectSameOrigin(W) is true, then return ? OrdinaryGet(this, P, Receiver).
     // NOTE: this is passed rather than W as OrdinaryGet and CrossOriginGet will invoke the [[GetOwnProperty]] internal method.
     if (is_platform_object_same_origin(*m_window))
-        return JS::Object::internal_get(property_key, receiver, cacheable_metadata);
+        return JS::Object::internal_get(property_key, receiver);
 
     // 4. Return ? CrossOriginGet(this, P, Receiver).
     // NOTE: this is passed rather than W as OrdinaryGet and CrossOriginGet will invoke the [[GetOwnProperty]] internal method.