From 07e3bb729db93a2ef2e3532cf5b480d059107c19 Mon Sep 17 00:00:00 2001
From: Luke Wilde <lukew@serenityos.org>
Date: Wed, 26 Oct 2022 18:09:24 +0100
Subject: [PATCH] LibWeb: Convert DOM::AbortSignal to use JS::SafeFunction

This protects the captured GC pointers automatically instead of
manually.
---
 Userland/Libraries/LibWeb/DOM/AbortSignal.cpp | 2 +-
 Userland/Libraries/LibWeb/DOM/AbortSignal.h   | 4 ++--
 Userland/Libraries/LibWeb/DOM/EventTarget.cpp | 5 +++--
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/Userland/Libraries/LibWeb/DOM/AbortSignal.cpp b/Userland/Libraries/LibWeb/DOM/AbortSignal.cpp
index bdee043078..f05a6d2f46 100644
--- a/Userland/Libraries/LibWeb/DOM/AbortSignal.cpp
+++ b/Userland/Libraries/LibWeb/DOM/AbortSignal.cpp
@@ -24,7 +24,7 @@ AbortSignal::AbortSignal(JS::Realm& realm)
 }
 
 // https://dom.spec.whatwg.org/#abortsignal-add
-void AbortSignal::add_abort_algorithm(Function<void()> abort_algorithm)
+void AbortSignal::add_abort_algorithm(JS::SafeFunction<void()> abort_algorithm)
 {
     // 1. If signal is aborted, then return.
     if (aborted())
diff --git a/Userland/Libraries/LibWeb/DOM/AbortSignal.h b/Userland/Libraries/LibWeb/DOM/AbortSignal.h
index dab9d78321..7437e21add 100644
--- a/Userland/Libraries/LibWeb/DOM/AbortSignal.h
+++ b/Userland/Libraries/LibWeb/DOM/AbortSignal.h
@@ -22,7 +22,7 @@ public:
 
     virtual ~AbortSignal() override = default;
 
-    void add_abort_algorithm(Function<void()>);
+    void add_abort_algorithm(JS::SafeFunction<void()>);
 
     // https://dom.spec.whatwg.org/#dom-abortsignal-aborted
     // An AbortSignal object is aborted when its abort reason is not undefined.
@@ -49,7 +49,7 @@ private:
 
     // https://dom.spec.whatwg.org/#abortsignal-abort-algorithms
     // FIXME: This should be a set.
-    Vector<Function<void()>> m_abort_algorithms;
+    Vector<JS::SafeFunction<void()>> m_abort_algorithms;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/DOM/EventTarget.cpp b/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
index f3b35d8a33..8a90e5e7f4 100644
--- a/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
+++ b/Userland/Libraries/LibWeb/DOM/EventTarget.cpp
@@ -170,9 +170,10 @@ void EventTarget::add_an_event_listener(DOMEventListener& listener)
 
     // 5. If listener’s signal is not null, then add the following abort steps to it:
     if (listener.signal) {
-        listener.signal->add_abort_algorithm([strong_event_target = JS::make_handle(*this), listener = JS::make_handle(&listener)]() mutable {
+        // NOTE: `this` and `listener` are protected by AbortSignal using JS::SafeFunction.
+        listener.signal->add_abort_algorithm([this, &listener]() mutable {
             // 1. Remove an event listener with eventTarget and listener.
-            strong_event_target->remove_an_event_listener(*listener);
+            remove_an_event_listener(listener);
         });
     }
 }