From 0ec433edce272297d477e5db4f6c2aa3adb8b24f Mon Sep 17 00:00:00 2001
From: Timothy Flynn <trflynn89@pm.me>
Date: Tue, 13 Dec 2022 18:39:25 -0500
Subject: [PATCH] LibJS: Explictly assert that a null GCPtr is not dereferenced

---
 Userland/Libraries/LibJS/Heap/GCPtr.h | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/Userland/Libraries/LibJS/Heap/GCPtr.h b/Userland/Libraries/LibJS/Heap/GCPtr.h
index 7eca3d7129..f0c0623afa 100644
--- a/Userland/Libraries/LibJS/Heap/GCPtr.h
+++ b/Userland/Libraries/LibJS/Heap/GCPtr.h
@@ -52,6 +52,7 @@ public:
     NonnullGCPtr& operator=(GCPtr<T> const& other)
     {
         m_ptr = const_cast<T*>(other.ptr());
+        VERIFY(m_ptr);
         return *this;
     }
 
@@ -186,8 +187,18 @@ public:
         return *this;
     }
 
-    T* operator->() const { return m_ptr; }
-    T& operator*() const { return *m_ptr; }
+    T* operator->() const
+    {
+        VERIFY(m_ptr);
+        return m_ptr;
+    }
+
+    T& operator*() const
+    {
+        VERIFY(m_ptr);
+        return *m_ptr;
+    }
+
     T* ptr() const { return m_ptr; }
 
     operator bool() const { return !!m_ptr; }