From 380e688123250c671e1b935490e73090e19e6ec8 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Tue, 6 Apr 2021 15:52:09 +0200
Subject: [PATCH] LibWeb: Remove nodes from their old parent in
 appendChild/insertBefore

---
 Userland/Libraries/LibWeb/DOM/Node.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Userland/Libraries/LibWeb/DOM/Node.cpp b/Userland/Libraries/LibWeb/DOM/Node.cpp
index 5b933a892e9..5bb5cffd7bc 100644
--- a/Userland/Libraries/LibWeb/DOM/Node.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Node.cpp
@@ -181,6 +181,8 @@ const Element* Node::parent_element() const
 
 RefPtr<Node> Node::append_child(NonnullRefPtr<Node> node, bool notify)
 {
+    if (node->parent())
+        node->parent()->remove_child(node);
     if (&node->document() != &document())
         document().adopt_node(node);
     TreeNode<Node>::append_child(node, notify);
@@ -201,6 +203,8 @@ RefPtr<Node> Node::insert_before(NonnullRefPtr<Node> node, RefPtr<Node> child, b
         dbgln("FIXME: Trying to insert_before() a bogus child");
         return nullptr;
     }
+    if (node->parent())
+        node->parent()->remove_child(node);
     if (&node->document() != &document())
         document().adopt_node(node);
     TreeNode<Node>::insert_before(node, child, notify);