From 83f6b8bc9a4a332d9532a4e0bebcf9c40d00df1b Mon Sep 17 00:00:00 2001
From: asynts <asynts@gmail.com>
Date: Fri, 27 Nov 2020 23:00:53 +0100
Subject: [PATCH] LibWeb: Two more edge cases for TreeNode::insert_before.

---
 Libraries/LibWeb/TreeNode.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Libraries/LibWeb/TreeNode.h b/Libraries/LibWeb/TreeNode.h
index 96e8155b61..604dcb6625 100644
--- a/Libraries/LibWeb/TreeNode.h
+++ b/Libraries/LibWeb/TreeNode.h
@@ -380,6 +380,12 @@ inline void TreeNode<T>::insert_before(NonnullRefPtr<T> node, RefPtr<T> child, b
     node->m_previous_sibling = child->m_previous_sibling;
     node->m_next_sibling = child;
 
+    if (child->m_previous_sibling)
+        child->m_previous_sibling->m_next_sibling = node;
+
+    if (m_first_child == child)
+        m_first_child = node;
+
     child->m_previous_sibling = node;
 
     if (m_first_child == child)