From 8547c1a74382a73eebafd94ce2dce15ca33d1c76 Mon Sep 17 00:00:00 2001
From: Tim Ledbetter <tim.ledbetter@ladybird.org>
Date: Wed, 5 Feb 2025 23:33:13 +0000
Subject: [PATCH] LibWeb: Ensure inert contenteditable elements are not
 editable

---
 Libraries/LibWeb/DOM/Node.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Libraries/LibWeb/DOM/Node.cpp b/Libraries/LibWeb/DOM/Node.cpp
index b02f7c2431a..251b38cf88f 100644
--- a/Libraries/LibWeb/DOM/Node.cpp
+++ b/Libraries/LibWeb/DOM/Node.cpp
@@ -1311,6 +1311,12 @@ bool Node::is_editable() const
     if (!parent() || !parent()->is_editable_or_editing_host())
         return false;
 
+    // https://html.spec.whatwg.org/multipage/interaction.html#inert-subtrees
+    // When a node is inert:
+    // - If it is editable, the node behaves as if it were non-editable.
+    if (is_inert())
+        return false;
+
     // and either it is an HTML element,
     if (is<HTML::HTMLElement>(this))
         return true;