From 99536449d5e59dd1ac5e85c09d47cb7b66ce6730 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sat, 28 Nov 2020 00:42:24 +0100
Subject: [PATCH] LibWeb: Don't generate layout nodes for DOM inside replaced
 elements

Before this change, we'd show both a <canvas>, and any fallback content
inside the <canvas> for browsers that don't support <canvas>. :^)
---
 Libraries/LibWeb/Layout/TreeBuilder.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Libraries/LibWeb/Layout/TreeBuilder.cpp b/Libraries/LibWeb/Layout/TreeBuilder.cpp
index bbcb690279..981b881be9 100644
--- a/Libraries/LibWeb/Layout/TreeBuilder.cpp
+++ b/Libraries/LibWeb/Layout/TreeBuilder.cpp
@@ -129,6 +129,10 @@ void TreeBuilder::create_layout_tree(DOM::Node& dom_node)
         }
     }
 
+    // Ignore fallback content inside replaced elements.
+    if (layout_node->is_replaced())
+        return;
+
     if (dom_node.has_children()) {
         push_parent(*layout_node);
         downcast<DOM::ParentNode>(dom_node).for_each_child([&](auto& dom_child) {