From 1b036355ced7cd6b8195970fef07383ba3561c4d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fernando=20Jim=C3=A9nez=20Moreno?= <ferjmoreno@gmail.com>
Date: Mon, 28 Jan 2019 18:12:31 +0100
Subject: [PATCH] Bind/unbind shadow host children to/from tree

---
 components/script/dom/element.rs | 20 ++++++++++++++++++++
 components/script/dom/node.rs    | 11 +++++++++--
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 5d23400e745..dac2d29e51f 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -2784,6 +2784,16 @@ impl VirtualMethods for Element {
             return;
         }
 
+        if self.is_shadow_host() {
+            let shadow_root = self.shadow_root.get().unwrap();
+            let shadow_root = shadow_root.upcast::<Node>();
+            shadow_root.set_flag(NodeFlags::IS_CONNECTED, tree_connected);
+            for node in shadow_root.children() {
+                node.set_flag(NodeFlags::IS_CONNECTED, tree_connected);
+                node.bind_to_tree(tree_connected);
+            }
+        }
+
         let doc = document_from_node(self);
         if let Some(ref value) = *self.id_attribute.borrow() {
             doc.register_named_element(self, value.clone());
@@ -2803,6 +2813,16 @@ impl VirtualMethods for Element {
             return;
         }
 
+        if self.is_shadow_host() {
+            let shadow_root = self.shadow_root.get().unwrap();
+            let shadow_root = shadow_root.upcast::<Node>();
+            shadow_root.set_flag(NodeFlags::IS_CONNECTED, false);
+            for node in shadow_root.children() {
+                node.set_flag(NodeFlags::IS_CONNECTED, false);
+                node.unbind_from_tree(context);
+            }
+        }
+
         let doc = document_from_node(self);
         let fullscreen = doc.GetFullscreenElement();
         if fullscreen.deref() == Some(self) {
diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index 25a0c4625e8..1585f81693e 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -643,7 +643,8 @@ impl Node {
     }
 
     fn is_shadow_including_inclusive_ancestor_of(&self, node: &Node) -> bool {
-        node.shadow_including_inclusive_ancestors().any(|ancestor| &*ancestor == self)
+        node.shadow_including_inclusive_ancestors()
+            .any(|ancestor| &*ancestor == self)
     }
 
     pub fn following_siblings(&self) -> impl Iterator<Item = DomRoot<Node>> {
@@ -1117,7 +1118,13 @@ impl Node {
                 return DomRoot::from_ref(&a);
             }
 
-            a = DomRoot::from_ref(a_root.downcast::<ShadowRoot>().unwrap().Host().upcast::<Node>());
+            a = DomRoot::from_ref(
+                a_root
+                    .downcast::<ShadowRoot>()
+                    .unwrap()
+                    .Host()
+                    .upcast::<Node>(),
+            );
         }
     }
 }