Issue #2135 - Bug 1066965: Make contentEditable and spellchecking to work in Shadow DOM

dom/base/Element.cpp

@@ -1725,10 +1725,11 @@ Element::BindToTree(nsIDocument* aDocument, nsIContent* aParent,
     if (!hadParent) {
       uint32_t editableDescendantChange = EditableInclusiveDescendantCount(this);
       if (editableDescendantChange != 0) {
-      // If we are binding a subtree root to the document, we need to update
-      // the editable descendant count of all the ancestors.
+        // If we are binding a subtree root to the document, we need to update
+        // the editable descendant count of all the ancestors. However, we don't
+        // cross the Shadow DOM boundary (expected behavior is unclear).
         nsIContent* parent = GetParent();
-        while (parent) {
+        while (parent && parent->IsElement()) {
           parent->ChangeEditableDescendantCount(editableDescendantChange);
           parent = parent->GetParent();
         }

dom/base/nsINode.cpp

@@ -273,6 +273,18 @@ nsINode* nsINode::GetRootNode(const GetRootNodeOptions& aOptions)
   return SubtreeRoot();
 }
 
+// TODO: was marked as constant.
+nsINode*
+nsINode::GetParentOrHostNode()
+{
+  if (mParent) {
+    return mParent;
+  }
+
+  ShadowRoot* shadowRoot = ShadowRoot::FromNode(this);
+  return shadowRoot ? shadowRoot->GetHost() : nullptr;
+}
+
 nsINode*
 nsINode::SubtreeRoot() const
 {

dom/base/nsINode.h

@@ -942,6 +942,12 @@ public:
     return mParent;
   }
 
+  /**
+   * This is similar to above, but in case 'this' is ShadowRoot, we return its
+   * host element.
+   */
+  nsINode* GetParentOrHostNode();
+
   /**
    * Returns the node that is the parent of this node in the flattened
    * tree. This differs from the normal parent if the node is filtered