The ASSERT in appendNode() should not fire when OBJECTS are cloned.

Source/core/editing/CompositeEditCommand.cpp

Index: Source/core/editing/CompositeEditCommand.cpp
diff --git a/Source/core/editing/CompositeEditCommand.cpp b/Source/core/editing/CompositeEditCommand.cpp
index e05df2ca12e94aeec032c1b456f1697eed4e9920..1b4edb9d2bac5188b9e7a2650c4422d1c82d49b0 100644
--- a/Source/core/editing/CompositeEditCommand.cpp
+++ b/Source/core/editing/CompositeEditCommand.cpp
@@ -360,7 +360,9 @@ void CompositeEditCommand::insertNodeAt(PassRefPtrWillBeRawPtr<Node> insertChild
 
 void CompositeEditCommand::appendNode(PassRefPtrWillBeRawPtr<Node> node, PassRefPtrWillBeRawPtr<ContainerNode> parent)
 {
-    ASSERT(canHaveChildrenForEditing(parent.get()));
+    // The useFallbackContent() is not set for cloned <object> nodes.
+    ASSERT(canHaveChildrenForEditing(parent.get())
+        || (parent->isElementNode() && toElement(parent.get())->tagQName() == objectTag));

[yosin_UTC9, 2014/11/20 01:26:41]

Could you add a comment why we check OBJECT element?

Note: We have OBJECT element here if |start| or |end| position are in OBJECT's
fallback content in |CompositeEditCommand::cloneParagraphUnderNewElement()|.

     applyCommandToComposite(AppendNodeCommand::create(parent, node));
 }