diff -r 000000000000 -r 6474c204b198 editor/libeditor/base/SplitElementTxn.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/editor/libeditor/base/SplitElementTxn.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,66 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef SplitElementTxn_h__
+#define SplitElementTxn_h__
+
+#include "EditTxn.h"                    // for EditTxn, NS_DECL_EDITTXN
+#include "nsCOMPtr.h"                   // for nsCOMPtr
+#include "nsCycleCollectionParticipant.h"
+#include "nsIDOMNode.h"                 // for nsIDOMNode
+#include "nsISupportsImpl.h"            // for NS_DECL_ISUPPORTS_INHERITED
+#include "nscore.h"                     // for NS_IMETHOD
+
+class nsEditor;
+
+/**
+ * A transaction that splits an element E into two identical nodes, E1 and E2
+ * with the children of E divided between E1 and E2.
+ */
+class SplitElementTxn : public EditTxn
+{
+public:
+  /** initialize the transaction.
+    * @param aEditor  the provider of core editing operations
+    * @param aNode    the node to split
+    * @param aOffset  the location within aNode to do the split.
+    *                 aOffset may refer to children of aNode, or content of aNode.
+    *                 The left node will have child|content 0..aOffset-1.
+    */
+  NS_IMETHOD Init (nsEditor   *aEditor,
+                   nsIDOMNode *aNode,
+                   int32_t     aOffset);
+
+  SplitElementTxn();
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(SplitElementTxn, EditTxn)
+
+  NS_DECL_EDITTXN
+
+  NS_IMETHOD RedoTransaction(void);
+
+  NS_IMETHOD GetNewNode(nsIDOMNode **aNewNode);
+
+protected:
+  
+  /** the element to operate upon */
+  nsCOMPtr<nsIDOMNode> mExistingRightNode;
+
+  /** the offset into mElement where the children of mElement are split.<BR>
+    * mOffset is the index of the first child in the right node. 
+    * -1 means the new node gets no children.
+    */
+  int32_t  mOffset;
+
+  /** the element we create when splitting mElement */
+  nsCOMPtr<nsIDOMNode> mNewLeftNode;
+
+  /** the parent shared by mExistingRightNode and mNewLeftNode */
+  nsCOMPtr<nsIDOMNode> mParent;
+  nsEditor*  mEditor;
+};
+
+#endif