diff --git a/mozilla/editor/base/EditTxn.cpp b/mozilla/editor/base/EditTxn.cpp
index f27751239fe..a24dcb14809 100644
--- a/mozilla/editor/base/EditTxn.cpp
+++ b/mozilla/editor/base/EditTxn.cpp
@@ -17,6 +17,9 @@
  */
 
 #include "EditTxn.h"
+#include "nsCOMPtr.h"
+#include "nsIDOMNode.h"
+#include "nsIDOMNodeList.h"
 
 static NS_DEFINE_IID(kISupportsIID, NS_ISUPPORTS_IID);
 static NS_DEFINE_IID(kITransactionIID, NS_ITRANSACTION_IID);
@@ -96,3 +99,54 @@ EditTxn::QueryInterface(REFNSIID aIID, void** aInstancePtr)
   *aInstancePtr = 0;
   return NS_NOINTERFACE;
 }
+
+
+/* =============================== Static helper methods ================================== */
+
+nsresult 
+EditTxn::SplitNode(nsIDOMNode * aNode,
+                   PRInt32      aOffset,
+                   nsIDOMNode*  aNewNode,
+                   nsIDOMNode*  aParent)
+{
+  nsCOMPtr<nsIDOMNode> resultNode;
+  nsresult result = aParent->InsertBefore(aNewNode, aNode, getter_AddRefs(resultNode));
+  if (NS_SUCCEEDED(result))
+  {
+    // split the children between the 2 nodes
+    // at this point, nNode has all the children
+    if (0<=aOffset) // don't bother unless we're going to move at least one child
+    {
+      nsCOMPtr<nsIDOMNodeList> childNodes;
+      result = aParent->GetChildNodes(getter_AddRefs(childNodes));
+      if ((NS_SUCCEEDED(result)) && (childNodes))
+      {
+        PRInt32 i=0;
+        for ( ; ((NS_SUCCEEDED(result)) && (i<aOffset)); i++)
+        {
+          nsCOMPtr<nsIDOMNode> childNode;
+          result = childNodes->Item(i, getter_AddRefs(childNode));
+          if ((NS_SUCCEEDED(result)) && (childNode))
+          {
+            result = aNode->RemoveChild(childNode, getter_AddRefs(resultNode));
+            if (NS_SUCCEEDED(result))
+            {
+              result = aNewNode->AppendChild(childNode, getter_AddRefs(resultNode));
+            }
+          }
+        }
+      }        
+    }
+  }
+  return result;
+}
+
+nsresult
+EditTxn::JoinNodes(nsIDOMNode * aNodeToKeep,
+                   nsIDOMNode * aNodeToJoin,
+                   nsIDOMNode * aParent,
+                   PRBool       aNodeToKeepIsFirst)
+{
+  nsresult result;
+  return result;
+}
\ No newline at end of file
diff --git a/mozilla/editor/base/EditTxn.h b/mozilla/editor/base/EditTxn.h
index af6e4224081..ac0201f0412 100644
--- a/mozilla/editor/base/EditTxn.h
+++ b/mozilla/editor/base/EditTxn.h
@@ -22,6 +22,8 @@
 #include "nsITransaction.h"
 class nsEditor;
 
+class nsIDOMNode;
+
 /**
  * base class for all document editing transactions.
  * provides access to the nsEditor that created this transaction.
@@ -50,6 +52,19 @@ public:
 
   virtual nsresult GetRedoString(nsString **aString);
 
+ // helper static methods.  maybe move these into editor class.
+
+  /** */
+  static  nsresult SplitNode(nsIDOMNode * aNode,
+                             PRInt32      aOffset,
+                             nsIDOMNode * aNewNode,
+                             nsIDOMNode * aParent);
+
+  static nsresult EditTxn::JoinNodes(nsIDOMNode * aNodeToKeep,
+                                     nsIDOMNode * aNodeToJoin,
+                                     nsIDOMNode * aParent,
+                                     PRBool       aNodeToKeepIsFirst);
+
 protected:
 
   nsEditor *mEditor;
diff --git a/mozilla/editor/base/SplitElementTxn.cpp b/mozilla/editor/base/SplitElementTxn.cpp
index a0ab3288fcd..ee040d801dc 100644
--- a/mozilla/editor/base/SplitElementTxn.cpp
+++ b/mozilla/editor/base/SplitElementTxn.cpp
@@ -20,7 +20,6 @@
 #include "editor.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeList.h"
-#include "nsIDOMDocument.h"
 #include "nsIDOMElement.h"
 
 // note that aEditor is not refcounted
@@ -56,35 +55,7 @@ nsresult SplitElementTxn::Do(void)
     // insert the new node
     if ((NS_SUCCEEDED(result)) && (nsnull!=mParent))
     {
-      nsCOMPtr<nsIDOMNode> resultNode;
-      result = mParent->InsertBefore(mNewNode, mNode, getter_AddRefs(resultNode));
-      if (NS_SUCCEEDED(result))
-      {
-        // split the children between the 2 nodes
-        // at this point, nNode has all the children
-        if (0<=mOffset) // don't bother unless we're going to move at least one child
-        {
-          nsCOMPtr<nsIDOMNodeList> childNodes;
-          result = mParent->GetChildNodes(getter_AddRefs(childNodes));
-          if ((NS_SUCCEEDED(result)) && (childNodes))
-          {
-            PRUint32 i=0;
-            for ( ; ((NS_SUCCEEDED(result)) && (i<mOffset)); i++)
-            {
-              nsCOMPtr<nsIDOMNode> childNode;
-              result = childNodes->Item(i, getter_AddRefs(childNode));
-              if ((NS_SUCCEEDED(result)) && (childNode))
-              {
-                result = mNode->RemoveChild(childNode, getter_AddRefs(resultNode));
-                if (NS_SUCCEEDED(result))
-                {
-                  result = mNewNode->AppendChild(childNode, getter_AddRefs(resultNode));
-                }
-              }
-            }
-          }
-        }
-      }        
+      result = EditTxn::SplitNode(mNode, mOffset, mNewNode, mParent);
     }
   }
   return result;
@@ -92,12 +63,15 @@ nsresult SplitElementTxn::Do(void)
 
 nsresult SplitElementTxn::Undo(void)
 {
-  return NS_OK;
+  // this assumes Do inserted the new node in front of the prior existing node
+  nsresult result = EditTxn::JoinNodes(mNode, mNewNode, mParent, PR_FALSE);
+  return result;
 }
 
 nsresult SplitElementTxn::Redo(void)
 {
-  return NS_OK;
+  nsresult result = EditTxn::SplitNode(mNode, mOffset, mNewNode, mParent);
+  return result;
 }
 
 nsresult SplitElementTxn::GetIsTransient(PRBool *aIsTransient)
diff --git a/mozilla/editor/core/EditTxn.cpp b/mozilla/editor/core/EditTxn.cpp
index f27751239fe..a24dcb14809 100644
--- a/mozilla/editor/core/EditTxn.cpp
+++ b/mozilla/editor/core/EditTxn.cpp
@@ -17,6 +17,9 @@
  */
 
 #include "EditTxn.h"
+#include "nsCOMPtr.h"
+#include "nsIDOMNode.h"
+#include "nsIDOMNodeList.h"
 
 static NS_DEFINE_IID(kISupportsIID, NS_ISUPPORTS_IID);
 static NS_DEFINE_IID(kITransactionIID, NS_ITRANSACTION_IID);
@@ -96,3 +99,54 @@ EditTxn::QueryInterface(REFNSIID aIID, void** aInstancePtr)
   *aInstancePtr = 0;
   return NS_NOINTERFACE;
 }
+
+
+/* =============================== Static helper methods ================================== */
+
+nsresult 
+EditTxn::SplitNode(nsIDOMNode * aNode,
+                   PRInt32      aOffset,
+                   nsIDOMNode*  aNewNode,
+                   nsIDOMNode*  aParent)
+{
+  nsCOMPtr<nsIDOMNode> resultNode;
+  nsresult result = aParent->InsertBefore(aNewNode, aNode, getter_AddRefs(resultNode));
+  if (NS_SUCCEEDED(result))
+  {
+    // split the children between the 2 nodes
+    // at this point, nNode has all the children
+    if (0<=aOffset) // don't bother unless we're going to move at least one child
+    {
+      nsCOMPtr<nsIDOMNodeList> childNodes;
+      result = aParent->GetChildNodes(getter_AddRefs(childNodes));
+      if ((NS_SUCCEEDED(result)) && (childNodes))
+      {
+        PRInt32 i=0;
+        for ( ; ((NS_SUCCEEDED(result)) && (i<aOffset)); i++)
+        {
+          nsCOMPtr<nsIDOMNode> childNode;
+          result = childNodes->Item(i, getter_AddRefs(childNode));
+          if ((NS_SUCCEEDED(result)) && (childNode))
+          {
+            result = aNode->RemoveChild(childNode, getter_AddRefs(resultNode));
+            if (NS_SUCCEEDED(result))
+            {
+              result = aNewNode->AppendChild(childNode, getter_AddRefs(resultNode));
+            }
+          }
+        }
+      }        
+    }
+  }
+  return result;
+}
+
+nsresult
+EditTxn::JoinNodes(nsIDOMNode * aNodeToKeep,
+                   nsIDOMNode * aNodeToJoin,
+                   nsIDOMNode * aParent,
+                   PRBool       aNodeToKeepIsFirst)
+{
+  nsresult result;
+  return result;
+}
\ No newline at end of file
diff --git a/mozilla/editor/core/EditTxn.h b/mozilla/editor/core/EditTxn.h
index af6e4224081..ac0201f0412 100644
--- a/mozilla/editor/core/EditTxn.h
+++ b/mozilla/editor/core/EditTxn.h
@@ -22,6 +22,8 @@
 #include "nsITransaction.h"
 class nsEditor;
 
+class nsIDOMNode;
+
 /**
  * base class for all document editing transactions.
  * provides access to the nsEditor that created this transaction.
@@ -50,6 +52,19 @@ public:
 
   virtual nsresult GetRedoString(nsString **aString);
 
+ // helper static methods.  maybe move these into editor class.
+
+  /** */
+  static  nsresult SplitNode(nsIDOMNode * aNode,
+                             PRInt32      aOffset,
+                             nsIDOMNode * aNewNode,
+                             nsIDOMNode * aParent);
+
+  static nsresult EditTxn::JoinNodes(nsIDOMNode * aNodeToKeep,
+                                     nsIDOMNode * aNodeToJoin,
+                                     nsIDOMNode * aParent,
+                                     PRBool       aNodeToKeepIsFirst);
+
 protected:
 
   nsEditor *mEditor;
diff --git a/mozilla/editor/core/SplitElementTxn.cpp b/mozilla/editor/core/SplitElementTxn.cpp
index a0ab3288fcd..ee040d801dc 100644
--- a/mozilla/editor/core/SplitElementTxn.cpp
+++ b/mozilla/editor/core/SplitElementTxn.cpp
@@ -20,7 +20,6 @@
 #include "editor.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeList.h"
-#include "nsIDOMDocument.h"
 #include "nsIDOMElement.h"
 
 // note that aEditor is not refcounted
@@ -56,35 +55,7 @@ nsresult SplitElementTxn::Do(void)
     // insert the new node
     if ((NS_SUCCEEDED(result)) && (nsnull!=mParent))
     {
-      nsCOMPtr<nsIDOMNode> resultNode;
-      result = mParent->InsertBefore(mNewNode, mNode, getter_AddRefs(resultNode));
-      if (NS_SUCCEEDED(result))
-      {
-        // split the children between the 2 nodes
-        // at this point, nNode has all the children
-        if (0<=mOffset) // don't bother unless we're going to move at least one child
-        {
-          nsCOMPtr<nsIDOMNodeList> childNodes;
-          result = mParent->GetChildNodes(getter_AddRefs(childNodes));
-          if ((NS_SUCCEEDED(result)) && (childNodes))
-          {
-            PRUint32 i=0;
-            for ( ; ((NS_SUCCEEDED(result)) && (i<mOffset)); i++)
-            {
-              nsCOMPtr<nsIDOMNode> childNode;
-              result = childNodes->Item(i, getter_AddRefs(childNode));
-              if ((NS_SUCCEEDED(result)) && (childNode))
-              {
-                result = mNode->RemoveChild(childNode, getter_AddRefs(resultNode));
-                if (NS_SUCCEEDED(result))
-                {
-                  result = mNewNode->AppendChild(childNode, getter_AddRefs(resultNode));
-                }
-              }
-            }
-          }
-        }
-      }        
+      result = EditTxn::SplitNode(mNode, mOffset, mNewNode, mParent);
     }
   }
   return result;
@@ -92,12 +63,15 @@ nsresult SplitElementTxn::Do(void)
 
 nsresult SplitElementTxn::Undo(void)
 {
-  return NS_OK;
+  // this assumes Do inserted the new node in front of the prior existing node
+  nsresult result = EditTxn::JoinNodes(mNode, mNewNode, mParent, PR_FALSE);
+  return result;
 }
 
 nsresult SplitElementTxn::Redo(void)
 {
-  return NS_OK;
+  nsresult result = EditTxn::SplitNode(mNode, mOffset, mNewNode, mParent);
+  return result;
 }
 
 nsresult SplitElementTxn::GetIsTransient(PRBool *aIsTransient)
diff --git a/mozilla/editor/libeditor/base/EditTxn.cpp b/mozilla/editor/libeditor/base/EditTxn.cpp
index f27751239fe..a24dcb14809 100644
--- a/mozilla/editor/libeditor/base/EditTxn.cpp
+++ b/mozilla/editor/libeditor/base/EditTxn.cpp
@@ -17,6 +17,9 @@
  */
 
 #include "EditTxn.h"
+#include "nsCOMPtr.h"
+#include "nsIDOMNode.h"
+#include "nsIDOMNodeList.h"
 
 static NS_DEFINE_IID(kISupportsIID, NS_ISUPPORTS_IID);
 static NS_DEFINE_IID(kITransactionIID, NS_ITRANSACTION_IID);
@@ -96,3 +99,54 @@ EditTxn::QueryInterface(REFNSIID aIID, void** aInstancePtr)
   *aInstancePtr = 0;
   return NS_NOINTERFACE;
 }
+
+
+/* =============================== Static helper methods ================================== */
+
+nsresult 
+EditTxn::SplitNode(nsIDOMNode * aNode,
+                   PRInt32      aOffset,
+                   nsIDOMNode*  aNewNode,
+                   nsIDOMNode*  aParent)
+{
+  nsCOMPtr<nsIDOMNode> resultNode;
+  nsresult result = aParent->InsertBefore(aNewNode, aNode, getter_AddRefs(resultNode));
+  if (NS_SUCCEEDED(result))
+  {
+    // split the children between the 2 nodes
+    // at this point, nNode has all the children
+    if (0<=aOffset) // don't bother unless we're going to move at least one child
+    {
+      nsCOMPtr<nsIDOMNodeList> childNodes;
+      result = aParent->GetChildNodes(getter_AddRefs(childNodes));
+      if ((NS_SUCCEEDED(result)) && (childNodes))
+      {
+        PRInt32 i=0;
+        for ( ; ((NS_SUCCEEDED(result)) && (i<aOffset)); i++)
+        {
+          nsCOMPtr<nsIDOMNode> childNode;
+          result = childNodes->Item(i, getter_AddRefs(childNode));
+          if ((NS_SUCCEEDED(result)) && (childNode))
+          {
+            result = aNode->RemoveChild(childNode, getter_AddRefs(resultNode));
+            if (NS_SUCCEEDED(result))
+            {
+              result = aNewNode->AppendChild(childNode, getter_AddRefs(resultNode));
+            }
+          }
+        }
+      }        
+    }
+  }
+  return result;
+}
+
+nsresult
+EditTxn::JoinNodes(nsIDOMNode * aNodeToKeep,
+                   nsIDOMNode * aNodeToJoin,
+                   nsIDOMNode * aParent,
+                   PRBool       aNodeToKeepIsFirst)
+{
+  nsresult result;
+  return result;
+}
\ No newline at end of file
diff --git a/mozilla/editor/libeditor/base/EditTxn.h b/mozilla/editor/libeditor/base/EditTxn.h
index af6e4224081..ac0201f0412 100644
--- a/mozilla/editor/libeditor/base/EditTxn.h
+++ b/mozilla/editor/libeditor/base/EditTxn.h
@@ -22,6 +22,8 @@
 #include "nsITransaction.h"
 class nsEditor;
 
+class nsIDOMNode;
+
 /**
  * base class for all document editing transactions.
  * provides access to the nsEditor that created this transaction.
@@ -50,6 +52,19 @@ public:
 
   virtual nsresult GetRedoString(nsString **aString);
 
+ // helper static methods.  maybe move these into editor class.
+
+  /** */
+  static  nsresult SplitNode(nsIDOMNode * aNode,
+                             PRInt32      aOffset,
+                             nsIDOMNode * aNewNode,
+                             nsIDOMNode * aParent);
+
+  static nsresult EditTxn::JoinNodes(nsIDOMNode * aNodeToKeep,
+                                     nsIDOMNode * aNodeToJoin,
+                                     nsIDOMNode * aParent,
+                                     PRBool       aNodeToKeepIsFirst);
+
 protected:
 
   nsEditor *mEditor;
diff --git a/mozilla/editor/libeditor/base/SplitElementTxn.cpp b/mozilla/editor/libeditor/base/SplitElementTxn.cpp
index a0ab3288fcd..ee040d801dc 100644
--- a/mozilla/editor/libeditor/base/SplitElementTxn.cpp
+++ b/mozilla/editor/libeditor/base/SplitElementTxn.cpp
@@ -20,7 +20,6 @@
 #include "editor.h"
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeList.h"
-#include "nsIDOMDocument.h"
 #include "nsIDOMElement.h"
 
 // note that aEditor is not refcounted
@@ -56,35 +55,7 @@ nsresult SplitElementTxn::Do(void)
     // insert the new node
     if ((NS_SUCCEEDED(result)) && (nsnull!=mParent))
     {
-      nsCOMPtr<nsIDOMNode> resultNode;
-      result = mParent->InsertBefore(mNewNode, mNode, getter_AddRefs(resultNode));
-      if (NS_SUCCEEDED(result))
-      {
-        // split the children between the 2 nodes
-        // at this point, nNode has all the children
-        if (0<=mOffset) // don't bother unless we're going to move at least one child
-        {
-          nsCOMPtr<nsIDOMNodeList> childNodes;
-          result = mParent->GetChildNodes(getter_AddRefs(childNodes));
-          if ((NS_SUCCEEDED(result)) && (childNodes))
-          {
-            PRUint32 i=0;
-            for ( ; ((NS_SUCCEEDED(result)) && (i<mOffset)); i++)
-            {
-              nsCOMPtr<nsIDOMNode> childNode;
-              result = childNodes->Item(i, getter_AddRefs(childNode));
-              if ((NS_SUCCEEDED(result)) && (childNode))
-              {
-                result = mNode->RemoveChild(childNode, getter_AddRefs(resultNode));
-                if (NS_SUCCEEDED(result))
-                {
-                  result = mNewNode->AppendChild(childNode, getter_AddRefs(resultNode));
-                }
-              }
-            }
-          }
-        }
-      }        
+      result = EditTxn::SplitNode(mNode, mOffset, mNewNode, mParent);
     }
   }
   return result;
@@ -92,12 +63,15 @@ nsresult SplitElementTxn::Do(void)
 
 nsresult SplitElementTxn::Undo(void)
 {
-  return NS_OK;
+  // this assumes Do inserted the new node in front of the prior existing node
+  nsresult result = EditTxn::JoinNodes(mNode, mNewNode, mParent, PR_FALSE);
+  return result;
 }
 
 nsresult SplitElementTxn::Redo(void)
 {
-  return NS_OK;
+  nsresult result = EditTxn::SplitNode(mNode, mOffset, mNewNode, mParent);
+  return result;
 }
 
 nsresult SplitElementTxn::GetIsTransient(PRBool *aIsTransient)