diff --git a/content/base/public/nsIDocumentEncoder.h b/content/base/public/nsIDocumentEncoder.h
index 75e8e8231d30..66db12cb4ff8 100644
--- a/content/base/public/nsIDocumentEncoder.h
+++ b/content/base/public/nsIDocumentEncoder.h
@@ -32,6 +32,7 @@ class nsIDOMRange;
 class nsISelection;
 class nsIOutputStream;
 class nsISupportsArray;
+class nsIDOMNode;
 
 
 #define NS_IDOCUMENT_ENCODER_IID                     \
@@ -56,9 +57,26 @@ class nsISupportsArray;
 #define NS_HTMLCOPY_TEXT_ENCODER_CID                      \
 { 0x7f915b01, 0x98fc, 0x11d4, { 0x8e, 0xb0, 0xa8, 0x03, 0xf8, 0x0f, 0xf1, 0xbc } }
 
-
+// {0BC1FAC0-B710-11d4-959F-0020183BF181}
+#define NS_IDOCUMENTENCODERNODEFIXUP_IID                     \
+{ 0xbc1fac0, 0xb710, 0x11d4, { 0x95, 0x9f, 0x0, 0x20, 0x18, 0x3b, 0xf1, 0x81 } }
+  
 #define NS_HTMLCOPY_ENCODER_CONTRACTID "@mozilla.org/layout/htmlCopyEncoder"
 
+class nsIDocumentEncoderNodeFixup : public nsISupports
+{
+public:
+
+  NS_DEFINE_STATIC_IID_ACCESSOR(NS_IDOCUMENTENCODERNODEFIXUP_IID)
+
+  /**
+   * Create a fixed up version of a node. This method is called before
+   * each node in a document is about to be persisted. The implementor
+   * may return a new node with fixed up attributes or nsnull. 
+   */
+  NS_IMETHOD FixupNode(nsIDOMNode *aNode, nsIDOMNode **aOutNode) = 0;
+};
+
 class nsIDocumentEncoder : public nsISupports
 {
 public:
@@ -172,6 +190,11 @@ public:
   NS_IMETHOD EncodeToStringWithContext(nsAWritableString& aEncodedString, 
                                        nsAWritableString& aContextString, 
                                        nsAWritableString& aInfoString) = 0;
+
+  /**
+   * Set the fixup object associated with node persistence.
+   */
+  NS_IMETHOD SetNodeFixup(nsIDocumentEncoderNodeFixup *aFixup) = 0;
 };
 
 #endif /* nsIDocumentEncoder_h__ */
diff --git a/content/base/src/nsDocumentEncoder.cpp b/content/base/src/nsDocumentEncoder.cpp
index e3df945ae8cd..9266d912843f 100644
--- a/content/base/src/nsDocumentEncoder.cpp
+++ b/content/base/src/nsDocumentEncoder.cpp
@@ -91,12 +91,12 @@ public:
   NS_IMETHOD SetRange(nsIDOMRange* aRange);
   NS_IMETHOD SetWrapColumn(PRUint32 aWC);
   NS_IMETHOD SetCharset(const nsAReadableString& aCharset);
-
   NS_IMETHOD EncodeToStream(nsIOutputStream* aStream);
   NS_IMETHOD EncodeToString(nsAWritableString& aOutputString);
   NS_IMETHOD EncodeToStringWithContext(nsAWritableString& aEncodedString, 
                                        nsAWritableString& aContextString,
                                        nsAWritableString& aInfoString);
+  NS_IMETHOD SetNodeFixup(nsIDocumentEncoderNodeFixup *aFixup);
                                        
 protected:
   nsresult SerializeNodeStart(nsIDOMNode* aNode, PRInt32 aStartOffset,
@@ -129,6 +129,7 @@ protected:
   nsCOMPtr<nsIContentSerializer> mSerializer;
   nsCOMPtr<nsIUnicodeEncoder>    mUnicodeEncoder;
   nsCOMPtr<nsIDOMNode>           mCommonParent;
+  nsCOMPtr<nsIDocumentEncoderNodeFixup> mNodeFixup;
 
   nsString          mMimeType;
   nsString          mCharset;
@@ -234,42 +235,52 @@ nsDocumentEncoder::SerializeNodeStart(nsIDOMNode* aNode, PRInt32 aStartOffset,
 {
   PRUint16 type;
 
-  aNode->GetNodeType(&type);
+  nsCOMPtr<nsIDOMNode> node;
+  if (mNodeFixup)
+  {
+    mNodeFixup->FixupNode(aNode, getter_AddRefs(node));
+  }
+  if (!node)
+  {
+    node = do_QueryInterface(aNode);
+  }
+
+  node->GetNodeType(&type);
   switch (type) {
     case nsIDOMNode::ELEMENT_NODE:
     {
-      nsCOMPtr<nsIDOMElement> element = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMElement> element = do_QueryInterface(node);
       mSerializer->AppendElementStart(element, aStr);
       break;
     }
     case nsIDOMNode::TEXT_NODE:
     {
-      nsCOMPtr<nsIDOMText> text = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMText> text = do_QueryInterface(node);
       mSerializer->AppendText(text, aStartOffset, aEndOffset, aStr);
       break;
     }
     case nsIDOMNode::CDATA_SECTION_NODE:
     {
-      nsCOMPtr<nsIDOMCDATASection> cdata = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMCDATASection> cdata = do_QueryInterface(node);
       mSerializer->AppendCDATASection(cdata, aStartOffset, aEndOffset, aStr);
       break;
     }
     case nsIDOMNode::PROCESSING_INSTRUCTION_NODE:
     {
-      nsCOMPtr<nsIDOMProcessingInstruction> pi = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMProcessingInstruction> pi = do_QueryInterface(node);
       mSerializer->AppendProcessingInstruction(pi, aStartOffset, aEndOffset,
                                                aStr);
       break;
     }
     case nsIDOMNode::COMMENT_NODE:
     {
-      nsCOMPtr<nsIDOMComment> comment = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMComment> comment = do_QueryInterface(node);
       mSerializer->AppendComment(comment, aStartOffset, aEndOffset, aStr);
       break;
     }
     case nsIDOMNode::DOCUMENT_TYPE_NODE:
     {
-      nsCOMPtr<nsIDOMDocumentType> doctype = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMDocumentType> doctype = do_QueryInterface(node);
       mSerializer->AppendDoctype(doctype, aStr);
       break;
     }
@@ -922,6 +933,14 @@ nsDocumentEncoder::EncodeToStringWithContext(nsAWritableString& aEncodedString,
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
+NS_IMETHODIMP
+nsDocumentEncoder::SetNodeFixup(nsIDocumentEncoderNodeFixup *aFixup)
+{
+  mNodeFixup = aFixup;
+  return NS_OK;
+}
+
+
 nsresult NS_NewTextEncoder(nsIDocumentEncoder** aResult); // make mac compiler happy
 
 nsresult
diff --git a/layout/base/public/nsIDocumentEncoder.h b/layout/base/public/nsIDocumentEncoder.h
index 75e8e8231d30..66db12cb4ff8 100644
--- a/layout/base/public/nsIDocumentEncoder.h
+++ b/layout/base/public/nsIDocumentEncoder.h
@@ -32,6 +32,7 @@ class nsIDOMRange;
 class nsISelection;
 class nsIOutputStream;
 class nsISupportsArray;
+class nsIDOMNode;
 
 
 #define NS_IDOCUMENT_ENCODER_IID                     \
@@ -56,9 +57,26 @@ class nsISupportsArray;
 #define NS_HTMLCOPY_TEXT_ENCODER_CID                      \
 { 0x7f915b01, 0x98fc, 0x11d4, { 0x8e, 0xb0, 0xa8, 0x03, 0xf8, 0x0f, 0xf1, 0xbc } }
 
-
+// {0BC1FAC0-B710-11d4-959F-0020183BF181}
+#define NS_IDOCUMENTENCODERNODEFIXUP_IID                     \
+{ 0xbc1fac0, 0xb710, 0x11d4, { 0x95, 0x9f, 0x0, 0x20, 0x18, 0x3b, 0xf1, 0x81 } }
+  
 #define NS_HTMLCOPY_ENCODER_CONTRACTID "@mozilla.org/layout/htmlCopyEncoder"
 
+class nsIDocumentEncoderNodeFixup : public nsISupports
+{
+public:
+
+  NS_DEFINE_STATIC_IID_ACCESSOR(NS_IDOCUMENTENCODERNODEFIXUP_IID)
+
+  /**
+   * Create a fixed up version of a node. This method is called before
+   * each node in a document is about to be persisted. The implementor
+   * may return a new node with fixed up attributes or nsnull. 
+   */
+  NS_IMETHOD FixupNode(nsIDOMNode *aNode, nsIDOMNode **aOutNode) = 0;
+};
+
 class nsIDocumentEncoder : public nsISupports
 {
 public:
@@ -172,6 +190,11 @@ public:
   NS_IMETHOD EncodeToStringWithContext(nsAWritableString& aEncodedString, 
                                        nsAWritableString& aContextString, 
                                        nsAWritableString& aInfoString) = 0;
+
+  /**
+   * Set the fixup object associated with node persistence.
+   */
+  NS_IMETHOD SetNodeFixup(nsIDocumentEncoderNodeFixup *aFixup) = 0;
 };
 
 #endif /* nsIDocumentEncoder_h__ */
diff --git a/layout/base/src/nsDocumentEncoder.cpp b/layout/base/src/nsDocumentEncoder.cpp
index e3df945ae8cd..9266d912843f 100644
--- a/layout/base/src/nsDocumentEncoder.cpp
+++ b/layout/base/src/nsDocumentEncoder.cpp
@@ -91,12 +91,12 @@ public:
   NS_IMETHOD SetRange(nsIDOMRange* aRange);
   NS_IMETHOD SetWrapColumn(PRUint32 aWC);
   NS_IMETHOD SetCharset(const nsAReadableString& aCharset);
-
   NS_IMETHOD EncodeToStream(nsIOutputStream* aStream);
   NS_IMETHOD EncodeToString(nsAWritableString& aOutputString);
   NS_IMETHOD EncodeToStringWithContext(nsAWritableString& aEncodedString, 
                                        nsAWritableString& aContextString,
                                        nsAWritableString& aInfoString);
+  NS_IMETHOD SetNodeFixup(nsIDocumentEncoderNodeFixup *aFixup);
                                        
 protected:
   nsresult SerializeNodeStart(nsIDOMNode* aNode, PRInt32 aStartOffset,
@@ -129,6 +129,7 @@ protected:
   nsCOMPtr<nsIContentSerializer> mSerializer;
   nsCOMPtr<nsIUnicodeEncoder>    mUnicodeEncoder;
   nsCOMPtr<nsIDOMNode>           mCommonParent;
+  nsCOMPtr<nsIDocumentEncoderNodeFixup> mNodeFixup;
 
   nsString          mMimeType;
   nsString          mCharset;
@@ -234,42 +235,52 @@ nsDocumentEncoder::SerializeNodeStart(nsIDOMNode* aNode, PRInt32 aStartOffset,
 {
   PRUint16 type;
 
-  aNode->GetNodeType(&type);
+  nsCOMPtr<nsIDOMNode> node;
+  if (mNodeFixup)
+  {
+    mNodeFixup->FixupNode(aNode, getter_AddRefs(node));
+  }
+  if (!node)
+  {
+    node = do_QueryInterface(aNode);
+  }
+
+  node->GetNodeType(&type);
   switch (type) {
     case nsIDOMNode::ELEMENT_NODE:
     {
-      nsCOMPtr<nsIDOMElement> element = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMElement> element = do_QueryInterface(node);
       mSerializer->AppendElementStart(element, aStr);
       break;
     }
     case nsIDOMNode::TEXT_NODE:
     {
-      nsCOMPtr<nsIDOMText> text = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMText> text = do_QueryInterface(node);
       mSerializer->AppendText(text, aStartOffset, aEndOffset, aStr);
       break;
     }
     case nsIDOMNode::CDATA_SECTION_NODE:
     {
-      nsCOMPtr<nsIDOMCDATASection> cdata = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMCDATASection> cdata = do_QueryInterface(node);
       mSerializer->AppendCDATASection(cdata, aStartOffset, aEndOffset, aStr);
       break;
     }
     case nsIDOMNode::PROCESSING_INSTRUCTION_NODE:
     {
-      nsCOMPtr<nsIDOMProcessingInstruction> pi = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMProcessingInstruction> pi = do_QueryInterface(node);
       mSerializer->AppendProcessingInstruction(pi, aStartOffset, aEndOffset,
                                                aStr);
       break;
     }
     case nsIDOMNode::COMMENT_NODE:
     {
-      nsCOMPtr<nsIDOMComment> comment = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMComment> comment = do_QueryInterface(node);
       mSerializer->AppendComment(comment, aStartOffset, aEndOffset, aStr);
       break;
     }
     case nsIDOMNode::DOCUMENT_TYPE_NODE:
     {
-      nsCOMPtr<nsIDOMDocumentType> doctype = do_QueryInterface(aNode);
+      nsCOMPtr<nsIDOMDocumentType> doctype = do_QueryInterface(node);
       mSerializer->AppendDoctype(doctype, aStr);
       break;
     }
@@ -922,6 +933,14 @@ nsDocumentEncoder::EncodeToStringWithContext(nsAWritableString& aEncodedString,
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
+NS_IMETHODIMP
+nsDocumentEncoder::SetNodeFixup(nsIDocumentEncoderNodeFixup *aFixup)
+{
+  mNodeFixup = aFixup;
+  return NS_OK;
+}
+
+
 nsresult NS_NewTextEncoder(nsIDocumentEncoder** aResult); // make mac compiler happy
 
 nsresult