diff -ru libxml2-2.6.26/include/libxml/parser.h libxml2-2.6.26-const/include/libxml/parser.h
--- libxml2-2.6.26/include/libxml/parser.h	2005-10-25 11:11:36.000000000 +0200
+++ libxml2-2.6.26-const/include/libxml/parser.h	2007-01-29 16:02:40.000000000 +0100
@@ -865,40 +865,40 @@
 		xmlParseExtParsedEnt	(xmlParserCtxtPtr ctxt);
 #ifdef LIBXML_SAX1_ENABLED
 XMLPUBFUN int XMLCALL		
-		xmlSAXUserParseFile	(xmlSAXHandlerPtr sax,
+		xmlSAXUserParseFile	(const xmlSAXHandlerPtr sax,
 					 void *user_data,
 					 const char *filename);
 XMLPUBFUN int XMLCALL		
-		xmlSAXUserParseMemory	(xmlSAXHandlerPtr sax,
+		xmlSAXUserParseMemory	(const xmlSAXHandlerPtr sax,
 					 void *user_data,
 					 const char *buffer,
 					 int size);
 XMLPUBFUN xmlDocPtr XMLCALL	
-		xmlSAXParseDoc		(xmlSAXHandlerPtr sax,
+		xmlSAXParseDoc		(const xmlSAXHandlerPtr sax,
 					 const xmlChar *cur,
 					 int recovery);
 XMLPUBFUN xmlDocPtr XMLCALL	
-		xmlSAXParseMemory	(xmlSAXHandlerPtr sax,
+		xmlSAXParseMemory	(const xmlSAXHandlerPtr sax,
 					 const char *buffer,
                                    	 int size,
 					 int recovery);
 XMLPUBFUN xmlDocPtr XMLCALL	
-		xmlSAXParseMemoryWithData (xmlSAXHandlerPtr sax,
+		xmlSAXParseMemoryWithData (const xmlSAXHandlerPtr sax,
 					 const char *buffer,
                                    	 int size,
 					 int recovery,
 					 void *data);
 XMLPUBFUN xmlDocPtr XMLCALL	
-		xmlSAXParseFile		(xmlSAXHandlerPtr sax,
+		xmlSAXParseFile		(const xmlSAXHandlerPtr sax,
 					 const char *filename,
 					 int recovery);
 XMLPUBFUN xmlDocPtr XMLCALL	
-		xmlSAXParseFileWithData	(xmlSAXHandlerPtr sax,
+		xmlSAXParseFileWithData	(const xmlSAXHandlerPtr sax,
 					 const char *filename,
 					 int recovery,
 					 void *data);
 XMLPUBFUN xmlDocPtr XMLCALL	
-		xmlSAXParseEntity	(xmlSAXHandlerPtr sax,
+		xmlSAXParseEntity	(const xmlSAXHandlerPtr sax,
 					 const char *filename);
 XMLPUBFUN xmlDocPtr XMLCALL	
 		xmlParseEntity		(const char *filename);
@@ -906,21 +906,21 @@
 
 #ifdef LIBXML_VALID_ENABLED
 XMLPUBFUN xmlDtdPtr XMLCALL	
-		xmlSAXParseDTD		(xmlSAXHandlerPtr sax,
+		xmlSAXParseDTD		(const xmlSAXHandlerPtr sax,
 					 const xmlChar *ExternalID,
 					 const xmlChar *SystemID);
 XMLPUBFUN xmlDtdPtr XMLCALL	
 		xmlParseDTD		(const xmlChar *ExternalID,
 					 const xmlChar *SystemID);
 XMLPUBFUN xmlDtdPtr XMLCALL	
-		xmlIOParseDTD		(xmlSAXHandlerPtr sax,
+		xmlIOParseDTD		(const xmlSAXHandlerPtr sax,
 					 xmlParserInputBufferPtr input,
 					 xmlCharEncoding enc);
 #endif /* LIBXML_VALID_ENABLE */
 #ifdef LIBXML_SAX1_ENABLED
 XMLPUBFUN int XMLCALL	
 		xmlParseBalancedChunkMemory(xmlDocPtr doc,
-					 xmlSAXHandlerPtr sax,
+					 const xmlSAXHandlerPtr sax,
 					 void *user_data,
 					 int depth,
 					 const xmlChar *string,
@@ -935,7 +935,7 @@
 #ifdef LIBXML_SAX1_ENABLED
 XMLPUBFUN int XMLCALL          
 		xmlParseBalancedChunkMemoryRecover(xmlDocPtr doc,
-                     xmlSAXHandlerPtr sax,
+                     const xmlSAXHandlerPtr sax,
                      void *user_data,
                      int depth,
                      const xmlChar *string,
@@ -943,7 +943,7 @@
                      int recover);
 XMLPUBFUN int XMLCALL		
 		xmlParseExternalEntity	(xmlDocPtr doc,
-					 xmlSAXHandlerPtr sax,
+					 const xmlSAXHandlerPtr sax,
 					 void *user_data,
 					 int depth,
 					 const xmlChar *URL,
@@ -998,7 +998,7 @@
  * Interfaces for the Push mode.
  */
 XMLPUBFUN xmlParserCtxtPtr XMLCALL 
-		xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax,
+		xmlCreatePushParserCtxt(const xmlSAXHandlerPtr sax,
 					 void *user_data,
 					 const char *chunk,
 					 int size,
@@ -1015,7 +1015,7 @@
  */
 
 XMLPUBFUN xmlParserCtxtPtr XMLCALL 
-		xmlCreateIOParserCtxt	(xmlSAXHandlerPtr sax,
+		xmlCreateIOParserCtxt	(const xmlSAXHandlerPtr sax,
 					 void *user_data,
 					 xmlInputReadCallback   ioread,
 					 xmlInputCloseCallback  ioclose,
diff libxml2-2.6.26/parser.c libxml2-2.6.26-const/parser.c
--- libxml2-2.6.26/parser.c	2006-04-23 11:39:15.000000000 +0200
+++ libxml2-2.6.26-const/parser.c	2007-01-29 16:02:38.000000000 +0100
@@ -112,7 +112,7 @@
 
 static xmlParserErrors
 xmlParseExternalEntityPrivate(xmlDocPtr doc, xmlParserCtxtPtr oldctxt,
-	              xmlSAXHandlerPtr sax,
+	              const xmlSAXHandlerPtr sax,
 		      void *user_data, int depth, const xmlChar *URL,
 		      const xmlChar *ID, xmlNodePtr *list);
 
@@ -10551,7 +10551,7 @@
  */
 
 xmlParserCtxtPtr
-xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax, void *user_data, 
+xmlCreatePushParserCtxt(const xmlSAXHandlerPtr sax, void *user_data, 
                         const char *chunk, int size, const char *filename) {
     xmlParserCtxtPtr ctxt;
     xmlParserInputPtr inputStream;
@@ -10696,7 +10696,7 @@
  * Returns the new parser context or NULL
  */
 xmlParserCtxtPtr
-xmlCreateIOParserCtxt(xmlSAXHandlerPtr sax, void *user_data,
+xmlCreateIOParserCtxt(const xmlSAXHandlerPtr sax, void *user_data,
 	xmlInputReadCallback   ioread, xmlInputCloseCallback  ioclose,
 	void *ioctx, xmlCharEncoding enc) {
     xmlParserCtxtPtr ctxt;
@@ -10763,7 +10763,7 @@
  */
 
 xmlDtdPtr
-xmlIOParseDTD(xmlSAXHandlerPtr sax, xmlParserInputBufferPtr input,
+xmlIOParseDTD(const xmlSAXHandlerPtr sax, xmlParserInputBufferPtr input,
 	      xmlCharEncoding enc) {
     xmlDtdPtr ret = NULL;
     xmlParserCtxtPtr ctxt;
@@ -10880,7 +10880,7 @@
  */
 
 xmlDtdPtr
-xmlSAXParseDTD(xmlSAXHandlerPtr sax, const xmlChar *ExternalID,
+xmlSAXParseDTD(const xmlSAXHandlerPtr sax, const xmlChar *ExternalID,
                           const xmlChar *SystemID) {
     xmlDtdPtr ret = NULL;
     xmlParserCtxtPtr ctxt;
@@ -11209,7 +11209,7 @@
 
 static xmlParserErrors
 xmlParseExternalEntityPrivate(xmlDocPtr doc, xmlParserCtxtPtr oldctxt,
-	              xmlSAXHandlerPtr sax,
+	              const xmlSAXHandlerPtr sax,
 		      void *user_data, int depth, const xmlChar *URL,
 		      const xmlChar *ID, xmlNodePtr *list) {
     xmlParserCtxtPtr ctxt;
@@ -11396,7 +11396,7 @@
  */
 
 int
-xmlParseExternalEntity(xmlDocPtr doc, xmlSAXHandlerPtr sax, void *user_data,
+xmlParseExternalEntity(xmlDocPtr doc, const xmlSAXHandlerPtr sax, void *user_data,
 	  int depth, const xmlChar *URL, const xmlChar *ID, xmlNodePtr *lst) {
     return(xmlParseExternalEntityPrivate(doc, NULL, sax, user_data, depth, URL,
 		                       ID, lst));
@@ -11423,7 +11423,7 @@
  */
 
 int
-xmlParseBalancedChunkMemory(xmlDocPtr doc, xmlSAXHandlerPtr sax,
+xmlParseBalancedChunkMemory(xmlDocPtr doc, const xmlSAXHandlerPtr sax,
      void *user_data, int depth, const xmlChar *string, xmlNodePtr *lst) {
     return xmlParseBalancedChunkMemoryRecover( doc, sax, user_data,
                                                 depth, string, lst, 0 );
@@ -11829,7 +11829,7 @@
  * the parsed chunk is not well balanced. 
  */
 int
-xmlParseBalancedChunkMemoryRecover(xmlDocPtr doc, xmlSAXHandlerPtr sax,
+xmlParseBalancedChunkMemoryRecover(xmlDocPtr doc, const xmlSAXHandlerPtr sax,
      void *user_data, int depth, const xmlChar *string, xmlNodePtr *lst, 
      int recover) {
     xmlParserCtxtPtr ctxt;
@@ -11979,7 +11979,7 @@
  */
 
 xmlDocPtr
-xmlSAXParseEntity(xmlSAXHandlerPtr sax, const char *filename) {
+xmlSAXParseEntity(const xmlSAXHandlerPtr sax, const char *filename) {
     xmlDocPtr ret;
     xmlParserCtxtPtr ctxt;
 
@@ -12174,7 +12174,7 @@
  */
 
 xmlDocPtr
-xmlSAXParseFileWithData(xmlSAXHandlerPtr sax, const char *filename,
+xmlSAXParseFileWithData(const xmlSAXHandlerPtr sax, const char *filename,
                         int recovery, void *data) {
     xmlDocPtr ret;
     xmlParserCtxtPtr ctxt;
@@ -12242,7 +12242,7 @@
  */
 
 xmlDocPtr
-xmlSAXParseFile(xmlSAXHandlerPtr sax, const char *filename,
+xmlSAXParseFile(const xmlSAXHandlerPtr sax, const char *filename,
                           int recovery) {
     return(xmlSAXParseFileWithData(sax,filename,recovery,NULL));
 }
@@ -12342,7 +12342,7 @@
  * Returns 0 in case of success or a error number otherwise
  */
 int
-xmlSAXUserParseFile(xmlSAXHandlerPtr sax, void *user_data,
+xmlSAXUserParseFile(const xmlSAXHandlerPtr sax, void *user_data,
                     const char *filename) {
     int ret = 0;
     xmlParserCtxtPtr ctxt;
@@ -12456,7 +12456,7 @@
  */
 
 xmlDocPtr
-xmlSAXParseMemoryWithData(xmlSAXHandlerPtr sax, const char *buffer,
+xmlSAXParseMemoryWithData(const xmlSAXHandlerPtr sax, const char *buffer,
 	          int size, int recovery, void *data) {
     xmlDocPtr ret;
     xmlParserCtxtPtr ctxt;
@@ -12505,7 +12505,7 @@
  * Returns the resulting document tree
  */
 xmlDocPtr
-xmlSAXParseMemory(xmlSAXHandlerPtr sax, const char *buffer,
+xmlSAXParseMemory(const xmlSAXHandlerPtr sax, const char *buffer,
 	          int size, int recovery) {
     return xmlSAXParseMemoryWithData(sax, buffer, size, recovery, NULL);
 }
@@ -12551,7 +12551,7 @@
  * 
  * Returns 0 in case of success or a error number otherwise
  */
-int xmlSAXUserParseMemory(xmlSAXHandlerPtr sax, void *user_data,
+int xmlSAXUserParseMemory(const xmlSAXHandlerPtr sax, void *user_data,
 			  const char *buffer, int size) {
     int ret = 0;
     xmlParserCtxtPtr ctxt;
@@ -12621,7 +12621,7 @@
  */
 
 xmlDocPtr
-xmlSAXParseDoc(xmlSAXHandlerPtr sax, const xmlChar *cur, int recovery) {
+xmlSAXParseDoc(const xmlSAXHandlerPtr sax, const xmlChar *cur, int recovery) {
     xmlDocPtr ret;
     xmlParserCtxtPtr ctxt;
     xmlSAXHandlerPtr oldsax = NULL;