fixing the xmlSAXParseDTD bug #119536 raised by Malcolm Tredinnick with

* parser.c: fixing the xmlSAXParseDTD bug #119536 raised by
  Malcolm Tredinnick with the patch he suggested.
Daniel
diff --git a/parser.c b/parser.c
index 82caf10..96acf99 100644
--- a/parser.c
+++ b/parser.c
@@ -9600,7 +9600,7 @@
 	if (ctxt->sax != NULL)
 	    xmlFree(ctxt->sax);
         ctxt->sax = sax;
-        ctxt->userData = NULL;
+        ctxt->userData = ctxt;
     }
 
     /*