try to find more places where xmlCanonicPath() must be used to convert

* DOCBparser.c SAX.c catalog.c debugXML.c parser.c: try to find
  more places where xmlCanonicPath() must be used to convert
  filenames to URLs, trying to fix #111088
Daniel
diff --git a/debugXML.c b/debugXML.c
index cbb74c0..9f762e1 100644
--- a/debugXML.c
+++ b/debugXML.c
@@ -1754,7 +1754,7 @@
 #ifdef LIBXML_XPATH_ENABLED
         ctxt->pctxt = xmlXPathNewContext(doc);
 #endif /* LIBXML_XPATH_ENABLED */
-        ctxt->filename = (char *) xmlStrdup((xmlChar *) filename);
+        ctxt->filename = (char *) xmlCanonicPath((xmlChar *) filename);
     } else
         return (-1);
     return (0);