made one of the changes suggested by Brian Krahmer allow to pass '--' on

* debugXML.c: made one of the changes suggested by Brian Krahmer
* testRegexp.c: allow to pass '--' on the command line to allow
  regexps starting with the character '-'
Daniel

svn path=/trunk/; revision=3697
diff --git a/debugXML.c b/debugXML.c
index 3985ad3..f66f596 100644
--- a/debugXML.c
+++ b/debugXML.c
@@ -3244,6 +3244,7 @@
                             "Unknown command %s\n", command);
         }
         free(cmdline);          /* not xmlFree here ! */
+	cmdline = NULL;
     }
 #ifdef LIBXML_XPATH_ENABLED
     xmlXPathFreeContext(ctxt->pctxt);