fix bug with empty ext list

git-svn-id: https://hamlib.svn.sourceforge.net/svnroot/hamlib/trunk@1181 7ae35d74-ebe9-4afe-98af-79ac388436b8

src/ext.c

@@ -2,7 +2,7 @@
  *  Hamlib Interface - extrq parameter interface
  *  Copyright (c) 2000,2001,2002 by Stephane Fillod
  *
- *	$Id: ext.c,v 1.1 2002-07-09 20:36:07 fillods Exp $
+ *	$Id: ext.c,v 1.2 2002-09-18 21:19:39 fillods Exp $
  *
  *   This library is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU Library General Public License as
@@ -92,7 +92,7 @@ const struct confparams *rig_ext_lookup(RIG *rig, const char *name)
 	for (cfp = rig->caps->extlevels; cfp && cfp->name; cfp++)
 		if (!strcmp(cfp->name, name))
 			return cfp;
-	for (cfp = rig->caps->extparms; cfp->name; cfp++)
+	for (cfp = rig->caps->extparms; cfp && cfp->name; cfp++)
 		if (!strcmp(cfp->name, name))
 			return cfp;
 	return NULL;