--- libaitio/inc/aitio.h	2012/07/31 15:58:08	1.22.2.14
+++ libaitio/inc/aitio.h	2012/07/31 16:04:52	1.22.2.15
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@elwix.org>
 *
 * $Author: misho $
-* $Id: aitio.h,v 1.22.2.14 2012/07/31 15:58:08 misho Exp $
+* $Id: aitio.h,v 1.22.2.15 2012/07/31 16:04:52 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -214,7 +214,7 @@ typedef struct {
 						} } while (0)
 #define AIT_SET_STR(_vl, _v)		do { ait_val_t *__val = (_vl); assert(__val); \
 						__val->val_type = string; \
-						if ((_v)) { \
+						if ((_v) && *(_v)) { \
 							__val->val.string = (int8_t*) io_strdup((_v)); \
 							AIT_LEN(__val) = strlen((const char*) \
 									__val->val.string) + 1; \