--- libaitio/inc/aitio.h	2012/07/30 14:58:31	1.22.2.8
+++ libaitio/inc/aitio.h	2012/07/31 12:34:23	1.22.2.9
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@elwix.org>
 *
 * $Author: misho $
-* $Id: aitio.h,v 1.22.2.8 2012/07/30 14:58:31 misho Exp $
+* $Id: aitio.h,v 1.22.2.9 2012/07/31 12:34:23 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -213,11 +213,15 @@ typedef struct {
 								memset(__val->val.buffer, 0, _len); \
 						} } while (0)
 #define AIT_SET_STR(_vl, _v)		do { ait_val_t *__val = (_vl); assert(__val); \
-						__val->val.string = (int8_t*) io_strdup((_v)); \
-						if (__val->val.string) { \
-							__val->val_type = string; \
+						__val->val_type = string; \
+						if ((_v)) { \
+							__val->val.string = (int8_t*) io_strdup((_v)); \
 							AIT_LEN(__val) = strlen((_v)) + 1; \
-						} } while (0)
+						} else { \
+							__val->val.string = NULL; \
+							AIT_LEN(__val) = 0; \
+						} \
+					} while (0)
 #define AIT_SET_STRCAT(_vl, _v)		do { ait_val_t *__val = (_vl); assert(__val); \
 						assert(AIT_TYPE(__val) == string); \
 						if (!__val->val.string) \