--- libelwix/src/ring.c	2025/09/26 08:58:05	1.1.2.1
+++ libelwix/src/ring.c	2025/09/26 09:22:24	1.1.2.2
@@ -3,7 +3,7 @@
 *  by Michael Pounov <misho@elwix.org>
 *
 * $Author: misho $
-* $Id: ring.c,v 1.1.2.1 2025/09/26 08:58:05 misho Exp $
+* $Id: ring.c,v 1.1.2.2 2025/09/26 09:22:24 misho Exp $
 *
 **************************************************************************
 The ELWIX and AITNET software is distributed under the following
@@ -140,6 +140,8 @@ rbuf_isfull(ringbuf_t *rbuf)
 {
 	if (!rbuf)
 		return -1;
+	if (!rbuf->rb_bufnum)
+		return 1;
 
 	return (((atomic_load_explicit(&rbuf->rb_head, memory_order_relaxed) + 1) % rbuf->rb_bufnum) ==
 		atomic_load_explicit(&rbuf->rb_tail, memory_order_acquire));