--- httpd_bench/httpd_bench.c	Mon Apr  5 12:06:41 1999
+++ httpd_bench-19990406v2/httpd_bench.c	Thu Apr  8 12:40:59 1999
@@ -45,6 +45,8 @@
 	((unsigned long) (((tv)->tv_sec * 1000000) + (tv)->tv_usec))
 #define tv_is_null(tv) \
 	(((tv)->tv_sec == 0) && ((tv)->tv_usec == 0))
+#define tv_is_valid(tv) \
+	(((tv)->tv_sec >= 0) && ((tv)->tv_usec >= 0))
 
 /* possible values for slot.s_state */
 #define ST_UNUSED	0x00
@@ -985,7 +987,7 @@
 		fs_writet = fs_write;
 
 		/* blocking is done with a possible timeout */
-		if (tv_is_null (&timer)) {
+		if (tv_is_valid (&timer)) {
 			dbg_printf ("blocking\n");
 			error = select (maxfd + 1, &fs_readt, &fs_writet, NULL, NULL);
 		} else {