Add a one second sleep before touching the spool directory. If the touch

occurs in the same second as the earlier operations to create the temporary
file and the cron(8) daemon is rescans the spool directory during that
second, then the daemon may miss a cron edit and not properly update its
internal database.

MFC after:	1 month

usr.sbin/cron/crontab/crontab.c

@@ -608,6 +608,15 @@ replace_cmd() {
 
 	log_it(RealUser, Pid, "REPLACE", User);
 
+	/*
+	 * Creating the 'tn' temp file has already updated the
+	 * modification time of the spool directory.  Sleep for a
+	 * second to ensure that poke_daemon() sets a later
+	 * modification time.  Otherwise, this can race with the cron
+	 * daemon scanning for updated crontabs.
+	 */
+	sleep(1);
+
 	poke_daemon();
 
 	return (0);