diff -up at-3.1.20/atd.c.aborted at-3.1.20/atd.c

--- at-3.1.20/atd.c.aborted	2017-09-14 15:31:47.971486148 +0200

+++ at-3.1.20/atd.c	2017-09-14 15:43:53.506567281 +0200

@@ -731,12 +731,17 @@ run_loop()

 	/* Is the file already locked?

 	 */

 	if (buf.st_nlink > 1) {

+	    if (run_time < buf.st_mtime)

+		run_time = buf.st_mtime;

 	    if (run_time + CHECK_INTERVAL <= now) {

-

 		/* Something went wrong the last time this was executed.

 		 * Let's remove the lockfile and reschedule.

+		 * We also change the timestamp to avoid rerunning the job more

+		 * than once every CHECK_INTERVAL.

 		 */

 		strncpy(lock_name, dirent->d_name, sizeof(lock_name));

+		if (utime(lock_name, 0) < 0)

+			syslog(LOG_ERR, "utime couldn't be set for lock file %s\n", lock_name);

 		lock_name[sizeof(lock_name)-1] = '\0';

 		lock_name[0] = '=';

 		unlink(lock_name);