From 0 Mon Sep 17 00:00:00 2001
From: Mikhail Efremov <sem@altlinux.org>
Date: Thu, 25 Oct 2012 17:46:19 +0400
Subject: [PATCH 16] Fix segfault in case of NULL timeout.

Handle cases in add_timeout() where the function is called with a NULL
value for the 'when' parameter.
Applied dhcp-4.2.0-add_timeout_when_NULL.patch from Fedora.
See https://bugzilla.redhat.com/show_bug.cgi?id=506626.

diff --git a/dhcp/common/dispatch.c b/dhcp/common/dispatch.c
index defaced..defaced 100644
--- a/dhcp/common/dispatch.c
+++ b/dhcp/common/dispatch.c
@@ -209,6 +209,10 @@ void add_timeout (when, where, what, ref, unref)
 	isc_interval_t interval;
 	isc_time_t expires;
 
+	if (when == NULL) {
+		return;
+	}
+
 	/* See if this timeout supersedes an existing timeout. */
 	t = (struct timeout *)0;
 	for (q = timeouts; q; q = q->next) {