From: Sven Eckelmann <sven.eckelmann@openmesh.com>
Date: Thu, 23 Nov 2017 15:04:35 +0100
Subject: batctl: Print dummy value when localtime failed

localtime can return NULL when the local time could not be calculated.
Accessing this NULL pointer is not allowed.

Fixes: 05f27bfcd302 ("add arp packets , change output")
Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

Origin: upstream, https://git.open-mesh.org/batctl.git/commit/09dd2dc0b4945c83bd07ad4bce64062239d901fb

diff --git a/tcpdump.c b/tcpdump.c
index 2125b66d0871c4a127425bfad0135a9f565cfb78..db9c46afecf3de94dbd4d9292df1fe0812fb8bfc 100644
--- a/tcpdump.c
+++ b/tcpdump.c
@@ -103,7 +103,11 @@ static int print_time(void)
 	gettimeofday(&tv, NULL);
 	tm = localtime(&tv.tv_sec);
 
-	printf("%02d:%02d:%02d.%06ld ", tm->tm_hour, tm->tm_min, tm->tm_sec, tv.tv_usec);
+	if (tm)
+		printf("%02d:%02d:%02d.%06ld ", tm->tm_hour, tm->tm_min, tm->tm_sec, tv.tv_usec);
+	else
+		printf("00:00:00.000000 ");
+
 	return 1;
 }