From f3f00a8548b3943f648143287fde7de721695f81 Mon Sep 17 00:00:00 2001
From: Unknown <tjkopena@cs.drexel.edu>
Date: Wed, 24 Jun 2009 10:57:52 -0400
Subject: [PATCH] Minor tweak to stats example.

---
 examples/stats/wifi-example-apps.cc | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/examples/stats/wifi-example-apps.cc b/examples/stats/wifi-example-apps.cc
index 00f5447a9..65a25b372 100644
--- a/examples/stats/wifi-example-apps.cc
+++ b/examples/stats/wifi-example-apps.cc
@@ -250,11 +250,14 @@ Receiver::Receive(Ptr<Socket> socket)
     }
 
     TimestampTag timestamp;
-    packet->FindFirstMatchingByteTag(timestamp);
-    Time tx = timestamp.GetTimestamp();
+    // Should never not be found since the sender is adding it, but
+    // you never know.
+    if (packet->FindFirstMatchingByteTag(timestamp)) {
+      Time tx = timestamp.GetTimestamp();
 
-    if (m_delay != 0) {
-      m_delay->Update(Simulator::Now() - tx);
+      if (m_delay != 0) {
+        m_delay->Update(Simulator::Now() - tx);
+      }
     }
 
     if (m_calc != 0) {