From 2f0d6028332927fb5c32cf669c9b0c6f500e0838 Mon Sep 17 00:00:00 2001
From: v2ray <admin@v2ray.com>
Date: Sun, 7 Aug 2016 08:45:03 +0200
Subject: [PATCH] nil pointer protection

---
 transport/internet/kcp/sending.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/transport/internet/kcp/sending.go b/transport/internet/kcp/sending.go
index e1136af5..826a3e6a 100644
--- a/transport/internet/kcp/sending.go
+++ b/transport/internet/kcp/sending.go
@@ -165,7 +165,7 @@ func (this *SendingWindow) Flush(current uint32, resend uint32, rto uint32, maxI
 		}
 	}
 
-	if inFlightSize > 0 && this.totalInFlightSize != 0 {
+	if this.onPacketLoss != nil && inFlightSize > 0 && this.totalInFlightSize != 0 {
 		rate := lost * 100 / this.totalInFlightSize
 		this.onPacketLoss(rate)
 	}