From be85033f8a476daf1e13e56ba253c27f2e63646f Mon Sep 17 00:00:00 2001
From: sta <sta.blockhead@gmail.com>
Date: Thu, 15 May 2014 16:24:44 +0900
Subject: [PATCH] Fix for issue #45

---
 websocket-sharp/WebSocket.cs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/websocket-sharp/WebSocket.cs b/websocket-sharp/WebSocket.cs
index 3d4192a7..99ef876b 100644
--- a/websocket-sharp/WebSocket.cs
+++ b/websocket-sharp/WebSocket.cs
@@ -1427,7 +1427,13 @@ namespace WebSocketSharp
 
     internal bool Ping (byte [] frame, int timeout)
     {
-      return send (frame) && _receivePong.WaitOne (timeout);
+      try {
+        var pong = _receivePong;
+        return send (frame) && pong != null && pong.WaitOne (timeout);
+      }
+      catch {
+        return false;
+      }
     }
 
     // As server, used to broadcast