From 115693ea4247a6d7ed5cea85564e40f23c8fffaa Mon Sep 17 00:00:00 2001
From: Lars Brubaker <larsbrubaker@gmail.com>
Date: Wed, 1 Apr 2015 11:19:03 -0700
Subject: [PATCH] More careful about checking for null serial port

---
 PrinterCommunication/PrinterConnectionAndCommunication.cs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/PrinterCommunication/PrinterConnectionAndCommunication.cs b/PrinterCommunication/PrinterConnectionAndCommunication.cs
index c4a911b76..c40f724ee 100644
--- a/PrinterCommunication/PrinterConnectionAndCommunication.cs
+++ b/PrinterCommunication/PrinterConnectionAndCommunication.cs
@@ -2117,8 +2117,11 @@ namespace MatterHackers.MatterControl.PrinterCommunication
 
                 CommunicationState = CommunicationStates.Disconnecting;
 				ReadThreadHolder.Join();
-				serialPort.Close();
-                serialPort.Dispose();
+				if (serialPort != null)
+				{
+					serialPort.Close();
+					serialPort.Dispose();
+				}
                 serialPort = null;
                 CommunicationState = CommunicationStates.Disconnected;
                 LinesToWriteQueue.Clear();