From 999e670ba1ecd89377ed70b2fac4a5adc402191d Mon Sep 17 00:00:00 2001
From: Lee Fogg <leefogg@users.noreply.github.com>
Date: Sun, 19 Apr 2020 14:46:23 +0100
Subject: [PATCH] Safety around ReadBytes

---
 Emux.GameBoy/Cartridge/BufferedExternalMemory.cs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Emux.GameBoy/Cartridge/BufferedExternalMemory.cs b/Emux.GameBoy/Cartridge/BufferedExternalMemory.cs
index ac96f5b..f154727 100644
--- a/Emux.GameBoy/Cartridge/BufferedExternalMemory.cs
+++ b/Emux.GameBoy/Cartridge/BufferedExternalMemory.cs
@@ -58,6 +58,9 @@ namespace Emux.GameBoy.Cartridge
 
 		public void ReadBytes(int address, byte[] buffer, int offset, int length)
 		{
+			if (memoryStream == null)
+				return;
+
 			memoryStream.Position = address;
 			memoryStream.Read(buffer, offset, length);
 		}