From 4316265c314f629e9a7fc81b810b0d17538868a4 Mon Sep 17 00:00:00 2001
From: Ryan Waterston <waterston.ryan@gmail.com>
Date: Mon, 4 Nov 2013 16:26:16 -0600
Subject: [PATCH] Fixed W5200 write() so it no longer crashes on length 0

---
 Avr/w5100.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Avr/w5100.cpp b/Avr/w5100.cpp
index 3cd7bfe..d17ad3b 100644
--- a/Avr/w5100.cpp
+++ b/Avr/w5100.cpp
@@ -164,6 +164,12 @@ uint16_t W5100Class::write(uint16_t _addr, const uint8_t *_buf, uint16_t _len)
 {
 	
 #ifdef W5200
+
+  // Initiating a transfer of length zero results
+  // in the interface crashing and becoming unresponsive.
+  if( _len == 0 )
+    return 0;
+
     setSS();
     SPI.transfer(_addr >> 8);
     SPI.transfer(_addr & 0xFF);