From 1b56de694b60a7a5e9ff72d2edabc8c14a9628f8 Mon Sep 17 00:00:00 2001
From: amcewen <amcewen@bcs.org.uk>
Date: Fri, 4 Feb 2011 21:44:51 +0000
Subject: [PATCH] Fixed bug in parsePacket where it could block indefinitely if
 called when no packets were available to be read.

---
 libraries/Ethernet/Udp.cpp | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/libraries/Ethernet/Udp.cpp b/libraries/Ethernet/Udp.cpp
index 2c8b10332..aed5d983b 100644
--- a/libraries/Ethernet/Udp.cpp
+++ b/libraries/Ethernet/Udp.cpp
@@ -121,20 +121,25 @@ void UDP::write(const uint8_t *buffer, size_t size)
 
 int UDP::parsePacket()
 {
-  //HACK - hand-parse the UDP packet using TCP recv method
-  uint8_t tmpBuf[8];
-  int ret =0;	
-  //read 8 header bytes and get IP and port from it
-  ret = recv(_sock,tmpBuf,8);
-  if (ret > 0)
+  if (available() > 0)
   {
-    _remoteIP = tmpBuf;
-    _remotePort = tmpBuf[4];
-    _remotePort = (_remotePort << 8) + tmpBuf[5];
-    // When we get here, any remaining bytes are the data
-    ret = available();
+    //HACK - hand-parse the UDP packet using TCP recv method
+    uint8_t tmpBuf[8];
+    int ret =0;	
+    //read 8 header bytes and get IP and port from it
+    ret = recv(_sock,tmpBuf,8);
+    if (ret > 0)
+    {
+      _remoteIP = tmpBuf;
+      _remotePort = tmpBuf[4];
+      _remotePort = (_remotePort << 8) + tmpBuf[5];
+      // When we get here, any remaining bytes are the data
+      ret = available();
+    }
+    return ret;
   }
-  return ret;
+  // There aren't any packets available
+  return 0;
 }
 
 int UDP::read()