From 039bae9710cbc1c4a6f6a24308359adb0f78e16e Mon Sep 17 00:00:00 2001
From: Martin Stein <martin.stein@genode-labs.com>
Date: Tue, 8 Oct 2013 10:40:33 +0200
Subject: [PATCH] base: make FIFO elements zero-pointer save

fix #904
---
 base/include/util/fifo.h | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/base/include/util/fifo.h b/base/include/util/fifo.h
index c20e5ea286..79302defd7 100644
--- a/base/include/util/fifo.h
+++ b/base/include/util/fifo.h
@@ -14,6 +14,8 @@
 #ifndef _INCLUDE__UTIL__FIFO_H_
 #define _INCLUDE__UTIL__FIFO_H_
 
+#include <base/printf.h>
+
 namespace Genode {
 
 	/*
@@ -166,7 +168,17 @@ namespace Genode {
 
 			Fifo_element(T *object) : _object(object) { }
 
-			inline T *object() { return _object; }
+			/**
+			 * Get typed object pointer
+			 *
+			 * Zero-pointer save: Returns 0 if this pointer is 0 to
+			 * cover the case of accessing an empty FIFO.
+			 */
+			inline T *object()
+			{
+				if (this) { return _object; }
+				return 0;
+			}
 	};
 }