From 3f8d9d71e2c10e5ebdf3b07f3d527d74411bc35a Mon Sep 17 00:00:00 2001
From: Ivan Grokhotkov <ivan@espressif.com>
Date: Tue, 8 Nov 2016 09:05:05 +0800
Subject: [PATCH] lwip: fix duplicate definition of O_NONBLOCK

LwIP will define O_NONBLOCK in sockets.h if it isn't defined yet.
If sys/fcntl.h is included after socket.h, there will be duplicate definition.
Work around by including sys/fcntl.h into lwipopts.h.

https://github.com/espressif/esp-idf/issues/75
---
 components/lwip/include/lwip/port/lwipopts.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/components/lwip/include/lwip/port/lwipopts.h b/components/lwip/include/lwip/port/lwipopts.h
index f70588750..d06e75685 100755
--- a/components/lwip/include/lwip/port/lwipopts.h
+++ b/components/lwip/include/lwip/port/lwipopts.h
@@ -35,6 +35,7 @@
 #include <stdlib.h>
 #include <time.h>
 #include <sys/time.h>
+#include <sys/fcntl.h>
 #include "esp_task.h"
 #include "sdkconfig.h"