From e9bd31b190233424da5d45b92c42130cf812550d Mon Sep 17 00:00:00 2001
From: Axel Lin <axel.lin@ingics.com>
Date: Tue, 20 Feb 2018 17:54:49 +0800
Subject: [PATCH] icmp6: Fix "LWIP_ICMP6_DATASIZE" redefined build warning if
 it was set to 0

Need to undefine LWIP_ICMP6_DATASIZE before change the setting.
While at it, also remove the unneeded #ifndef LWIP_ICMP6_DATASIZE
checking because it is set in lwip/opt.h.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
---
 src/core/ipv6/icmp6.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/core/ipv6/icmp6.c b/src/core/ipv6/icmp6.c
index 62be025f..167738a0 100644
--- a/src/core/ipv6/icmp6.c
+++ b/src/core/ipv6/icmp6.c
@@ -57,10 +57,8 @@
 
 #include <string.h>
 
-#ifndef LWIP_ICMP6_DATASIZE
-#define LWIP_ICMP6_DATASIZE   8
-#endif
 #if LWIP_ICMP6_DATASIZE == 0
+#undef LWIP_ICMP6_DATASIZE
 #define LWIP_ICMP6_DATASIZE   8
 #endif