From f20705b36d074f5c8f8ffc457645ab9cb948e807 Mon Sep 17 00:00:00 2001
From: Gioacchino Mazzurco <gio@eigenlab.org>
Date: Sun, 15 Apr 2018 12:32:39 +0200
Subject: [PATCH] Workaround for systems that miss IPV6_V6ONLY

This should improve compatibility with old systems that miss
IPV6_V6ONLY and in particular for Windows XP
---
 libretroshare/src/util/rsnet.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/libretroshare/src/util/rsnet.h b/libretroshare/src/util/rsnet.h
index 1d028e991..a5381702c 100644
--- a/libretroshare/src/util/rsnet.h
+++ b/libretroshare/src/util/rsnet.h
@@ -58,6 +58,15 @@ int inet_aton(const char *name, struct in_addr *addr);
 #endif
 /********************************** WINDOWS/UNIX SPECIFIC PART ******************/
 
+/**
+ * Workaround for binary compatibility between Windows XP (which miss
+ * IPV6_V6ONLY define), and newer Windows that has it.
+ * @see http://lua-users.org/lists/lua-l/2013-04/msg00191.html
+ */
+#ifndef IPV6_V6ONLY
+#	define IPV6_V6ONLY 27
+#endif
+
 /* 64 bit conversions */
 #ifndef ntohll
 uint64_t ntohll(uint64_t x);