From fb1979c0ea821f4895240e38676e77075ed53525 Mon Sep 17 00:00:00 2001
From: "Roger A. Light" <roger@atchoo.org>
Date: Thu, 11 Apr 2019 21:26:29 +0100
Subject: [PATCH] Fix build on SmartOS due to missing IPV6_V6ONLY.

Thanks to Matt Ingenthron.

Closes #1212.
---
 ChangeLog.txt | 3 +++
 src/net.c     | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/ChangeLog.txt b/ChangeLog.txt
index ca4d1c55..f58a4903 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -47,6 +47,9 @@ Client features:
 - Add explicit support for TLS v1.3.
 - Drop support for TLS v1.0.
 
+Broker fixes:
+- Fix build on SmartOS due to missing IPV6_V6ONLY. Closes #1212.
+
 Client fixes:
 - mosquitto_pub wouldn't always publish all messages when using `-l` and
   QoS>0. This has been fixed.
diff --git a/src/net.c b/src/net.c
index 6d72b503..7b6793cb 100644
--- a/src/net.c
+++ b/src/net.c
@@ -470,8 +470,10 @@ int net__socket_listen(struct mosquitto__listener *listener)
 		ss_opt = 1;
 		setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &ss_opt, sizeof(ss_opt));
 #endif
+#ifdef IPV6_V6ONLY
 		ss_opt = 1;
 		setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &ss_opt, sizeof(ss_opt));
+#endif
 
 		if(net__socket_nonblock(&sock)){
 			return 1;