From 7d8bb51a8059a673bd57efba03b04142a0ba9d35 Mon Sep 17 00:00:00 2001
From: David Gauchard <gauchard@laas.fr>
Date: Wed, 24 Jul 2019 17:55:59 +0200
Subject: [PATCH] igmp: force on selected interface (avoid crash *sometimes*)

---
 libraries/ESP8266mDNS/src/LEAmDNS_Helpers.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/ESP8266mDNS/src/LEAmDNS_Helpers.cpp b/libraries/ESP8266mDNS/src/LEAmDNS_Helpers.cpp
index d99a57f24a..8ec6446d76 100644
--- a/libraries/ESP8266mDNS/src/LEAmDNS_Helpers.cpp
+++ b/libraries/ESP8266mDNS/src/LEAmDNS_Helpers.cpp
@@ -199,7 +199,7 @@ bool MDNSResponder::_allocUDPContext(void) {
     //TODO: set multicast address (lwip_joingroup() is IPv4 only at the time of writing)
     multicast_addr.addr = DNS_MQUERY_IPV6_GROUP_INIT;
 #endif
-    if (ERR_OK == igmp_joingroup(IP4_ADDR_ANY4, ip_2_ip4(&multicast_addr))) {
+    if (ERR_OK == igmp_joingroup(&m_netif->ip_addr, ip_2_ip4(&multicast_addr))) {
         m_pUDPContext = new UdpContext;
         m_pUDPContext->ref();