From 98d2c1a0736e715ad5d433dfb3d51d101475a4c6 Mon Sep 17 00:00:00 2001
From: David Cermak <cermak@espressif.com>
Date: Fri, 3 May 2019 16:37:43 +0200
Subject: [PATCH] mdns:  fixed mdns crashing on reception of txt packet without
 a corresponding service closes #2866

* Original commit: espressif/esp-idf@af48977f21cea6b18dae10b2c8b64a78acfc647f
---
 components/mdns/mdns.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/mdns/mdns.c b/components/mdns/mdns.c
index 8c9767942..e88672f82 100644
--- a/components/mdns/mdns.c
+++ b/components/mdns/mdns.c
@@ -2886,7 +2886,7 @@ void mdns_parse_packet(mdns_rx_packet_t * packet)
                         col = 1;
                     } else if (!clas) {
                         col = -1;
-                    } else {
+                    } else if (service) { // only detect txt collision if service existed
                         col = _mdns_check_txt_collision(service->service, data_ptr, data_len);
                     }
                     if (col && !_mdns_server->interfaces[packet->tcpip_if].pcbs[packet->ip_protocol].probe_running) {