From 3ed39f27981e7738c0a454f9e83b8e5164b7078b Mon Sep 17 00:00:00 2001
From: xueyunfei <xueyunfei@espressif.com>
Date: Thu, 23 May 2019 14:52:05 +0800
Subject: [PATCH] fix dns crash

---
 src/core/dns.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/core/dns.c b/src/core/dns.c
index f80d9240..90e9d72f 100644
--- a/src/core/dns.c
+++ b/src/core/dns.c
@@ -1064,7 +1064,11 @@ dns_check_entry(u8_t i)
       entry->server_idx = 0;
       entry->tmr = 1;
       entry->retries = 0;
-
+#if ESP_DNS
+      while((entry->server_idx < DNS_MAX_SERVERS) && ip_addr_isany_val(dns_servers[entry->server_idx])) {
+        entry->server_idx++;
+      }
+#endif
       /* send DNS packet for this entry */
       err = dns_send(i);
       if (err != ERR_OK) {