From cef8ce81f7633eab2b96f14141447a8e46689b46 Mon Sep 17 00:00:00 2001
From: Andy Green <andy@warmcat.com>
Date: Tue, 5 Jan 2021 08:27:25 +0000
Subject: [PATCH] client: dns-sort: classify on no source if dest ads

---
 lib/core-net/client/sort-dns.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/core-net/client/sort-dns.c b/lib/core-net/client/sort-dns.c
index 7b6a013d1..0957a90a6 100644
--- a/lib/core-net/client/sort-dns.c
+++ b/lib/core-net/client/sort-dns.c
@@ -463,6 +463,11 @@ lws_sort_dns_dcomp(const lws_dns_sort_t *da, const lws_dns_sort_t *db)
 	 * Label(Source(DB)) = Label(DB), then prefer DB
 	 */
 
+	if (!da->source)
+		return SAS_PREFER_B;
+	if (!db->source)
+		return SAS_PREFER_A;
+
 	lws_sort_dns_classify(&da->source->dest, &score_srca);
 	lws_sort_dns_classify(&db->source->dest, &score_srcb);