From 430c0ce76a02b2ca74040fd9f8bf8955298d529f Mon Sep 17 00:00:00 2001
From: Colin Vidal <colin@isc.org>
Date: Thu, 4 Dec 2025 16:42:11 +0100
Subject: [PATCH] support EDE 13 (Cached Error)

Extended DNS Error 13 (Cached Error) is now returned when the server
answers a message from a cached SERVFAIL.

See RFC 8914 section 4.14.
---
 lib/ns/query.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/ns/query.c b/lib/ns/query.c
index 3f7f0935aa..929b2bbbcd 100644
--- a/lib/ns/query.c
+++ b/lib/ns/query.c
@@ -6832,6 +6832,7 @@ ns__query_sfcache(query_ctx_t *qctx) {
 									 "0");
 		}
 
+		dns_ede_add(&qctx->client->edectx, DNS_EDE_CACHEDERROR, NULL);
 		qctx->client->inner.attributes |= NS_CLIENTATTR_NOSETFC;
 		QUERY_ERROR(qctx, DNS_R_SERVFAIL);
 		return ns_query_done(qctx);