Commit bf722059bb for bind

commit bf722059bb3d10b8e18ae5fbf399af7a95ac69d1
Author: Ondřej Surý <ondrej@isc.org>
Date:   Sun Oct 18 15:06:42 2026 +0200

    Remove obsolete EMSGSIZE handling from ns_client

    UDP sockets have allowed fragmentation since 2021, making the
    EMSGSIZE truncation path unreachable for responses limited by
    max-udp-size.

diff --git a/lib/ns/client.c b/lib/ns/client.c
index e4456c6c5a..218c324d65 100644
--- a/lib/ns/client.c
+++ b/lib/ns/client.c
@@ -337,20 +337,10 @@ client_senddone(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
 			isc_histomulti_detach(&hmpin);
 		}
 	} else {
-		if (!client->inner.tcp && result == ISC_R_MAXSIZE) {
-			ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
-				      NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
-				      "send exceeded maximum size: truncating");
-			client->query.answered = false;
-			client->inner.rcode_override = dns_rcode_noerror;
-			ns_client_error(client, ISC_R_MAXSIZE);
-		} else {
-			ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
-				      NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
-				      "send failed: %s",
-				      isc_result_totext(result));
-			isc_nm_bad_request(handle);
-		}
+		ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
+			      NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
+			      "send failed: %s", isc_result_totext(result));
+		isc_nm_bad_request(handle);
 	}

 	isc_nmhandle_detach(&handle);
@@ -857,7 +847,6 @@ void
 ns_client_error(ns_client_t *client, isc_result_t result) {
 	dns_message_t *message = NULL;
 	dns_rcode_t rcode;
-	bool trunc = false;

 	REQUIRE(NS_CLIENT_VALID(client));

@@ -871,10 +860,6 @@ ns_client_error(ns_client_t *client, isc_result_t result) {
 		rcode = (dns_rcode_t)(client->inner.rcode_override & 0xfff);
 	}

-	if (result == ISC_R_MAXSIZE) {
-		trunc = true;
-	}
-
 #if NS_CLIENT_DROPPORT
 	/*
 	 * Don't send FORMERR to ports on the drop port list.
@@ -976,9 +961,6 @@ ns_client_error(ns_client_t *client, isc_result_t result) {
 	}

 	message->rcode = rcode;
-	if (trunc) {
-		message->flags |= DNS_MESSAGEFLAG_TC;
-	}

 	if (rcode == dns_rcode_formerr) {
 		/*