From 70debce5146a36c0d123cd4db4d309f9b56288d5 Mon Sep 17 00:00:00 2001
From: Till Faelligen <tfaelligen@gmail.com>
Date: Tue, 15 Mar 2022 15:49:46 +0100
Subject: [PATCH] Ensure we return a non-empty list

---
 federationapi/routing/query.go | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/federationapi/routing/query.go b/federationapi/routing/query.go
index 47d3b2df9..d73891946 100644
--- a/federationapi/routing/query.go
+++ b/federationapi/routing/query.go
@@ -70,7 +70,9 @@ func RoomAliasToID(
 				util.GetLogger(httpReq.Context()).WithError(err).Error("senderAPI.QueryJoinedHostServerNamesInRoom failed")
 				return jsonerror.InternalServerError()
 			}
-
+			if !serverQueryReq.ExcludeSelf && len(serverQueryRes.ServerNames) == 0 {
+				serverQueryRes.ServerNames = []gomatrixserverlib.ServerName{domain}
+			}
 			resp = gomatrixserverlib.RespDirectory{
 				RoomID:  queryRes.RoomID,
 				Servers: serverQueryRes.ServerNames,