From 5e4b461e0158daa76872956729b73ccdccefbf10 Mon Sep 17 00:00:00 2001
From: Till <2353100+S7evinK@users.noreply.github.com>
Date: Mon, 28 Nov 2022 11:26:03 +0100
Subject: [PATCH] Return empty JSON if we don't have any protocols to return
 (#2892)

This should help with Element reporting `The homeserver may be too old
to support third party networks.`
---
 clientapi/routing/thirdparty.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/clientapi/routing/thirdparty.go b/clientapi/routing/thirdparty.go
index e757cd411..7a62da449 100644
--- a/clientapi/routing/thirdparty.go
+++ b/clientapi/routing/thirdparty.go
@@ -36,9 +36,15 @@ func Protocols(req *http.Request, asAPI appserviceAPI.AppServiceInternalAPI, dev
 		return jsonerror.InternalServerError()
 	}
 	if !resp.Exists {
+		if protocol != "" {
+			return util.JSONResponse{
+				Code: http.StatusNotFound,
+				JSON: jsonerror.NotFound("The protocol is unknown."),
+			}
+		}
 		return util.JSONResponse{
-			Code: http.StatusNotFound,
-			JSON: jsonerror.NotFound("The protocol is unknown."),
+			Code: http.StatusOK,
+			JSON: struct{}{},
 		}
 	}
 	if protocol != "" {