From c4d9b374927309e327c19f1985ad65c3b78ab5ee Mon Sep 17 00:00:00 2001
From: Kegan Dougal <kegan@matrix.org>
Date: Wed, 17 Jun 2020 13:54:47 +0100
Subject: [PATCH 1/2] add test

---
 sytest-whitelist | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sytest-whitelist b/sytest-whitelist
index 8f3d128d7..244cfe8cc 100644
--- a/sytest-whitelist
+++ b/sytest-whitelist
@@ -331,3 +331,4 @@ Can download file 'ascii'
 Can download file 'name with spaces'
 Can download file 'name;with;semicolons'
 Can download specifying a different ASCII file name
+Inbound /v1/send_join rejects joins from other servers

From 38053a5bb7af9bba522225fc62bee73d363bff85 Mon Sep 17 00:00:00 2001
From: Kegsay <kegan@matrix.org>
Date: Wed, 17 Jun 2020 13:55:55 +0100
Subject: [PATCH 2/2] Do not wrap send_join errors on /v1/send_join (#1143)

* Do not wrap v1 send_join errors in [code, body]

* Don't wrap errors
---
 federationapi/routing/routing.go | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/federationapi/routing/routing.go b/federationapi/routing/routing.go
index 649a43c66..645f397de 100644
--- a/federationapi/routing/routing.go
+++ b/federationapi/routing/routing.go
@@ -18,6 +18,7 @@ import (
 	"net/http"
 
 	"github.com/gorilla/mux"
+	"github.com/matrix-org/dendrite/clientapi/jsonerror"
 	eduserverAPI "github.com/matrix-org/dendrite/eduserver/api"
 	federationSenderAPI "github.com/matrix-org/dendrite/federationsender/api"
 	"github.com/matrix-org/dendrite/internal/config"
@@ -203,12 +204,20 @@ func Setup(
 			res := SendJoin(
 				httpReq, request, cfg, rsAPI, keys, roomID, eventID,
 			)
+			// not all responses get wrapped in [code, body]
+			var body interface{}
+			body = []interface{}{
+				res.Code, res.JSON,
+			}
+			jerr, ok := res.JSON.(*jsonerror.MatrixError)
+			if ok {
+				body = jerr
+			}
+
 			return util.JSONResponse{
 				Headers: res.Headers,
 				Code:    res.Code,
-				JSON: []interface{}{
-					res.Code, res.JSON,
-				},
+				JSON:    body,
 			}
 		},
 	)).Methods(http.MethodPut)