From 2738d429beb7fb2def31236b38727fd22c785304 Mon Sep 17 00:00:00 2001
From: Till Faelligen <2353100+S7evinK@users.noreply.github.com>
Date: Fri, 22 Sep 2023 17:19:52 +0200
Subject: [PATCH] Move redacts to the client API, which should satisfy clients
 and federation

---
 clientapi/routing/redaction.go        |  8 ++++-
 syncapi/synctypes/clientevent.go      | 12 --------
 syncapi/synctypes/clientevent_test.go | 44 ---------------------------
 3 files changed, 7 insertions(+), 57 deletions(-)

diff --git a/clientapi/routing/redaction.go b/clientapi/routing/redaction.go
index aa579db64..f331a73c7 100644
--- a/clientapi/routing/redaction.go
+++ b/clientapi/routing/redaction.go
@@ -34,7 +34,8 @@ import (
 )
 
 type redactionContent struct {
-	Reason string `json:"reason"`
+	Reason  string `json:"reason"`
+	Redacts string `json:"redacts"`
 }
 
 type redactionResponse struct {
@@ -151,6 +152,11 @@ func SendRedaction(
 		Type:     spec.MRoomRedaction,
 		Redacts:  eventID,
 	}
+
+	// Room version 11 expects the "redacts" field on the
+	// content field, so add it here as well
+	r.Redacts = eventID
+
 	err = proto.SetContent(r)
 	if err != nil {
 		util.GetLogger(req.Context()).WithError(err).Error("proto.SetContent failed")
diff --git a/syncapi/synctypes/clientevent.go b/syncapi/synctypes/clientevent.go
index d894a3906..6812f8332 100644
--- a/syncapi/synctypes/clientevent.go
+++ b/syncapi/synctypes/clientevent.go
@@ -141,18 +141,6 @@ func ToClientEvent(se gomatrixserverlib.PDU, format ClientEventFormat, userIDFor
 		Redacts:        se.Redacts(),
 	}
 
-	// RoomVersion V11 moved the "redacts" field to "content", so add it there as well
-	// For compatibility with older clients, we keep the "redacts" top-level field.
-	// TODO: At which point do we remove "redacts" from the top-level?
-	if se.Type() == spec.MRoomRedaction && se.Version() == gomatrixserverlib.RoomVersionV11 && ce.Redacts != "" {
-		v11content, err := sjson.SetBytes(ce.Content, "redacts", ce.Redacts)
-		if err != nil {
-			logrus.WithError(err).Warn("failed to set content.redacts")
-		} else {
-			ce.Content = v11content
-		}
-	}
-
 	switch format {
 	case FormatAll:
 		ce.RoomID = se.RoomID().String()
diff --git a/syncapi/synctypes/clientevent_test.go b/syncapi/synctypes/clientevent_test.go
index 00364d02c..662f9ea43 100644
--- a/syncapi/synctypes/clientevent_test.go
+++ b/syncapi/synctypes/clientevent_test.go
@@ -154,50 +154,6 @@ func TestToClientEvent(t *testing.T) { // nolint: gocyclo
 	}
 }
 
-// Merely tests that the top-level "redacts" is copied to "content.redacts" and keeps the top-level
-// one as is
-func TestToClientEventRedactionV11(t *testing.T) { // nolint: gocyclo
-	ev, err := gomatrixserverlib.MustGetRoomVersion(gomatrixserverlib.RoomVersionV11).NewEventFromTrustedJSON([]byte(`{
-		"type": "m.room.redaction",
-		"state_key": "",
-		"event_id": "$test",
-		"room_id": "!test:localhost",
-		"sender": "@test:localhost",
-		"content": {
-			"reason": "Hello World"
-		},
-		"origin_server_ts": 123456,
-		"unsigned": {
-			"prev_content": {
-				"name": "Goodbye World"
-			}
-		},
-		"redacts": "$abc"
-	}`), false)
-	if err != nil {
-		t.Fatalf("failed to create Event: %s", err)
-	}
-
-	ce, err := ToClientEvent(ev, FormatAll, func(roomID spec.RoomID, senderID spec.SenderID) (*spec.UserID, error) {
-		return queryUserIDForSender(senderID)
-	})
-	if err != nil {
-		t.Fatalf("failed to create ClientEvent: %s", err)
-	}
-
-	j, err := json.Marshal(ce)
-	if err != nil {
-		t.Fatalf("failed to Marshal ClientEvent: %s", err)
-	}
-	// Marshal sorts keys in structs by the order they are defined in the struct, which is alphabetical
-	out := `{"content":{"reason":"Hello World","redacts":"$abc"},"event_id":"$test","origin_server_ts":123456,` +
-		`"room_id":"!test:localhost","sender":"@test:localhost","state_key":"","type":"m.room.redaction",` +
-		`"unsigned":{"prev_content":{"name":"Goodbye World"}},"redacts":"$abc"}`
-	if !bytes.Equal([]byte(out), j) {
-		t.Errorf("ClientEvent marshalled to wrong bytes: wanted \n%s, got \n%s", out, string(j))
-	}
-}
-
 func TestToClientFormatSync(t *testing.T) {
 	ev, err := gomatrixserverlib.MustGetRoomVersion(gomatrixserverlib.RoomVersionV1).NewEventFromTrustedJSON([]byte(`{
 		"type": "m.room.name",