From 1be77d2a97a4ad92725b33103a652b2ce2e1f275 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Wed, 6 May 2020 15:10:44 +0100
Subject: [PATCH] Loopback invite events

---
 roomserver/internal/input.go        | 16 +++++++++++-----
 roomserver/internal/input_events.go | 18 +++++++++---------
 2 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/roomserver/internal/input.go b/roomserver/internal/input.go
index 19ebea660..e45dca3a5 100644
--- a/roomserver/internal/input.go
+++ b/roomserver/internal/input.go
@@ -58,15 +58,21 @@ func (r *RoomserverInternalAPI) InputRoomEvents(
 	// We lock as processRoomEvent can only be called once at a time
 	r.mutex.Lock()
 	defer r.mutex.Unlock()
+	for i := range request.InputInviteEvents {
+		if event, e := processInviteEvent(ctx, r.DB, r, request.InputInviteEvents[i]); e != nil {
+			return e
+		} else {
+			request.InputRoomEvents = append(request.InputRoomEvents, api.InputRoomEvent{
+				Kind:         api.KindNew,
+				Event:        *event,
+				AuthEventIDs: event.AuthEventIDs(),
+			})
+		}
+	}
 	for i := range request.InputRoomEvents {
 		if response.EventID, err = processRoomEvent(ctx, r.DB, r, request.InputRoomEvents[i]); err != nil {
 			return err
 		}
 	}
-	for i := range request.InputInviteEvents {
-		if err = processInviteEvent(ctx, r.DB, r, request.InputInviteEvents[i]); err != nil {
-			return err
-		}
-	}
 	return nil
 }
diff --git a/roomserver/internal/input_events.go b/roomserver/internal/input_events.go
index 6da63716c..0021c5a50 100644
--- a/roomserver/internal/input_events.go
+++ b/roomserver/internal/input_events.go
@@ -134,9 +134,9 @@ func processInviteEvent(
 	db storage.Database,
 	ow OutputRoomEventWriter,
 	input api.InputInviteEvent,
-) (err error) {
+) (returned *gomatrixserverlib.HeaderedEvent, err error) {
 	if input.Event.StateKey() == nil {
-		return fmt.Errorf("invite must be a state event")
+		return nil, fmt.Errorf("invite must be a state event")
 	}
 
 	roomID := input.Event.RoomID()
@@ -151,7 +151,7 @@ func processInviteEvent(
 
 	updater, err := db.MembershipUpdater(ctx, roomID, targetUserID, input.RoomVersion)
 	if err != nil {
-		return err
+		return nil, err
 	}
 	succeeded := false
 	defer func() {
@@ -189,7 +189,7 @@ func processInviteEvent(
 		// For now we will implement option 2. Since in the abesence of a retry
 		// mechanism it will be equivalent to option 1, and we don't have a
 		// signalling mechanism to implement option 3.
-		return nil
+		return nil, nil
 	}
 
 	event := input.Event.Unwrap()
@@ -199,7 +199,7 @@ func processInviteEvent(
 		// most likely to be if the event came in over federation) then use
 		// that.
 		if err = event.SetUnsignedField("invite_room_state", input.InviteRoomState); err != nil {
-			return err
+			return nil, err
 		}
 	} else {
 		// There's no invite room state, so let's have a go at building it
@@ -208,22 +208,22 @@ func processInviteEvent(
 		// the invite room state, if we don't then we just fail quietly.
 		if irs, ierr := buildInviteStrippedState(ctx, db, input); ierr == nil {
 			if err = event.SetUnsignedField("invite_room_state", irs); err != nil {
-				return err
+				return nil, err
 			}
 		}
 	}
 
 	outputUpdates, err := updateToInviteMembership(updater, &event, nil, input.Event.RoomVersion)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	if err = ow.WriteOutputEvents(roomID, outputUpdates); err != nil {
-		return err
+		return nil, err
 	}
 
 	succeeded = true
-	return nil
+	return &input.Event, nil
 }
 
 func buildInviteStrippedState(