From 190e262ceca0a928ffbaacb92375e6bc511212e8 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue, 13 Oct 2020 17:49:54 +0100
Subject: [PATCH] Revert "lookupEvent sends outliers"

This reverts commit 3e1655644105a542b806e28d6d2536fbd23ecc83.
---
 federationapi/routing/send.go | 49 +++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 19 deletions(-)

diff --git a/federationapi/routing/send.go b/federationapi/routing/send.go
index 080b1247f..24e29a18d 100644
--- a/federationapi/routing/send.go
+++ b/federationapi/routing/send.go
@@ -416,13 +416,38 @@ func (t *txnReq) retrieveMissingAuthEvents(
 	if len(servers) > 5 {
 		servers = servers[:5]
 	}
-
+withNextEvent:
 	for missingAuthEventID := range missingAuthEvents {
-		if _, err := t.lookupEvent(ctx, stateResp.RoomVersion, missingAuthEventID, true, servers); err != nil {
-			logger.WithError(err).Warnf("Failed to retrieve auth event %q", missingAuthEventID)
-			continue
+	withNextServer:
+		for _, server := range servers {
+			logger.Infof("Retrieving missing auth event %q from %q", missingAuthEventID, server)
+			tx, err := t.federation.GetEvent(ctx, server, missingAuthEventID)
+			if err != nil {
+				logger.WithError(err).Warnf("Failed to retrieve auth event %q", missingAuthEventID)
+				continue withNextServer
+			}
+			ev, err := gomatrixserverlib.NewEventFromUntrustedJSON(tx.PDUs[0], stateResp.RoomVersion)
+			if err != nil {
+				logger.WithError(err).Warnf("Failed to unmarshal auth event %q", missingAuthEventID)
+				continue withNextServer
+			}
+			if err = api.SendInputRoomEvents(
+				context.Background(),
+				t.rsAPI,
+				[]api.InputRoomEvent{
+					{
+						Kind:         api.KindOutlier,
+						Event:        ev.Headered(stateResp.RoomVersion),
+						AuthEventIDs: ev.AuthEventIDs(),
+						SendAsServer: api.DoNotSendToOtherServers,
+					},
+				},
+			); err != nil {
+				return fmt.Errorf("api.SendEvents: %w", err)
+			}
+			delete(missingAuthEvents, missingAuthEventID)
+			continue withNextEvent
 		}
-		delete(missingAuthEvents, missingAuthEventID)
 	}
 
 	if missing := len(missingAuthEvents); missing > 0 {
@@ -1016,20 +1041,6 @@ func (t *txnReq) lookupEvent(ctx context.Context, roomVersion gomatrixserverlib.
 		return nil, verifySigError{event.EventID(), err}
 	}
 	h := event.Headered(roomVersion)
-	if err := api.SendInputRoomEvents(
-		context.Background(),
-		t.rsAPI,
-		[]api.InputRoomEvent{
-			{
-				Kind:         api.KindOutlier,
-				Event:        h,
-				AuthEventIDs: h.AuthEventIDs(),
-				SendAsServer: api.DoNotSendToOtherServers,
-			},
-		},
-	); err != nil {
-		return nil, fmt.Errorf("api.SendInputRoomEvents: %w", err)
-	}
 	t.newEvents[h.EventID()] = true
 	return &h, nil
 }