Don't create rooms with no messages when backfilling

historysync.go

@@ -114,6 +114,12 @@ func (user *User) createOrUpdatePortalAndBackfillWithLock(req *database.Backfill
 		return
 	}
 
+	allMsgs := user.bridge.DB.HistorySyncQuery.GetMessagesBetween(user.MXID, conv.ConversationID, req.TimeStart, req.TimeEnd, req.MaxTotalEvents)
+	if len(allMsgs) == 0 {
+		user.log.Debugfln("Not backfilling %s: no bridgeable messages found", portal.Key.JID)
+		return
+	}
+
 	if len(portal.MXID) == 0 {
 		user.log.Debugln("Creating portal for", portal.Key.JID, "as part of history sync handling")
 		err := portal.CreateMatrixRoom(user, nil, true, false)
@@ -123,46 +129,41 @@ func (user *User) createOrUpdatePortalAndBackfillWithLock(req *database.Backfill
 		}
 	}
 
-	allMsgs := user.bridge.DB.HistorySyncQuery.GetMessagesBetween(user.MXID, conv.ConversationID, req.TimeStart, req.TimeEnd, req.MaxTotalEvents)
-
-	if len(allMsgs) > 0 {
-		user.log.Debugfln("Backfilling %d messages in %s, %d messages at a time", len(allMsgs), portal.Key.JID, req.MaxBatchEvents)
-		toBackfill := allMsgs[0:]
-		insertionEventIds := []id.EventID{}
-		for {
-			if len(toBackfill) == 0 {
-				break
-			}
-
-			var msgs []*waProto.WebMessageInfo
-			if len(toBackfill) <= req.MaxBatchEvents {
-				msgs = toBackfill
-				toBackfill = toBackfill[0:0]
-			} else {
-				msgs = toBackfill[len(toBackfill)-req.MaxBatchEvents:]
-				toBackfill = toBackfill[:len(toBackfill)-req.MaxBatchEvents]
-			}
-
-			if len(msgs) > 0 {
-				time.Sleep(time.Duration(req.BatchDelay) * time.Second)
-				user.log.Debugfln("Backfilling %d messages in %s", len(msgs), portal.Key.JID)
-				insertionEventIds = append(insertionEventIds, portal.backfill(user, msgs)...)
-			}
+	user.log.Debugfln("Backfilling %d messages in %s, %d messages at a time", len(allMsgs), portal.Key.JID, req.MaxBatchEvents)
+	toBackfill := allMsgs[0:]
+	var insertionEventIds []id.EventID
+	for {
+		if len(toBackfill) == 0 {
+			break
 		}
-		user.log.Debugfln("Finished backfilling %d messages in %s", len(allMsgs), portal.Key.JID)
-		if len(insertionEventIds) > 0 {
-			portal.sendPostBackfillDummy(
-				time.Unix(int64(allMsgs[len(allMsgs)-1].GetMessageTimestamp()), 0),
-				insertionEventIds[0])
+
+		var msgs []*waProto.WebMessageInfo
+		if len(toBackfill) <= req.MaxBatchEvents {
+			msgs = toBackfill
+			toBackfill = toBackfill[0:0]
+		} else {
+			msgs = toBackfill[len(toBackfill)-req.MaxBatchEvents:]
+			toBackfill = toBackfill[:len(toBackfill)-req.MaxBatchEvents]
 		}
-		user.log.Debugfln("Deleting %d history sync messages after backfilling", len(allMsgs))
-		err := user.bridge.DB.HistorySyncQuery.DeleteMessages(user.MXID, conv.ConversationID, allMsgs)
-		if err != nil {
-			user.log.Warnfln("Failed to delete %d history sync messages after backfilling: %v", len(allMsgs), err)
+
+		if len(msgs) > 0 {
+			time.Sleep(time.Duration(req.BatchDelay) * time.Second)
+			user.log.Debugfln("Backfilling %d messages in %s (queue ID: %d)", len(msgs), portal.Key.JID, req.QueueID)
+			insertionEventIds = append(insertionEventIds, portal.backfill(user, msgs)...)
 		}
-	} else {
-		user.log.Debugfln("Not backfilling %s: no bridgeable messages found", portal.Key.JID)
 	}
+	user.log.Debugfln("Finished backfilling %d messages in %s (queue ID: %d)", len(allMsgs), portal.Key.JID, req.QueueID)
+	if len(insertionEventIds) > 0 {
+		portal.sendPostBackfillDummy(
+			time.Unix(int64(allMsgs[len(allMsgs)-1].GetMessageTimestamp()), 0),
+			insertionEventIds[0])
+	}
+	user.log.Debugfln("Deleting %d history sync messages after backfilling", len(allMsgs))
+	err := user.bridge.DB.HistorySyncQuery.DeleteMessages(user.MXID, conv.ConversationID, allMsgs)
+	if err != nil {
+		user.log.Warnfln("Failed to delete %d history sync messages after backfilling: %v", len(allMsgs), err)
+	}
+
 	if !conv.MarkedAsUnread && conv.UnreadCount == 0 {
 		user.markSelfReadFull(portal)
 	}