fix(wallet): accessing tokens block range nil on empty acc.

Fixed a crash in local notification service on a nil block number
in HistoryReady event

services/local-notifications/core_test.go

@@ -122,7 +122,6 @@ func TestTransactionNotification(t *testing.T) {
 
 	feed.Send(walletevent.Event{
 		Type:     transfer.EventRecentHistoryReady,
-		BlockNumber: big.NewInt(0),
 		Accounts: []common.Address{header.Address},
 	})
 

services/local-notifications/database.go

@@ -41,6 +41,9 @@ func (db *Database) GetWalletPreference() (rst NotificationPreference, err error
 	pref := db.db.QueryRow("SELECT service, event, identifier, enabled FROM local_notifications_preferences WHERE service = 'wallet' AND event = 'transaction' AND identifier = 'all'")
 
 	err = pref.Scan(&rst.Service, &rst.Event, &rst.Identifier, &rst.Enabled)
+	if err == sql.ErrNoRows {
+		return rst, nil
+	}
 	return
 }
 

services/local-notifications/transaction.go

@@ -143,7 +143,7 @@ func (s *Service) SubscribeWallet(publisher *event.Feed) error {
 
 	s.StartWalletWatcher()
 
-	return nil
+	return err
 }
 
 // StartWalletWatcher - Forward wallet events to notifications
@@ -167,6 +167,7 @@ func (s *Service) StartWalletWatcher() {
 	maxKnownBlocks := map[common.Address]*big.Int{}
 	go func() {
 		defer s.walletTransmitter.wg.Done()
+		historyReady := false
 		for {
 			select {
 			case <-s.walletTransmitter.quit:
@@ -180,7 +181,7 @@ func (s *Service) StartWalletWatcher() {
 				}
 				return
 			case event := <-events:
-				if event.Type == transfer.EventNewTransfers && len(maxKnownBlocks) > 0 && event.BlockNumber != nil {
+				if event.Type == transfer.EventNewTransfers && historyReady && event.BlockNumber != nil {
 					newBlocks := false
 					for _, address := range event.Accounts {
 						if _, ok := maxKnownBlocks[address]; !ok {
@@ -200,6 +201,8 @@ func (s *Service) StartWalletWatcher() {
 						})
 					}
 				} else if event.Type == transfer.EventRecentHistoryReady {
+					historyReady = true
+					if event.BlockNumber != nil {
 						for _, address := range event.Accounts {
 							if _, ok := maxKnownBlocks[address]; !ok {
 								maxKnownBlocks[address] = event.BlockNumber
@@ -208,6 +211,7 @@ func (s *Service) StartWalletWatcher() {
 					}
 				}
 			}
+		}
 	}()
 }
 

services/wallet/transfer/commands_sequential.go

@@ -817,7 +817,7 @@ func (c *loadBlocksAndTransfersCommand) fetchHistoryBlocks(ctx context.Context,
 	// If we blockRange is nil, we need to load all blocks from `fromNum` to `toNum`
 	// As current implementation checks ETH first then tokens, tokens ranges maybe behind ETH ranges in
 	// cases when block searching was interrupted, so we use tokens ranges
-	if blockRange != nil {
+	if blockRange != nil && blockRange.tokens != nil {
 		if blockRange.tokens.LastKnown != nil && toNum.Cmp(blockRange.tokens.LastKnown) > 0 {
 			ranges = append(ranges, []*big.Int{blockRange.tokens.LastKnown, toNum})
 		}