Roll-forward "Add preliminary support for persisting pre-saved history entries remotely"

This rolls-forward commit 66916c27cb.

client/lib/lib.go

@@ -600,7 +600,10 @@ func ProcessDeletionRequests(ctx context.Context) error {
 	db := hctx.GetDb(ctx)
 	for _, request := range deletionRequests {
 		for _, entry := range request.Messages.Ids {
-			res := db.Where("device_id = ? AND end_time = ?", entry.DeviceId, entry.Date).Delete(&data.HistoryEntry{})
+			// Note that entry.StartTime is not always present (for legacy reasons) and entry.EndTime is also
+			// not always present (for pre-saved entries). So we just check that one of them matches.
+			tx := db.Where("device_id = ? AND (start_time = ? OR end_time = ?)", entry.DeviceId, entry.StartTime, entry.EndTime)
+			res := tx.Delete(&data.HistoryEntry{})
 			if res.Error != nil {
 				return fmt.Errorf("DB error: %w", res.Error)
 			}