ios - NSPersistentStoreDidImportUbiquitousContentChangesNotification returns empty -

i have issue use coredata + icloud sync.

sometimes, notification, nspersistentstoredidimportubiquitouscontentchangesnotification, returns empty array in inserted, updated , deleted.

if notification called when have changes, why return empty notification?

thanks!!!

code calls notification:

 - (void)persistentstoredidchange:(nsnotification*)notification  {      dlog(@"change detected! notification: %@", notification.description)       [__managedobjectcontext performblockandwait:^(void)      {          [__managedobjectcontext mergechangesfromcontextdidsavenotification:notification];           for(id<coredatadelegate>delegate in _delegates)          {              if([delegate respondstoselector:@selector(persistentstoredidchange)])                 [delegate persistentstoredidchange];           }      }];  } 

it sometimes. it's pretty minor issue compared many severe problems of icloud core data.

what when receiving notification check inserted, updated, , deleted objects first, , don't go ahead merge process unless find something. like

nsdictionary *userinfo = [notification userinfo]; if (([userinfo objectforkey:nsinsertedobjectskey] > 0) ||      ([userinfo objectforkey:nsupdatedobjectskey] > 0) ||      ([userinfo objectforkey:nsdeletedobjectskey] > 0))  {     // merge... }