iOS Core Data - unexpected memory leak

I have Multi-threaded core data setup - it works very well. In this setup I have a series of functions that grab required data and so forth. They all work well except for this one which is causing a small leak - but it adds up quite fast and crashes the app.

- (id)getRecordOfType:(NSString *)type WithCode:(NSString *)codeString{
    id returnObj = nil;

    NSFetchRequest *request = [[NSFetchRequest alloc] init];
    [request setEntity:[NSE开发者_如何转开发ntityDescription entityForName:type inManagedObjectContext:self.managedObjectContext]];

    NSPredicate *categoryPred = [NSPredicate predicateWithFormat:[@"code='" stringByAppendingFormat:@"%@'", codeString]];
    [request setPredicate:categoryPred];
    categoryPred = nil;

    if (![request entity]) {
        [request release]; request = nil;
        return nil;
    }

    NSError *error;
    NSMutableArray *results = [[self.managedObjectContext executeFetchRequest:request error:&error] mutableCopy];

    for (id tmpObj in results) {
        if([(NSString *)[tmpObj code] isEqualToString:codeString])
            returnObj = tmpObj;
            break;
    }

    [results release];
    [request release];

return returnObj;
}

If anyone can shed some light here it would be greatly appreciated.

Thanks in advance,

Michael

I cannot spot easily a memory leak. On the other hand, I think that a memory leak is not easily the cause of a crash, only in case you run out of memory. Anyway, it seems to me that there is a problem with your code that could possibly be causing the crash:

from results,

    NSMutableArray *results = [[self.managedObjectContext executeFetchRequest:request error:&error] mutableCopy];

you select an object:

           returnObj = tmpObj;

and the return it after releasing results:

[results release];
...
return returnObj;

It is my understanding that releasing an array will also release all of its object, so you are returning an object which could be deallocated at any moment (or even just deallocated).