App crashes in iOS7 but not in 8 &9 due to NSDictionary autorelease

Question

+ (NSString *)getValueforLocale:(NSString*) i18nkey :(NSString*)locale{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
    NSLog(@"paths are : %@",paths);
    NSString *libraryDirectory = [paths objectAtIndex:0];
    NSLog(@"libraryDirectory : %@",libraryDirectory);
    NSString *filePath = [libraryDirectory stringByAppendingPathComponent:@"I8nDB"];
    filePath = [filePath stringByAppendingPathComponent:locale];
    NSLog(@"file path is : %@",filePath);
    BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:filePath];
    if(fileExists)
    {
        NSDictionary *dict = [[[NSDictionary alloc] initWithContentsOfFile:filePath]autorelease];
        NSDictionary *resourceBundle = [[[NSDictionary alloc] init]autorelease];
        NSString *keyValue = [[[NSString alloc]init]autorelease];
        resourceBundle = [dict valueForKey:@"hash"];
        keyValue=[resourceBundle valueForKey:i18nkey];
        NSLog(@"value for %@ is(container) : %@",i18nkey,keyValue);
        if(keyValue != nil || keyValue != NULL)
        {
            return keyValue;
        }
        else
        {
            NSLog(@"key not found in the container file");
            NSString *path = [[NSBundle mainBundle] pathForResource:@"Localizable"
                                                             ofType:@"strings"
                                                        inDirectory:nil
                                                    forLocalization:locale];
            NSLog(@"path for %@ is : %@",locale,path);
            fileExists = [[NSFileManager defaultManager] fileExistsAtPath:path];
            if(fileExists)
            {
                NSDictionary *dict = [[NSDictionary dictionaryWithContentsOfFile:path]autorelease];
                NSLog(@"value for %@ is(resources) : %@",i18nkey,[dict objectForKey:i18nkey]);
                return [dict objectForKey:i18nkey];
            }
            else
            {
                return NULL;
            }
        }
    }
    else
    {
        NSLog(@"%@ locale does not exist in container",locale);
        NSString *path = [[NSBundle mainBundle] pathForResource:@"Localizable"
                                                         ofType:@"strings"
                                                    inDirectory:nil
                                                forLocalization:locale];
        NSLog(@"path for %@ in resources is : %@",locale,path);
        fileExists = [[NSFileManager defaultManager] fileExistsAtPath:path];
        if(fileExists)
        {
            NSDictionary *dict = [[NSDictionary dictionaryWithContentsOfFile:path]autorelease];
            NSLog(@"value for %@ is : %@",i18nkey,[dict objectForKey:i18nkey]);
            return [dict objectForKey:i18nkey];
        }
        else
        {
            return NULL;
        }
    }
}

If we remove Autorelease from the above code, it is working in iOS7 if not the app is crashing

My Main concern is why it doesn't crash in iOS8&9 and only crashes in iOS7 is there in change related to autorelease over these versions

Answer 1

Why don't you use ARC? Then you won't need autorelease... See http://rypress.com/tutorials/objective-c/memory-management

Your problem might be related to the settings about ARC.

Answer 2

in Your code you only alloc a dictionary in

NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:filePath];

so you only need to care about it, another object is not owned by You! so You don't need release or autorelease them.

Try flowing code

+ (NSString *)getValueforLocale:(NSString*) i18nkey :(NSString*)locale
    {
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
        NSLog(@"paths are : %@",paths);
        NSString *libraryDirectory = [paths objectAtIndex:0];
        NSLog(@"libraryDirectory : %@",libraryDirectory);
        NSString *filePath = [libraryDirectory stringByAppendingPathComponent:@"I8nDB"];
        filePath = [filePath stringByAppendingPathComponent:locale];
        NSLog(@"file path is : %@",filePath);
        BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:filePath];
        if(fileExists)
        {
            NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:filePath];
            //NSDictionary *resourceBundle = [[[NSDictionary alloc] init]autorelease];
            //NSString *keyValue = [[[NSString alloc]init]autorelease];
            NSDictionary *resourceBundle = [dict valueForKey:@"hash"];
            // relese dict here because not use after
            [dict release];
            NSString *keyValue=[resourceBundle valueForKey:i18nkey];
            NSLog(@"value for %@ is(container) : %@",i18nkey,keyValue);
            if(keyValue != nil || keyValue != NULL)
            {
                return keyValue;
            }
            else
            {
                NSLog(@"key not found in the container file");
                NSString *path = [[NSBundle mainBundle] pathForResource:@"Localizable"
                                                                 ofType:@"strings"
                                                            inDirectory:nil
                                                        forLocalization:locale];
                NSLog(@"path for %@ is : %@",locale,path);
                fileExists = [[NSFileManager defaultManager] fileExistsAtPath:path];
                if(fileExists)
                {
                    // NSDictionary *dict = [[NSDictionary dictionaryWithContentsOfFile:path]autorelease];
                    NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:path];
                    NSLog(@"value for %@ is(resources) : %@",i18nkey,[dict objectForKey:i18nkey]);
                    return [dict objectForKey:i18nkey];
                }
                else
                {
                    return NULL;
                }
            }
        }
        else
        {
            NSLog(@"%@ locale does not exist in container",locale);
            NSString *path = [[NSBundle mainBundle] pathForResource:@"Localizable"
                                                             ofType:@"strings"
                                                        inDirectory:nil
                                                    forLocalization:locale];
            NSLog(@"path for %@ in resources is : %@",locale,path);
            fileExists = [[NSFileManager defaultManager] fileExistsAtPath:path];
            if(fileExists)
            {
                // NSDictionary *dict = [[NSDictionary dictionaryWithContentsOfFile:path]autorelease];
                NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:path];
                NSLog(@"value for %@ is : %@",i18nkey,[dict objectForKey:i18nkey]);
                return [dict objectForKey:i18nkey];
            }
            else
            {
                return NULL;
            }
        }
    }

Answer 3

In manual reference counting, retains and releases need to be balanced.

In

NSDictionary *dict = [[[NSDictionary alloc] initWithContentsOfFile:filePath]autorelease];
NSDictionary *resourceBundle = [[[NSDictionary alloc] init]autorelease];

the retains and releases are balanced, because alloc (along with retain, new, copy, mutableCopy) returns a retained instance, and autorelease counts as a release.

However, in

NSDictionary *dict = [[NSDictionary dictionaryWithContentsOfFile:path]autorelease];

you have an overrelease because you are autorelease something that you have not retained.

iOS version has absolutely nothing to do with it.