tomnewton / posixerror

debug project

posixerror

This demonstrates an issue with NSURLSession's discretionary property and building with Android Studio vs XCode on the iOS simulator.

Getting Started

NSURLSessionConfiguration Discretionary property breaks redirects on iOS Simulators when running from Android Studio, but not XCode.

See the comments here: PosixerrorPlugin.m.

-(void)runBackgroundDownload {
    NSURLSessionConfiguration* config = [NSURLSessionConfiguration backgroundSessionConfigurationWithIdentifier:@"MY_EXAMPLE_IDENTIFIER"];
    [config setSessionSendsLaunchEvents:YES];
    
    
    // NOTE: If you set [config setDiscretionary:NO]; you don't have any issues
    // whatsoever.
    
    //
    // THE ISSUE:
    //
    // If you set [config setDiscretionary:YES]; you get an NSPOSIXErrorDomain error
    // for any URL that REDIRECTS when you build and run from Android Studio?!?!?
    // If you build and run this from XCode - no error!
    
    // When thing run properly you'll see PROGRESS!! and COMPLETE!! in the debug output.
    // When the issue is triggered, you'll see the following in the debug output in Android Studio.
    // ERROR: Error Domain=NSPOSIXErrorDomain Code=22 "Invalid argument" UserInfo={_kCFStreamErrorCodeKey=22, _kCFStreamErrorDomainKey=1}
    
    // To demonstrate:
    [config setDiscretionary:YES];
    
    //
    // Config 1: This url DOES redirect and demonstrates the strange issue I'm seeing.
    //
    // 1) Build and run from XCode and everything runs just fine.
    // 2) Build and run from Android Studio, Fails with NSPOSIXErrorDoman invalid argument.
    NSURL* url = [NSURL URLWithString:@"https://traffic.megaphone.fm/GLT8678602522.mp3"];
    // Could it be that the way the debugger is attached is causing an issue? I've seen some strange
    // recent discussion of something similar here on the Xamarin project:
    // https://bugzilla.xamarin.com/show_bug.cgi?id=59793
   
    
    // Config 2: This url does NOT redirect - so works whether or not you build and run from Android Studio
    // or XCode. If you want to prove it to yourself, just uncomment the url below.
    //NSURL* url = [NSURL URLWithString:@"https://dcs.megaphone.fm/GLT8678602522.mp3?key=c6acd2ee217fb8c6ab3fabb9be0920e0"];

    NSURLSession* session = [NSURLSession sessionWithConfiguration:config delegate:(id<NSURLSessionDelegate>)self delegateQueue:nil];
    
    
    NSLog(@"URL we're loading is: %@", url.absoluteString);
    
    
    NSURLSessionDownloadTask* task = [session downloadTaskWithURL:url];
    
    [task resume];
}