Open Radar

 
When an app is suspended whilst playing a movie delivered via HTTP Live Streaming to an MPMoviePlayerController data is silently downloaded in the background if the user changes from using a Wifi network to a 3G network or vice versa.

This occurs even when the app has not opted-in to any background tasks by including the UIBackgroundModes key in the app's info.plist.

This is Not Good as the user has no way to know that audio/video data is being downloaded and it can only be stopped by forcibly terminating the app. It is Particularly Bad if the user is using a cellular connection and has exceeded their monthly allowance for data as they could incur very large data bills without knowing why.


Steps to Reproduce:

Create a new iPhone project.
- Add the MediaPlayer framework.
- Initialise a MPMoviePlayerController with the URL to a HTTP Live Streaming video.
- Add the MPMoviePlayerController's view to the view hierarchy (it doesn't seem to happen when using a MPMoviePlayerViewController).
- Run the app whilst watching traffic using a proxy (such as Charles)
- See video data being downloaded
- Suspend the app
- See video data stop
- Toggle wifi off and on again
- See video data start being downloaded again silently in the background


Expected Results:

When the app is suspended it should no longer download any data unless it has explicitly opted in to one of the supported 'background modes'.

Actual Results:

When the app is suspended and the user's network state changes data is downloaded in the background.

Regression:

This only seems to happen when using an MPMoviePlayerController whose view is added to a custom view hierarchy. It doesn't seem to happen when using a MPMoviePlayerViewController. I've observed this on iPhones and iPads running various versions of iOS4, but on iOS5 beta 7 it seems to only download a single video segment once it starts silently downloading data again.