Runtime exception after playback when app is backgrounded
- play any media from your local library
- stop playback to reveal the library
- background the app pressing the home button or doing the respective gesture
- the app will assert-fail on line 299 in MediaLibraryService.swift because it tries to save playback progress while there is no valid media object.
This is with HEAD (a12cb2ee) on iOS 12.latest with iPhone 8.
backtrace: https://pastebin.com/t9bEfd9G