Open Radar

 
When loading a PDF into a PDFView immediately after the PDFView has been loaded from a NIB, then releasing that PDFView a few seconds later, the PDFView tries to access a previously freed object which causes the app to crash. It appears what is happening is:

1) PDFView is loaded from NIB
2) PDFDocument is loaded into PDFView
3) PDFView calls -[PDFView(PDFViewInternal) handleInitialContentRenderSkip], which creates an NSTimer with the +[NSTimer timerWithTimeInterval:target:selector:userInfo:repeats:] method, but does not retain it
4) A few seconds later, the user closes the window, thereby releasing the PDFView
5) In the -[PDFView dealloc] method, -[NSTimer invalidate] is called on the previously freed NSTimer
6) The app crashes

This does not happen every time. I believe it is most likely to happen when opening a larger PDF file for the first time (i.e. when it is not already in the filesystem cache and takes a bit longer to load).