Stopping NSPrintOperation From Crashing Application - swift

Question

I have the following lines of code to print the webView content.
let directoryURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let printOpts: NSDictionary = [NSPrintJobDisposition: NSPrintSaveJob, NSPrintSaveJob: directoryURL, NSPrintScalingFactor: 2.0]
let printInfo = NSPrintInfo(dictionary: printOpts as! [String : AnyObject])
printInfo.horizontalPagination = .autoPagination
printInfo.verticalPagination = .autoPagination
let printOperation = NSPrintOperation(view: webView.mainFrame.frameView, printInfo: printInfo)
printOperation.printPanel.options = [.showsOrientation, .showsPaperSize, .showsPreview, .showsPageSetupAccessory, .showsScaling, .showsPrintSelection]
printOperation.run()
The problem is that it sometimes causes the application to crash when the user interacts with the print operation panel.
If I just click on the cancel button, the application can crash. And if I try to set a different scale rate, it can sometimes crash. I don't know why the application will crash. It's always the last line. What am I doing wrong? Thanks.

Answer 1

There's a bug in the print panel code when .showsCopies is not in the options. It has a use-after-free bug with the Copies-related subviews. It removes them from the view hierarchy, allowing them to be deallocated. However, it keeps a dangling reference to the text field and tries to operate on it in various circumstances. For example, it sometimes tries to make it the first responder.
You basically should just never try to suppress the Copies field.

Answer 2

my code for print a pdf from URL for OS X:
let printInfo = NSPrintInfo.shared
let manager = FileManager.default
do{
let directoryURL = try manager.url(for: .documentDirectory, in:.userDomainMask, appropriateFor:nil, create:true)
let docURL = NSURL(string:"XX.pdf", relativeTo:directoryURL)
let pdfDoc = PDFDocument.init(url: docURL! as URL)
let page = CGRect(x: 0, y: 0, width: 595.2, height: 1841.8) // A4, 72 dpi
let pdfView : PDFView = PDFView.init(frame: page)
pdfView.document = pdfDoc
let operation: NSPrintOperation = NSPrintOperation(view: pdfView, printInfo: printInfo)
operation.printPanel.options.insert(NSPrintPanel.Options.showsPaperSize)
operation.printPanel.options.insert(NSPrintPanel.Options.showsOrientation)
operation.run()
}catch{
}