Mac printing issue when chosing "Save to PDF" in native dialog.

When we try to print, and choose "Save to PDF" in the print dialog, the printing is successful but the main window of the application appears to stop responding to user input. The application menu responds, though. This only affects "Save to PDF". "Open in Preview..." and printing to a printer both behave normally. This also seems like some kind of issue with Qt not processing the completion message from OS X when we close the QPainter and QPrinter objects. We need someone to investigate whether we are missing some kind of call or flag, or whether there's a bug in Qt for OS X.

Note that this only happens when opening the dialog by calling QPrintDialog::open.

See attached example application.

The sequence is:
-User clicks print button
-Application displays a Print Dialog. First, select "Open in Preview" in this dialog.
-Application displays a modal dialog box to indicate that printing is in progress.
Application uses the printer created by the dialog and creates a QPainter. It calls painter>begin(printer) and writes the text "Page 1". It then calls printer->newPage() and writes "Page 2" through "Page 5".
-Application closes the printer and the modal dialog box.

If you had selected "Open in Preview", you should now see Preview launch and show a five page document. You can click on the checkbox and see that it toggles. Now, repeat and select "Save as PDF". Notice that no modal progress dialog is displayed – the application returns immediately. Now try clicking the checkbox, and notice that it does not toggle.