The app's logic runs while the main window is minimised, without the
frame that acts on a close. Two quits there queued the main window's close
twice: the first let it take over another window, and the second then
quit the app over that window's unsaved changes, as answered.
- close_current queues a window's close only once.
- Test: quitting_twice_before_the_window_draws_closes_it_once.
- docs/hardware-parity.md revision history.