Note: This bug is always reproducible only if embedding Qt into native Cocoa NSView.

The QML FileDialog can be opened and closed from code using open() and close() methods. When FileDialog is created with default modality settings Qt.WindowModal some controls and menus are disabled (e.g. window close, minimise, zoom buttons).
If the dialog is dismissed using dialog controls (e.g. Cancel button), the modal state is exited.
If the dialog is dismissed using dialog's close() method the state is modal not exited, even though it should.

I've attached sample project based on embeddedqwindow Qt example.
Steps to reproduce:
1. Build the project (I've used it with Kits 5.7.0, 5.6.2 and 5.5.1)
2. Run the project
3. Click Open File Dialog button
4. Dialog should open
5. Click Close File Dialog button
6. Dialog should close
7. Try using window buttons (close, minimise, zoom)... no reaction
8. Quit the app... crash