[grzybr1]

On Windows, closing the window lets DefWindowProc destroy it, and the main loop then ends on WM_QUIT before iterate() is called, so an application can't ask anything (e.g. about unsaved changes). The SDL2 backend instead sets done = true before iterate(done), which the application can reset.

This handles WM_CLOSE in WndProc (sets a flag instead of destroying the window) and passes it to the application as done = true before iterate(done), matching SDL2. A minimised window is restored first so the frame actually runs. The window is still destroyed in the existing cleanup after the loop.

For applications that ignore done, closing behaves as before, except that iterate() runs one more frame with done == true (as with SDL2).

Please note that I have neither built or tested this myself.

[grzybr1]

I have now tested this on Windows against af507cc (the commit that libtem is pointing at today).

Closing with unsaved changes asks, without them it closes immediately, minimised-and-closed restores the window first.