A window without a minimize or maximize box can still be programmatically
minimized by the Windows API. However, some WMs will refuse to change the
state and not allow it to be maximized again, despite it being minimized,
due to lacking those functions, thus not sending WM_STATE change notifications
when clicking the minimized window on the taskbar.

Heroes of Might and Magic V does this, for example, when losing focus. It
minimizes itself. When maximizing it by clicking on the taskbar it won't
send a WM_STATE change notification (since it was never changed) and fail
to maximize properly, showing a black screen (the game will still think it
is minimized).
Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>