Crash or display bug when minimizing the window during transitions.

[SleepKirby]

If you minimize the Ren'Py window in the middle of a transition (like a dissolve), and then you un-minimize it, the game display will break:
In Windows 7 using the Basic theme, the display will be totally gone; the Ren'Py window will become a hollow window.
In Windows 7 using the Aero theme, the display will be completely black.

In this state, Ren'Py will still respond to all inputs, but the display will remain broken. The only way I found to get the display back was to resize the Ren'Py window. Otherwise, you'll either have to quit the game blind, or use Task Manager to close Ren'Py.

*Update* In some cases with multiple transitions in a row (possibly with pause statements in the mix), minimizing between transitions will crash the game: either the game will immediately crash with a Microsoft Visual C++ Runtime Error, or it will be impossible to un-minimize the game, leaving Task Manager as the only solution (meanwhile, the music might be stuck repeating a short segment).

May or may not be related to this other bug: https://bugs.launchpad.net/bugs/802831 "Display bug when entering game menu screen during a transition."

Demonstration game, same as for the bug linked above: http://lemmasoft.renai.us/forums/viewtopic.php?f=8&t=10891
However, there's only one transition in this demo, so this only applies to the display problem, not the crash problem. Let me know if an example of the crash is needed.

The bugs were seen on a Windows 7 computer, and can be replicated consistently. I don't know if a similar effect happens on other OSes or configurations.

Happens in Ren'Py 6.12.1.1520 and 6.12.0e. As far as I can tell, it doesn't happen in 6.10.2.

[Tom Rothamel (renpytom)]

I think I have a pretty good idea of how to fix this, but the fix will require fairly major changes to how Ren'Py deals with iconification. So I'm going to defer the fix to the 6.13 major release.