[compiz] decoration mask

[Danny Baumann]

Hi,

> Yes, I think comparing the names is a workaround which works
> for the moment.
> 
> I didn't try with group though since it doesn't work with compiz just yet.

The only Beryl-specific thing group is using right now (at least that
I'm aware of) is the offscreen interface. This is needed to properly
hide the non-top tab windows until window unmapping and pixmap
deallocation can be splitted in the X server.
If anyone of you has any pointer how to properly hide windows without
unmapping on a per-plugin basis, please let me know. We (as the group
developers) have no interest in hindering group being used with Compiz,
the problem is just that we aren't aware of any solution to the window
hiding which doesn't involve core changes.

Thanks,

Danny