[Bug 5913] New: Several InvalidateRect calls suddenly show the Explorer Desktop (Notes 7)

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=5913

Summary: Several InvalidateRect calls suddenly show the Explorer
                    Desktop (Notes 7)
           Product: Wine
           Version: 0.9.18.
          Platform: Other
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: wine-programs
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Hello,

several InvalidateRect(NULL,NULL,true) calls end in a messed X11 Desktop Window.
The explorer desktop is suddenly painted with the default black brush.
The best way to reproduce this:
for (int i=0;i<1000;i++)
  InvalidateRect(NULL,NULL, true);
Sometimes it shows the wine desktop after 10 loops and sometimes not even after
1000 loops. The problem is, that the explorer desktop (from time to time)
receives a WM_ERASEBKGRND and than triggers it's internal paint routine.

Program to reproduce: Notes Client opening the Administrator Client or the
mentioned InvalidateRect loop