[Bug 6302] New: crash in GetLongPathNameW

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=6302

Summary: crash in GetLongPathNameW
           Product: Wine
           Version: CVS
          Platform: Other
        OS/Version: other
            Status: NEW
          Keywords: download
          Severity: normal
          Priority: P2
         Component: wine-kernel
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

Hi, PowerDVDTrial crashes in GetLongPathNameW. It calls GetLongPathNameW like 
GetLongPathName(NULL,NULL,0). I don't know if this strange call is because of
not fully successfull installation process, but i think it should not crash
wine. The patch i'll attach hereafter avoids the crash, but i do not know if
it's fully correct, so i attach  it here so hopefully someone can review this.