[Bug 18914] New: ITaskbarList CoCreateInstance function returns wrong value

http://bugs.winehq.org/show_bug.cgi?id=18914

Summary: ITaskbarList CoCreateInstance function returns wrong
                    value
           Product: Wine
           Version: unspecified
          Platform: PC
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: shdocvw
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

ITaskbarList implementation, CoCreateInstance Function seems to return "1" upon
failure.
According to http://msdn.microsoft.com/en-us/library/ms686615.aspx it shall
return null

"ppv [out] 
Address of pointer variable that receives the interface pointer requested in
riid.
Upon successful return, *ppv contains the requested interface pointer.
Upon failure, *ppv contains NULL."

Regression testing showed the following committ:
8e12ad4faeb9274a6a038638eed261f3cfae63f6 is first bad commit
commit 8e12ad4faeb9274a6a038638eed261f3cfae63f6
Author: Henri Verbeet 
Date:   Tue Mar 24 10:09:25 2009 +0100

shdocvw: Add a stub ITaskbarList implementation.

Based on a patch by Louis Lenders. Although MSDN claims this should be in
    shell32, it really is in shdocvw.

:040000 040000 e62b56f5579c2943ada67d31f64b59429a1fe4f6
a6f1d4963fa7c84bd2e8744f60cf2915ab981359 M   dlls
:040000 040000 73b71d886ed76916e3c994c2e2756c352b6df6c1
da408b56e12c9c1af4f834840c6a0fcf263595eb M   include