Q216986: BUG: QueryInterface Returning E_NOINTERFACE

Article: Q216986
Product(s): Microsoft SourceSafe
Version(s): WINDOWS:5.0,6.0
Operating System(s): 
Keyword(s): kbAutomation kbSSafe500bug kbSSafe600bug _IK
Last Modified: 01-MAY-2001

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The information in this article applies to:

- Microsoft Visual SourceSafe for Windows, versions 5.0, 6.0 
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SYMPTOMS
========

When creating OLE Automation in C that communicates with Microsoft Visual
SourceSafe (VSS), if the program is created using VSS 5.0 OLE Automation and is
then run on a computer that is using VSS 6.0, QueryInterface for versions can
fail for the IID_IVSSVersion.

CAUSE
=====

The VSS 6.0 Automation ignores the 5.0 IID_IVSSVersion.


RESOLUTION
==========

If you have to create code that will run on computers using VSS 5.0 or VSS 6.0,
see the following steps.

1. Follow the steps in:

  HOWTO: Write automation for computers using VSS 5 or VSS 6.

2. Create two separate programs and call the correct one based on what version
  of VSS the computer is using.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Follow the steps in:

  HOWTO: Open a SourceSafe Database with OLE Automation in C++

2. Add the following code at the top of the program:

     #include <objbase.h>
     #include <initguid.h>
     #include <stdio.h>

     #define MAKEHR(iStat) MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF,(USHORT) (iStat))
   

3. Add the following code where the "// Add code here..." is:

     IVSSVersions* pVersions = NULL;
     IVSSVersion* pVersion = NULL;
     IVSSItem* pItem = NULL;
     IUnknown* pEnumerator = NULL;
     IEnumVARIANT* pVariant = NULL;
     Variant v;
     unsigned long actual;
     int error, nointerface;
     BSTR Root = SysAllocString(L"$/");

     VariantInit(&v);
     pVdb->get_VSSItem(Root, FALSE, &pItem);
     pItem->get_Versions(0, &pVersions);
     pVersions->_NewEnum(&pEnumerator);
     pEnumerator->QueryInterface(IID_IEnumVARIANT, (void **) &pVariant);
     pEnumerator->Release();
     pVariant->Next((unsigned long) 1, &v, &actual);
     error = v.pdispVal->QueryInterface(IID_IVSSVersion, (void **) &pVersion);
     nointerface = MAKEHR(E_NOINTERFACE);
     if (error == nointerface)
     printf("No Interface Error.\n");

4. Compile and run the program. You should get an error number returned from the
  QueryInterface call with IID_IVSSVersion.

NOTE: This code should be created on a computer with VSS 5.0 and then run on a
computer with VSS 6.0. If you want to create and run the program on a VSS 6.0
computer, use IID_IVSSVersionOld instead of IID_IVSSVersion.

Additional query words: OLE Automation

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Keywords          : kbAutomation kbSSafe500bug kbSSafe600bug _IK 
Technology        : kbSSafeSearch kbAudDeveloper kbSSafe600 kbSSafe500
Version           : WINDOWS:5.0,6.0
Issue type        : kbbug
Solution Type     : kbpending

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