BUG: QueryInterface Returning E_NOINTERFACE (216986)


The information in this article applies to:

  • Microsoft Visual SourceSafe for Windows 5.0
  • Microsoft Visual SourceSafe for Windows 6.0
This article was previously published under Q216986

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 that this is a bug in the Microsoft products that are 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.
Modification Type:MajorLast Reviewed:10/15/2002
Keywords:kbAutomation kbBug kbDSupport KB216986
©2002 Microsoft Corporation. All rights reserved.