Q248194: BUG: get_Version Returns S_OK Even if the Version Does Not Exist

Article: Q248194
Product(s): Microsoft SourceSafe
Version(s): WINDOWS:5.0,6.0
Operating System(s): 
Keyword(s): kbAutomation kbSSafe500bug kbSSafe600bug _IK kbGrpDSSSafe
Last Modified: 01-MAY-2001

-------------------------------------------------------------------------------
The information in this article applies to:

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

SYMPTOMS
========

When trying to get a specific version of a file or project, the get_Version
function returns successfully and has a valid item even if that item does not
exist in the database.

RESOLUTION
==========

Instead of checking the HRESULT or whether the IVSSItem is not null, check the
get_VersionNumber after calling get_Version. Compare the version numbers to make
sure the version is valid. For example, place the following code inside the
pVdb->get_VSSItem if statement:

  // Used to store the latest version number of the item
  long originalnumber, num;

  // Store the latest version number of the item
  vssi->get_VersionNumber(&originalnumber);

  // Get the version at the label (this label will fail)
  CComVariant varLabel = -51;
  vssi->get_Version(varLabel, &vx);

  // Get the version number of the returned item
  vx->get_VersionNumber(&num);

  // Compare the versions and see if the item is valid
  if ( num > 0 && num <= originalnumber )
     printf("Valid label.");

  // Release the item
  vx->Release();

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. Create a Win32 Console Application in Microsoft Visual C++.

2. Add the following code to the project.

NOTE: This is the same code as in the following Microsoft Knowledge Base
Article:

  Q169927 HOWTO: Get History Using SourceSafe OLE Automation in C++


  #include <atlbase.h>
  #include <comdef.h>
  #include <initguid.h>
  #include "ssauto.h"

  int main ()
  {
     CLSID clsid;
     IClassFactory *pClf;
     IVSSDatabase *pVdb;
     BSTR bstrPath = SysAllocString(L"c:\\Program Files\\Microsoft Visual Studio\\Common\\VSS\\srcsafe.ini");
     BSTR bstrUName = SysAllocString(L"guest");
     BSTR bstrUPass = SysAllocString(L"");

     CoInitialize(0);
     if(S_OK == CLSIDFromProgID(L"SourceSafe", &clsid ))
     {
        if(S_OK == CoGetClassObject( clsid, CLSCTX_ALL, NULL,
           IID_IClassFactory, (void**)&pClf ))
        {
           if(S_OK == pClf->CreateInstance( NULL, IID_IVSSDatabase,
              (void **) &pVdb ))
           {
              if(S_OK == pVdb->Open(bstrPath, bstrUName, bstrUPass))
              {
                 // Get the root project
                 BSTR bstrName = SysAllocString(L"$/");
                 IVSSItem *vx;
                 IVSSItem *vssi;

                 if( S_OK == pVdb->get_VSSItem(bstrName, FALSE, &vssi) )
                 {
                    // Get the version at the label (this label should fail)
                    CComVariant varLabel = -51;
                    if( S_OK == vssi->get_Version(varLabel, &vx) )
                    {
                       // This prints out even though the label in invalid
                       printf("Should not be here.");

                       vx->Release();
                    }

                    vssi->Release();
                 }

                 SysFreeString(bstrName);
              }

              pVdb->Release();
           }

           pClf->Release();
        }
     }

     CoUninitialize();

     SysFreeString(bstrPath);
     SysFreeString(bstrUName);
     SysFreeString(bstrUPass);
     return 0;
  }

3. Download and add the ssauto.h header file that is used to integrate with
  Visual SourceSafe from the following Microsoft Web site:

  Microsoft Visual SourceSafe Home Page

4. Run the program.

REFERENCES
==========

For additional information, click the article number below to view the article
in the Microsoft Knowledge Base:

  Q196197 PRB: Getting a File from Project Label Using OLE Automation

Additional query words: ssauto

======================================================================
Keywords          : kbAutomation kbSSafe500bug kbSSafe600bug _IK kbGrpDSSSafe 
Technology        : kbSSafeSearch kbAudDeveloper kbSSafe600 kbSSafe500
Version           : WINDOWS:5.0,6.0
Hardware          : x86
Issue type        : kbbug
Solution Type     : kbnofix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.