};

> I've got the function below which shows the Data Link dialog box in an
> MMC snapin.  Everything works
> fine.  However in debug mode, when the function returns, we always get
> the error:

> Invalid Address specified to RtlSizeHeap( 00080000, 000E0574 )

> in the VC6.0 debug window. A dialog which also says

> User Breakpoint called from code at 0x77f7f570.  Also appears.  We
> originally had WCHAR buffers, but
> thought that changing these to CComBSTR would automatically release
> any memory within the buffers.

> Code follows below:

> CComBSTR GetDataSource(LPOLESTR lpbstrConn)
> {

>     CComBSTR bstr;

>     IUnknown *     pUnkDataSource = NULL;
>     IDataInitialize *pIDataInitialize = NULL;
>     IDBPromptInitialize *     pIDBPromptInitialize = NULL;

>     CoCreateInstance(     CLSID_DataLinks,
>                    NULL,
>                    CLSCTX_INPROC_SERVER,
>                    IID_IDataInitialize,
>                    (void**)&pIDataInitialize
>               );
>     try
>     {
>          pIDataInitialize->GetDataSource(     NULL,
>                                   CLSCTX_INPROC_SERVER,
>                                   lpbstrConn,
>                                   IID_IUnknown,
>                                   (IUnknown**)&pUnkDataSource
>                              );
>     }
>     catch(...)
>     {
>     }
>     CoCreateInstance(     CLSID_DataLinks,
>                              NULL,
>                              CLSCTX_INPROC_SERVER,
>                              IID_IDBPromptInitialize,
>                              (void**)&pIDBPromptInitialize
>                              );

>     pIDBPromptInitialize->PromptDataSource(
>                              NULL,
>                              GetDesktopWindow(),
>                              DBPROMPTOPTIONS_PROPERTYSHEET,
>                              0,
>                              NULL,
>                              NULL,
>                              IID_IUnknown,
>                              (IUnknown**)&pUnkDataSource
>                              );

>     pIDataInitialize->GetInitializationString(pUnkDataSource,false,
> &bstr);

>     if (pIDBPromptInitialize)
>          pIDBPromptInitialize->Release();
>     if (pIDataInitialize)
>          pIDataInitialize->Release();
>     if (pUnkDataSource)
>          pUnkDataSource->Release();

>     return _T("");
> };

> LPOLESTR and BSTR are not the same. Even though they are typedef'ed in
> the same way, the memory for them is allocated differently. A string
> returned by IDataInitialize::GetInitializationString is supposed to be
> freed with CoTaskMemFree, but CComBSTR uses SysFreeString. You cannot
> use CComBSTR here.
> --
> With best wishes,
>     Igor Tandetnik

> "For every complex problem, there is a solution that is simple, neat,
> and wrong." H.L. Mencken

> > I've got the function below which shows the Data Link dialog box in an
> > MMC snapin.  Everything works
> > fine.  However in debug mode, when the function returns, we always get
> > the error:

> > Invalid Address specified to RtlSizeHeap( 00080000, 000E0574 )

> > in the VC6.0 debug window. A dialog which also says

> > User Breakpoint called from code at 0x77f7f570.  Also appears.  We
> > originally had WCHAR buffers, but
> > thought that changing these to CComBSTR would automatically release
> > any memory within the buffers.

> > Code follows below:

> > CComBSTR GetDataSource(LPOLESTR lpbstrConn)
> > {

> >     CComBSTR bstr;

> >     IUnknown *     pUnkDataSource = NULL;
> >     IDataInitialize *pIDataInitialize = NULL;
> >     IDBPromptInitialize *     pIDBPromptInitialize = NULL;

> >     CoCreateInstance(     CLSID_DataLinks,
> >                    NULL,
> >                    CLSCTX_INPROC_SERVER,
> >                    IID_IDataInitialize,
> >                    (void**)&pIDataInitialize
> >               );
> >     try
> >     {
> >          pIDataInitialize->GetDataSource(     NULL,
> >                                   CLSCTX_INPROC_SERVER,
> >                                   lpbstrConn,
> >                                   IID_IUnknown,
> >                                   (IUnknown**)&pUnkDataSource
> >                              );
> >     }
> >     catch(...)
> >     {
> >     }
> >     CoCreateInstance(     CLSID_DataLinks,
> >                              NULL,
> >                              CLSCTX_INPROC_SERVER,
> >                              IID_IDBPromptInitialize,
> >                              (void**)&pIDBPromptInitialize
> >                              );

> >     pIDBPromptInitialize->PromptDataSource(
> >                              NULL,
> >                              GetDesktopWindow(),
> >                              DBPROMPTOPTIONS_PROPERTYSHEET,
> >                              0,
> >                              NULL,
> >                              NULL,
> >                              IID_IUnknown,
> >                              (IUnknown**)&pUnkDataSource
> >                              );

> >     pIDataInitialize->GetInitializationString(pUnkDataSource,false,
> > &bstr);

> >     if (pIDBPromptInitialize)
> >          pIDBPromptInitialize->Release();
> >     if (pIDataInitialize)
> >          pIDataInitialize->Release();
> >     if (pUnkDataSource)
> >          pUnkDataSource->Release();

> >     return _T("");
> > };