How to handle Bad pointer ( Applcation: IE sidebar as COM Object , VCC++)

Hi,
I have my Vertical sidebar with IE. It is causing a problem when I logout of secured sites (https://).

The history is here:
There was problem in IR5.0 and that was fixed by a piece of code (under SUPPORT_IE5)in sidebar. The bug was fixed in IE6.0 and sidebar was happy with IE6.0 But now with IE7.0, when I logout of secured sites,
URL for the below function is passed something link “{????}” by IE (as we can not go to the previous page of some secured site once logged out of it.) So obviously URL -> bstrlVal ends up as a bad pointer.

Now please suggest me where can I initialize the pointer (URL) as the value to this is passed by IE depending with URL of Main browser address bar and URL of sidebar. It is enough atlease If I could catch the URL when it has NULL Pointer in it.

Please suggest.


HRESULT __stdcall BPCompanion:: DocumentComplete(IDispatch* pDisp, VARIANT* URL)
{
DEBUG_TRACE("DocumentComplete");

// Call Script Function
CallScript(pDisp, CComBSTR(L"BeforeNavigation"));

if (NULL != URL)
DEBUG_TRACE("URL %S", URL->bstrVal);

//IE 5
#ifdef SUPPORT_IE5
if (pDisp == m_spWebBrowser)
{
if (!URL || CComBSTR(URL->bstrVal) == CComBSTR("about:blank"))
{
SetFocus();
CallScript(pDisp, CComBSTR(L"RHSDocumentComplete"));
}
//Baseer: Avoid IE 5 Crash
//Call NavigateError explicitly
if (URL){
if ( wcsstr(URL->bstrVal, L"shdoclc.dll/dnserror.htm#") != NULL ){
DEBUG_TRACE("Calling NavigateError for IE5.0 crash resolution");
NavigateError(pDisp, URL);
}
}
}else{
if (URL){
Now the code fails here
& crashes if ( wcsstr(URL->bstrVal, L"bpworldcompanion.dll") != NULL ){
DEBUG_TRACE("Calling RHSDocumentComplete for IE5.0 crash resolution");
CallScript(pDisp, CComBSTR(L"RHSDocumentComplete"));
}
}

}
#else
if (pDisp == m_spWebBrowser)
{
if (!URL || CComBSTR(URL->bstrVal) == CComBSTR("about:blank"))
{
SetFocus();
}
}
#endif

return S_OK;
}