BUG: GetRowsEx() Incorrectly Handles Null Field Values

MORE INFORMATION

Sample Code

#define FETCH_SIZE 2
#define MAX_FIRST_NAME_LENGTH 20
// Perform C++ GetRowsEx against the Employee table
void CGetRowsDlg::DoGetRowsEx()
{
    LPEMP           pEmpRows = new EMP[FETCH_SIZE];
    CListBox        *pListBox = (CListBox*)GetDlgItem(IDD_GETROWSLISTEX);
    CString         strLBRow;
    TCHAR           szId[16];
    LONG            lNumRecords;
    LONG            lCount;
    TCHAR           pBuf[MAX_EMP_REC * 15]; // allow avg of 15 chars/name

    while (!m_cEmpRecordSet.GetEOF())
    {

        //Clear values in buffer for variable-length fields
        for (long lCnt = 0; lCnt < FETCH_SIZE; lCnt++)
        {
          _strnset(pEmpRows[lCnt].strFirstName,'\0',
              MAX_FIRST_NAME_LENGTH);
          pEmpRows[lCnt].strLastName=NULL;
        }

       try
        {
        lNumRecords = m_cEmpRecordSet.GetRowsEx(pEmpRows, sizeof(EMP),
                        &Bindings[0], sizeof(Bindings) / 
                        sizeof(DAORSETBINDING),
                        pBuf, sizeof(pBuf),
                        FETCH_SIZE);
        }
    catch (CdbException e)
        {
        //Differentiate between GetRowsEx Errors and other CdbExceptions
        // see defines in DAOGETRW.H
        if( e.m_hr == E_ROWTOOSHORT ||
            e.m_hr == E_BADBINDINFO ||
            e.m_hr == E_COLUMNUNAVAILABLE )
            {
                AfxMessageBox(_T("Error in GetRowsEx call."));
            }
        else
            {
                AfxMessageBox(_T("General CdbException"));
            }
        delete [] pEmpRows;
        return;
        }

    //Step through the returned rows
    for (lCount = 0; lCount < lNumRecords; lCount++)
        {
        strLBRow.Empty();
        wsprintf(szId, _T("%d,  "), pEmpRows[lCount].lEmpId);
        strLBRow += szId;
        if (pEmpRows[lCount].strLastName!=NULL)
            strLBRow += pEmpRows[lCount].strLastName;
        else
            strLBRow += "null";

        strLBRow += _T(", ");
        if (pEmpRows[lCount].strFirstName[0]=='\0')
            strLBRow += "null";
        else
            strLBRow += (LPCTSTR) pEmpRows[lCount].strFirstName;
        pListBox->AddString(strLBRow);
        }

      if (!m_cEmpRecordSet.GetEOF())
         m_cEmpRecordSet.MoveNext(); // Need to move to next unread
                                     // record before fetching the next
                                     // set of records.
    }

    delete [] pEmpRows;
}