PVS-Studio warning V560 for NetDefender

SIZE CPPHtmlDrawer::DrawHtmlString (
  CPPString & sHtml, LPCRECT lpRect)
{
  ....
  nIdRes = 0;
  nIdDll = 0;
  while (nIndex < sProperties.GetLength())
  {
    ....
    if (sParameter == _T("idres"))
      nIdRes = GetLengthUnit(sValue, nIdRes);
    else if (sParameter == _T("iddll"))
      nIdRes = GetLengthUnit(sValue, nIdDll);
    ....
  }
  if (nIdRes || nIdDll)
  ....
}

Most likely this is what should be written here: nIdDll = GetLengthUnit(sValue, nIdDll);

This suspicious code was found in NetDefender project by PVS-Studio static code analyzer.
Warning message is:
V560 A part of conditional expression is always false: nIdDll. pphtmldrawer.cpp 2723

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