Rich Text, html still fail to find high-dpi images

static QString resolveFileName(QString fileName, QUrl *url, qreal targetDevicePixelRatio,
                               qreal *sourceDevicePixelRatio)
{
    ...
    if (targetDevicePixelRatio <= 1.0)
        return fileName;

    // try to find a Nx version
    return qt_findAtNxFile(fileName, targetDevicePixelRatio, sourceDevicePixelRatio);
}

const QString res = qt_findAtNxFile(fileName, targetDevicePixelRatio, sourceDevicePixelRatio);
  if(res != fileName)
    *url = QUrl(res);
  return res;