message: calib3d: check input values in dls
diff: @@ -653,6 +653,7 @@ bool dls::is_empty(const cv::Mat * M)
  bool dls::positive_eigenvalues(const cv::Mat * eigenvalues)
  {
  + CV_Assert(eigenvalues && !eigenvalues->empty());
  cv::MatConstIterator_<double> it = eigenvalues->begin<double>();
  return *(it) > 0 && *(it+1) > 0 && *(it+2) > 0;
  }
  