message: calib3d: cv::findContours() doesn't require to clone input
diff: @@ -538,7 +538,11 @@ int cvFindChessboardCorners( const void* arr, CvSize pattern_size,
  int max_quad_buf_size = 0;
  cvFree(&quads);
  cvFree(&corners);
  +#ifdef USE_CV_FINDCONTOURS
  + Mat binarized_img = thresh_img_new;
  +#else
  Mat binarized_img = thresh_img_new.clone(); // make clone because cvFindContours modifies the source image
  +#endif
  int quad_count = icvGenerateQuads( &quads, &corners, storage, binarized_img, flags, &max_quad_buf_size );
  PRINTF("Quad count: %d/%d\n", quad_count, (pattern_size.width/2+1)*(pattern_size.height/2+1));
  SHOW_QUADS("New quads", thresh_img_new, quads, quad_count);
  @@ -604,7 +608,11 @@ int cvFindChessboardCorners( const void* arr, CvSize pattern_size,
  int max_quad_buf_size = 0;
  cvFree(&quads);
  cvFree(&corners);
  +#ifdef USE_CV_FINDCONTOURS
  + Mat binarized_img = thresh_img;
  +#else
  Mat binarized_img = (useAdaptive) ? thresh_img : thresh_img.clone(); // make clone because cvFindContours modifies the source image
  +#endif
  int quad_count = icvGenerateQuads( &quads, &corners, storage, binarized_img, flags, &max_quad_buf_size);
  PRINTF("Quad count: %d/%d\n", quad_count, (pattern_size.width/2+1)*(pattern_size.height/2+1));
  SHOW_QUADS("Old quads", thresh_img, quads, quad_count);
  