void vp9_swap_current_and_last_seg_map(VP9_COMMON *cm) {
 const int tmp = cm->seg_map_idx;
  cm->seg_map_idx = cm->prev_seg_map_idx;
  cm->prev_seg_map_idx = tmp;

  cm->current_frame_seg_map = cm->seg_map_array[cm->seg_map_idx];
  cm->last_frame_seg_map = cm->seg_map_array[cm->prev_seg_map_idx];
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.