anchor.diff:      call print_status(name, case_id, case_success, success)
   
       ! CASE 2: Change the ``s`` parameter, no corresponding node.
  -    curr_node%index_first = 3
  -    curr_node%s = 1.0_dp
  -    curr_node%interior_curve = first
  +    curr_node = Intersection(1.0_dp, -1.0_dp, 3, -1, first)
       remaining = 3
       call to_front( &
            0, intersections(:0), unused, remaining, &
  
positive.code:     call print_status(name, case_id, case_success, success)
  
      ! CASE 3: Change the ``s`` parameter, new corner node exists.
      curr_node%index_first = 2
      curr_node%s = 1.0_dp
      curr_node%interior_curve = first
      intersections(1)%index_first = 3
      intersections(1)%s = 0.0
      intersections(1)%index_second = 1
      intersections(1)%t = 0.5
      intersections(1)%interior_curve = IntersectionClassification_TANGENT_FIRST
      unused = [1, 3, 4, 6]
      remaining = 4
      call to_front( &
  
negative.code:     nodes1(2, :) = [0.75_dp, 1.0_dp]
      edges_second(1)%nodes = nodes1
  
      intersection_ = Intersection(0.5_dp, 0.5_dp, 1, 1)
  
      call classify_intersection( &
           edges_first, edges_second, intersection_, enum_, status)
  