anchor.diff:           associated(intersections(1)%first, first) .AND. &
            associated(intersections(1)%second, second))
       call print_status(name, case_id, case_success, success)
  -    deallocate(intersections)
       num_intersections = 0
   
       ! CASE 2: Lines that **do not** intersect.
  
positive.code:     candidates(2, 1)%nodes = fixed_quadratic2
      call subdivide_curve(candidates(2, 1), left2, right2)
  
      case_success = .NOT. allocated(intersections)
      call intersect_one_round( &
           num_candidates, candidates, num_intersections, intersections, &
           next_candidates, num_next_candidates, py_exc)
      case_success = ( &
           case_success .AND. &
           .NOT. allocated(intersections) .AND. &
           num_intersections == 0 .AND. &
           num_next_candidates == 2 .AND. &
  
negative.code:          status == ALL_INTERSECTIONS_SUCCESS)
      call print_status(name, case_id, case_success, success)
      deallocate(candidates)
  
      ! CASE 3: Tangent curves, with a ``py_exc`` failure due to parallel lines.
      allocate(candidates(2, 1))
  