Gamemaker Pathfinding

if (mp_grid_path(grid, path0, x,y, mouse_x,mouse_y, true))
{
    var i = 0, ii = 2;
    while (ii < path_get_number(path0))
    {
        if (!collision_line(path_get_point_x(path0, i),path_get_point_y(path0, i), path_get_point_x(path0, ii),path_get_point_y(path0, ii), objectWall, true, true) && ii < path_get_number(path0) - 1)
        {
            ii++;
        }
        else
        {
            repeat((ii - 2) - i)
            {
                path_delete_point(path0, i + 1);
            }

            i++;
            ii = i + 2;
        }
    }

    path_delete_point(path0, path_get_number(path0) - 2);

    path_start(path0, 2, path_action_stop, true);
}