[boost] [bgl] Bug in depth_first_search (and therefore topological_sort...)

From: Loïc Joly (loic.joly_at_[hidden])
Date: 2006-07-24 09:57:10

Hello,

There is a bug in the boost graph library in depth_first_search. When we 
look at the implementation, we can see in file 
boost/graph/depth_first_search.hpp):

     detail::dfs_dispatch<C>::apply
       (g,
        choose_param(get_param(params, graph_visitor),
                     make_dfs_visitor(null_visitor())),
        choose_param(get_param(params, root_vertex_t()),
                     *vertices(g).first),
        params,
        get_param(params, vertex_color)
        );

This code makes the assumption the the graph is non-empty, since it 
calls *vertices(g).first. For empty graphs, this call fails.

Best regards,

-- 
Loïc