id,summary,reporter,owner,description,type,status,priority,milestone,component,resolution,keywords,cc,merged,author,reviewer,upstream,work_issues,branch,commit,dependencies,stopgaps
15060,The empty graph once again,darij,,"{{{
sage: Graph({}).is_connected()
True
}}}
If my understanding of good terminology is correct, this should not be the case (see http://ncatlab.org/nlab/show/too+simple+to+be+simple ). Note that {{{Graph({}).is_tree()}}} correctly returns {{{False}}}.
Another issue is that
{{{
Graph({}).is_triangle_free()
}}}
seems to allocate lots of RAM and possibly die with a MemoryError (it did so on the Sage cell server; on my machine I had to ctrl-alt-del the VM). The culprit seems to be {{{Bitset(capacity=0)}}}. It looks like {{{is_triangle_free}}} is the only method ever using the {{{Bitset(capacity=X)}}} construction, so I'm not opening up a new ticket for this.",defect,new,major,sage-6.1,combinatorics,,"graphs, border cases, bitset, memleak",sage-combinat,,,,N/A,,,,,