id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
15627 (disjoint) Union of graphs with multiple edges ncohen "Err... Right now, the disjoint union of two graphs with multiedges/loops is the disjoint union of those two graphs without loops nor multiple edges. That's clearly missing from the code.
Here is the new behaviour
{{{
Multiple edges and loops::
sage: g = Graph(multiedges=True, loops=True)
sage: g.add_edges(graphs.PetersenGraph().edges())
sage: g.add_edges(graphs.PetersenGraph().edges())
sage: g.add_edge(0,0)
sage: g.add_edge(0,0,""Hey"")
sage: g.add_edge(0,9)
sage: g.add_edge(0,9)
sage: g.add_edge(0,9)
sage: (2*g.size()) == (2*g).size()
True
Immutable input ? Immutable output::
sage: g = g.copy(immutable=True)
sage: (2*g)._backend
}}}
I hate multiedges. I hate loops. I hate labels.
Nathann" defect closed major sage-6.2 graph theory fixed SimonKing chapoton Nathann Cohen Frédéric Chapoton N/A 9f1716eea045ef52356433458dc1c6b708fdf13e #15623