id,summary,reporter,owner,description,type,status,priority,milestone,component,resolution,keywords,cc,work_issues,upstream,reviewer,author,merged,dependencies,stopgaps 10812,the certify=True option causes Graph.is_isomorphic to crash,fwellen,somebody,"Here are two isomorphic multi-graphs, that are recognized by is_isomorphic as being isomorphic and cause is_isomorphic to crash on certify=True. (Sage-4.6 from source on 64bit-Fedora) {{{ sage: G = Graph(multiedges = True, loops = True) sage: H = Graph(multiedges = True, loops = True) sage: G.add_edges([(0,1,0),(1,0,1),(1,1,2),(0,0,3)]) sage: H.add_edges([(0,1,3),(1,0,2),(1,1,1),(0,0,0)]) sage: G.is_isomorphic(H, certify=True) --------------------------------------------------------------------------- KeyError Traceback (most recent call last) /home/felix/sage-4.6/ in () /home/felix/sage/local/lib/python2.6/site-packages/sage/graphs/generic_graph.pyc in is_isomorphic(self, other, certify, verbosity, edge_labels) 14135 isom_trans = {} 14136 for v in isom: > 14137 isom_trans[self_vertices[v]] = G2_to[isom[v]] 14138 return True, isom_trans 14139 KeyError: 0 }}}",defect,closed,major,sage-duplicate/invalid/wontfix,graph theory,duplicate,Graph isomorphism,,,N/A,,,,,