Opened 7 years ago

Closed 6 years ago

#13787 closed defect (fixed)

Bug in GenericGraph.line_graph() when the vertices cannot be compared

Reported by: ncohen Owned by: jason, ncohen, rlm
Priority: major Milestone: sage-5.8
Component: graph theory Keywords:
Cc: chapoton Merged in: sage-5.8.beta0
Authors: Nathann Cohen Reviewers: Frédéric Chapoton
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description

Reported by Georgi Guninski :

sage: g=graphs.KneserGraph(7,1)
sage: C = graphs.CompleteGraph(7)
sage: C.is_isomorphic(g)
True
sage: C.line_graph().is_isomorphic(g.line_graph())
False

Attachments (2)

trac_13787.patch (5.7 KB) - added by ncohen 6 years ago.
trac-13787-review-fc.patch (1.9 KB) - added by chapoton 6 years ago.

Download all attachments as: .zip

Change History (10)

comment:1 Changed 7 years ago by ncohen

  • Status changed from new to needs_review

Changed 6 years ago by ncohen

comment:2 Changed 6 years ago by ncohen

  • Cc chapoton added

Implementing Frederic s remark. Much better this way :-)

Nathann

comment:3 Changed 6 years ago by chapoton

This patch is ok for me. Nathann, if you are happy with the cosmetic changes in the review patch, you can set a positive review when the bot gives a green light.

comment:4 Changed 6 years ago by ncohen

  • Reviewers set to Frédéric Chapoton
  • Status changed from needs_review to positive_review

Yeahhhhhhhhhhh !! Thank you very much Frederic :-)

My patch got a green light by itself, and your changes (thanks for them too!) are not likely to produce bugs outside of generic_graph.py. I just applied both on beta4 without any problems and all tests pass on that file, so I set it to positive_review before I forget.

Nathann

comment:5 Changed 6 years ago by jdemeyer

  • Milestone changed from sage-5.7 to sage-5.8

comment:6 Changed 6 years ago by jdemeyer

  • Status changed from positive_review to needs_work

trac-13787-review-fc.patch needs a proper commit message.

Changed 6 years ago by chapoton

comment:7 Changed 6 years ago by chapoton

  • Status changed from needs_work to positive_review

added commit message, back to positive review

comment:8 Changed 6 years ago by jdemeyer

  • Merged in set to sage-5.8.beta0
  • Resolution set to fixed
  • Status changed from positive_review to closed
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