fix the output of method `acyclic_orientations`

[dcoudert]

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This PR fixes the issue with the output of method acyclic_orientations reported in https://ask.sagemath.org/question/79427/the-acyclic-orientations-function-behaves-unexpectedly/. Now the method outputs digraphs with the correct orientation of the arcs.

:memo: Checklist

• [x] The title is concise and informative.
• [x] The description explains in detail what this PR is about.
• [x] I have linked a relevant issue or discussion.
• [x] I have created tests covering the changes.
• [x] I have updated the documentation and checked the documentation preview.

:hourglass: Dependencies

[github-actions[bot]]

Documentation preview for this PR (built with commit 8e7f772a23aeaa23c94ea7e9dc1518aa61557c42; changes) is ready! :tada: This preview will update shortly after each push to this PR.

[dimpase]

Not checking asksage, I've opened https://github.com/sagemath/sage/issues/38758 to consider a bigger change.

[dimpase]

can we have a shorter doctest - there is no need to list all these 18 things. Instead, something like

sage: g = Graph([(0,1),(1,2),(2,3),(3,0),(0,2)])
sage: len(set([tuple(d.edges(labels=false)) for d in g.acyclic_orientations()]))
18

[dcoudert]

can we have a shorter doctest - there is no need to list all these 18 things. Instead, something like

sage: g = Graph([(0,1),(1,2),(2,3),(3,0),(0,2)])
sage: len(set([tuple(d.edges(labels=false)) for d in g.acyclic_orientations()]))
18

(I have edited my answer): yes, we can do that

[dimpase]

other than that, good to go

[dcoudert]

apart from a shorter doctest, could you also put the link to askbot in the commit message, and a short explainer?

I'm not sure to get what you ask for. I can ask a link to this PR :issue:`38757` or to issue #38758 in the doctest. Do you want something more ?

[dimpase]

apart from a shorter doctest, could you also put the link to askbot in the commit message, and a short explainer?

I'm not sure to get what you ask for. I can ask a link to this PR :issue:`38757` or to issue #38758 in the doctest. Do you want something more ?

perhaps also something like "return a properly relabeled digraph, not just the arc labeling to describe the orientation" ? Needless to say, this, and issue #38758 (no need for rst markup), goes after the 2nd line of the commit message.

[dimpase]

regarding the commit message, I meant the attached, to replace the branch here withcommitmessage.patch.txt