Re: [Monotone-devel] propagate oddities (bugs?), sure lca bugs

[Joel Rosdahl]

Christof Petig <address@hidden> writes:

> While trying to demonstrate monotone propagate to a friend I
> stumbled over some problems:
>
> Monotone-viz shows propagate nodes as rectangles but merge nodes as
> circles. This indicates that there is a difference in data
> structures but I can't imagine the semantical difference (I used
> (the 3 argument) explicit_merge as an emergency fallback which did
> exactly what I (thought I) asked propagate to do).

I think Monotone-viz just looks at the revision's log message to
determine whether it's a merge node.

> But since I did not write down the proposed heads* to merge I can
> only guess/hope that at least _they_ were correctly chosen (since
> the merge already happened in my database I cannot reproduce the
> command). Though Monotone chose (and will choose) the wrong
> ancestor, that I can tell for sure:
>
> monotone lca e3623ca77d2a8b45817ecaa5b67018c453652830
> 7d5918d0181f7bb9adba2ee63234146d23bcf83e
>
> should be 0b17415d7aa112060e8ead9ae7a486510dc61a9d
> but is ce860bae312c4bb8483d5b3b2a8cd3bebe2323d5
>
> So to make a long email short:
> - I can give a reproducible failure for the lca algorithm (in HEAD)

I can reproduce the LCA bug too, using your command above.
Fortunately, it's not as critical as it sounds since merge, propagate
and explicit_merge-with-three-arguments use the DOM+ANC algorithm
which is untouched by my fat fingers. :-) To see the ancestor produced
by that algorithm, use "monotone lcad". The LCA algorithm is only used
by the diff and update-with-an-argument commands, and they really only
need *a* common ancestor, not the LCA, to work properly.

Sorry about the bug. And I don't have time to go bug hunting for a
while. :-/

        Regards,
        Joel

-- 
Joel Rosdahl <address@hidden>
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