The append-revisions-only can of worms

[Martin Pool]

On 16 July 2011 20:17, Max Bowsher <_ at maxb.eu> wrote:
> I've tracked down a cause of some of the AppendRevisionsOnlyViolation
> failures.
>
> When a package is uploaded to Debian and synced to Ubuntu, there's a
> race condition between Launchpad's Debian metadata importer and the UDD
> package importer.
>
> If the UDD package importer tries to import the package in the window
> when Launchpad knows of the Ubuntu publication but not of the Debian
> publication, then the new package version gets imported first into the
> Ubuntu branch.
>
> Later, when the Debian publication becomes visible, Launchpad sees that
> this particular (package,version) has already been imported.... and
> tries to pull the Ubuntu branch into the Debian sid branch.
>
> And of course, if the package has *ever* had an Ubuntu specific upload,
> that's an AppendRevisionsOnlyViolation.

So naively, pulling the later Debian version from the Ubuntu branch
into the Debian branch ought to not be a problem for
append_revisions_only, because the imported Debian version ought to be
a proper descendent of the earlier Debian import revision.

Is the problem that when taken from the Ubuntu branch, the mainline moves?

Perhaps one fix would be to notice when we're importing a changelog
entry for what looks like a Debian upload, then defer until we see the
Debian publication?  We could even get a way to prod Launchpad to add
the Debian publication earlier?

m