prepare-upload pushes unnecessarily when sponsoring

[Robie Basak]

When sponsoring an upload, it'd be nice to be able to point to the sponsoree branch instead of making the sponsor push to their own. prepare-upload could do this by fetching/updating the remote ref and checking that the HEAD commit is reachable from it. If it is not, then fall back to the push-to-own-remote behaviour; otherwise use the remote.

[Robie Basak (racb)]

The --branch and --remote options would still be needed to detect which remote ref to use. So it'd be push-to-that-remote if the remote branch isn't up-to-date.

[Steve Langasek (vorlon)]

Just hit this painfully while trying to sponsor openjdk-17. The repository is huge and pushing a copy to my own namespace just for sponsoring is dire.

Worked around by having the sponsoree run `git ubuntu prepare-upload args` for me.

[Robie Basak (racb)]

> The repository is huge and pushing a copy to my own namespace just for sponsoring is dire.

Did you try it? I'm under the impression that it should be quick due to being a hardlink based clone on the Launchpad end.

The plan in the bug description is:

> prepare-upload could do this by fetching/updating the remote ref and checking that the HEAD commit is reachable from it.

Would that have been acceptable to you in this use case?

[Steve Langasek (vorlon)]

On Thu, Mar 02, 2023 at 08:28:10AM -0000, Robie Basak wrote:
> > The repository is huge and pushing a copy to my own namespace just for
> sponsoring is dire.

> Did you try it? I'm under the impression that it should be quick due to
> being a hardlink based clone on the Launchpad end.

I did and it was spending a long time trying to push.

> The plan in the bug description is:
>
> > prepare-upload could do this by fetching/updating the remote ref and
> checking that the HEAD commit is reachable from it.

> Would that have been acceptable to you in this use case?

Yes.

[Robie Basak (racb)]

Fixed in 1.1.