Importer processes supposedly incremental imports from the beginning of time

[Robie Basak]

I'm not sure if it's happening in all cases, but for example "git ubuntu import -v hello --no-push" shows it starting by processing 2.1.1-4. Instead, I expect it to start from somewhere fairly recent, such as a version packaged in the current Debian or Ubuntu series or similar.

Root cause: the code that determines the start point is failing to match against the current branch heads because it uses date_published instead of date_created.

This was previously discussed here: https://irclogs.ubuntu.com/2020/04/16/%23launchpad.html#t13:45 and the importer spec adjusted accordingly.

Summary: date_published isn't really relevant to us, and it's possible that it is never populated in some edge cases. In particular, "published" in this sense isn't what git-ubuntu means by published. git-ubuntu wants the timestamp of the point when Launchpad first makes it visible to us via the API. date_published for Launchpad means when its "publisher" ran, which is related to making the package appear in an apt suite. The latter isn't relevant to git-ubuntu. So date_created is what we should use in all cases.

We already use date_created for the timestamp of the git commit that we create when we import a Launchpad source publication. So when we determine the start point, we need to match against date_created also.

[Robie Basak (racb)]

Fixed in 1.1.