Code review comment for lp:~edwin-grubbs/launchpad/bug-676966-disallow-merging-people-with-ppas

I think that the restriction on merging people with PPAs with or without publications is wrong. I originally suggested that we allow the merge to take place even though there's a PPA as long as it has no packages (i.e. it's a brand new one). Deleting these types of PPAs has zero affect other than to change its status; there's nothing to actually delete on disk.

The +archivesubscriptions problem should be solved differently.

Also, has_existing_ppa and has_ppa_with_published_packages
should not be properties on IPerson, they should be on IArchiveSet so
that Soyuz-specific queries are kept in the lp.soyuz domain.

The Bugs team made this mistake with one of their bits of code that knows too
much about Soyuz publishing tables and caused circular imports when running
bin/test. It also makes future changes to soyuz code harder because the coder will not expect this sort of code to be outside the soyuz domain.

I recommend that this be fixed ASAP as tech debt. I filed bug 693357 about this.