rfc: permissions on package branches

[Martin Pool]

We have a question in <https://bugs.launchpad.net/bugs/516709> about
what the permissions on official package branches ought to be, and how
they should be explained to the user.

The basic thing is that Launchpad knows who is allowed to write to a
package, and it already has special code that gives those people
read/write access to the package branch.  In the common case where the
package branch is owned by a bot/celebrity that will never do anything
itself, this is fine.  However, it is perhaps a problem if an existing
branch owned by a human is marked as official for a particular
package.

At the moment the permissions are unioned: the nominal owner of the
branch keeps write access, and the package uploaders get right access
too.

There are a few options here and we'd appreciate hearing from Ubuntu
people how they think it should work:

0- No change: the nominal owner keeps write access.

1- Don't allow branches owned by non-celebrities to become the
official branch for a package.  Instead, you need to push from that
branch into the real official branch.

2- When the branch becomes an official package branch, the owner loses
write access (unless they're also an uploader.)  That's what
<https://code.launchpad.net/~jml/launchpad/owner-cannot-write-to-official-branch-516709/+merge/29446>
would do.  It seems potentially confusing.

3- Something else?

Let us know what you think either here or on that bug.  Also if you
think we ought to ask eg the TB, please tell me.

Martin