ProductSeries.setPackaging() should not change existing records

[Abel Deuring]

If ProductSeries.setPackaging() changes an existing packaging record, two problem can arise:

1. An IntegrityError can occur. This happens, when two different source packages of the same distroseries are linked to the same productseries: The method iterates over self.packagings; the iteration stops at the first packaging for the "right" distroseries. If setPackaging() is called with the parameters of the second existing packaging, the iteration stops at the first packaging, and the subsequent code sets the property sourcepackagename. Then we would have two records for one sourcepackage, which a DB contraint does not allow:

    "packaging__distroseries__sourcepackagename__key" UNIQUE, btree (distroseries, sourcepackagename)

2. Changing an existing record without triggered a related translation sharing job causes inconcsistencies with translation sharing.

[Abel Deuring (adeuring)]

note that we can have two or more sourcepackage of one distroseries linked to one productseries, if the packging links are created in sourcepackage views.

[Launchpad QA Bot (lpqabot)]

Fixed in stable r12832 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/12832>.