Judging by my post I think I suspected that aptitude treated <pkgname>/precise as <pkgname>/<suite> rather than <pkgname>/<codename>, resulting in a weird downgrade, but it appears that at least on 16.04 it behaves as I'd expect.
I'm no longer using 12.04, so it might take me a while to fire up a VM to respond to the request.
It has been a while.
Judging by my post I think I suspected that aptitude treated <pkgname>/precise as <pkgname>/<suite> rather than <pkgname> /<codename> , resulting in a weird downgrade, but it appears that at least on 16.04 it behaves as I'd expect.
I'm no longer using 12.04, so it might take me a while to fire up a VM to respond to the request.