Cannot modify upstream of packages I can upload in Ubuntu

From #launchpad:

(14:19:45) adeuring: lool: it is indeed a permissions problem, and a deliberate one: Because the packaging link affects upstream translation sharing, only package maintainers and some people with "special powers" can change an existing link. Intorduced in LP revision 12801, april this year
(14:20:16) lifeless: adeuring: but lool is a maintainer; he's core dev.
(14:20:25) lifeless: adeuring: what do you mean by 'package maintainers' precisely?
(14:20:43) adeuring: lifeless: let me check the source code...
(14:20:56) lifeless: actually its 12:20 *am* here
(14:20:58) lifeless: so I'm going to go
(14:21:14) lool: I have uploads power to Ubuntu and I also happen to be the registrant of linux-linaro ;-)
(14:21:16) adeuring: lifeless: it's the relase maintainer
(14:21:16) lifeless: but if it uses the 'maintainer' field or something, thats *debian* metadata and meaningless for permissions in Ubuntu
(14:22:18) lifeless: adeuring: spr.maintainer or something?
(14:22:30) adeuring: lifeless: lp.registry.model.packaging.Packaging.userCanDelete()
(14:22:52) adeuring: self.sourcepackage.currentrelease.maintainer
(14:23:06) lifeless: thats faulty then
(14:23:20) lifeless: thats letting debian maintainers garden Ubuntu metadata and excluding Ubuntu maintainers from doing it.
(14:23:43) adeuring: the was to avoid an unnecessary load by job which are triggered for translation sharing
(14:23:53) adeuring: s/the was/the idea was/
(14:24:20) lifeless: bigjools: ^ I have to sleep, but can you help educate / point adeuring at the right way to determine 'maintains this in Ubuntu' (e.g. can upload it to O or any -proposed
(14:24:40) lifeless: adeuring: sure, the intent was fine, but the check used is looking at a meaningless field
(14:24:57) bigjools: IArchive.canUpload()
(14:25:04) lifeless: night
(14:25:11) adeuring: thanks
(14:27:32) james_w: preferably a check that doesn't prevent people doing it when the series is frozen I guess :-)

I think the permission should be the same one there than the one for bug #365098
  and (see its regression bug #797088). So using the launchpad.Edit permission on SourcePackage would work.

Btw, you can get the SourcePackage from the the distro series + source packagename fields of the Packaging.

Also, FWIW, userCan* model methods usually take the user as parameter. That's not the case here which is a definitive wart.

Fixed in stable r13271 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/13271>.