IntegrityError with unknown milestone when changing bug's project

It doesn't seem to be related directly with the target product & milestone, I've just changed it successfully.
Perhaps it is related with the lack of permission to unset target milestone (launchpad.1.1.11) while changing the product, this action it executed behind the scenes.

I can't say for sure why it crashed for me but not for you.
This permission problem could be the culprit.

I suppose you'll have to dig into the OOPS to figure it out at 100%

I do not think it is possible to get an oops following the paths in the older oopses because the code changed. Milestones are rejected when the product is retargeted. The is still a problem though. The integrity error has happened this year and it was caused by a mismatch of products: OOPS-1532EC1035 shows that the user reported an issue against update-manager (id=963), but the milestone that was selected actually belongs to Landscape (id=1964). I am puzzled the by landscape fields in the report.

I can produce this oops still. I misread the field names an *who* was making the change. The form fields are named after the project because the view works with multiple bugtasks. There is no issue when the milestone field is included in the form.

The oops shows a non-privileged user changing the project using +editstatus. He does not have permission to set the status or the milestone, the fields are not included. The view is passing the existing milestone instead of clearing it.

Fixed in stable r12640 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/12640>.