836288 - Change FK on_delete behavior for Forum.last_post and Thread.last_post

Status: RESOLVED FIXED

(support.mozilla.org :: Forum, task, P1)

Description

[Ricky Rosario [:rrosario, :r1cky]]

We've had this bug that keeps coming back to bite us. Basically, if you delete a user you end up deleting all the user's content. That is good. The problem is we have this last_post field on Forum and Thread that is a FK to the post. If you end up deleting that post the delete cascades and takes the forum with it.

Django now supports better behavior:
https://docs.djangoproject.com/en/dev/ref/models/fields/#django.db.models.ForeignKey.on_delete

Those FK are nullable so let's just set on_delete to SET_NULL.

Comment 1

[Ricky Rosario [:rrosario, :r1cky]]

Pull request:
https://github.com/mozilla/kitsune/pull/1096

On master:
https://github.com/mozilla/kitsune/commit/9c61716ce6e3388352f0e2844ec17f33e6047ee9

Comment 2

[Ricky Rosario [:rrosario, :r1cky]]

Deployed just now.