[1.9.x] Refs #24505 -- Forwardported 1.8.5 release note.

  (:ticket:`24921`).

* Fixed the ``manage.py test --keepdb`` option on Oracle (:ticket:`25421`).

* Fixed incorrect queries with multiple many-to-many fields on a model with the

  same 'to' model and with ``related_name`` set to '+' (:ticket:`24505`,

  :ticket:`25486`).