django/docs/releases/1.8.4.txt

==========================
Django 1.8.4 release notes
==========================

*August 18, 2015*

Django 1.8.4 fixes a security issue and several bugs in 1.8.3.

Denial-of-service possibility in ``logout()`` view by filling session store
===========================================================================

Previously, a session could be created when anonymously accessing the
:func:`django.contrib.auth.views.logout` view (provided it wasn't decorated
with :func:`~django.contrib.auth.decorators.login_required` as done in the
admin). This could allow an attacker to easily create many new session records
by sending repeated requests, potentially filling up the session store or
causing other users' session records to be evicted.

The :class:`~django.contrib.sessions.middleware.SessionMiddleware` has been
modified to no longer create empty session records, including when
:setting:`SESSION_SAVE_EVERY_REQUEST` is active.

Bugfixes
========

* Added the ability to serialize values from the newly added
  :class:`~django.db.models.UUIDField` (:ticket:`25019`).

* Added a system check warning if the old ``TEMPLATE_*`` settings are defined
  in addition to the new ``TEMPLATES`` setting.

* Fixed ``QuerySet.raw()`` so ``InvalidQuery`` is not raised when using the
  ``db_column`` name of a ``ForeignKey`` field with ``primary_key=True``
  (:ticket:`12768`).

* Prevented an exception in ``TestCase.setUpTestData()`` from leaking the
  transaction (:ticket:`25176`).

* Fixed ``has_changed()`` method in ``contrib.postgres.forms.HStoreField``
  (:ticket:`25215`, :ticket:`25233`).

* Fixed the recording of squashed migrations when running the ``migrate``
  command (:ticket:`25231`).

* Moved the :ref:`unsaved model instance assignment data loss check
  <unsaved-model-instance-check-18>` to ``Model.save()`` to allow easier usage
  of in-memory models (:ticket:`25160`).

* Prevented ``varchar_patterns_ops`` and ``text_patterns_ops`` indexes for
  ``ArrayField`` (:ticket:`25180`).