---
title: "Django 1.8.2 release notes"
version: 2.2
locale: es
source: https://docs.djangoproject.com/es/2.2/releases/1.8.2/
canonical: https://djangodocs.dev/es/2.2/releases/1.8.2/
---
# Django 1.8.2 release notes

*May 20, 2015*

Django 1.8.2 fixes a security issue and several bugs in 1.8.1.

## Fixed session flushing in the `cached_db` backend

A change to `session.flush()` in the `cached_db` session backend in Django
1.8 mistakenly sets the session key to an empty string rather than `None`. An
empty string is treated as a valid session key and the session cookie is set
accordingly. Any users with an empty string in their session cookie will use
the same session store. `session.flush()` is called by
`django.contrib.auth.logout()` and, more seriously, by
`django.contrib.auth.login()` when a user switches accounts. If a user is
logged in and logs in again to a different account (without logging out) the
session is flushed to avoid reuse. After the session is flushed (and its
session key becomes `''`) the account details are set on the session and the
session is saved. Any users with an empty string in their session cookie will
now be logged into that account.

## Bugfixes

- Fixed check for template engine alias uniqueness ([#24685](https://code.djangoproject.com/ticket/24685)).
- Fixed crash when reusing the same `Case` instance in a query
  ([#24752](https://code.djangoproject.com/ticket/24752)).
- Corrected join promotion for `Case` expressions. For example, annotating a
  query with a  `Case` expression could unexpectedly filter out results
  ([#24766](https://code.djangoproject.com/ticket/24766)).
- Fixed negated `Q` objects in expressions. Cases like
  `Case(When(~Q(friends__age__lte=30)))` tried to generate a subquery which
  resulted in a crash ([#24705](https://code.djangoproject.com/ticket/24705)).
- Fixed incorrect GROUP BY clause generation on MySQL when the query’s model
  has a self-referential foreign key ([#24748](https://code.djangoproject.com/ticket/24748)).
- Implemented `ForeignKey.get_db_prep_value()` so that `ForeignKey`s
  pointing to [`UUIDField`](/es/2.2/ref/models/fields/#django.db.models.UUIDField) and inheritance on models
  with `UUIDField` primary keys work correctly ([#24698](https://code.djangoproject.com/ticket/24698),
  [#24712](https://code.djangoproject.com/ticket/24712)).
- Fixed `isnull` lookup for `HStoreField` ([#24751](https://code.djangoproject.com/ticket/24751)).
- Fixed a MySQL crash when a migration removes a combined index (unique\_together
  or index\_together) containing a foreign key ([#24757](https://code.djangoproject.com/ticket/24757)).
- Fixed session cookie deletion when using [`SESSION_COOKIE_DOMAIN`](/es/2.2/ref/settings/#std-setting-SESSION_COOKIE_DOMAIN)
  ([#24799](https://code.djangoproject.com/ticket/24799)).
- On PostgreSQL, when no access is granted for the `postgres` database,
  Django now falls back to the default database when it normally requires a
  «no database» connection ([#24791](https://code.djangoproject.com/ticket/24791)).
- Fixed display of `contrib.admin`’s `ForeignKey` widget when it’s used
  in a row with other fields ([#24784](https://code.djangoproject.com/ticket/24784)).