Pin django to latest version 2.2.1

[pyup-bot]

This PR pins Django to the latest release 2.2.1.

Changelog

2.2.1

==========================

*May 1, 2019*

Django 2.2.1 fixes several bugs in 2.2.

Bugfixes
========

* Fixed a regression in Django 2.1 that caused the incorrect quoting of
database user password when using :djadmin:`dbshell` on Oracle
(:ticket:`30307`).

* Added compatibility for ``psycopg2`` 2.8 (:ticket:`30331`).

* Fixed a regression in Django 2.2 that caused a crash when loading the
template for the technical 500 debug page (:ticket:`30324`).

* Fixed crash of ``ordering`` argument in
:class:`~django.contrib.postgres.aggregates.ArrayAgg` and
:class:`~django.contrib.postgres.aggregates.StringAgg` when it contains an
expression with params (:ticket:`30332`).

* Fixed a regression in Django 2.2 that caused a single instance fast-delete
to not set the primary key to ``None`` (:ticket:`30330`).

* Prevented :djadmin:`makemigrations` from generating infinite migrations for
check constraints and partial indexes when ``condition`` contains
a :class:`~python:range` object (:ticket:`30350`).

* Reverted an optimization in Django 2.2 (:ticket:`29725`) that caused the
inconsistent behavior of ``count()`` and ``exists()`` on a reverse
many-to-many relationship with a custom manager (:ticket:`30325`).

* Fixed a regression in Django 2.2 where
:class:`~django.core.paginator.Paginator` crashes if ``object_list`` is
a queryset ordered or aggregated over a nested ``JSONField`` key transform
(:ticket:`30335`).

* Fixed a regression in Django 2.2 where ``IntegerField`` validation of
database limits crashes if ``limit_value`` attribute in a custom validator is
callable (:ticket:`30328`).

* Fixed a regression in Django 2.2 where
:class:`~django.contrib.postgres.search.SearchVector` generates SQL that is
not indexable (:ticket:`30385`).

* Fixed a regression in Django 2.2 that caused an exception to be raised when
a custom error handler could not be imported (:ticket:`30318`).

* Relaxed the system check added in Django 2.2 for the admin app's dependencies
to reallow use of
:class:`~django.contrib.sessions.middleware.SessionMiddleware` subclasses,
rather than requiring :mod:`django.contrib.sessions` to be in
:setting:`INSTALLED_APPS` (:ticket:`30312`).

* Increased the default timeout when using ``Watchman`` to 5 seconds to prevent
falling back to ``StatReloader`` on larger projects and made it customizable
via the ``DJANGO_WATCHMAN_TIMEOUT`` environment variable (:ticket:`30361`).

* Fixed a regression in Django 2.2 that caused a crash when migrating
permissions for proxy models if the target permissions already existed. For
example, when a permission had been created manually or a model had been
migrated from concrete to proxy (:ticket:`30351`).

* Fixed a regression in Django 2.2 that caused a crash of :djadmin:`runserver`
when URLConf modules raised exceptions (:ticket:`30323`).

* Fixed a regression in Django 2.2 where changes were not reliably detected by
auto-reloader when using ``StatReloader`` (:ticket:`30323`).

* Fixed a migration crash on Oracle and PostgreSQL when adding a check
constraint with a ``contains``, ``startswith``, or ``endswith`` lookup (or
their case-insensitive variant) (:ticket:`30408`).

* Fixed a migration crash on Oracle and SQLite when adding a check constraint
with ``condition`` contains ``|`` (``OR``) operator (:ticket:`30412`).


========================

2.2

========================

*April 1, 2019*

Welcome to Django 2.2!

These release notes cover the :ref:`new features <whats-new-2.2>`, as well as
some :ref:`backwards incompatible changes <backwards-incompatible-2.2>` you'll
want to be aware of when upgrading from Django 2.1 or earlier. We've
:ref:`begun the deprecation process for some features
<deprecated-features-2.2>`.

See the :doc:`/howto/upgrade-version` guide if you're updating an existing
project.

Django 2.2 is designated as a :term:`long-term support release`. It will
receive security updates for at least three years after its release. Support
for the previous LTS, Django 1.11, will end in April 2020.

Python compatibility
====================

Django 2.2 supports Python 3.5, 3.6, and 3.7. We **highly recommend** and only
officially support the latest release of each series.

.. _whats-new-2.2:

What's new in Django 2.2
========================

Constraints
-----------

The new :class:`~django.db.models.CheckConstraint` and
:class:`~django.db.models.UniqueConstraint` classes enable adding custom
database constraints. Constraints are added to models using the
:attr:`Meta.constraints <django.db.models.Options.constraints>` option.

Minor features
--------------

:mod:`django.contrib.admin`
~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Added a CSS class to the column headers of
:class:`~django.contrib.admin.TabularInline`.

:mod:`django.contrib.auth`
~~~~~~~~~~~~~~~~~~~~~~~~~~

* The ``HttpRequest`` is now passed as the first positional argument to
:meth:`.RemoteUserBackend.configure_user`, if it accepts it.

:mod:`django.contrib.gis`
~~~~~~~~~~~~~~~~~~~~~~~~~

* Added Oracle support for the
:class:`~django.contrib.gis.db.models.functions.Envelope` function.

* Added SpatiaLite support for the :lookup:`coveredby` and :lookup:`covers`
lookups.

:mod:`django.contrib.postgres`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* The new ``ordering`` argument for
:class:`~django.contrib.postgres.aggregates.ArrayAgg` and
:class:`~django.contrib.postgres.aggregates.StringAgg` determines the
ordering of the aggregated elements.

* The new :class:`~django.contrib.postgres.indexes.BTreeIndex`,
:class:`~django.contrib.postgres.indexes.HashIndex` and
:class:`~django.contrib.postgres.indexes.SpGistIndex` classes allow
creating ``B-Tree``, ``hash``, and ``SP-GiST`` indexes in the database.

* :class:`~django.contrib.postgres.indexes.BrinIndex` now has the
``autosummarize`` parameter.

* The new ``search_type`` parameter of
:class:`~django.contrib.postgres.search.SearchQuery` allows searching for
a phrase or raw expression.

:mod:`django.contrib.staticfiles`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Added path matching to the :option:`collectstatic --ignore` option so that
patterns like ``/vendor/*.js`` can be used.

Database backends
~~~~~~~~~~~~~~~~~

* Added result streaming for :meth:`.QuerySet.iterator` on SQLite.

Generic Views
~~~~~~~~~~~~~

* The new :meth:`View.setup <django.views.generic.base.View.setup>` hook
initializes view attributes before calling
:meth:`~django.views.generic.base.View.dispatch`. It allows mixins to setup
instance attributes for reuse in child classes.

Internationalization
~~~~~~~~~~~~~~~~~~~~

* Added support and translations for the Armenian language.

Management Commands
~~~~~~~~~~~~~~~~~~~

* The new :option:`--force-color` option forces colorization of the command
output.

* :djadmin:`inspectdb` now creates models for foreign tables on PostgreSQL.

* :option:`inspectdb --include-views` now creates models for materialized views
on Oracle and PostgreSQL.

* The new :option:`inspectdb --include-partitions` option allows creating
models for partition tables on PostgreSQL. In older versions, models are
created child tables instead the parent.

* :djadmin:`inspectdb` now introspects :class:`~django.db.models.DurationField`
for Oracle and PostgreSQL, and :class:`~django.db.models.AutoField` for
SQLite.

* On Oracle, :djadmin:`dbshell` is wrapped with ``rlwrap``, if available.
``rlwrap`` provides a command history and editing of keyboard input.

* The new :option:`makemigrations --no-header` option avoids writing header
comments in generated migration file(s). This option is also available for
:djadmin:`squashmigrations`.

* :djadmin:`runserver` can now use `Watchman
<https://facebook.github.io/watchman/>`_ to improve the performance of
watching a large number of files for changes.

Migrations
~~~~~~~~~~

* The new :option:`migrate --plan` option prints the list of migration
operations that will be performed.

* ``NoneType`` can now be serialized in migrations.

* You can now :ref:`register custom serializers <custom-migration-serializers>`
for migrations.

Models
~~~~~~

* Added support for PostgreSQL operator classes (:attr:`.Index.opclasses`).

* Added support for partial indexes (:attr:`.Index.condition`).

* Added the :class:`~django.db.models.functions.NullIf` and
:class:`~django.db.models.functions.Reverse` database functions, as well as
many :ref:`math database functions <math-functions>`.

* Setting the new ``ignore_conflicts`` parameter of
:meth:`.QuerySet.bulk_create` to ``True`` tells the database to ignore
failure to insert rows that fail uniqueness constraints or other checks.

* The new :class:`~django.db.models.functions.ExtractIsoYear` function extracts
ISO-8601 week-numbering years from :class:`~django.db.models.DateField` and
:class:`~django.db.models.DateTimeField`, and the new :lookup:`iso_year`
lookup allows querying by an ISO-8601 week-numbering year.

* The new :meth:`.QuerySet.bulk_update` method allows efficiently updating
specific fields on multiple model instances.

* Django no longer always starts a transaction when a single query is being
performed, such as ``Model.save()``, ``QuerySet.update()``, and
``Model.delete()``. This improves the performance of autocommit by reducing
the number of database round trips.

* Added SQLite support for the :class:`~django.db.models.StdDev` and
:class:`~django.db.models.Variance` functions.

* The handling of ``DISTINCT`` aggregation is added to the
:class:`~django.db.models.Aggregate` class. Adding :attr:`allow_distinct =
True <django.db.models.Aggregate.allow_distinct>` as a class attribute on
``Aggregate`` subclasses allows a ``distinct`` keyword argument to be
specified on initialization to ensure that the aggregate function is only
called for each distinct value of ``expressions``.

* The :meth:`.RelatedManager.add`, :meth:`~.RelatedManager.create`,
:meth:`~.RelatedManager.remove`,  :meth:`~.RelatedManager.set`,
``get_or_create()``, and ``update_or_create()`` methods are now allowed on
many-to-many relationships with intermediate models. The new
``through_defaults`` argument is used to specify values for new intermediate
model instance(s).

Requests and Responses
~~~~~~~~~~~~~~~~~~~~~~

* Added :attr:`.HttpRequest.headers` to allow simple access to a request's
headers.

Serialization
~~~~~~~~~~~~~

* You can now deserialize data using natural keys containing :ref:`forward
references <natural-keys-and-forward-references>` by passing
``handle_forward_references=True`` to ``serializers.deserialize()``.
Additionally, :djadmin:`loaddata` handles forward references automatically.

Tests
~~~~~

* The new :meth:`.SimpleTestCase.assertURLEqual` assertion checks for a given
URL, ignoring the ordering of the query string.
:meth:`~.SimpleTestCase.assertRedirects` uses the new assertion.

* The test :class:`~.django.test.Client` now supports automatic JSON
serialization of list and tuple ``data`` when
``content_type='application/json'``.

* The new :setting:`ORACLE_MANAGED_FILES <TEST_ORACLE_MANAGED_FILES>` test
database setting allows using Oracle Managed Files (OMF) tablespaces.

* Deferrable database constraints are now checked at the end of each
:class:`~django.test.TestCase` test on SQLite 3.20+, just like on other
backends that support deferrable constraints. These checks aren't implemented
for older versions of SQLite because they would require expensive table
introspection there.

* :class:`~django.test.runner.DiscoverRunner` now skips the setup of databases
not :ref:`referenced by tests<testing-multi-db>`.

URLs
~~~~

* The new :attr:`.ResolverMatch.route` attribute stores the route of the
matching URL pattern.

Validators
~~~~~~~~~~

* :class:`.MaxValueValidator`, :class:`.MinValueValidator`,
:class:`.MinLengthValidator`, and :class:`.MaxLengthValidator` now accept
a callable ``limit_value``.

.. _backwards-incompatible-2.2:

Backwards incompatible changes in 2.2
=====================================

Database backend API
--------------------

This section describes changes that may be needed in third-party database
backends.

* Third-party database backends must implement support for table check
constraints or set ``DatabaseFeatures.supports_table_check_constraints`` to
``False``.

* Third party database backends must implement support for ignoring
constraints or uniqueness errors while inserting or set
``DatabaseFeatures.supports_ignore_conflicts`` to ``False``.

* Third party database backends must implement introspection for
``DurationField`` or set ``DatabaseFeatures.can_introspect_duration_field``
to ``False``.

* ``DatabaseFeatures.uses_savepoints`` now defaults to ``True``.

* Third party database backends must implement support for partial indexes or
set ``DatabaseFeatures.supports_partial_indexes`` to ``False``.

* ``DatabaseIntrospection.table_name_converter()`` and
``column_name_converter()`` are removed. Third party database backends may
need to instead implement ``DatabaseIntrospection.identifier_converter()``.
In that case, the constraint names that
``DatabaseIntrospection.get_constraints()`` returns must be normalized by
``identifier_converter()``.

* SQL generation for indexes is moved from :class:`~django.db.models.Index` to
``SchemaEditor`` and these ``SchemaEditor`` methods are added:

* ``_create_primary_key_sql()`` and ``_delete_primary_key_sql()``
* ``_delete_index_sql()`` (to pair with ``_create_index_sql()``)
* ``_delete_unique_sql`` (to pair with ``_create_unique_sql()``)
* ``_delete_fk_sql()`` (to pair with ``_create_fk_sql()``)
* ``_create_check_sql()`` and ``_delete_check_sql()``

* The third argument of ``DatabaseWrapper.__init__()``,
``allow_thread_sharing``, is removed.

Admin actions are no longer collected from base ``ModelAdmin`` classes
----------------------------------------------------------------------

For example, in older versions of Django::

 from django.contrib import admin

 class BaseAdmin(admin.ModelAdmin):
     actions = ['a']

 class SubAdmin(BaseAdmin):
     actions = ['b']

``SubAdmin`` would have actions ``'a'`` and ``'b'``.

Now ``actions`` follows standard Python inheritance. To get the same result as
before::

 class SubAdmin(BaseAdmin):
     actions = BaseAdmin.actions + ['b']

:mod:`django.contrib.gis`
-------------------------

* Support for GDAL 1.9 and 1.10 is dropped.

``TransactionTestCase`` serialized data loading
-----------------------------------------------

Initial data migrations are now loaded in
:class:`~django.test.TransactionTestCase` at the end of the test, after the
database flush. In older versions, this data was loaded at the beginning of the
test, but this prevents the :option:`test --keepdb` option from working
properly (the database was empty at the end of the whole test suite). This
change shouldn't have an impact on your tests unless you've customized
:class:`~django.test.TransactionTestCase`'s internals.

``sqlparse`` is required dependency
-----------------------------------

To simplify a few parts of Django's database handling, `sqlparse
<https://pypi.org/project/sqlparse/>`_ is now a required dependency. It's
automatically installed along with Django.

``cached_property`` aliases
---------------------------

In usage like::

 from django.utils.functional import cached_property

 class A:

     cached_property
     def base(self):
         return ...

     alias = base

``alias`` is not cached. Where the problem can be detected (Python 3.6 and
later), such usage now raises ``TypeError: Cannot assign the same
cached_property to two different names ('base' and 'alias').``

Use this instead::

 import operator

 class A:

     ...

     alias = property(operator.attrgetter('base'))

Permissions for proxy models
----------------------------

:ref:`Permissions for proxy models <proxy-models-permissions-topic>` are now
created using the content type of the proxy model rather than the content type
of the concrete model. A migration will update existing permissions when you
run :djadmin:`migrate`.

In the admin, the change is transparent for proxy models having the same
``app_label`` as their concrete model. However, in older versions, users with
permissions for a proxy model with a *different* ``app_label`` than its
concrete model couldn't access the model in the admin. That's now fixed, but
you might want to audit the permissions assignments for such proxy models
(``[add|view|change|delete]_myproxy``) prior to upgrading to ensure the new
access is appropriate.

Finally, proxy model permission strings must be updated to use their own
``app_label``. For example, for ``app.MyProxyModel`` inheriting from
``other_app.ConcreteModel``, update
``user.has_perm('other_app.add_myproxymodel')`` to
``user.has_perm('app.add_myproxymodel')``.

Merging of form ``Media`` assets
--------------------------------

Form ``Media`` assets are now merged using a topological sort algorithm, as the
old pairwise merging algorithm is insufficient for some cases. CSS and
JavaScript files which don't include their dependencies may now be sorted
incorrectly (where the old algorithm produced results correctly by
coincidence).

Audit all ``Media`` classes for any missing dependencies. For example,
widgets depending on ``django.jQuery`` must specify
``js=['admin/js/jquery.init.js', ...]`` when :ref:`declaring form media assets
<assets-as-a-static-definition>`.

Miscellaneous
-------------

* To improve readability, the ``UUIDField`` form field now displays values with
dashes, e.g. ``550e8400-e29b-41d4-a716-446655440000`` instead of
``550e8400e29b41d4a716446655440000``.

* On SQLite, ``PositiveIntegerField`` and ``PositiveSmallIntegerField`` now
include a check constraint to prevent negative values in the database. If you
have existing invalid data and run a migration that recreates a table, you'll
see ``CHECK constraint failed``.

* For consistency with WSGI servers, the test client now sets the
``Content-Length`` header to a string rather than an integer.

* The return value of :func:`django.utils.text.slugify` is no longer marked as
HTML safe.

* The default truncation character used by the :tfilter:`urlizetrunc`,
:tfilter:`truncatechars`, :tfilter:`truncatechars_html`,
:tfilter:`truncatewords`, and :tfilter:`truncatewords_html` template filters
is now the real ellipsis character (``…``) instead of 3 dots. You may have to
adapt some test output comparisons.

* Support for bytestring paths in the template filesystem loader is removed.

* :func:`django.utils.http.urlsafe_base64_encode` now returns a string instead
of a bytestring, and :func:`django.utils.http.urlsafe_base64_decode` may no
longer be passed a bytestring.

* Support for ``cx_Oracle`` < 6.0 is removed.

* The minimum supported version of ``mysqlclient`` is increased from 1.3.7 to
1.3.13.

* The minimum supported version of SQLite is increased from 3.7.15 to 3.8.3.

* In an attempt to provide more semantic query data, ``NullBooleanSelect`` now
renders ``<option>`` values of ``unknown``, ``true``, and ``false`` instead
of ``1``, ``2``, and ``3``. For backwards compatibility, the old values are
still accepted as data.

* :attr:`Group.name <django.contrib.auth.models.Group.name>` ``max_length``
is increased from 80 to 150 characters.

* Tests that violate deferrable database constraints now error when run on
SQLite 3.20+, just like on other backends that support such constraints.

* To catch usage mistakes, the test :class:`~django.test.Client` and
:func:`django.utils.http.urlencode` now raise ``TypeError`` if ``None`` is
passed as a value to encode because ``None`` can't be encoded in GET and POST
data. Either pass an empty string or omit the value.

* The :djadmin:`ping_google` management command now defaults to ``https``
instead of ``http`` for the sitemap's URL. If your site uses http, use the
new :option:`ping_google --sitemap-uses-http` option. If you use the
:func:`~django.contrib.sitemaps.ping_google` function, set the new
``sitemap_uses_https`` argument to ``False``.

* :djadmin:`runserver` no longer supports `pyinotify` (replaced by Watchman).

* The :class:`~django.db.models.Avg`, :class:`~django.db.models.StdDev`, and
:class:`~django.db.models.Variance` aggregate functions now return a
``Decimal`` instead of a ``float`` when the input is ``Decimal``.

* Tests will fail on SQLite if apps without migrations have relations to apps
with migrations. This has been a documented restriction since migrations were
added in Django 1.7, but it fails more reliably now. You'll see tests failing
with errors like ``no such table: <app_label>_<model>``. This was observed
with several third-party apps that had models in tests without migrations.
You must add migrations for such models.

.. _deprecated-features-2.2:

Features deprecated in 2.2
==========================

Model ``Meta.ordering`` will no longer affect ``GROUP BY`` queries
------------------------------------------------------------------

A model's ``Meta.ordering`` affecting ``GROUP BY`` queries (such as
``.annotate().values()``) is a common source of confusion. Such queries now
issue a deprecation warning with the advice to add an ``order_by()`` to retain
the current query. ``Meta.ordering`` will be ignored in such queries starting
in Django 3.1.

Miscellaneous
-------------

* ``django.utils.timezone.FixedOffset`` is deprecated in favor of
:class:`datetime.timezone`.

* The undocumented ``QuerySetPaginator`` alias of
``django.core.paginator.Paginator`` is deprecated.

* The ``FloatRangeField`` model and form fields in ``django.contrib.postgres``
are deprecated in favor of a new name, ``DecimalRangeField``, to match the
underlying ``numrange`` data type used in the database.

* The ``FILE_CHARSET`` setting is deprecated. Starting with Django 3.1, files
read from disk must be UTF-8 encoded.

* ``django.contrib.staticfiles.storage.CachedStaticFilesStorage`` is
deprecated due to the intractable problems that it has. Use
:class:`.ManifestStaticFilesStorage` or a third-party cloud storage instead.

* :meth:`.RemoteUserBackend.configure_user` is now passed ``request`` as the
first positional argument, if it accepts it. Support for overrides that don't
accept it will be removed in Django 3.1.

* The :attr:`.SimpleTestCase.allow_database_queries`,
:attr:`.TransactionTestCase.multi_db`, and :attr:`.TestCase.multi_db`
attributes are deprecated in favor of :attr:`.SimpleTestCase.databases`,
:attr:`.TransactionTestCase.databases`, and :attr:`.TestCase.databases`.
These new attributes allow databases dependencies to be declared in order to
prevent unexpected queries against non-default databases to leak state
between tests. The previous behavior of ``allow_database_queries=True`` and
``multi_db=True`` can be achieved by setting ``databases='__all__'``.


==========================

2.1.8

==========================

*April 1, 2019*

Django 2.1.8 fixes a bug in 2.1.7.

Bugfixes
========

* Prevented admin inlines for a ``ManyToManyField``\'s implicit through model
from being editable if the user only has the view permission
(:ticket:`30289`).


==========================

2.1.7

==========================

*February 11, 2019*

Django 2.1.7 fixes a packaging error in 2.1.6.

Bugfixes
========

* Corrected packaging error from 2.1.6 (:ticket:`30175`).


==========================

2.1.5

==========================

*January 4, 2019*

Django 2.1.5 fixes a security issue and several bugs in 2.1.4.

CVE-2019-3498: Content spoofing possibility in the default 404 page
-------------------------------------------------------------------

An attacker could craft a malicious URL that could make spoofed content appear
on the default page generated by the ``django.views.defaults.page_not_found()``
view.

The URL path is no longer displayed in the default 404 template and the
``request_path`` context variable is now quoted to fix the issue for custom
templates that use the path.

Bugfixes
========

* Fixed compatibility with mysqlclient 1.3.14 (:ticket:`30013`).

* Fixed a schema corruption issue on SQLite 3.26+. You might have to drop and
rebuild your SQLite database if you applied a migration while using an older
version of Django with SQLite 3.26 or later (:ticket:`29182`).

* Prevented SQLite schema alterations while foreign key checks are enabled to
avoid the possibility of schema corruption (:ticket:`30023`).

* Fixed a regression in Django 2.1.4 (which enabled keep-alive connections)
where request body data isn't properly consumed for such connections
(:ticket:`30015`).

* Fixed a regression in Django 2.1.4 where
``InlineModelAdmin.has_change_permission()`` is incorrectly called with a
non-``None`` ``obj`` argument during an object add (:ticket:`30050`).


==========================

2.1.4

==========================

*December 3, 2018*

Django 2.1.4 fixes several bugs in 2.1.3.

Bugfixes
========

* Corrected the default password list that ``CommonPasswordValidator`` uses by
lowercasing all passwords to match the format expected by the validator
(:ticket:`29952`).

* Prevented repetitive calls to ``geos_version_tuple()`` in the ``WKBWriter``
class in an attempt to fix a random crash involving ``LooseVersion``
(:ticket:`29959`).

* Fixed keep-alive support in ``runserver`` after it was disabled to fix
another issue in Django 2.0 (:ticket:`29849`).

* Fixed admin view-only change form crash when using
``ModelAdmin.prepopulated_fields`` (:ticket:`29929`).

* Fixed "Please correct the errors below" error message when editing an object
in the admin if the user only has the "view" permission on inlines
(:ticket:`29930`).


==========================

2.1.3

==========================

*November 1, 2018*

Django 2.1.3 fixes several bugs in 2.1.2.

Bugfixes
========

* Fixed a regression in Django 2.0 where combining ``Q`` objects with ``__in``
lookups and lists crashed (:ticket:`29838`).

* Fixed a regression in Django 1.11 where ``django-admin shell`` may hang
on startup (:ticket:`29774`).

* Fixed a regression in Django 2.0 where test databases aren't reused with
``manage.py test --keepdb`` on MySQL (:ticket:`29827`).

* Fixed a regression where cached foreign keys that use ``to_field`` were
incorrectly cleared in ``Model.save()`` (:ticket:`29896`).

* Fixed a regression in Django 2.0 where ``FileSystemStorage`` crashes with
``FileExistsError`` if concurrent saves try to create the same directory
(:ticket:`29890`).


==========================

2.1.2

==========================

*October 1, 2018*

Django 2.1.2 fixes a security issue and several bugs in 2.1.1. Also, the latest
string translations from Transifex are incorporated.

CVE-2018-16984: Password hash disclosure to "view only" admin users
===================================================================

If an admin user has the change permission to the user model, only part of the
password hash is displayed in the change form. Admin users with the view (but
not change) permission to the user model were displayed the entire hash. While
it's typically infeasible to reverse a strong password hash, if your site uses
weaker password hashing algorithms such as MD5 or SHA1, it could be a problem.

Bugfixes
========

* Fixed a regression where nonexistent joins in ``F()`` no longer raised
``FieldError`` (:ticket:`29727`).

* Fixed a regression where files starting with a tilde or underscore weren't
ignored by the migrations loader (:ticket:`29749`).

* Made migrations detect changes to ``Meta.default_related_name``
(:ticket:`29755`).

* Added compatibility for ``cx_Oracle`` 7 (:ticket:`29759`).

* Fixed a regression in Django 2.0 where unique index names weren't quoted
(:ticket:`29778`).

* Fixed a regression where sliced queries with multiple columns with the same
name crashed on Oracle 12.1 (:ticket:`29630`).

* Fixed a crash when a user with the view (but not change) permission made a
POST request to an admin user change form (:ticket:`29809`).


==========================

2.1.1

==========================

*August 31, 2018*

Django 2.1.1 fixes several bugs in 2.1.

Bugfixes
========

* Fixed a race condition in ``QuerySet.update_or_create()`` that could result
in data loss (:ticket:`29499`).

* Fixed a regression where ``QueryDict.urlencode()`` crashed if the dictionary
contains a non-string value (:ticket:`29627`).

* Fixed a regression in Django 2.0 where using ``manage.py test --keepdb``
fails on PostgreSQL if the database exists and the user doesn't have
permission to create databases (:ticket:`29613`).

* Fixed a regression in Django 2.0 where combining ``Q`` objects with ``__in``
lookups and lists crashed (:ticket:`29643`).

* Fixed translation failure of ``DurationField``'s "overflow" error message
(:ticket:`29623`).

* Fixed a regression where the admin change form crashed if the user doesn't
have the 'add' permission to a model that uses ``TabularInline``
(:ticket:`29637`).

* Fixed a regression where a ``related_query_name`` reverse accessor wasn't set
up when a ``GenericRelation`` is declared on an abstract base model
(:ticket:`29653`).

* Fixed the test client's JSON serialization of a request data dictionary for
structured content type suffixes (:ticket:`29662`).

* Made the admin change view redirect to the changelist view after a POST if
the user has the 'view' permission (:ticket:`29663`).

* Fixed admin change view crash for view-only users if the form has an extra
form field (:ticket:`29682`).

* Fixed a regression in Django 2.0.5 where ``QuerySet.values()`` or
``values_list()`` after combining querysets with ``extra()`` with
``union()``, ``difference()``, or ``intersection()`` crashed due to
mismatching columns (:ticket:`29694`).

* Fixed crash if ``InlineModelAdmin.has_add_permission()`` doesn't accept the
``obj`` argument (:ticket:`29723`).


========================

2.1

========================

*August 1, 2018*

Welcome to Django 2.1!

These release notes cover the :ref:`new features <whats-new-2.1>`, as well as
some :ref:`backwards incompatible changes <backwards-incompatible-2.1>` you'll
want to be aware of when upgrading from Django 2.0 or earlier. We've
:ref:`dropped some features<removed-features-2.1>` that have reached the end of
their deprecation cycle, and we've :ref:`begun the deprecation process for some
features <deprecated-features-2.1>`.

See the :doc:`/howto/upgrade-version` guide if you're updating an existing
project.

Python compatibility
====================

Django 2.1 supports Python 3.5, 3.6, and 3.7. Django 2.0 is the last version to
support Python 3.4.  We **highly recommend** and only officially support the
latest release of each series.

.. _whats-new-2.1:

What's new in Django 2.1
========================

Model "view" permission
-----------------------

A "view" permission is added to the model :attr:`Meta.default_permissions
<django.db.models.Options.default_permissions>`. The new permissions will be
created automatically when running :djadmin:`migrate`.

This allows giving users read-only access to models in the admin.
:meth:`.ModelAdmin.has_view_permission` is new. The implementation is backwards
compatible in that there isn't a need to assign the "view" permission to allow
users who have the "change" permission to edit objects.

There are a couple of :ref:`backwards incompatible considerations
<view_permission_backwards_incompatible>`.

Minor features
--------------

:mod:`django.contrib.admin`
~~~~~~~~~~~~~~~~~~~~~~~~~~~

* :attr:`.ModelAdmin.search_fields` now accepts any lookup such as
``field__exact``.

* jQuery is upgraded from version 2.2.3 to 3.3.1.

* The new :meth:`.ModelAdmin.delete_queryset` method allows customizing the
deletion process of the "delete selected objects" action.

* You can now :ref:`override the default admin site
<overriding-default-admin-site>`.

* The new :attr:`.ModelAdmin.sortable_by` attribute and
:meth:`.ModelAdmin.get_sortable_by` method allow limiting the columns that
can be sorted in the change list page.

* The ``admin_order_field`` attribute for elements in
:attr:`.ModelAdmin.list_display` may now be a query expression.

* The new :meth:`.ModelAdmin.get_deleted_objects()` method allows customizing
the deletion process of the delete view and the "delete selected" action.

* The ``actions.html``, ``change_list_results.html``, ``date_hierarchy.html``,
``pagination.html``, ``prepopulated_fields_js.html``, ``search_form.html``,
and ``submit_line.html`` templates can now be :ref:`overridden per app or
per model <admin-templates-overridden-per-app-or-model>` (besides overridden
globally).

* The admin change list and change form object tools can now be :ref:`overridden
per app, per model, or globally <admin-templates-overridden-per-app-or-model>`
with ``change_list_object_tools.html`` and
``change_form_object_tools.html`` templates.

* :meth:`.InlineModelAdmin.has_add_permission` is now passed the parent object
as the second positional argument, ``obj``.

* Admin actions may now :ref:`specify permissions <admin-action-permissions>`
to limit their availability to certain users.

:mod:`django.contrib.auth`
~~~~~~~~~~~~~~~~~~~~~~~~~~

* :djadmin:`createsuperuser` now gives a prompt to allow bypassing the
:setting:`AUTH_PASSWORD_VALIDATORS` checks.

:mod:`django.contrib.gis`
~~~~~~~~~~~~~~~~~~~~~~~~~

* The new :meth:`.GEOSGeometry.buffer_with_style` method is a version of
:meth:`~.GEOSGeometry.buffer` that allows customizing the style of the
buffer.

* :class:`~django.contrib.gis.forms.widgets.OpenLayersWidget` is now based on
OpenLayers 4.6.5 (previously 3.20.1).

:mod:`django.contrib.sessions`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Added the :setting:`SESSION_COOKIE_SAMESITE` setting to set the ``SameSite``
cookie flag on session cookies.

Cache
~~~~~

* The :ref:`local-memory cache backend <local-memory-caching>` now uses a
least-recently-used (LRU) culling strategy rather than a pseudo-random one.

* The new :meth:`~django.core.caches.cache.touch` method of the :ref:`low-level
cache API <low-level-cache-api>` updates the timeout of cache keys.

CSRF
~~~~

* Added the :setting:`CSRF_COOKIE_SAMESITE` setting to set the ``SameSite``
cookie flag on CSRF cookies.

Forms
~~~~~

* The widget for ``ImageField`` now renders with the HTML attribute
``accept="image/*"``.

Internationalization
~~~~~~~~~~~~~~~~~~~~

* Added the :meth:`~django.utils.translation.get_supported_language_variant`
function.

* Untranslated strings for territorial language variants now use the
translations of the generic language. For example, untranslated ``pt_BR``
strings use ``pt`` translations.

Management Commands
~~~~~~~~~~~~~~~~~~~

* The new :option:`inspectdb --include-views` option allows creating models
for database views.

* The :class:`~django.core.management.BaseCommand` class now uses a custom help
formatter so that the standard options like ``--verbosity`` or ``--settings``
appear last in the help output, giving a more prominent position to subclassed
command's options.

Migrations
~~~~~~~~~~

* Added support for serialization of ``functools.partialmethod`` objects.

* To support frozen environments, migrations may be loaded from ``.pyc`` files.

Models
~~~~~~

* Models can now use ``__init_subclass__()`` from :pep:`487`.

* A ``BinaryField`` may now be set to ``editable=True`` if you wish to include
it in model forms.

* A number of new text database functions are added:
:class:`~django.db.models.functions.Chr`,
:class:`~django.db.models.functions.Left`,
:class:`~django.db.models.functions.LPad`,
:class:`~django.db.models.functions.LTrim`,
:class:`~django.db.models.functions.Ord`,
:class:`~django.db.models.functions.Repeat`,
:class:`~django.db.models.functions.Replace`,
:class:`~django.db.models.functions.Right`,
:class:`~django.db.models.functions.RPad`,
:class:`~django.db.models.functions.RTrim`, and
:class:`~django.db.models.functions.Trim`.

* The new :class:`~django.db.models.functions.TruncWeek` function truncates
:class:`~django.db.models.DateField` and
:class:`~django.db.models.DateTimeField` to the Monday of a week.

* Query expressions can now be negated using a minus sign.

* :meth:`.QuerySet.order_by` and :meth:`distinct(*fields) <.QuerySet.distinct>`
now support using field transforms.

* :class:`~django.db.models.BooleanField` can now be ``null=True``. This is
encouraged instead of :class:`~django.db.models.NullBooleanField`, which will
likely be deprecated in the future.

* The new :meth:`.QuerySet.explain` method displays the database's execution
plan of a queryset's query.

*  :meth:`.QuerySet.raw` now supports :meth:`~.QuerySet.prefetch_related`.

Requests and Responses
~~~~~~~~~~~~~~~~~~~~~~

* Added :meth:`.HttpRequest.get_full_path_info`.

* Added the ``samesite`` argument to :meth:`.HttpResponse.set_cookie` to allow
setting the ``SameSite`` cookie flag.

* The new ``as_attachment`` argument for :class:`~django.http.FileResponse`
sets the ``Content-Disposition`` header to make the browser ask if the user
wants to download the file. ``FileResponse`` also tries to set the
``Content-Type`` and ``Content-Length`` headers where appropriate.

Templates
~~~~~~~~~

* The new :tfilter:`json_script` filter safely outputs a Python object as JSON,
wrapped in a ``<script>`` tag, ready for use with JavaScript.

Tests
~~~~~

* Added test :class:`~django.test.Client` support for 307 and 308 redirects.

* The test :class:`~django.test.Client` now serializes a request data
dictionary as JSON if ``content_type='application/json'``. You can customize
the JSON encoder with test client's ``json_encoder`` parameter.

* The new :meth:`.SimpleTestCase.assertWarnsMessage` method is a simpler
version of :meth:`~unittest.TestCase.assertWarnsRegex`.

.. _backwards-incompatible-2.1:

Backwards incompatible changes in 2.1
=====================================

Database backend API
--------------------

This section describes changes that may be needed in third-party database
backends.

* To adhere to :pep:`249`, exceptions where a database doesn't support a
feature are changed from :exc:`NotImplementedError` to
:exc:`django.db.NotSupportedError`.

* Renamed the ``allow_sliced_subqueries`` database feature flag to
``allow_sliced_subqueries_with_in``.

* ``DatabaseOperations.distinct_sql()`` now requires an additional ``params``
argument and returns a tuple of SQL and parameters instead of a SQL string.

* ``DatabaseFeatures.introspected_boolean_field_type`` is changed from a method
to a property.

:mod:`django.contrib.gis`
-------------------------

* Support for SpatiaLite 4.0 is removed.

Dropped support for MySQL 5.5
-----------------------------

The end of upstream support for MySQL 5.5 is December 2018. Django 2.1 supports
MySQL 5.6 and higher.

Dropped support for PostgreSQL 9.3
----------------------------------

The end of upstream support for PostgreSQL 9.3 is September 2018. Django 2.1
supports PostgreSQL 9.4 and higher.

Removed ``BCryptPasswordHasher`` from the default ``PASSWORD_HASHERS`` setting
------------------------------------------------------------------------------

If you used bcrypt with Django 1.4 or 1.5 (before ``BCryptSHA256PasswordHasher``
was added in Django 1.6), you might have some passwords that use the
``BCryptPasswordHasher`` hasher.

You can check if that's the case like this::

 from django.contrib.auth import get_user_model
 User = get_user_model()
 User.objects.filter(password__startswith='bcrypt$$')

If you want to continue to allow those passwords to be used, you'll
have to define the :setting:`PASSWORD_HASHERS` setting (if you don't already)
and include ``'django.contrib.auth.hashers.BCryptPasswordHasher'``.

Moved ``wrap_label`` widget template context variable
-----------------------------------------------------

To fix the lack of ``<label>`` when using ``RadioSelect`` and
``CheckboxSelectMultiple`` with ``MultiWidget``, the ``wrap_label`` context
variable now appears as an attribute of each option. For example, in a custom
``input_option.html`` template, change ``{% if wrap_label %}`` to
``{% if widget.wrap_label %}``.

``SameSite`` cookies
--------------------

The cookies used for ``django.contrib.sessions``, ``django.contrib.messages``,
and Django's CSRF protection now set the ``SameSite`` flag to ``Lax`` by
default. Browsers that respect this flag won't send these cookies on
cross-origin requests. If you rely on the old behavior, set the
:setting:`SESSION_COOKIE_SAMESITE` and/or :setting:`CSRF_COOKIE_SAMESITE`
setting to ``None``.

.. _view_permission_backwards_incompatible:

Considerations for the new model "view" permission
--------------------------------------------------

Custom admin forms need to take the view-only case into account
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

With the new "view" permission, existing custom admin forms may raise errors
when a user doesn't have the change permission because the form might access
nonexistent fields. Fix this by overriding :meth:`.ModelAdmin.get_form` and
checking if the user has the "change" permissions and returning the default
form if not::

 class MyAdmin(admin.ModelAdmin):
     def get_form(self, request, obj=None, **kwargs):
         if not self.has_change_permission(request, obj):
             return super().get_form(request, obj, **kwargs)
         return CustomForm

New default view permission could allow unwanted access to admin views
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you have a custom permission with a codename of the form
``view_<modelname>``, the new view permission handling in the admin will allow
view access to the changelist and detail pages for those models. If this is
unwanted, you must change your custom permission codename.

Miscellaneous
-------------

* The minimum supported version of ``mysqlclient`` is increased from 1.3.3 to
1.3.7.

* Support for SQLite < 3.7.15 is removed.

* The date format of ``Set-Cookie``'s ``Expires`` directive is changed to
follow :rfc:`7231section-7.1.1.1` instead of Netscape's cookie standard.
Hyphens present in dates like ``Tue, 25-Dec-2018 22:26:13 GMT`` are removed.
This change should be merely cosmetic except perhaps for antiquated browsers
that don't parse the new format.

* ``allowed_hosts`` is now a required argument of private API
``django.utils.http.is_safe_url()``.

* The ``multiple`` attribute rendered by the
:class:`~django.forms.SelectMultiple` widget now uses HTML5 boolean syntax
rather than XHTML's ``multiple="multiple"``.

* HTML rendered by form widgets no longer includes a closing slash on void
elements, e.g. ``<br>``. This is incompatible within XHTML, although some
widgets already used aspects of HTML5 such as boolean attributes.

* The value of :class:`~django.forms.SelectDateWidget`'s empty options is
changed from 0 to an empty string, which mainly may require some adjustments
in tests that compare HTML.

* :meth:`.User.has_usable_password` and the
:func:`~django.contrib.auth.hashers.is_password_usable` function no longer
return ``False`` if the password is ``None`` or an empty string, or if the
password uses a hasher that's not in the :setting:`PASSWORD_HASHERS` setting.
This undocumented behavior was a regression in Django 1.6 and prevented users
with such passwords from requesting a password reset. Audit your code to
confirm that your usage of these APIs don't rely on the old behavior.

* Since migrations are now loaded from ``.pyc`` files, you might need to delete
them if you're working in a mixed Python 2 and Python 3 environment.

* Using ``None`` as a :class:`~django.contrib.postgres.fields.JSONField` lookup
value now matches objects that have the specified key and a null value rather
than objects that don't have the key.

* The admin CSS class ``field-box`` is renamed to ``fieldBox`` to prevent
conflicts with the class given to model fields named "box".

* Since the admin's ``actions.html``, ``change_list_results.html``,
``date_hierarchy.html``, ``pagination.html``, ``prepopulated_fields_js.html``,
``search_form.html``, and ``submit_line.html`` templates can now be
overridden per app or per model, you may need to rename existing templates
with those names that were written for a different purpose.

* ``QuerySet.raw()`` now caches its results like regular querysets. Use
``iterator()`` if you don't want caching.

* The database router :meth:`allow_relation` method is called in more cases.
Improperly written routers may need to be updated accordingly.

* Translations are no longer deactivated before running management commands.
If your custom command requires translations to be deactivated (for example,
to insert untranslated content into the database), use the new
:ref:`no_translations decorator <management-commands-and-locales>`.

* Management commands no longer allow the abbreviated forms of the
``--settings`` and ``--pythonpath`` arguments.

* The private ``django.db.models.sql.constants.QUERY_TERMS`` constant is
removed. The :meth:`~.RegisterLookupMixin.get_lookup`
and :meth:`~.RegisterLookupMixin.get_lookups` methods
of the :ref:`Lookup Registration API <lookup-registration-api>` may be
suitable alternatives. Compared to the ``QUERY_TERMS`` constant, they allow
your code to also account for any custom lookups that have been registered.

* Compatibility with ``py-bcrypt`` is removed as it's unmaintained. Use `bcrypt
<https://pypi.org/project/bcrypt/>`_ instead.

.. _deprecated-features-2.1:

Features deprecated in 2.1
==========================

Miscellaneous
-------------

* The ``ForceRHR`` GIS function is deprecated in favor of the new
:class:`~django.contrib.gis.db.models.functions.ForcePolygonCW` function.

* ``django.utils.http.cookie_date()`` is deprecated in favor of
:func:`~django.utils.http.http_date`, which follows the format of the latest
RFC.

* ``{% load staticfiles %}`` and ``{% load admin_static %}`` are deprecated
in favor of ``{% load static %}``, which works the same.

* ``django.contrib.staticfiles.templatetags.static()`` is deprecated in favor
of ``django.templatetags.static.static()``.

* Support for :meth:`.InlineModelAdmin.has_add_permission` methods that don't
accept ``obj`` as the second positional argument will be removed in Django
3.0.

.. _removed-features-2.1:

Features removed in 2.1
=======================

These features have reached the end of their deprecation cycle and are removed
in Django 2.1. See :ref:`deprecated-features-1.11` for details, including how
to remove usage of these features.

* ``contrib.auth.views.login()``, ``logout()``, ``password_change()``,
``password_change_done()``, ``password_reset()``, ``password_reset_done()``,
``password_reset_confirm()``, and ``password_reset_complete()`` are removed.

* The ``extra_context`` parameter of ``contrib.auth.views.logout_then_login()``
is removed.

* ``django.test.runner.setup_databases()`` is removed.

* ``django.utils.translation.string_concat()`` is removed.

* ``django.core.cache.backends.memcached.PyLibMCCache`` no longer supports
passing ``pylibmc`` behavior settings as top-level attributes of ``OPTIONS``.

* The ``host`` parameter of ``django.utils.http.is_safe_url()`` is removed.

* Silencing of exceptions raised while rendering the ``{% include %}`` template
tag is removed.

* ``DatabaseIntrospection.get_indexes()`` is removed.

* The ``authenticate()`` method of authentication backends requires ``request``
as the first positional argument.

* The ``django.db.models.permalink()`` decorator is removed.

* The ``USE_ETAGS`` setting is removed. ``CommonMiddleware`` and
``django.utils.cache.patch_response_headers()`` no longer set ETags.

* The ``Model._meta.has_auto_field`` attribute is removed.

* ``url()``'s support for inline flags in regular expression groups (``(?i)``,
``(?L)``, ``(?m)``, ``(?s)``, and ``(?u)``) is removed.

* Support for ``Widget.render()`` methods without the ``renderer`` argument
is removed.


===========================

2.0.13

===========================

*February 12, 2019*

Django 2.0.13 fixes a regression in 2.0.12/2.0.11.

Bugfixes
========

* Fixed crash in ``django.utils.numberformat.format_number()`` when the number
has over 200 digits (:ticket:`30177`).


===========================

2.0.12

===========================

*February 11, 2019*

Django 2.0.12 fixes a packaging error in 2.0.11.

Bugfixes
========

* Corrected packaging error from 2.0.11 (:ticket:`30175`).


===========================

2.0.10

===========================

*January 4, 2019*

Django 2.0.10 fixes a security issue and several bugs in 2.0.9.

CVE-2019-3498: Content spoofing possibility in the default 404 page
-------------------------------------------------------------------

An attacker could craft a malicious URL that could make spoofed content appear
on the default page generated by the ``django.views.defaults.page_not_found()``
view.

The URL path is no longer displayed in the default 404 template and the
``request_path`` context variable is now quoted to fix the issue for custom
templates that use the path.

Bugfixes
========

* Prevented repetitive calls to ``geos_version_tuple()`` in the ``WKBWriter``
class in an attempt to fix a random crash involving ``LooseVersion`` since
Django 2.0.6 (:ticket:`29959`).

* Fixed a schema corruption issue on SQLite 3.26+. You might have to drop and
rebuild your SQLite database if you applied a migration while using an older
version of Django with SQLite 3.26 or later (:ticket:`29182`).

* Prevented SQLite schema alterations while foreign key checks are enabled to
avoid the possibility of schema corruption (:ticket:`30023`).


==========================

2.0.9

==========================

*October 1, 2018*

Django 2.0.9 fixes a data loss bug in 2.0.8.

Bugfixes
========

* Fixed a race condition in ``QuerySet.update_or_create()`` that could result
in data loss (:ticket:`29499`).


==========================

2.0.8

==========================

*August 1, 2018*

Django 2.0.8 fixes a security issue and several bugs in 2.0.7.

CVE-2018-14574: Open redirect possibility in ``CommonMiddleware``
=================================================================

If the :class:`~django.middleware.common.CommonMiddleware` and the
:setting:`APPEND_SLASH` setting are both enabled, and if the project has a
URL pattern that accepts any path ending in a slash (many content management
systems have such a pattern), then a request to a maliciously crafted URL of
that site could lead to a redirect to another site, enabling phishing and other
attacks.

``CommonMiddleware`` now escapes leading slashes to prevent redirects to other
domains.

Bugfixes
========

* Fixed a regression in Django 2.0.7 that broke the ``regex`` lookup on MariaDB
(even though MariaDB isn't officially supported) (:ticket:`29544`).

* Fixed a regression where ``django.template.Template`` crashed if the
``template_string`` argument is lazy (:ticket:`29617`).


==========================

2.0.7

==========================

*July 2, 2018*

Django 2.0.7 fixes several bugs in 2.0.6.

Bugfixes
========

* Fixed admin changelist crash when using a query expression without ``asc()``
or ``desc()`` in the page's ordering (:ticket:`29428`).

* Fixed admin check crash when using a query expression in
``ModelAdmin.ordering`` (:ticket:`29428`).

* Fixed ``__regex`` and ``__iregex`` lookups with MySQL 8 (:ticket:`29451`).

* Fixed migrations crash with namespace packages on Python 3.7
(:ticket:`28814`).


==========================

2.0.6

==========================

*June 1, 2018*

Django 2.0.6 fixes several bugs in 2.0.5.

Bugfixes
========

* Fixed a regression that broke custom template filters that use decorators
(:ticket:`29400`).

* Fixed detection of custom URL converters in included patterns
(:ticket:`29415`).

* Fixed a regression that added an unnecessary subquery to the ``GROUP BY``
clause on MySQL when using a ``RawSQL`` annotation (:ticket:`29416`).

* Fixed ``WKBWriter.write()`` and ``write_hex()`` for empty polygons on
GEOS 3.6.1+ (:ticket:`29460`).

* Fixed a regression in Django 1.10 that could result in large memory usage
when making edits using ``ModelAdmin.list_editable`` (:ticket:`28462`).


==========================

2.0.5

==========================

*May 1, 2018*

Django 2.0.5 fixes several bugs in 2.0.4.

Bugfixes
========

* Corrected the import paths that ``inspectdb`` generates for
``django.contrib.postgres`` fields (:ticket:`29307`).

* Fixed a regression in Django 1.11.8 where altering a field with a unique
constraint may drop and rebuild more foreign keys than necessary
(:ticket:`29193`).

* Fixed crashes in ``django.contrib.admindocs`` when a view is a callable
object, such as ``django.contrib.syndication.views.Feed`` (:ticket:`29296`).

* Fixed a regression in Django 2.0.4 where ``QuerySet.values()`` or
``values_list()`` after combining an annotated and unannotated queryset with
``union()``, ``difference()``, or ``intersection()`` crashed due to mismatching
columns (:ticket:`29286`).


==========================

2.0.4

==========================

*April 2, 2018*

Django 2.0.4 fixes several bugs in 2.0.3.

Bugfixes
========

* Fixed a crash when filtering with an ``Exists()`` annotation of a queryset
containing a single field (:ticket:`29195`).

* Fixed admin autocomplete widget's translations for `zh-hans` and `zh-hant`
languages (:ticket:`29213`).

* Corrected admin's autocomplete widget to add a space after custom classes
(:ticket:`29221`).

* Fixed ``PasswordResetConfirmView`` crash when using a user model with a
``UUIDField`` primary key and the reset URL contains an encoded primary key
value that decodes to an invalid UUID (:ticket:`29206`).

* Fixed a regression in Django 1.11.8 where combining two annotated
``values_list()`` querysets with ``union()``, ``difference()``, or
``intersection()`` crashed due to mismatching columns (:ticket:`29229`).

* Fixed a regression in Django 1.11 where an empty choice could be initially
selected for the ``SelectMultiple`` and ``CheckboxSelectMultiple`` widgets
(:ticket:`29273`).

* Fixed a regression in Django 2.0 where ``OpenLayersWidget`` deserialization
ignored the widget map's SRID and assumed 4326 (WGS84) (:ticket:`29116`).


==========================

2.0.3

==========================

*March 6, 2018*

Django 2.0.3 fixes two security issues and several bugs in 2.0.2. Also, the
latest string translations from Transifex are incorporated.

CVE-2018-7536: Denial-of-service possibility in ``urlize`` and ``urlizetrunc`` template filters
===============================================================================================

The ``django.utils.html.urlize()`` function was extremely slow to evaluate
certain inputs due to catastrophic backtracking vulnerabilities in two regular
expressions. The ``urlize()`` function is used to implement the ``urlize`` and
``urlizetrunc`` template filters, which were thus vulnerable.

The problematic regular expressions are replaced with parsing logic that
behaves similarly.

CVE-2018-7537: Denial-of-service possibility in ``truncatechars_html`` and ``truncatewords_html`` template filters
==================================================================================================================

If ``django.utils.text.Truncator``'s ``chars()`` and ``words()`` methods were
passed the ``html=True`` argument, they were extremely slow to evaluate certain
inputs due to a catastrophic backtracking vulnerability in a regular
expression. The ``chars()`` and ``words()`` methods are used to implement the
``truncatechars_html`` and ``truncatewords_html`` template filters, which were
thus vulnerable.

The backtracking problem in the regular expression is fixed.

Bugfixes
========

* Fixed a regression that caused sliced ``QuerySet.distinct().order_by()``
followed by ``count()`` to crash (:ticket:`29108`).

* Prioritized the datetime and time input formats without ``%f`` for the Thai
locale to fix the admin time picker widget displaying "undefined"
(:ticket:`29109`).

* Fixed crash with ``QuerySet.order_by(Exists(...))`` (:ticket:`29118`).

* Made ``Q.deconstruct()`` deterministic with multiple keyword arguments
(:ticket:`29125`). You may need to modify ``Q``'s in existing migrations, or
accept an autogenerated migration.

* Fixed a regression where a ``When()`` expression with a list argument crashes
(:ticket:`29166`).

* Fixed crash when using a ``Window()`` expression in a subquery
(:ticket:`29172`).

* Fixed ``AbstractBaseUser.normalize_username()`` crash if the ``username``
argument isn't a string (:ticket:`29176`).


==========================

2.0.2

==========================

*February 1, 2018*

Django 2.0.2 fixes a security issue and several bugs in 2.0.1.

CVE-2018-6188: Information leakage in ``AuthenticationForm``
============================================================

A regression in Django 1.11.8 made
:class:`~django.contrib.auth.forms.AuthenticationForm` run its
``confirm_login_allowed()`` method even if an incorrect password is entered.
This can leak information about a user, depending on what messages
``confirm_login_allowed()`` raises. If ``confirm_login_allowed()`` isn't
overridden, an attacker enter an arbitrary username and see if that user has
been set to ``is_active=False``. If ``confirm_login_allowed()`` is overridden,
more sensitive details could be leaked.

This issue is fixed with the caveat that ``AuthenticationForm`` can no longer
raise the "This account is inactive." error if the authentication backend
rejects inactive users (the default authentication backend, ``ModelBackend``,
has done that since Django 1.10). This issue will be revisited for Django 2.1
as a fix to address the caveat will likely be too invasive for inclusion in
older versions.

Bugfixes
========

* Fixed hidden content at the bottom of the "The install worked successfully!"
page for some languages (:ticket:`28885`).

* Fixed incorrect foreign key nullification if a model has two foreign keys to
the same model and a target model is deleted (:ticket:`29016`).

* Fixed regression in the use of ``QuerySet.values_list(..., flat=True)``
followed by ``annotate()`` (:ticket:`29067`).

* Fixed a regression where a queryset that annotates with geometry objects
crashes (:ticket:`29054`).

* Fixed a regression where ``contrib.auth.authenticate()`` crashes if an
authentication backend doesn't accept ``request`` and a later one does
(:ticket:`29071`).

* Fixed a regression where ``makemigrations`` crashes if a migrations directory
doesn't have an ``__init__.py`` file (:ticket:`29091`).

* Fixed crash when entering an invalid uuid in ``ModelAdmin.raw_id_fields``
(:ticket:`29094`).


==========================

2.0.1

==========================

*January 1, 2018*

Django 2.0.1 fixes several bugs in 2.0.

Bugfixes
========

* Fixed a regression in Django 1.11 that added newlines between ``MultiWidget``'s
subwidgets (:ticket:`28890`).

* Fixed incorrect class-based model index name generation for models with
quoted ``db_table`` (:ticket:`28876`).

* Fixed incorrect foreign key constraint name for models with quoted
``db_table`` (:ticket:`28876`).

* Fixed a regression in caching of a ``GenericForeignKey`` when the referenced
model instance uses more than one level of multi-table inheritance
(:ticket:`28856`).

* Reallowed filtering a queryset with ``GeometryField=None`` (:ticket:`28896`).

* Corrected admin check to allow a ``OneToOneField`` in
``ModelAdmin.autocomplete_fields`` (:ticket:`28898`).

* Fixed a regression on SQLite where ``DecimalField`` returned a result with
trailing zeros in the fractional part truncated (:ticket:`28915`).

* Fixed crash in the ``testserver`` command startup (:ticket:`28941`).

* Fixed crash when coercing a translatable URL pattern to ``str``
(:ticket:`28947`).

* Fixed crash on SQLite when renaming a field in a model referenced by a
``ManyToManyField`` (:ticket:`28884`).

* Fixed a crash when chaining ``values()`` or ``values_list()`` after
``QuerySet.select_for_update(of=(...))`` (:ticket:`28944`).

* Fixed admin changelist crash when using a query expression in the page's
ordering (:ticket:`28958`).


========================

2.0

========================

*December 2, 2017*

Welcome to Django 2.0!

These release notes cover the :ref:`new features <whats-new-2.0>`, as well as
some :ref:`backwards incompatible changes <backwards-incompatible-2.0>` you'll
want to be aware of when upgrading from Django 1.11 or earlier. We've
:ref:`dropped some features<removed-features-2.0>` that have reached the end of
their deprecation cycle, and we've :ref:`begun the deprecation process for some
features <deprecated-features-2.0>`.

This release starts Django's use of a :ref:`loose form of semantic versioning
<internal-release-cadence>`, but there aren't any major backwards incompatible
changes that might be expected of a 2.0 release. Upgrading should be a similar
amount of effort as past feature releases.

See the :doc:`/howto/upgrade-version` guide if you're updating an existing
project.

Python compatibility
====================

Django 2.0 supports Python 3.4, 3.5, 3.6, and 3.7. We **highly recommend** and
only officially support the latest release of each series.

The Django 1.11.x series is the last to support Python 2.7.

Django 2.0 will be the last release series to support Python 3.4. If you plan
a deployment of Python 3.4 beyond the end-of-life for Django 2.0 (April 2019),
stick with Django 1.11 LTS (supported until April 2020) instead. Note, however,
that the end-of-life for Python 3.4 is March 2019.

Third-party library support for older version of Django
=======================================================

Following the release of Django 2.0, we suggest that third-party app authors
drop support for all versions of Django prior to 1.11. At that time, you should
be able to run your package's tests using ``python -Wd`` so that deprecation
warnings do appear. After making the deprecation warning fixes, your app should
be compatible with Django 2.0.

.. _whats-new-2.0:

What's new in Django 2.0
========================

Simplified URL routing syntax
-----------------------------

The new :func:`django.urls.path()` function allows a simpler, more readable URL
routing syntax. For example, this example from previous Django releases::

 url(r'^articles/(?P<year>[0-9]{4})/$', views.year_archive),

could be written as::

 path('articles/<int:year>/', views.year_archive),

The new syntax supports type coercion of URL parameters. In the example, the
view will receive the ``year`` keyword argument as an integer rather than as
a string. Also, the URLs that will match are slightly less constrained in the
rewritten example. For example, the year 10000 will now match since the year
integers aren't constrained to be exactly four digits long as they are in the
regular expression.

The ``django.conf.urls.url()`` function from pr

[coveralls]

Coverage remained the same at 89.655% when pulling ad90983 on pyup-pin-django-2.2.1 into cd70b60 on master.

[coveralls]

Coverage remained the same at 89.655% when pulling ad90983 on pyup-pin-django-2.2.1 into cd70b60 on master.

[coveralls]

Coverage remained the same at 89.655% when pulling ad90983 on pyup-pin-django-2.2.1 into cd70b60 on master.