# Django 2.2.9.dev20191202104323 文档

# Django 1.9.1 release notes

January 2, 2016

Django 1.9.1 fixes several bugs in 1.9.

## Bugfixes

- Fixed `BaseCache.get_or_set()` with the `DummyCache` backend (#25840).
- Fixed a regression in `FormMixin` causing forms to be validated twice (#25548, #26018).
- Fixed a system check crash with nested `ArrayField`s (#25867).
- Fixed a state bug when migrating a `SeparateDatabaseAndState` operation backwards (#25896).
- Fixed a regression in `CommonMiddleware` causing `If-None-Match` checks to always return HTTP 200 (#25900).
- Fixed missing `varchar/text_pattern_ops` index on `CharField` and `TextField` respectively when using `AlterField` on PostgreSQL (#25412).
- Fixed admin's delete confirmation page's summary counts of related objects (#25883).
- Added `from __future__ import unicode_literals` to the default `apps.py` created by `startapp` on Python 2 (#25909). Add this line to your own `apps.py` files created using Django 1.9 if you want your migrations to work on both Python 2 and Python 3.
- Prevented `QuerySet.delete()` from crashing on MySQL when querying across relations (#25882).
- Fixed evaluation of zero-length slices of `QuerySet.values()` (#25894).
- Fixed a state bug when using an `AlterModelManagers` operation (#25852).
- Fixed `TypedChoiceField` change detection with nullable fields (#25942).
- Fixed incorrect timezone warnings in custom admin templates that don't have a `data-admin-utc-offset` attribute in the `body` tag. (#25845).
- Fixed a regression which prevented using a language not in Django's default language list (`LANGUAGES`) (#25915).
- Avoided hiding some exceptions, like an invalid `INSTALLED_APPS` setting, behind `AppRegistryNotReady` when starting `runserver` (#25510). This regression appeared in 1.8.5 as a side effect of fixing #24704 and by mistake the fix wasn't applied to the `stable/1.9.x` branch.
- Fixed `migrate --fake-initial` detection of many-to-many tables (#25922).
- Restored the functionality of the admin's `list_editable` add and change buttons (#25903).
- Fixed `isnull` query lookup for `ForeignObject` (#25972).
- Fixed a regression in the admin which ignored line breaks in read-only fields instead of converting them to `<br>` (#25465).
- Fixed incorrect object reference in `SingleObjectMixin.get_context_object_name()` (#26006).
- Made `loaddata` skip disabling and enabling database constraints when it doesn't load any fixtures (#23372).
- Restored `contrib.auth` hashers compatibility with py-bcrypt (#26016).
- Fixed a crash in `QuerySet.values()/values_list()` after an `annotate()` and `order_by()` when `values()/values_list()` includes a field not in the `order_by()` (#25316).