It contained models, forms and admin objects causing undesirable
import side effects. Refs #16368.

Thanks to Ramiro, Carl and Loïc for the review.

Refs #21169

The `remove()` and `clear()` methods of the related managers created by
`ForeignKey`, `GenericForeignKey`, and `ManyToManyField` suffered from a
number of issues. Some operations ran multiple data modifying queries without
wrapping them in a transaction, and some operations didn't respect default
filtering when it was present (i.e. when the default manager on the related
model implemented a custom `get_queryset()`).

Fixing the issues introduced some backward incompatible changes:

- The implementation of `remove()` for `ForeignKey` related managers changed
  from a series of `Model.save()` calls to a single `QuerySet.update()` call.
  The change means that `pre_save` and `post_save` signals aren't called anymore.

- The `remove()` and `clear()` methods for `GenericForeignKey` related
  managers now perform bulk delete so `Model.delete()` isn't called anymore.

- The `remove()` and `clear()` methods for `ManyToManyField` related
  managers perform nested queries when filtering is involved, which may
  or may not be an issue depending on the database and the data itself.

Refs. #3871, #21174.

Thanks Anssi Kääriäinen and Tim Graham for the reviews.

Signed-off-by: Jason Myers <jason@jasonamyers.com>

Thanks to Collin Anderson for the suggestion and Tim Graham for
reviewing the patch.

Additionally this patch solves the orthogonal problem that specialized
`QuerySet` like `ValuesQuerySet` didn't inherit from the current `QuerySet`
type. This wasn't an issue until now because we didn't officially support
custom `QuerySet` but it became necessary with the introduction of this new
feature.

Thanks aaugustin, akaariai, carljm, charettes, mjtamlyn, shaib and timgraham
for the reviews.

* Renamed the __unicode__ methods
* Applied the python_2_unicode_compatible decorator
* Removed the StrAndUnicode mix-in that is superseded by
  python_2_unicode_compatible
* Kept the __unicode__ methods in classes that specifically
  test it under Python 2

Thanks Vinay Sajip for the support of his django3 branch and
Jannis Leidel for the review.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13774 bcc190cf-cafb-0310-a4f2-bffc1f526a37

Fixed #2101 -- Renamed `maxlength` argument to `max_length` for oldforms `FormField`s and db model `Field`s.  This is fully backwards compatible at the moment since the legacy `maxlength` argument is still supported.  Using `maxlength` will, however, issue a `PendingDeprecationWarning` when used.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@5803 bcc190cf-cafb-0310-a4f2-bffc1f526a37

backwards compatible for all practical purposes.

Fixed #2391, #2489, #2996, #3322, #3344, #3370, #3406, #3432, #3454, #3492, #3582, #3690, #3878, #3891, #3937, #4039, #4141, #4227, #4286, #4291, #4300, #4452, #4702


git-svn-id: http://code.djangoproject.com/svn/django/trunk@5609 bcc190cf-cafb-0310-a4f2-bffc1f526a37

Refs #2333 - Modified runtests script to use new testing framework. Migrated existing tests to use Django testing framework. All the 'othertests' have been migrated into 'regressiontests', and converted into doctests/unittests, as appropriate. 


git-svn-id: http://code.djangoproject.com/svn/django/trunk@3661 bcc190cf-cafb-0310-a4f2-bffc1f526a37

Changed all model unit tests to use __str__() instead of __repr__(). Also slightly changed related-object DoesNotExist exception message to use repr instead of str

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3075 bcc190cf-cafb-0310-a4f2-bffc1f526a37

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3028 bcc190cf-cafb-0310-a4f2-bffc1f526a37

MERGED MAGIC-REMOVAL BRANCH TO TRUNK. This change is highly backwards-incompatible. Please read http://code.djangoproject.com/wiki/RemovingTheMagic for upgrade instructions.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@2809 bcc190cf-cafb-0310-a4f2-bffc1f526a37