This fixes a broad class of bugs involving filters that look for missing
related models and fields. Most of them don't seem to have been reported
(the added tests cover the root cause). The exception is that this has
also fixed#9868.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@9979 bcc190cf-cafb-0310-a4f2-bffc1f526a37
* Model init no longer performs a database query to refetch the related objects it is passed.
* Model init now caches unsaved related objects correctly, too. (Previously, accessing the field would raise `DoesNotExist` error for `null=False` fields.)
* Added tests for assigning `None` to `null=True` `ForeignKey` fields (refs #6886).
git-svn-id: http://code.djangoproject.com/svn/django/trunk@8185 bcc190cf-cafb-0310-a4f2-bffc1f526a37
* Raise a ValueError if you try to assign the wrong type of object.
* Raise a ValueError if you try to assign None to a field not specified with null=True.
* Cache the set value at set time instead of just at lookup time.
This is a slightly backwards-incompatible change; see BackwardsIncompatibleChanges for more details.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@7574 bcc190cf-cafb-0310-a4f2-bffc1f526a37
