Added model Meta option for swappable models, and made auth.User a swappable model

django/conf/global_settings.py

@@ -488,6 +488,8 @@ PROFANITIES_LIST = ()
 # AUTHENTICATION #
 ##################
 
+AUTH_USER_MODEL = 'auth.User'
+
 AUTHENTICATION_BACKENDS = ('django.contrib.auth.backends.ModelBackend',)
 
 LOGIN_URL = '/accounts/login/'

django/contrib/admin/models.py

@@ -1,6 +1,6 @@
 from django.db import models
+from django.conf import settings
 from django.contrib.contenttypes.models import ContentType
-from django.contrib.auth.models import User
 from django.contrib.admin.util import quote
 from django.utils.translation import ugettext_lazy as _
 from django.utils.encoding import smart_unicode
@@ -10,14 +10,16 @@ ADDITION = 1
 CHANGE = 2
 DELETION = 3
 
+
 class LogEntryManager(models.Manager):
     def log_action(self, user_id, content_type_id, object_id, object_repr, action_flag, change_message=''):
         e = self.model(None, None, user_id, content_type_id, smart_unicode(object_id), object_repr[:200], action_flag, change_message)
         e.save()
 
+
 class LogEntry(models.Model):
     action_time = models.DateTimeField(_('action time'), auto_now=True)
-    user = models.ForeignKey(User)
+    user = models.ForeignKey(settings.AUTH_USER_MODEL)
     content_type = models.ForeignKey(ContentType, blank=True, null=True)
     object_id = models.TextField(_('object id'), blank=True, null=True)
     object_repr = models.CharField(_('object repr'), max_length=200)

django/contrib/auth/models.py

@@ -93,6 +93,7 @@ class GroupManager(models.Manager):
     def get_by_natural_key(self, name):
         return self.get(name=name)
 
+
 class Group(models.Model):
     """
     Groups are a generic way of categorizing users to apply permissions, or
@@ -197,8 +198,6 @@ def _user_get_all_permissions(user, obj):
 
 
 def _user_has_perm(user, perm, obj):
-    anon = user.is_anonymous()
-    active = user.is_active
     for backend in auth.get_backends():
         if hasattr(backend, "has_perm"):
             if obj is not None:
@@ -211,8 +210,6 @@ def _user_has_perm(user, perm, obj):
 
 
 def _user_has_module_perms(user, app_label):
-    anon = user.is_anonymous()
-    active = user.is_active
     for backend in auth.get_backends():
         if hasattr(backend, "has_module_perms"):
             if backend.has_module_perms(user, app_label):
@@ -220,7 +217,54 @@ def _user_has_module_perms(user, app_label):
     return False
 
 
-class User(models.Model):
+class AbstractBaseUser(models.Model):
+    password = models.CharField(_('password'), max_length=128)
+
+    class Meta:
+        abstract = True
+
+    def is_anonymous(self):
+        """
+        Always returns False. This is a way of comparing User objects to
+        anonymous users.
+        """
+        return False
+
+    def is_authenticated(self):
+        """
+        Always return True. This is a way to tell if the user has been
+        authenticated in templates.
+        """
+        return True
+
+    def set_password(self, raw_password):
+        self.password = make_password(raw_password)
+
+    def check_password(self, raw_password):
+        """
+        Returns a boolean of whether the raw_password was correct. Handles
+        hashing formats behind the scenes.
+        """
+        def setter(raw_password):
+            self.set_password(raw_password)
+            self.save()
+        return check_password(raw_password, self.password, setter)
+
+    def set_unusable_password(self):
+        # Sets a value that will never be a valid hash
+        self.password = make_password(None)
+
+    def has_usable_password(self):
+        return is_password_usable(self.password)
+
+    def get_full_name(self):
+        raise NotImplementedError()
+
+    def get_short_name(self):
+        raise NotImplementedError()
+
+
+class User(AbstractBaseUser):
     """
     Users within the Django authentication system are represented by this
     model.
@@ -233,7 +277,6 @@ class User(models.Model):
     first_name = models.CharField(_('first name'), max_length=30, blank=True)
     last_name = models.CharField(_('last name'), max_length=30, blank=True)
     email = models.EmailField(_('e-mail address'), blank=True)
-    password = models.CharField(_('password'), max_length=128)
     is_staff = models.BooleanField(_('staff status'), default=False,
         help_text=_('Designates whether the user can log into this admin '
                     'site.'))
@@ -257,6 +300,7 @@ class User(models.Model):
     class Meta:
         verbose_name = _('user')
         verbose_name_plural = _('users')
+        swappable = 'AUTH_USER_MODEL'
 
     def __unicode__(self):
         return self.username
@@ -267,20 +311,6 @@ class User(models.Model):
     def get_absolute_url(self):
         return "/users/%s/" % urllib.quote(smart_str(self.username))
 
-    def is_anonymous(self):
-        """
-        Always returns False. This is a way of comparing User objects to
-        anonymous users.
-        """
-        return False
-
-    def is_authenticated(self):
-        """
-        Always return True. This is a way to tell if the user has been
-        authenticated in templates.
-        """
-        return True
-
     def get_full_name(self):
         """
         Returns the first_name plus the last_name, with a space in between.
@@ -288,26 +318,6 @@ class User(models.Model):
         full_name = u'%s %s' % (self.first_name, self.last_name)
         return full_name.strip()
 
-    def set_password(self, raw_password):
-        self.password = make_password(raw_password)
-
-    def check_password(self, raw_password):
-        """
-        Returns a boolean of whether the raw_password was correct. Handles
-        hashing formats behind the scenes.
-        """
-        def setter(raw_password):
-            self.set_password(raw_password)
-            self.save()
-        return check_password(raw_password, self.password, setter)
-
-    def set_unusable_password(self):
-        # Sets a value that will never be a valid hash
-        self.password = make_password(None)
-
-    def has_usable_password(self):
-        return is_password_usable(self.password)
-
     def get_group_permissions(self, obj=None):
         """
         Returns a list of permission strings that this user has through his/her

django/contrib/comments/models.py

@@ -1,15 +1,15 @@
-from django.contrib.auth.models import User
+from django.conf import settings
 from django.contrib.comments.managers import CommentManager
 from django.contrib.contenttypes import generic
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.sites.models import Site
-from django.db import models
 from django.core import urlresolvers
+from django.db import models
 from django.utils.translation import ugettext_lazy as _
 from django.utils import timezone
-from django.conf import settings
 
-COMMENT_MAX_LENGTH = getattr(settings,'COMMENT_MAX_LENGTH',3000)
+COMMENT_MAX_LENGTH = getattr(settings, 'COMMENT_MAX_LENGTH', 3000)
+
 
 class BaseCommentAbstractModel(models.Model):
     """
@@ -39,6 +39,7 @@ class BaseCommentAbstractModel(models.Model):
             args=(self.content_type_id, self.object_pk)
         )
 
+
 class Comment(BaseCommentAbstractModel):
     """
     A user comment about some object.
@@ -47,7 +48,7 @@ class Comment(BaseCommentAbstractModel):
     # Who posted this comment? If ``user`` is set then it was an authenticated
     # user; otherwise at least user_name should have been set and the comment
     # was posted by a non-authenticated user.
-    user        = models.ForeignKey(User, verbose_name=_('user'),
+    user        = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name=_('user'),
                     blank=True, null=True, related_name="%(class)s_comments")
     user_name   = models.CharField(_("user's name"), max_length=50, blank=True)
     user_email  = models.EmailField(_("user's email address"), blank=True)
@@ -115,6 +116,7 @@ class Comment(BaseCommentAbstractModel):
 
     def _get_name(self):
         return self.userinfo["name"]
+
     def _set_name(self, val):
         if self.user_id:
             raise AttributeError(_("This comment was posted by an authenticated "\
@@ -124,6 +126,7 @@ class Comment(BaseCommentAbstractModel):
 
     def _get_email(self):
         return self.userinfo["email"]
+
     def _set_email(self, val):
         if self.user_id:
             raise AttributeError(_("This comment was posted by an authenticated "\
@@ -133,6 +136,7 @@ class Comment(BaseCommentAbstractModel):
 
     def _get_url(self):
         return self.userinfo["url"]
+
     def _set_url(self, val):
         self.user_url = val
     url = property(_get_url, _set_url, doc="The URL given by the user who posted this comment")
@@ -153,6 +157,7 @@ class Comment(BaseCommentAbstractModel):
         }
         return _('Posted by %(user)s at %(date)s\n\n%(comment)s\n\nhttp://%(domain)s%(url)s') % d
 
+
 class CommentFlag(models.Model):
     """
     Records a flag on a comment. This is intentionally flexible; right now, a
@@ -166,7 +171,7 @@ class CommentFlag(models.Model):
     design users are only allowed to flag a comment with a given flag once;
     if you want rating look elsewhere.
     """
-    user      = models.ForeignKey(User, verbose_name=_('user'), related_name="comment_flags")
+    user      = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name=_('user'), related_name="comment_flags")
     comment   = models.ForeignKey(Comment, verbose_name=_('comment'), related_name="flags")
     flag      = models.CharField(_('flag'), max_length=30, db_index=True)
     flag_date = models.DateTimeField(_('date'), default=None)

django/core/management/commands/sqlall.py

@@ -4,6 +4,7 @@ from django.core.management.base import AppCommand
 from django.core.management.sql import sql_all
 from django.db import connections, DEFAULT_DB_ALIAS
 
+
 class Command(AppCommand):
     help = "Prints the CREATE TABLE, custom SQL and CREATE INDEX SQL statements for the given model module name(s)."
 

django/core/management/commands/syncdb.py

@@ -68,6 +68,7 @@ class Command(NoArgsCommand):
                 if router.allow_syncdb(db, m)])
             for app in models.get_apps()
         ]
+
         def model_installed(model):
             opts = model._meta
             converter = connection.introspection.table_name_converter
@@ -101,7 +102,6 @@ class Command(NoArgsCommand):
                     cursor.execute(statement)
                 tables.append(connection.introspection.table_name_converter(model._meta.db_table))
 
-
         transaction.commit_unless_managed(using=db)
 
         # Send the post_syncdb signal, so individual apps can do whatever they need

django/core/management/commands/validate.py

@@ -1,5 +1,6 @@
 from django.core.management.base import NoArgsCommand
 
+
 class Command(NoArgsCommand):
     help = "Validates all installed models."
 

django/core/management/sql.py

@@ -6,6 +6,7 @@ from django.core.management.base import CommandError
 from django.db import models
 from django.db.models import get_models
 
+
 def sql_create(app, style, connection):
     "Returns a list of the CREATE TABLE SQL statements for the given app."
 
@@ -52,6 +53,7 @@ def sql_create(app, style, connection):
 
     return final_output
 
+
 def sql_delete(app, style, connection):
     "Returns a list of the DROP TABLE SQL statements for the given app."
 
@@ -80,7 +82,7 @@ def sql_delete(app, style, connection):
             opts = model._meta
             for f in opts.local_fields:
                 if f.rel and f.rel.to not in to_delete:
-                    references_to_delete.setdefault(f.rel.to, []).append( (model, f) )
+                    references_to_delete.setdefault(f.rel.to, []).append((model, f))
 
             to_delete.add(model)
 
@@ -96,6 +98,7 @@ def sql_delete(app, style, connection):
 
     return output[::-1]  # Reverse it, to deal with table dependencies.
 
+
 def sql_flush(style, connection, only_django=False):
     """
     Returns a list of the SQL statements used to flush the database.
@@ -112,6 +115,7 @@ def sql_flush(style, connection, only_django=False):
     )
     return statements
 
+
 def sql_custom(app, style, connection):
     "Returns a list of the custom table modifying SQL statements for the given app."
     output = []
@@ -123,6 +127,7 @@ def sql_custom(app, style, connection):
 
     return output
 
+
 def sql_indexes(app, style, connection):
     "Returns a list of the CREATE INDEX SQL statements for all models in the given app."
     output = []
@@ -130,10 +135,12 @@ def sql_indexes(app, style, connection):
         output.extend(connection.creation.sql_indexes_for_model(model, style))
     return output
 
+
 def sql_all(app, style, connection):
     "Returns a list of CREATE TABLE SQL, initial-data inserts, and CREATE INDEX SQL for the given module."
     return sql_create(app, style, connection) + sql_custom(app, style, connection) + sql_indexes(app, style, connection)
 
+
 def custom_sql_for_model(model, style, connection):
     opts = model._meta
     app_dir = os.path.normpath(os.path.join(os.path.dirname(models.get_app(model._meta.app_label).__file__), 'sql'))

django/core/management/validation.py

@@ -3,6 +3,7 @@ import sys
 from django.core.management.color import color_style
 from django.utils.itercompat import is_iterable
 
+
 class ModelErrorCollection:
     def __init__(self, outfile=sys.stdout):
         self.errors = []
@@ -13,6 +14,7 @@ class ModelErrorCollection:
         self.errors.append((context, error))
         self.outfile.write(self.style.ERROR("%s: %s\n" % (context, error)))
 
+
 def get_validation_errors(outfile, app=None):
     """
     Validates all models that are part of the specified app. If no app name is provided,
@@ -54,7 +56,7 @@ def get_validation_errors(outfile, app=None):
                     e.add(opts, '"%s": CharFields require a "max_length" attribute that is a positive integer.' % f.name)
             if isinstance(f, models.DecimalField):
                 decimalp_ok, mdigits_ok = False, False
-                decimalp_msg ='"%s": DecimalFields require a "decimal_places" attribute that is a non-negative integer.'
+                decimalp_msg = '"%s": DecimalFields require a "decimal_places" attribute that is a non-negative integer.'
                 try:
                     decimal_places = int(f.decimal_places)
                     if decimal_places < 0:
@@ -121,6 +123,10 @@ def get_validation_errors(outfile, app=None):
                 if isinstance(f.rel.to, (str, unicode)):
                     continue
 
+                # Make sure the model we're related hasn't been swapped out
+                if f.rel.to._meta.swapped:
+                    e.add(opts, "'%s' defines a relation with the model '%s.%s', which has been swapped out. Update the relation to point at settings.%s." % (f.name, f.rel.to._meta.app_label, f.rel.to._meta.object_name, f.rel.to._meta.swappable))
+
                 # Make sure the related field specified by a ForeignKey is unique
                 if not f.rel.to._meta.get_field(f.rel.field_name).unique:
                     e.add(opts, "Field '%s' under model '%s' must have a unique=True constraint." % (f.rel.field_name, f.rel.to.__name__))
@@ -163,6 +169,10 @@ def get_validation_errors(outfile, app=None):
                 if isinstance(f.rel.to, (str, unicode)):
                     continue
 
+            # Make sure the model we're related hasn't been swapped out
+            if f.rel.to._meta.swapped:
+                e.add(opts, "'%s' defines a relation with the model '%s.%s', which has been swapped out. Update the relation to point at settings.%s." % (f.name, f.rel.to._meta.app_label, f.rel.to._meta.object_name, f.rel.to._meta.swappable))
+
             # Check that the field is not set to unique.  ManyToManyFields do not support unique.
             if f.unique:
                 e.add(opts, "ManyToManyFields cannot be unique.  Remove the unique argument on '%s'." % f.name)
@@ -276,7 +286,8 @@ def get_validation_errors(outfile, app=None):
         # Check ordering attribute.
         if opts.ordering:
             for field_name in opts.ordering:
-                if field_name == '?': continue
+                if field_name == '?':
+                    continue
                 if field_name.startswith('-'):
                     field_name = field_name[1:]
                 if opts.order_with_respect_to and field_name == '_order':

django/db/backends/creation.py

@@ -34,7 +34,7 @@ class BaseDatabaseCreation(object):
             (list_of_sql, pending_references_dict)
         """
         opts = model._meta
-        if not opts.managed or opts.proxy:
+        if not opts.managed or opts.proxy or opts.swapped:
             return [], {}
         final_output = []
         table_output = []
@@ -88,7 +88,7 @@ class BaseDatabaseCreation(object):
                           style.SQL_TABLE(qn(opts.db_table)) + ' (']
         for i, line in enumerate(table_output):  # Combine and add commas.
             full_statement.append(
-                '    %s%s' % (line, i < len(table_output)-1 and ',' or ''))
+                '    %s%s' % (line, i < len(table_output) - 1 and ',' or ''))
         full_statement.append(')')
         if opts.db_tablespace:
             tablespace_sql = self.connection.ops.tablespace_sql(
@@ -137,11 +137,11 @@ class BaseDatabaseCreation(object):
         """
         from django.db.backends.util import truncate_name
 
-        if not model._meta.managed or model._meta.proxy:
+        opts = model._meta
+        if not opts.managed or opts.proxy or opts.swapped:
             return []
         qn = self.connection.ops.quote_name
         final_output = []
-        opts = model._meta
         if model in pending_references:
             for rel_class, f in pending_references[model]:
                 rel_opts = rel_class._meta
@@ -166,7 +166,7 @@ class BaseDatabaseCreation(object):
         """
         Returns the CREATE INDEX SQL statements for a single model.
         """
-        if not model._meta.managed or model._meta.proxy:
+        if not model._meta.managed or model._meta.proxy or model._meta.swapped:
             return []
         output = []
         for f in model._meta.local_fields:
@@ -205,7 +205,7 @@ class BaseDatabaseCreation(object):
         Return the DROP TABLE and restraint dropping statements for a single
         model.
         """
-        if not model._meta.managed or model._meta.proxy:
+        if not model._meta.managed or model._meta.proxy or model._meta.swapped:
             return []
         # Drop the table now
         qn = self.connection.ops.quote_name
@@ -222,7 +222,7 @@ class BaseDatabaseCreation(object):
 
     def sql_remove_table_constraints(self, model, references_to_delete, style):
         from django.db.backends.util import truncate_name
-        if not model._meta.managed or model._meta.proxy:
+        if not model._meta.managed or model._meta.proxy or model._meta.swapped:
             return []
         output = []
         qn = self.connection.ops.quote_name

django/db/models/base.py

@@ -230,6 +230,7 @@ class ModelBase(type):
         if opts.order_with_respect_to:
             cls.get_next_in_order = curry(cls._get_next_or_previous_in_order, is_next=True)
             cls.get_previous_in_order = curry(cls._get_next_or_previous_in_order, is_next=False)
+
             # defer creating accessors on the foreign class until we are
             # certain it has been created
             def make_foreign_order_accessors(field, model, cls):
@@ -260,6 +261,7 @@ class ModelBase(type):
 
         signals.class_prepared.send(sender=cls)
 
+
 class ModelState(object):
     """
     A class for storing instance state
@@ -271,6 +273,7 @@ class ModelState(object):
         # This impacts validation only; it has no effect on the actual save.
         self.adding = True
 
+
 class Model(object):
     __metaclass__ = ModelBase
     _deferred = False
@@ -585,7 +588,6 @@ class Model(object):
             signals.post_save.send(sender=origin, instance=self, created=(not record_exists),
                                    update_fields=update_fields, raw=raw, using=using)
 
-
     save_base.alters_data = True
 
     def delete(self, using=None):
@@ -609,7 +611,7 @@ class Model(object):
         order = not is_next and '-' or ''
         param = smart_str(getattr(self, field.attname))
         q = Q(**{'%s__%s' % (field.name, op): param})
-        q = q|Q(**{field.name: param, 'pk__%s' % op: self.pk})
+        q = q | Q(**{field.name: param, 'pk__%s' % op: self.pk})
         qs = self.__class__._default_manager.using(self._state.db).filter(**kwargs).filter(q).order_by('%s%s' % (order, field.name), '%spk' % order)
         try:
             return qs[0]
@@ -915,6 +917,7 @@ def get_absolute_url(opts, func, self, *args, **kwargs):
 class Empty(object):
     pass
 
+
 def simple_class_factory(model, attrs):
     """Used to unpickle Models without deferred fields.
 
@@ -924,6 +927,7 @@ def simple_class_factory(model, attrs):
     """
     return model
 
+
 def model_unpickle(model, attrs, factory):
     """
     Used to unpickle Model subclasses with deferred fields.
@@ -932,5 +936,6 @@ def model_unpickle(model, attrs, factory):
     return cls.__new__(cls)
 model_unpickle.__safe_for_unpickle__ = True
 
+
 def subclass_exception(name, parents, module):
     return type(name, parents, {'__module__': module})

django/db/models/fields/related.py

@@ -20,6 +20,7 @@ RECURSIVE_RELATIONSHIP_CONSTANT = 'self'
 
 pending_lookups = {}
 
+
 def add_lazy_relation(cls, field, relation, operation):
     """
     Adds a lookup on ``cls`` when a related field is defined using a string,
@@ -76,6 +77,7 @@ def add_lazy_relation(cls, field, relation, operation):
         value = (cls, field, operation)
         pending_lookups.setdefault(key, []).append(value)
 
+
 def do_pending_lookups(sender, **kwargs):
     """
     Handle any pending relations to the sending model. Sent from class_prepared.
@@ -86,6 +88,7 @@ def do_pending_lookups(sender, **kwargs):
 
 signals.class_prepared.connect(do_pending_lookups)
 
+
 #HACK
 class RelatedField(object):
     def contribute_to_class(self, cls, name):
@@ -219,6 +222,7 @@ class RelatedField(object):
         # "related_name" option.
         return self.rel.related_name or self.opts.object_name.lower()
 
+
 class SingleRelatedObjectDescriptor(object):
     # This class provides the functionality that makes the related-object
     # managers available as attributes on a model class, for fields that have
@@ -305,6 +309,7 @@ class SingleRelatedObjectDescriptor(object):
         setattr(instance, self.cache_name, value)
         setattr(value, self.related.field.get_cache_name(), instance)
 
+
 class ReverseSingleRelatedObjectDescriptor(object):
     # This class provides the functionality that makes the related-object
     # managers available as attributes on a model class, for fields that have
@@ -429,6 +434,7 @@ class ReverseSingleRelatedObjectDescriptor(object):
         if value is not None and not self.field.rel.multiple:
             setattr(value, self.field.related.get_cache_name(), instance)
 
+
 class ForeignRelatedObjectsDescriptor(object):
     # This class provides the functionality that makes the related-object
     # managers available as attributes on a model class, for fields that have
@@ -751,6 +757,7 @@ def create_many_related_manager(superclass, rel):
 
     return ManyRelatedManager
 
+
 class ManyRelatedObjectsDescriptor(object):
     # This class provides the functionality that makes the related-object
     # managers available as attributes on a model class, for fields that have
@@ -859,6 +866,7 @@ class ReverseManyRelatedObjectsDescriptor(object):
         manager.clear()
         manager.add(*value)
 
+
 class ManyToOneRel(object):
     def __init__(self, to, field_name, related_name=None, limit_choices_to=None,
         parent_link=False, on_delete=None):
@@ -890,6 +898,7 @@ class ManyToOneRel(object):
                     self.field_name)
         return data[0]
 
+
 class OneToOneRel(ManyToOneRel):
     def __init__(self, to, field_name, related_name=None, limit_choices_to=None,
         parent_link=False, on_delete=None):
@@ -899,6 +908,7 @@ class OneToOneRel(ManyToOneRel):
         )
         self.multiple = False
 
+
 class ManyToManyRel(object):
     def __init__(self, to, related_name=None, limit_choices_to=None,
             symmetrical=True, through=None):
@@ -923,15 +933,17 @@ class ManyToManyRel(object):
         """
         return self.to._meta.pk
 
+
 class ForeignKey(RelatedField, Field):
     empty_strings_allowed = False
     default_error_messages = {
         'invalid': _('Model %(model)s with pk %(pk)r does not exist.')
     }
     description = _("Foreign Key (type determined by related field)")
+
     def __init__(self, to, to_field=None, rel_class=ManyToOneRel, **kwargs):
         try:
-            to_name = to._meta.object_name.lower()
+            to._meta.object_name.lower()
         except AttributeError:  # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
             assert isinstance(to, basestring), "%s(%r) is invalid. First parameter to ForeignKey must be either a model, a model name, or the string %r" % (self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT)
         else:
@@ -1049,6 +1061,7 @@ class ForeignKey(RelatedField, Field):
             return IntegerField().db_type(connection=connection)
         return rel_field.db_type(connection=connection)
 
+
 class OneToOneField(ForeignKey):
     """
     A OneToOneField is essentially the same as a ForeignKey, with the exception
@@ -1057,6 +1070,7 @@ class OneToOneField(ForeignKey):
     rather than returning a list.
     """
     description = _("One-to-one relationship")
+
     def __init__(self, to, to_field=None, **kwargs):
         kwargs['unique'] = True
         super(OneToOneField, self).__init__(to, to_field, OneToOneRel, **kwargs)
@@ -1076,12 +1090,14 @@ class OneToOneField(ForeignKey):
         else:
             setattr(instance, self.attname, data)
 
+
 def create_many_to_many_intermediary_model(field, klass):
     from django.db import models
     managed = True
     if isinstance(field.rel.to, basestring) and field.rel.to != RECURSIVE_RELATIONSHIP_CONSTANT:
         to_model = field.rel.to
         to = to_model.split('.')[-1]
+
         def set_managed(field, model, cls):
             field.rel.through._meta.managed = model._meta.managed or cls._meta.managed
         add_lazy_relation(klass, field, to_model, set_managed)
@@ -1118,8 +1134,10 @@ def create_many_to_many_intermediary_model(field, klass):
         to: models.ForeignKey(to_model, related_name='%s+' % name, db_tablespace=field.db_tablespace)
     })
 
+
 class ManyToManyField(RelatedField, Field):
     description = _("Many-to-many relationship")
+
     def __init__(self, to, **kwargs):
         try:
             assert not to._meta.abstract, "%s cannot define a relation with abstract class %s" % (self.__class__.__name__, to._meta.object_name)
@@ -1134,7 +1152,7 @@ class ManyToManyField(RelatedField, Field):
         kwargs['rel'] = ManyToManyRel(to,
             related_name=kwargs.pop('related_name', None),
             limit_choices_to=kwargs.pop('limit_choices_to', None),
-            symmetrical=kwargs.pop('symmetrical', to==RECURSIVE_RELATIONSHIP_CONSTANT),
+            symmetrical=kwargs.pop('symmetrical', to == RECURSIVE_RELATIONSHIP_CONSTANT),
             through=kwargs.pop('through', None))
 
         self.db_table = kwargs.pop('db_table', None)
@@ -1165,7 +1183,7 @@ class ManyToManyField(RelatedField, Field):
         if hasattr(self, cache_attr):
             return getattr(self, cache_attr)
         for f in self.rel.through._meta.fields:
-            if hasattr(f,'rel') and f.rel and f.rel.to == related.model:
+            if hasattr(f, 'rel') and f.rel and f.rel.to == related.model:
                 setattr(self, cache_attr, getattr(f, attr))
                 return getattr(self, cache_attr)
 
@@ -1176,7 +1194,7 @@ class ManyToManyField(RelatedField, Field):
             return getattr(self, cache_attr)
         found = False
         for f in self.rel.through._meta.fields:
-            if hasattr(f,'rel') and f.rel and f.rel.to == related.parent_model:
+            if hasattr(f, 'rel') and f.rel and f.rel.to == related.parent_model:
                 if related.model == related.parent_model:
                     # If this is an m2m-intermediate to self,
                     # the first foreign key you find will be
@@ -1221,7 +1239,8 @@ class ManyToManyField(RelatedField, Field):
         # The intermediate m2m model is not auto created if:
         #  1) There is a manually specified intermediate, or
         #  2) The class owning the m2m field is abstract.
-        if not self.rel.through and not cls._meta.abstract:
+        #  3) The class owning the m2m field has been swapped out.
+        if not self.rel.through and not cls._meta.abstract and not cls._meta.swapped:
             self.rel.through = create_many_to_many_intermediary_model(self, cls)
 
         # Add the descriptor for the m2m relation

django/db/models/loading.py

@@ -13,6 +13,7 @@ import threading
 __all__ = ('get_apps', 'get_app', 'get_models', 'get_model', 'register_models',
         'load_app', 'app_cache_ready')
 
+
 class AppCache(object):
     """
     A cache that stores installed applications and their models. Used to

django/db/models/options.py

@@ -17,7 +17,8 @@ get_verbose_name = lambda class_name: re.sub('(((?<=[a-z])[A-Z])|([A-Z](?![A-Z]|
 DEFAULT_NAMES = ('verbose_name', 'verbose_name_plural', 'db_table', 'ordering',
                  'unique_together', 'permissions', 'get_latest_by',
                  'order_with_respect_to', 'app_label', 'db_tablespace',
-                 'abstract', 'managed', 'proxy', 'auto_created')
+                 'abstract', 'managed', 'proxy', 'swappable', 'auto_created')
+
 
 class Options(object):
     def __init__(self, meta, app_label=None):
@@ -50,6 +51,7 @@ class Options(object):
         # in the end of the proxy_for_model chain. In particular, for
         # concrete models, the concrete_model is always the class itself.
         self.concrete_model = None
+        self.swappable = None
         self.parents = SortedDict()
         self.duplicate_targets = {}
         self.auto_created = False
@@ -213,6 +215,14 @@ class Options(object):
         return raw
     verbose_name_raw = property(verbose_name_raw)
 
+    def _swapped(self):
+        """
+        Has this model been swapped out for another?
+        """
+        model_label = '%s.%s' % (self.app_label, self.object_name)
+        return self.swappable and getattr(settings, self.swappable, None) not in (None, model_label)
+    swapped = property(_swapped)
+
     def _fields(self):
         """
         The getter for self.fields. This returns the list of field objects

django/test/utils.py

@@ -27,7 +27,7 @@ class Approximate(object):
     def __eq__(self, other):
         if self.val == other:
             return True
-        return round(abs(self.val-other), self.places) == 0
+        return round(abs(self.val - other), self.places) == 0
 
 
 class ContextList(list):
@@ -45,7 +45,7 @@ class ContextList(list):
 
     def __contains__(self, key):
         try:
-            value = self[key]
+            self[key]
         except KeyError:
             return False
         return True
@@ -187,9 +187,11 @@ class override_settings(object):
         if isinstance(test_func, type) and issubclass(test_func, TransactionTestCase):
             original_pre_setup = test_func._pre_setup
             original_post_teardown = test_func._post_teardown
+
             def _pre_setup(innerself):
                 self.enable()
                 original_pre_setup(innerself)
+
             def _post_teardown(innerself):
                 original_post_teardown(innerself)
                 self.disable()
@@ -218,4 +220,3 @@ class override_settings(object):
             new_value = getattr(settings, key, None)
             setting_changed.send(sender=settings._wrapped.__class__,
                                  setting=key, value=new_value)
-

docs/ref/settings.txt

@@ -120,6 +120,15 @@ Default: Not defined
 The site-specific user profile model used by this site. See
 :ref:`auth-profiles`.
 
+.. setting:: AUTH_USER_MODEL
+
+AUTH_USER_MODEL
+---------------
+
+Default: 'auth.User'
+
+The model to use to represent a User. See :ref:`auth-custom-user`.
+
 .. setting:: CACHES
 
 CACHES

docs/topics/auth.txt

@@ -1723,6 +1723,13 @@ Fields
         group.permissions.remove(permission, permission, ...)
         group.permissions.clear()
 
+.. _auth-custom-user:
+
+Customizing the User model
+==========================
+
+TODO
+
 .. _authentication-backends:
 
 Other authentication sources

tests/modeltests/invalid_models/invalid_models/models.py

@@ -19,11 +19,12 @@ class FieldErrors(models.Model):
     decimalfield5 = models.DecimalField(max_digits=10, decimal_places=10)
     filefield = models.FileField()
     choices = models.CharField(max_length=10, choices='bad')
-    choices2 = models.CharField(max_length=10, choices=[(1,2,3),(1,2,3)])
+    choices2 = models.CharField(max_length=10, choices=[(1, 2, 3), (1, 2, 3)])
     index = models.CharField(max_length=10, db_index='bad')
     field_ = models.CharField(max_length=10)
     nullbool = models.BooleanField(null=True)
 
+
 class Target(models.Model):
     tgt_safe = models.CharField(max_length=10)
     clash1 = models.CharField(max_length=10)
@@ -31,12 +32,14 @@ class Target(models.Model):
 
     clash1_set = models.CharField(max_length=10)
 
+
 class Clash1(models.Model):
     src_safe = models.CharField(max_length=10)
 
     foreign = models.ForeignKey(Target)
     m2m = models.ManyToManyField(Target)
 
+
 class Clash2(models.Model):
     src_safe = models.CharField(max_length=10)
 
@@ -46,6 +49,7 @@ class Clash2(models.Model):
     m2m_1 = models.ManyToManyField(Target, related_name='id')
     m2m_2 = models.ManyToManyField(Target, related_name='src_safe')
 
+
 class Target2(models.Model):
     clash3 = models.CharField(max_length=10)
     foreign_tgt = models.ForeignKey(Target)
@@ -54,6 +58,7 @@ class Target2(models.Model):
     m2m_tgt = models.ManyToManyField(Target)
     clashm2m_set = models.ManyToManyField(Target)
 
+
 class Clash3(models.Model):
     src_safe = models.CharField(max_length=10)
 
@@ -63,12 +68,15 @@ class Clash3(models.Model):
     m2m_1 = models.ManyToManyField(Target2, related_name='foreign_tgt')
     m2m_2 = models.ManyToManyField(Target2, related_name='m2m_tgt')
 
+
 class ClashForeign(models.Model):
     foreign = models.ForeignKey(Target2)
 
+
 class ClashM2M(models.Model):
     m2m = models.ManyToManyField(Target2)
 
+
 class SelfClashForeign(models.Model):
     src_safe = models.CharField(max_length=10)
     selfclashforeign = models.CharField(max_length=10)
@@ -77,6 +85,7 @@ class SelfClashForeign(models.Model):
     foreign_1 = models.ForeignKey("SelfClashForeign", related_name='id')
     foreign_2 = models.ForeignKey("SelfClashForeign", related_name='src_safe')
 
+
 class ValidM2M(models.Model):
     src_safe = models.CharField(max_length=10)
     validm2m = models.CharField(max_length=10)
@@ -92,6 +101,7 @@ class ValidM2M(models.Model):
     m2m_3 = models.ManyToManyField('self')
     m2m_4 = models.ManyToManyField('self')
 
+
 class SelfClashM2M(models.Model):
     src_safe = models.CharField(max_length=10)
     selfclashm2m = models.CharField(max_length=10)
@@ -106,120 +116,148 @@ class SelfClashM2M(models.Model):
     m2m_3 = models.ManyToManyField('self', symmetrical=False)
     m2m_4 = models.ManyToManyField('self', symmetrical=False)
 
+
 class Model(models.Model):
     "But it's valid to call a model Model."
-    year = models.PositiveIntegerField() #1960
+    year = models.PositiveIntegerField()  # 1960
-    make = models.CharField(max_length=10) #Aston Martin
+    make = models.CharField(max_length=10)  # Aston Martin
-    name = models.CharField(max_length=10) #DB 4 GT
+    name = models.CharField(max_length=10)  # DB 4 GT
+
 
 class Car(models.Model):
     colour = models.CharField(max_length=5)
     model = models.ForeignKey(Model)
 
+
 class MissingRelations(models.Model):
     rel1 = models.ForeignKey("Rel1")
     rel2 = models.ManyToManyField("Rel2")
 
+
 class MissingManualM2MModel(models.Model):
     name = models.CharField(max_length=5)
     missing_m2m = models.ManyToManyField(Model, through="MissingM2MModel")
 
+
 class Person(models.Model):
     name = models.CharField(max_length=5)
 
+
 class Group(models.Model):
     name = models.CharField(max_length=5)
     primary = models.ManyToManyField(Person, through="Membership", related_name="primary")
     secondary = models.ManyToManyField(Person, through="Membership", related_name="secondary")
     tertiary = models.ManyToManyField(Person, through="RelationshipDoubleFK", related_name="tertiary")
 
+
 class GroupTwo(models.Model):
     name = models.CharField(max_length=5)
     primary = models.ManyToManyField(Person, through="Membership")
     secondary = models.ManyToManyField(Group, through="MembershipMissingFK")
 
+
 class Membership(models.Model):
     person = models.ForeignKey(Person)
     group = models.ForeignKey(Group)
     not_default_or_null = models.CharField(max_length=5)
 
+
 class MembershipMissingFK(models.Model):
     person = models.ForeignKey(Person)
 
+
 class PersonSelfRefM2M(models.Model):
     name = models.CharField(max_length=5)
     friends = models.ManyToManyField('self', through="Relationship")
     too_many_friends = models.ManyToManyField('self', through="RelationshipTripleFK")
 
+
 class PersonSelfRefM2MExplicit(models.Model):
     name = models.CharField(max_length=5)
     friends = models.ManyToManyField('self', through="ExplicitRelationship", symmetrical=True)
 
+
 class Relationship(models.Model):
     first = models.ForeignKey(PersonSelfRefM2M, related_name="rel_from_set")
     second = models.ForeignKey(PersonSelfRefM2M, related_name="rel_to_set")
     date_added = models.DateTimeField()
 
+
 class ExplicitRelationship(models.Model):
     first = models.ForeignKey(PersonSelfRefM2MExplicit, related_name="rel_from_set")
     second = models.ForeignKey(PersonSelfRefM2MExplicit, related_name="rel_to_set")
     date_added = models.DateTimeField()
 
+
 class RelationshipTripleFK(models.Model):
     first = models.ForeignKey(PersonSelfRefM2M, related_name="rel_from_set_2")
     second = models.ForeignKey(PersonSelfRefM2M, related_name="rel_to_set_2")
     third = models.ForeignKey(PersonSelfRefM2M, related_name="too_many_by_far")
     date_added = models.DateTimeField()
 
+
 class RelationshipDoubleFK(models.Model):
     first = models.ForeignKey(Person, related_name="first_related_name")
     second = models.ForeignKey(Person, related_name="second_related_name")
     third = models.ForeignKey(Group, related_name="rel_to_set")
     date_added = models.DateTimeField()
 
+
 class AbstractModel(models.Model):
     name = models.CharField(max_length=10)
+
     class Meta:
         abstract = True
 
+
 class AbstractRelationModel(models.Model):
     fk1 = models.ForeignKey('AbstractModel')
     fk2 = models.ManyToManyField('AbstractModel')
 
+
 class UniqueM2M(models.Model):
     """ Model to test for unique ManyToManyFields, which are invalid. """
     unique_people = models.ManyToManyField(Person, unique=True)
 
+
 class NonUniqueFKTarget1(models.Model):
     """ Model to test for non-unique FK target in yet-to-be-defined model: expect an error """
     tgt = models.ForeignKey('FKTarget', to_field='bad')
 
+
 class UniqueFKTarget1(models.Model):
     """ Model to test for unique FK target in yet-to-be-defined model: expect no error """
     tgt = models.ForeignKey('FKTarget', to_field='good')
 
+
 class FKTarget(models.Model):
     bad = models.IntegerField()
     good = models.IntegerField(unique=True)
 
+
 class NonUniqueFKTarget2(models.Model):
     """ Model to test for non-unique FK target in previously seen model: expect an error """
     tgt = models.ForeignKey(FKTarget, to_field='bad')
 
+
 class UniqueFKTarget2(models.Model):
     """ Model to test for unique FK target in previously seen model: expect no error """
     tgt = models.ForeignKey(FKTarget, to_field='good')
 
+
 class NonExistingOrderingWithSingleUnderscore(models.Model):
     class Meta:
         ordering = ("does_not_exist",)
 
+
 class InvalidSetNull(models.Model):
     fk = models.ForeignKey('self', on_delete=models.SET_NULL)
 
+
 class InvalidSetDefault(models.Model):
     fk = models.ForeignKey('self', on_delete=models.SET_DEFAULT)
 
+
 class UnicodeForeignKeys(models.Model):
     """Foreign keys which can translate to ascii should be OK, but fail if
     they're not."""
@@ -230,9 +268,11 @@ class UnicodeForeignKeys(models.Model):
     # when adding the errors in core/management/validation.py
     #bad = models.ForeignKey(u'★')
 
+
 class PrimaryKeyNull(models.Model):
     my_pk_field = models.IntegerField(primary_key=True, null=True)
 
+
 class OrderByPKModel(models.Model):
     """
     Model to test that ordering by pk passes validation.
@@ -243,6 +283,42 @@ class OrderByPKModel(models.Model):
     class Meta:
         ordering = ('pk',)
 
+
+class SwappableModel(models.Model):
+    """A model that can be, but isn't swapped out.
+
+    References to this model *shoudln't* raise any validation error.
+    """
+    name = models.CharField(max_length=100)
+
+    class Meta:
+        swappable = 'TEST_SWAPPABLE_MODEL'
+
+
+class SwappedModel(models.Model):
+    """A model that is swapped out.
+
+    References to this model *should* raise a validation error.
+    Requires TEST_SWAPPED_MODEL to be defined in the test environment;
+    this is guaranteed by the test runner using @override_settings.
+    """
+    name = models.CharField(max_length=100)
+
+    class Meta:
+        swappable = 'TEST_SWAPPED_MODEL'
+
+
+class HardReferenceModel(models.Model):
+    fk_1 = models.ForeignKey(SwappableModel, related_name='fk_hardref1')
+    fk_2 = models.ForeignKey('invalid_models.SwappableModel', related_name='fk_hardref2')
+    fk_3 = models.ForeignKey(SwappedModel, related_name='fk_hardref3')
+    fk_4 = models.ForeignKey('invalid_models.SwappedModel', related_name='fk_hardref4')
+    m2m_1 = models.ManyToManyField(SwappableModel, related_name='m2m_hardref1')
+    m2m_2 = models.ManyToManyField('invalid_models.SwappableModel', related_name='m2m_hardref2')
+    m2m_3 = models.ManyToManyField(SwappedModel, related_name='m2m_hardref3')
+    m2m_4 = models.ManyToManyField('invalid_models.SwappedModel', related_name='m2m_hardref4')
+
+
 model_errors = """invalid_models.fielderrors: "charfield": CharFields require a "max_length" attribute that is a positive integer.
 invalid_models.fielderrors: "charfield2": CharFields require a "max_length" attribute that is a positive integer.
 invalid_models.fielderrors: "charfield3": CharFields require a "max_length" attribute that is a positive integer.
@@ -351,6 +427,10 @@ invalid_models.nonuniquefktarget2: Field 'bad' under model 'FKTarget' must have
 invalid_models.nonexistingorderingwithsingleunderscore: "ordering" refers to "does_not_exist", a field that doesn't exist.
 invalid_models.invalidsetnull: 'fk' specifies on_delete=SET_NULL, but cannot be null.
 invalid_models.invalidsetdefault: 'fk' specifies on_delete=SET_DEFAULT, but has no default value.
+invalid_models.hardreferencemodel: 'fk_3' defines a relation with the model 'invalid_models.SwappedModel', which has been swapped out. Update the relation to point at settings.TEST_SWAPPED_MODEL.
+invalid_models.hardreferencemodel: 'fk_4' defines a relation with the model 'invalid_models.SwappedModel', which has been swapped out. Update the relation to point at settings.TEST_SWAPPED_MODEL.
+invalid_models.hardreferencemodel: 'm2m_3' defines a relation with the model 'invalid_models.SwappedModel', which has been swapped out. Update the relation to point at settings.TEST_SWAPPED_MODEL.
+invalid_models.hardreferencemodel: 'm2m_4' defines a relation with the model 'invalid_models.SwappedModel', which has been swapped out. Update the relation to point at settings.TEST_SWAPPED_MODEL.
 """
 
 if not connection.features.interprets_empty_strings_as_nulls:

tests/modeltests/invalid_models/tests.py

@@ -6,6 +6,7 @@ from django.core.management.validation import get_validation_errors
 from django.db.models.loading import cache, load_app
 
 from django.utils import unittest
+from django.test.utils import override_settings
 
 
 class InvalidModelTestCase(unittest.TestCase):
@@ -31,14 +32,18 @@ class InvalidModelTestCase(unittest.TestCase):
         cache._get_models_cache = {}
         sys.stdout = self.old_stdout
 
+    # Technically, this isn't an override -- TEST_SWAPPED_MODEL must be
+    # set to *something* in order for the test to work. However, it's
+    # easier to set this up as an override than to require every developer
+    # to specify a value in their test settings.
+    @override_settings(TEST_SWAPPED_MODEL='invalid_models.Target')
     def test_invalid_models(self):
-
         try:
             module = load_app("modeltests.invalid_models.invalid_models")
         except Exception:
             self.fail('Unable to load invalid model module')
 
-        count = get_validation_errors(self.stdout, module)
+        get_validation_errors(self.stdout, module)
         self.stdout.seek(0)
         error_log = self.stdout.read()
         actual = error_log.split('\n')