Refs #16508 -- Made Model.__init__() aware of virtual fields.

It's no longer necessary for GenericForeignKey (and any other virtual fields)
to intercept the field's values using the pre_init signal.

django/contrib/contenttypes/fields.py

@@ -6,7 +6,7 @@ from django.contrib.contenttypes.models import ContentType
 from django.core import checks
 from django.core.exceptions import FieldDoesNotExist, ObjectDoesNotExist
 from django.db import DEFAULT_DB_ALIAS, models, router, transaction
-from django.db.models import DO_NOTHING, signals
+from django.db.models import DO_NOTHING
 from django.db.models.base import ModelBase, make_foreign_order_accessors
 from django.db.models.fields.related import (
     ForeignObject, ForeignObjectRel, ReverseManyToOneDescriptor,
@@ -54,11 +54,6 @@ class GenericForeignKey(object):
         self.model = cls
         self.cache_attr = "_%s_cache" % name
         cls._meta.add_field(self, private=True)
-
-        # Only run pre-initialization field assignment on non-abstract models
-        if not cls._meta.abstract:
-            signals.pre_init.connect(self.instance_pre_init, sender=cls)
-
         setattr(cls, name, self)
 
     def get_filter_kwargs_for_object(self, obj):
@@ -162,20 +157,6 @@ class GenericForeignKey(object):
             else:
                 return []
 
-    def instance_pre_init(self, signal, sender, args, kwargs, **_kwargs):
-        """
-        Handle initializing an object with the generic FK instead of
-        content_type and object_id fields.
-        """
-        if self.name in kwargs:
-            value = kwargs.pop(self.name)
-            if value is not None:
-                kwargs[self.ct_field] = self.get_content_type(obj=value)
-                kwargs[self.fk_field] = value._get_pk_val()
-            else:
-                kwargs[self.ct_field] = None
-                kwargs[self.fk_field] = None
-
     def get_content_type(self, obj=None, id=None, using=None):
         if obj is not None:
             return ContentType.objects.db_manager(obj._state.db).get_for_model(

django/db/models/base.py

@@ -452,11 +452,14 @@ class Model(six.with_metaclass(ModelBase)):
         if kwargs:
             for prop in list(kwargs):
                 try:
-                    if isinstance(getattr(self.__class__, prop), property):
+                    # Any remaining kwargs must correspond to properties or
+                    # virtual fields.
+                    if (isinstance(getattr(self.__class__, prop), property) or
+                            self._meta.get_field(prop)):
                         if kwargs[prop] is not DEFERRED:
                             setattr(self, prop, kwargs[prop])
                         del kwargs[prop]
-                except AttributeError:
+                except (AttributeError, FieldDoesNotExist):
                     pass
             if kwargs:
                 raise TypeError("'%s' is an invalid keyword argument for this function" % list(kwargs)[0])

docs/releases/1.10.txt

@@ -400,6 +400,9 @@ Models
 * A proxy model may now inherit multiple proxy models that share a common
   non-abstract parent class.
 
+* ``Model.__init__()`` now sets values of virtual fields from its keyword
+  arguments.
+
 Requests and Responses
 ~~~~~~~~~~~~~~~~~~~~~~