Fixed #10728 -- corrected subclassing of Fields who use the SubfieldBase metaclass. Thanks to G2P and George Sakkis for their work on the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14443 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/fields/subclassing.py

@@ -79,7 +79,8 @@ class SubfieldBase(LegacyConnection):
     def __new__(cls, base, name, attrs):
         new_class = super(SubfieldBase, cls).__new__(cls, base, name, attrs)
         new_class.contribute_to_class = make_contrib(
-                attrs.get('contribute_to_class'))
+            new_class, attrs.get('contribute_to_class')
+        )
         return new_class
 
 class Creator(object):
@@ -97,7 +98,7 @@ class Creator(object):
     def __set__(self, obj, value):
         obj.__dict__[self.field.name] = self.field.to_python(value)
 
-def make_contrib(func=None):
+def make_contrib(superclass, func=None):
     """
     Returns a suitable contribute_to_class() method for the Field subclass.
 
@@ -110,7 +111,7 @@ def make_contrib(func=None):
         if func:
             func(self, cls, name)
         else:
-            super(self.__class__, self).contribute_to_class(cls, name)
+            super(superclass, self).contribute_to_class(cls, name)
         setattr(cls, self.name, Creator(self))
 
     return contribute_to_class

tests/modeltests/field_subclassing/fields.py

@@ -52,6 +52,9 @@ class SmallField(models.Field):
             return []
         raise TypeError('Invalid lookup type: %r' % lookup_type)
 
+class SmallerField(SmallField):
+    pass
+
 
 class JSONField(models.TextField):
     __metaclass__ = models.SubfieldBase

tests/modeltests/field_subclassing/models.py

@@ -5,7 +5,7 @@ Tests for field subclassing.
 from django.db import models
 from django.utils.encoding import force_unicode
 
-from fields import Small, SmallField, JSONField
+from fields import Small, SmallField, SmallerField, JSONField
 
 
 class MyModel(models.Model):
@@ -15,5 +15,8 @@ class MyModel(models.Model):
     def __unicode__(self):
         return force_unicode(self.name)
 
+class OtherModel(models.Model):
+    data = SmallerField()
+
 class DataModel(models.Model):
     data = JSONField()

tests/modeltests/field_subclassing/tests.py

@@ -2,7 +2,7 @@ from django.core import serializers
 from django.test import TestCase
 
 from fields import Small
-from models import DataModel, MyModel
+from models import DataModel, MyModel, OtherModel
 
 
 class CustomField(TestCase):
@@ -73,3 +73,9 @@ class CustomField(TestCase):
             ],
             lambda m: str(m.data)
         )
+
+    def test_field_subclassing(self):
+        o = OtherModel.objects.create(data=Small("a", "b"))
+        o = OtherModel.objects.get()
+        self.assertEqual(o.data.first, "a")
+        self.assertEqual(o.data.second, "b")