Ticket #11892: 11892.deferred_model_eq.diff

tests/modeltests/defer/models.py

@@ -183 +183 @@
 >>> obj.name = "bb"
 >>> obj.save()
 
+# Model instances of the same type and same ID are considered equal 
+# make sure this is true for deferred models as well
+>>> s1 = Secondary.objects.get(first='x1')
+>>> s2 = Secondary.objects.defer('first').get(pk=s1.pk)
+>>> s3 = Secondary.objects.defer('second').get(pk=s1.pk)
+>>> s1 == s2
+True
+>>> s2 == s1
+True
+>>> s2 == s3
+True
+>>> s3 == s2
+True
+
 # Finally, we need to flush the app cache for the defer module.
 # Using only/defer creates some artifical entries in the app cache
 # that messes up later tests. Purge all entries, just to be sure.

django/db/models/base.py

@@ -336 +336 @@
         return '%s object' % self.__class__.__name__
 
     def __eq__(self, other):
-        return isinstance(other, self.__class__) and self._get_pk_val() == other._get_pk_val()
+        self_model = self.__class__
+        other_model = other.__class__
+        if self_model._deferred:
+            self_model = self_model.__bases__[0]
+        if getattr(other_model, '_deferred', False):
+            other_model = other_model.__bases__[0]
+        return issubclass(other_model, self_model) and self._get_pk_val() == other._get_pk_val()
 
     def __ne__(self, other):
         return not self.__eq__(other)