magic-removal: laid groundwork for subclassing.

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@2432 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/base.py

@@ -35,6 +35,12 @@ class ModelBase(type):
         new_class.add_to_class('_meta', Options(attrs.pop('Meta', None)))
         new_class.add_to_class('DoesNotExist', types.ClassType('DoesNotExist', (ObjectDoesNotExist,), {}))
 
+        # Build complete list of parents
+        for base in bases:
+            if '_meta' in dir(base):
+                new_class._meta.parents.append(base)
+                new_class._meta.parents.extend(base._meta.parents)
+
         model_module = sys.modules[new_class.__module__]
 
         if getattr(new_class._meta, 'app_label', None) is None:
@@ -46,6 +52,11 @@ class ModelBase(type):
         for obj_name, obj in attrs.items():
             new_class.add_to_class(obj_name, obj)
 
+        # Add Fields inherited from parents
+        for parent in new_class._meta.parents:
+            for field in parent._meta.fields:
+                field.contribute_to_class(new_class, field.name)
+
         new_class._prepare()
 
         register_models(new_class._meta.app_label, new_class)

django/db/models/options.py

@@ -31,6 +31,7 @@ class Options:
         self.pk = None
         self.has_auto_field = False
         self.one_to_one_field = None
+        self.parents = []
 
     def merge_meta(self):
         meta_attrs = self.meta.__dict__