Removed ModelDict.

Its only difference with OrderedDict is that it didn't deepcopy its
keys. However it wasn't used anywhere with models modules as keys, only
as values. So this commit doesn't result in any change in functionality.

1 files changed, 4 insertions, 15 deletions

diff --git a/django/apps/cache.py b/django/apps/cache.py
index 7410151b88..8afe3dd4cf 100644
--- a/django/apps/cache.py
+++ b/django/apps/cache.py
@@ -1,7 +1,6 @@
 "Utilities for loading models and the modules that contain them."
 
 from collections import OrderedDict
-import copy
 import imp
 from importlib import import_module
 import os
@@ -19,16 +18,6 @@ __all__ = ('get_apps', 'get_app', 'get_models', 'get_model', 'register_models',
 MODELS_MODULE_NAME = 'models'
 
 
-class ModelDict(OrderedDict):
-    """
-    We need to special-case the deepcopy for this, as the keys are modules,
-    which can't be deep copied.
-    """
-    def __deepcopy__(self, memo):
-        return self.__class__([(key, copy.deepcopy(value, memo))
-                               for key, value in self.items()])
-
-
 class UnavailableApp(Exception):
     pass
 
@@ -44,7 +33,7 @@ def _initialize():
 
         # Mapping of app_labels to a dictionary of model names to model code.
         # May contain apps that are not installed.
-        app_models=ModelDict(),
+        app_models=OrderedDict(),
 
         # Mapping of app_labels to errors raised when trying to import the app.
         app_errors={},
@@ -277,12 +266,12 @@ class BaseAppCache(object):
         if app_mod:
             app_label = self._label_for(app_mod)
             if app_label in self.app_labels:
-                app_list = [self.app_models.get(app_label, ModelDict())]
+                app_list = [self.app_models.get(app_label, OrderedDict())]
             else:
                 app_list = []
         else:
             if only_installed:
-                app_list = [self.app_models.get(app_label, ModelDict())
+                app_list = [self.app_models.get(app_label, OrderedDict())
                             for app_label in six.iterkeys(self.app_labels)]
             else:
                 app_list = six.itervalues(self.app_models)
@@ -332,7 +321,7 @@ class BaseAppCache(object):
             # Store as 'name: model' pair in a dictionary
             # in the app_models dictionary
             model_name = model._meta.model_name
-            model_dict = self.app_models.setdefault(app_label, ModelDict())
+            model_dict = self.app_models.setdefault(app_label, OrderedDict())
             if model_name in model_dict:
                 # The same model may be imported via different paths (e.g.
                 # appname.models and project.appname.models). We use the source