django-core-patch.diff

diff --git a/django/contrib/admin/checks.py b/django/contrib/admin/checks.py
index d8f7fe5..7a7c651 100644
--- a/django/contrib/admin/checks.py
+++ b/django/contrib/admin/checks.py
@@ -560,9 +560,10 @@ class ModelAdminChecks(BaseModelAdminChecks):
                     id='admin.E105',
                 )
             ]
-        elif not issubclass(inline.model, models.Model):
-            return must_be('a Model', option='%s.model' % inline_label,
-                           obj=cls, id='admin.E106')
+        # Strict check on django.db.models.Model. We could potentially remove this?
+        #elif not issubclass(inline.model, models.Model):
+            #return must_be('a Model', option='%s.model' % inline_label,
+                           #obj=cls, id='admin.E106')
         else:
             return inline.check(model)
 
@@ -897,6 +898,7 @@ class InlineModelAdminChecks(BaseModelAdminChecks):
         try:
             _get_foreign_key(parent_model, cls.model, fk_name=cls.fk_name)
         except ValueError as e:
+            _get_foreign_key(parent_model, cls.model, fk_name=cls.fk_name)
             return [checks.Error(e.args[0], hint=None, obj=cls, id='admin.E202')]
         else:
             return []
diff --git a/django/db/models/options.py b/django/db/models/options.py
index 4a2ab10..76d5b4c 100644
--- a/django/db/models/options.py
+++ b/django/db/models/options.py
@@ -82,9 +82,110 @@ def normalize_together(option_together):
 def make_immutable_fields_list(name, data):
     return ImmutableList(data, warning=IMMUTABLE_WARNING % name)
 
+class CachedPropertiesMixin(object):
+
+    @cached_property
+    def fields(self):
+        """
+        Returns a list of all forward fields on the model and its parents,
+        excluding ManyToManyFields.
+
+        Private API intended only to be used by Django itself; get_fields()
+        combined with filtering of field properties is the public API for
+        obtaining this field list.
+        """
+        # For legacy reasons, the fields property should only contain forward
+        # fields that are not virtual or with a m2m cardinality. Therefore we
+        # pass these three filters as filters to the generator.
+        # The third lambda is a longwinded way of checking f.related_model - we don't
+        # use that property directly because related_model is a cached property,
+        # and all the models may not have been loaded yet; we don't want to cache
+        # the string reference to the related_model.
+        is_not_an_m2m_field = lambda f: not (f.is_relation and f.many_to_many)
+        is_not_a_generic_relation = lambda f: not (f.is_relation and f.one_to_many)
+        is_not_a_generic_foreign_key = lambda f: not (
+            f.is_relation and f.many_to_one and not (hasattr(f.rel, 'to') and f.rel.to)
+        )
+        return make_immutable_fields_list(
+            "fields",
+            (f for f in self._get_fields(reverse=False) if
+            is_not_an_m2m_field(f) and is_not_a_generic_relation(f)
+            and is_not_a_generic_foreign_key(f))
+        )
+
+    @cached_property
+    def concrete_fields(self):
+        """
+        Returns a list of all concrete fields on the model and its parents.
+
+        Private API intended only to be used by Django itself; get_fields()
+        combined with filtering of field properties is the public API for
+        obtaining this field list.
+        """
+        try:
+            return make_immutable_fields_list(
+                "concrete_fields", (f for f in self.fields if f.concrete)
+            )
+        except AttributeError:
+            import ipdb; ipdb.set_trace()
+
+    @cached_property
+    def local_concrete_fields(self):
+        """
+        Returns a list of all concrete fields on the model.
+
+        Private API intended only to be used by Django itself; get_fields()
+        combined with filtering of field properties is the public API for
+        obtaining this field list.
+        """
+        return make_immutable_fields_list(
+            "local_concrete_fields", (f for f in self.local_fields if f.concrete)
+        )
+
+    @raise_deprecation(suggested_alternative="get_fields()")
+    def get_fields_with_model(self):
+        return [self._map_model(f) for f in self.get_fields()]
+
+    @raise_deprecation(suggested_alternative="get_fields()")
+    def get_concrete_fields_with_model(self):
+        return [self._map_model(f) for f in self.concrete_fields]
+
+    @cached_property
+    def many_to_many(self):
+        """
+        Returns a list of all many to many fields on the model and its parents.
+
+        Private API intended only to be used by Django itself; get_fields()
+        combined with filtering of field properties is the public API for
+        obtaining this list.
+        """
+        return make_immutable_fields_list(
+            "many_to_many",
+            (f for f in self._get_fields(reverse=False)
+            if f.is_relation and f.many_to_many)
+        )
+
+    @cached_property
+    def related_objects(self):
+        """
+        Returns all related objects pointing to the current model. The related
+        objects can come from a one-to-one, one-to-many, or many-to-many field
+        relation type.
+
+        Private API intended only to be used by Django itself; get_fields()
+        combined with filtering of field properties is the public API for
+        obtaining this field list.
+        """
+        all_related_fields = self._get_fields(forward=False, reverse=True, include_hidden=True)
+        return make_immutable_fields_list(
+            "related_objects",
+            (obj for obj in all_related_fields
+            if not obj.hidden or obj.field.many_to_many)
+        )
+
 
 @python_2_unicode_compatible
-class Options(object):
+class Options(CachedPropertiesMixin):
     FORWARD_PROPERTIES = ('fields', 'many_to_many', 'concrete_fields',
                           'local_concrete_fields', '_forward_fields_map')
     REVERSE_PROPERTIES = ('related_objects', 'fields_map', '_relation_tree')
@@ -373,102 +474,6 @@ class Options(object):
                     return swapped_for
         return None
 
-    @cached_property
-    def fields(self):
-        """
-        Returns a list of all forward fields on the model and its parents,
-        excluding ManyToManyFields.
-
-        Private API intended only to be used by Django itself; get_fields()
-        combined with filtering of field properties is the public API for
-        obtaining this field list.
-        """
-        # For legacy reasons, the fields property should only contain forward
-        # fields that are not virtual or with a m2m cardinality. Therefore we
-        # pass these three filters as filters to the generator.
-        # The third lambda is a longwinded way of checking f.related_model - we don't
-        # use that property directly because related_model is a cached property,
-        # and all the models may not have been loaded yet; we don't want to cache
-        # the string reference to the related_model.
-        is_not_an_m2m_field = lambda f: not (f.is_relation and f.many_to_many)
-        is_not_a_generic_relation = lambda f: not (f.is_relation and f.one_to_many)
-        is_not_a_generic_foreign_key = lambda f: not (
-            f.is_relation and f.many_to_one and not (hasattr(f.rel, 'to') and f.rel.to)
-        )
-        return make_immutable_fields_list(
-            "fields",
-            (f for f in self._get_fields(reverse=False) if
-            is_not_an_m2m_field(f) and is_not_a_generic_relation(f)
-            and is_not_a_generic_foreign_key(f))
-        )
-
-    @cached_property
-    def concrete_fields(self):
-        """
-        Returns a list of all concrete fields on the model and its parents.
-
-        Private API intended only to be used by Django itself; get_fields()
-        combined with filtering of field properties is the public API for
-        obtaining this field list.
-        """
-        return make_immutable_fields_list(
-            "concrete_fields", (f for f in self.fields if f.concrete)
-        )
-
-    @cached_property
-    def local_concrete_fields(self):
-        """
-        Returns a list of all concrete fields on the model.
-
-        Private API intended only to be used by Django itself; get_fields()
-        combined with filtering of field properties is the public API for
-        obtaining this field list.
-        """
-        return make_immutable_fields_list(
-            "local_concrete_fields", (f for f in self.local_fields if f.concrete)
-        )
-
-    @raise_deprecation(suggested_alternative="get_fields()")
-    def get_fields_with_model(self):
-        return [self._map_model(f) for f in self.get_fields()]
-
-    @raise_deprecation(suggested_alternative="get_fields()")
-    def get_concrete_fields_with_model(self):
-        return [self._map_model(f) for f in self.concrete_fields]
-
-    @cached_property
-    def many_to_many(self):
-        """
-        Returns a list of all many to many fields on the model and its parents.
-
-        Private API intended only to be used by Django itself; get_fields()
-        combined with filtering of field properties is the public API for
-        obtaining this list.
-        """
-        return make_immutable_fields_list(
-            "many_to_many",
-            (f for f in self._get_fields(reverse=False)
-            if f.is_relation and f.many_to_many)
-        )
-
-    @cached_property
-    def related_objects(self):
-        """
-        Returns all related objects pointing to the current model. The related
-        objects can come from a one-to-one, one-to-many, or many-to-many field
-        relation type.
-
-        Private API intended only to be used by Django itself; get_fields()
-        combined with filtering of field properties is the public API for
-        obtaining this field list.
-        """
-        all_related_fields = self._get_fields(forward=False, reverse=True, include_hidden=True)
-        return make_immutable_fields_list(
-            "related_objects",
-            (obj for obj in all_related_fields
-            if not obj.hidden or obj.field.many_to_many)
-        )
-
     @raise_deprecation(suggested_alternative="get_fields()")
     def get_m2m_with_model(self):
         return [self._map_model(f) for f in self.many_to_many]
diff --git a/django/forms/fields.py b/django/forms/fields.py
index 57d6a75..26422b7 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -135,8 +135,11 @@ class Field(six.with_metaclass(RenameFieldMethods, object)):
         return value
 
     def validate(self, value):
-        if value in self.empty_values and self.required:
-            raise ValidationError(self.error_messages['required'], code='required')
+        try:
+            if value in self.empty_values and self.required:
+                raise ValidationError(self.error_messages['required'], code='required')
+        except TypeError:
+            import ipdb; ipdb.set_trace()
 
     def run_validators(self, value):
         if value in self.empty_values:
diff --git a/django/utils/encoding.py b/django/utils/encoding.py
index 99c9da8..2d60a77 100644
--- a/django/utils/encoding.py
+++ b/django/utils/encoding.py
@@ -98,6 +98,7 @@ def force_text(s, encoding='utf-8', strings_only=False, errors='strict'):
             # SafeText at the end.
             s = s.decode(encoding, errors)
     except UnicodeDecodeError as e:
+        import ipdb; ipdb.set_trace()
         if not isinstance(s, Exception):
             raise DjangoUnicodeDecodeError(s, *e.args)
         else: