Patch for django bug where EmptyQuerySet actually needs the model to be set (or…

Patch for django bug where EmptyQuerySet actually needs the model to be set (or it can't raise a DoesNotExist exception).

wiki/managers.py

@@ -91,7 +91,7 @@ class ArticleFkEmptyQuerySet(ArticleFkEmptyQuerySetMixin, EmptyQuerySet):
 
 class ArticleManager(models.Manager):
     def get_empty_query_set(self):
-        return ArticleEmptyQuerySet()
+        return ArticleEmptyQuerySet(model=self.model)
     def get_query_set(self):
         return ArticleQuerySet(self.model, using=self._db)
     def active(self):
@@ -127,7 +127,7 @@ class URLPathQuerySet(QuerySet, ArticleFkQuerySetMixin):
 class URLPathManager(TreeManager):
     
     def get_empty_query_set(self):
-        return URLPathEmptyQuerySet()
+        return URLPathEmptyQuerySet(model=self.model)
     
     def get_query_set(self):
         """Return a QuerySet with the same ordering as the TreeManager."""