Fixed #12142 -- EmptyQuerySet.update() no longer updates all rows in the database

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12171 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/query.py

@@ -1089,6 +1089,12 @@ class EmptyQuerySet(QuerySet):
         """
         return self
 
+    def update(self, **kwargs):
+        """
+        Don't update anything.
+        """
+        return 0
+
     # EmptyQuerySet is always an empty result in where-clauses (and similar
     # situations).
     value_annotation = False

tests/modeltests/lookup/models.py

@@ -295,6 +295,8 @@ DoesNotExist: Article matching query does not exist.
 []
 >>> Article.objects.none().count()
 0
+>>> Article.objects.none().update(headline="This should not take effect")
+0
 >>> [article for article in Article.objects.none().iterator()]
 []