magic-removal: Changed QuerySet.in_bulk() to check for tuple or list, because it was accepting strings, which are iterable.

git-svn-id: http://code.djangoproject.com/svn/django/branches/magic-removal@2250 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/query.py

@@ -195,10 +195,7 @@ class QuerySet(object):
     ##################################################
 
     def in_bulk(self, id_list):
-        try:
-            iter(id_list)
-        except TypeError:
-            assert False, "in_bulk() must be provided with a list of IDs."
+        assert isinstance(id_list, (tuple,  list)), "in_bulk() must be provided with a list of IDs."
         id_list = list(id_list)
         assert id_list != [], "in_bulk() cannot be passed an empty ID list."
         return self._clone(klass=InBulkQuerySet, _id_list=id_list)