Fixed #10796 -- Corrected a pickling problem introduced by [10522]. Thanks to carljm for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10526 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 11 insertions, 3 deletions

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index df4de2a750..f4bf8b2b07 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -124,8 +124,13 @@ class BaseQuery(object):
         obj_dict['related_select_cols'] = []
         del obj_dict['connection']
 
-        # Fields can't be pickled, so we pickle the list of field names instead.
-        obj_dict['select_fields'] = [f.name for f in obj_dict['select_fields']]
+        # Fields can't be pickled, so if a field list has been
+        # specified, we pickle the list of field names instead.
+        # None is also a possible value; that can pass as-is
+        obj_dict['select_fields'] = [
+            f is not None and f.name or None
+            for f in obj_dict['select_fields']
+        ]
         return obj_dict
 
     def __setstate__(self, obj_dict):
@@ -133,7 +138,10 @@ class BaseQuery(object):
         Unpickling support.
         """
         # Rebuild list of field instances
-        obj_dict['select_fields'] = [obj_dict['model']._meta.get_field(name) for name in obj_dict['select_fields']]
+        obj_dict['select_fields'] = [
+            name is not None and obj_dict['model']._meta.get_field(name) or None
+            for name in obj_dict['select_fields']
+        ]
 
         self.__dict__.update(obj_dict)
         # XXX: Need a better solution for this when multi-db stuff is