[1.1.X] Fixed #12240 - select_related doesn't work correctly when mixing nullable and non-nullable keys

  
Thanks to embe for report and Alex for fix.

Backport of 12719 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@12720 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 2 insertions, 8 deletions

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 36a83036a9..6b9f4b6d56 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -1361,10 +1361,7 @@ class BaseQuery(object):
             avoid = avoid_set.copy()
             dupe_set = orig_dupe_set.copy()
             table = f.rel.to._meta.db_table
-            if nullable or f.null:
-                promote = True
-            else:
-                promote = False
+            promote = nullable or f.null
             if model:
                 int_opts = opts
                 alias = root_alias
@@ -1415,10 +1412,7 @@ class BaseQuery(object):
                 next = requested.get(f.name, {})
             else:
                 next = False
-            if f.null is not None:
-                new_nullable = f.null
-            else:
-                new_nullable = None
+            new_nullable = f.null or promote
             for dupe_opts, dupe_col in dupe_set:
                 self.update_dupe_avoidance(dupe_opts, dupe_col, alias)
             self.fill_related_selections(f.rel.to._meta, alias, cur_depth + 1,