Fixed #11082 -- Ensured that subqueries used in an exclude(X__in=) clause aren't pre-evaluated. Thanks to Henry Andrews for the report, and clement for the fix.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10929 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 18 insertions, 1 deletions

diff --git a/django/db/models/query.py b/django/db/models/query.py
index 0f34fb8a5a..46a86fc03c 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -7,6 +7,8 @@ try:
 except NameError:
     from sets import Set as set     # Python 2.3 fallback
 
+from copy import deepcopy
+
 from django.db import connection, transaction, IntegrityError
 from django.db.models.aggregates import Aggregate
 from django.db.models.fields import DateField
@@ -40,6 +42,17 @@ class QuerySet(object):
     # PYTHON MAGIC METHODS #
     ########################
 
+    def __deepcopy__(self, memo):
+        """
+        Deep copy of a QuerySet doesn't populate the cache
+        """
+        obj_dict = deepcopy(self.__dict__, memo)
+        obj_dict['_iter'] = None
+
+        obj = self.__class__()
+        obj.__dict__.update(obj_dict)
+        return obj
+
     def __getstate__(self):
         """
         Allows the QuerySet to be pickled.
diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 15b9fd6366..23f99e41ad 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -1625,10 +1625,14 @@ class BaseQuery(object):
                             entry.negate()
                             self.where.add(entry, AND)
                             break
-                elif not (lookup_type == 'in' and not value) and field.null:
+                elif not (lookup_type == 'in'
+                            and not hasattr(value, 'as_sql')
+                            and not hasattr(value, '_as_sql')
+                            and not value) and field.null:
                     # Leaky abstraction artifact: We have to specifically
                     # exclude the "foo__in=[]" case from this handling, because
                     # it's short-circuited in the Where class.
+                    # We also need to handle the case where a subquery is provided
                     entry = self.where_class()
                     entry.add((Constraint(alias, col, None), 'isnull', True), AND)
                     entry.negate()