Made it possible to pickle DateQuerySets.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8455 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 18 insertions, 1 deletions

diff --git a/django/db/models/sql/datastructures.py b/django/db/models/sql/datastructures.py
index cb54a564f8..913d8fde25 100644
--- a/django/db/models/sql/datastructures.py
+++ b/django/db/models/sql/datastructures.py
@@ -85,7 +85,7 @@ class Date(object):
     def __init__(self, col, lookup_type, date_sql_func):
         self.col = col
         self.lookup_type = lookup_type
-        self.date_sql_func= date_sql_func
+        self.date_sql_func = date_sql_func
 
     def relabel_aliases(self, change_map):
         c = self.col
diff --git a/django/db/models/sql/subqueries.py b/django/db/models/sql/subqueries.py
index 5ca041cbde..cea2a58d39 100644
--- a/django/db/models/sql/subqueries.py
+++ b/django/db/models/sql/subqueries.py
@@ -343,6 +343,23 @@ class DateQuery(Query):
     date field. This requires some special handling when converting the results
     back to Python objects, so we put it in a separate class.
     """
+    def __getstate__(self):
+        """
+        Special DateQuery-specific pickle handling.
+        """
+        for elt in self.select:
+            if isinstance(elt, Date):
+                # Eliminate a method reference that can't be pickled. The
+                # __setstate__ method restores this.
+                elt.date_sql_func = None
+        return super(DateQuery, self).__getstate__()
+
+    def __setstate__(self, obj_dict):
+        super(DateQuery, self).__setstate__(obj_dict)
+        for elt in self.select:
+            if isinstance(elt, Date):
+                self.date_sql_func = self.connection.ops.date_trunc_sql
+
     def results_iter(self):
         """
         Returns an iterator over the results from executing this query.