Fixed #13328 -- Added a __getstate__/__setstate__ pair to fields so that…

Fixed #13328 -- Added a __getstate__/__setstate__ pair to fields so that callable default values aren't pickled. Thanks to bkonkle for the report, and Vitaly Babiy for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12977 bcc190cf-cafb-0310-a4f2-bffc1f526a37

AUTHORS

@@ -57,6 +57,7 @@ answer newbie questions, and generally made Django that much better:
     David Avsajanishvili <avsd05@gmail.com>
     Mike Axiak <axiak@mit.edu>
     Niran Babalola <niran@niran.org>
+    Vitaly Babiy <vbabiy86@gmail.com>
     Morten Bagai <m@bagai.com>
     Jeff Balogh <jbalogh@mozilla.com>
     Mikaël Barbero <mikael.barbero nospam at nospam free.fr>

django/db/models/fields/__init__.py

@@ -132,6 +132,19 @@ class Field(object):
         memodict[id(self)] = obj
         return obj
 
+    def __getstate__(self):
+        "Don't try to pickle a callable default value"
+        obj_dict = self.__dict__.copy()
+        del obj_dict['default']
+        return obj_dict
+
+    def __setstate__(self, data):
+        "When unpickling, restore the callable default"
+        self.__dict__.update(data)
+
+        # Restore the default
+        self.default = self.model._meta.get_field_by_name(self.name)[0].default
+
     def to_python(self, value):
         """
         Converts the input value into the expected Python data type, raising
@@ -233,6 +246,7 @@ class Field(object):
 
     def contribute_to_class(self, cls, name):
         self.set_attributes_from_name(name)
+        self.model = cls
         cls._meta.add_field(self)
         if self.choices:
             setattr(cls, 'get_%s_display' % self.name, curry(cls._get_FIELD_display, field=self))

django/db/models/fields/proxy.py

@@ -10,7 +10,10 @@ class OrderWrt(fields.IntegerField):
     A proxy for the _order database field that is used when
     Meta.order_with_respect_to is specified.
     """
-    name = '_order'
-    attname = '_order'
-    column = '_order'
 
+    def __init__(self, model, *args, **kwargs):
+        super(OrderWrt, self).__init__(*args, **kwargs)
+        self.model = model
+        self.attname = '_order'
+        self.column = '_order'
+        self.name = '_order'

django/db/models/options.py

@@ -104,11 +104,11 @@ class Options(object):
             self.db_table = "%s_%s" % (self.app_label, self.module_name)
             self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
 
-
     def _prepare(self, model):
         if self.order_with_respect_to:
             self.order_with_respect_to = self.get_field(self.order_with_respect_to)
             self.ordering = ('_order',)
+            self._order = OrderWrt(model)
         else:
             self.order_with_respect_to = None
 
@@ -331,7 +331,7 @@ class Options(object):
         for f, model in self.get_fields_with_model():
             cache[f.name] = (f, model, True, False)
         if self.order_with_respect_to:
-            cache['_order'] = OrderWrt(), None, True, False
+            cache['_order'] = self._order, None, True, False
         if app_cache_ready():
             self._name_map = cache
         return cache

tests/regressiontests/queryset_pickle/models.py

+import datetime
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 
+class Numbers(object):
+
+    @classmethod
+    def get_number(self):
+        return 2
+
 class Group(models.Model):
     name = models.CharField(_('name'), max_length=100)
 
 class Event(models.Model):
     group = models.ForeignKey(Group)
+
+class Happening(models.Model):
+    when = models.DateTimeField(blank=True, default=datetime.datetime.now)
+    name = models.CharField(blank=True, max_length=100, default=lambda:"test")
+    number = models.IntegerField(blank=True, default=Numbers.get_number)

tests/regressiontests/queryset_pickle/tests.py

 import pickle
+import datetime
 
 from django.test import TestCase
 
-from models import Group, Event
+from models import Group, Event, Happening
 
 
 class PickleabilityTestCase(TestCase):
@@ -12,3 +13,15 @@ class PickleabilityTestCase(TestCase):
     def test_related_field(self):
         g = Group.objects.create(name="Ponies Who Own Maybachs")
         self.assert_pickles(Event.objects.filter(group=g.id))
+
+    def test_datetime_callable_default_all(self):
+        self.assert_pickles(Happening.objects.all())
+
+    def test_datetime_callable_default_filter(self):
+        self.assert_pickles(Happening.objects.filter(when=datetime.datetime.now()))
+
+    def test_lambda_as_default(self):
+        self.assert_pickles(Happening.objects.filter(name="test"))
+
+    def test_callable_as_default(self):
+        self.assert_pickles(Happening.objects.filter(number=1))