Django Bug

bug.py

from django.db import models


class Owner(models.Model):
    pass


class Thing(models.Model):
    owner = models.ForeignKey(Owner, related_name='things')

    date = models.DateField()


class Error(models.Model):
    owner = models.ForeignKey(Owner, related_name='errors')

    date = models.DateField()


from django.db.models import F
# This works
Error.objects.filter(owner__things__date=F('date'))
#
## This Doesnt
Error.objects.exclude(owner__things__date=F('date'))

query.sql

# Django 1.6.1
# In [7]: print Error.objects.exclude(owner__things__date=F('date')).query
SELECT `arst_error`.`id`, `arst_error`.`owner_id`, `arst_error`.`date` FROM `arst_error` WHERE NOT (`arst_error`.`owner_id` IN (SELECT U2.`owner_id` FROM `arst_error` U0 INNER JOIN `arst_thing` U2 ON ( U1.`id` = U2.`owner_id` ) WHERE U2.`date` =  U0.`date`))

# In [8]: print Error.objects.filter(owner__things__date=F('date')).query
SELECT `arst_error`.`id`, `arst_error`.`owner_id`, `arst_error`.`date` FROM `arst_error` INNER JOIN `arst_owner` ON ( `arst_error`.`owner_id` = `arst_owner`.`id` ) INNER JOIN `arst_thing` ON ( `arst_owner`.`id` = `arst_thing`.`owner_id` ) WHERE `arst_thing`.`date` =  `arst_error`.`date`

# Django 1.7.
#>>> print Error.objects.exclude(owner__things__date=F('date')).query
SELECT "arst_error"."id", "arst_error"."owner_id", "arst_error"."date" FROM "arst_error" WHERE NOT ("arst_error"."owner_id" IN (SELECT U2."owner_id" FROM "arst_error" U0 INNER JOIN "arst_thing" U2 ON ( U1."id" = U2."owner_id" ) WHERE U2."date" =  U0."date"))
#>>> print Error.objects.filter(owner__things__date=F('date')).query
SELECT "arst_error"."id", "arst_error"."owner_id", "arst_error"."date" FROM "arst_error" INNER JOIN "arst_owner" ON ( "arst_error"."owner_id" = "arst_owner"."id" ) INNER JOIN "arst_thing" ON ( "arst_owner"."id" = "arst_thing"."owner_id" ) WHERE "arst_thing"."date" =  "arst_error"."date"