ORM bug with using exclude in conjunction with Q objects

[Yeago]

Here's a shell session which illustrates the problem.

>>> from tapped.deck.models import Deck
>>> from django.db.models import Q
>>> Deck.objects.filter(user__username='nammertime')
[<Deck: Walled Out (Legacy) *Private*>, <Deck: Reign of Fire (Legacy) *Private*>, <Deck: Wake of the Cataclysm (Legacy) *Private*>, <Deck: WMDs (Extended) *Private*>, <Deck: Chernabog (Legacy) *Private*>, <Deck: Dark Alliance (Legacy) *Private*>, <Deck: Elf Horde (Legacy) *Private*>, <Deck: Natural Selection *Private*>, <Deck: Sliver Rush (Legacy) *Private*>, <Deck: Rath's Last Conscripts (Legacy) *Private*>, <Deck: Furious Assault (Legacy) *Private*>, <Deck: Urza's Venom (Legacy) *Private*>, <Deck: Sapling EDH (Legacy) *Private*>, <Deck: Ashling EDH (Legacy) *Private*>]
>>> Deck.objects.filter(user__username='nammertime').count()
14
>>> Deck.objects.filter(user__username='nammertime').exclude(category='pro').exclude(category='precon')
[<Deck: Walled Out (Legacy) *Private*>, <Deck: Reign of Fire (Legacy) *Private*>, <Deck: Wake of the Cataclysm (Legacy) *Private*>, <Deck: WMDs (Extended) *Private*>, <Deck: Chernabog (Legacy) *Private*>, <Deck: Dark Alliance (Legacy) *Private*>, <Deck: Elf Horde (Legacy) *Private*>, <Deck: Natural Selection *Private*>, <Deck: Sliver Rush (Legacy) *Private*>, <Deck: Rath's Last Conscripts (Legacy) *Private*>, <Deck: Furious Assault (Legacy) *Private*>, <Deck: Urza's Venom (Legacy) *Private*>, <Deck: Sapling EDH (Legacy) *Private*>, <Deck: Ashling EDH (Legacy) *Private*>]
>>> Deck.objects.filter(user__username='nammertime').exclude(category='pro').exclude(category='precon').count()
14
>>> Deck.objects.filter(user__username='nammertime').exclude(Q(category='pro')|Q(category='precon'))


>>> Deck.objects.filter(user__username='nammertime').exclude(Q(category='pro')|Q(category='precon'))
[]
>>> Deck.objects.filter(user__username='nammertime').exclude(Q(category='pro')|Q(category='precon')).count()
0
>>> Deck.objects.filter(user__username='nammertime').filter(category='pro')
[]
>>> Deck.objects.filter(user__username='nammertime').filter(category='precon')
[]
>>> Deck.objects.filter(user__username='nammertime').exclude(Q(category='pro')|Q(category='precon')).query.as_sql()
('SELECT `deck_deck`.`id`, `deck_deck`.`format_id`, `deck_deck`.`name`, `deck_deck`.`slug`, `deck_deck`.`user_id`, `deck_deck`.`description`, `deck_deck`.`profile_cardinality`, `deck_deck`.`date_added`, `deck_deck`.`date_updated`, `deck_deck`.`date_refreshed`, `deck_deck`.`is_private`, `deck_deck`.`category`, `deck_deck`.`preconstructed_set_id`, `deck_deck`.`cost`, `deck_deck`.`view_count_cache`, `deck_deck`.`comment_count_cache`, `deck_deck`.`data_generated`, `deck_deck`.`image_token`, `deck_deck`.`similar_due`, `deck_deck`.`rating_votes`, `deck_deck`.`rating_score` FROM `deck_deck` INNER JOIN `auth_user` ON (`deck_deck`.`user_id` = `auth_user`.`id`) WHERE (`auth_user`.`username` = %s  AND NOT ((`deck_deck`.`category` = %s  OR `deck_deck`.`category` = %s )))', ('nammertime', 'pro', 'precon'))
>>> Deck.objects.filter(user__username='nammertime').exclude(category='pro').exclude(category='precon').query.as_sql()
('SELECT `deck_deck`.`id`, `deck_deck`.`format_id`, `deck_deck`.`name`, `deck_deck`.`slug`, `deck_deck`.`user_id`, `deck_deck`.`description`, `deck_deck`.`profile_cardinality`, `deck_deck`.`date_added`, `deck_deck`.`date_updated`, `deck_deck`.`date_refreshed`, `deck_deck`.`is_private`, `deck_deck`.`category`, `deck_deck`.`preconstructed_set_id`, `deck_deck`.`cost`, `deck_deck`.`view_count_cache`, `deck_deck`.`comment_count_cache`, `deck_deck`.`data_generated`, `deck_deck`.`image_token`, `deck_deck`.`similar_due`, `deck_deck`.`rating_votes`, `deck_deck`.`rating_score` FROM `deck_deck` INNER JOIN `auth_user` ON (`deck_deck`.`user_id` = `auth_user`.`id`) WHERE (`auth_user`.`username` = %s  AND NOT (`deck_deck`.`category` = %s  AND NOT (`deck_deck`.`category` IS NULL)) AND NOT (`deck_deck`.`category` = %s  AND NOT (`deck_deck`.`category` IS NULL)))', ('nammertime', 'pro', 'precon'))

[Yeago]

​http://dpaste.com/159557/