Unexpected select_related() behaviour

[panni@…]

select_related() sometimes seems to break queries with multiple chained .exclude's.
Let's say we're having the following example:

Thread.objects.exclude(forum__type = 'fcin').exclude(forum__type = 'stin').exclude(forum__type = 'suin').exclude(forum__type = 'fc').order_by('-creationDate')[:8]

returns:

u'SELECT `forum_thread`.`id`,`forum_thread`.`forum_id`,`forum_thread`.`headline`,`forum_thread`.`author_id`,`forum_thread`.`author_user_id`,`forum_thread`.`text`,`forum_thread`.`creationDate`,`forum_thread`.`updateDate`,`forum_thread`.`hitCount` 
FROM `forum_thread` INNER JOIN `forum_forum` AS `forum_thread__forum` ON `forum_thread`.`forum_id` = `forum_thread__forum`.`id` 
WHERE ((NOT (`forum_thread__forum`.`type` = fcin)) 
AND (NOT (`forum_thread__forum`.`type` = stin)) 
AND (NOT (`forum_thread__forum`.`type` = suin)) 
AND (NOT (`forum_thread__forum`.`type` = fc)))
ORDER BY `forum_thread`.`creationDate` DESC LIMIT 8 '

resulting in three results

Thread.objects.select_related().exclude(forum__type = 'fcin').exclude(forum__type = 'stin').exclude(forum__type = 'suin').exclude(forum__type = 'fc').order_by('-creationDate')[:8]

returns:

u'SELECT `forum_thread`.`id`,`forum_thread`.`forum_id`,`forum_thread`.`headline`,`forum_thread`.`author_id`,`forum_thread`.`author_user_id`,`forum_thread`.`text`,`forum_thread`.`creationDate`,`forum_thread`.`updateDate`,`forum_thread`.`hitCount`,`forum_forum`.`id`,`forum_forum`.`parent_id`,`forum_forum`.`name`,`forum_forum`.`description`,`forum_forum`.`type`,`forum_forum`.`hitCount`,`forum_forum`.`forumFCTeam_id`,`forum_forum`.`forumFCPlayer_id`,`community_userprofile`.`id`,`community_userprofile`.`gender`,`community_userprofile`.`birthdaydate`,`community_userprofile`.`city`,`community_userprofile`.`zip`,`community_userprofile`.`picture`,`community_userprofile`.`organisation`,`community_userprofile`.`taskInOrganisation`,`community_userprofile`.`ICQ`,`community_userprofile`.`MSN`,`community_userprofile`.`Skype`,`community_userprofile`.`website`,`community_userprofile`.`irc_channel`,`community_userprofile`.`forumThreadCount`,`community_userprofile`.`forumPostCount`,`community_userprofile`.`gBookEntriesMade`,`community_userprofile`.`commentCount`,`community_userprofile`.`globalForumAdmin`,`community_userprofile`.`occupation`,`community_userprofile`.`occupationDetails`,`community_userprofile`.`aboutMe`,`community_userprofile`.`favGame_id`,`community_userprofile`.`favGameCustom`,`community_userprofile`.`favSeries`,`community_userprofile`.`favFood`,`community_userprofile`.`favClub`,`community_userprofile`.`favDrink`,`community_userprofile`.`favMovie`,`community_userprofile`.`favBook`,`community_userprofile`.`favMobile`,`community_userprofile`.`favBand`,`community_userprofile`.`favSong`,`community_userprofile`.`favCarBrand`,`community_userprofile`.`favCar`,`community_userprofile`.`favSport`,`community_userprofile`.`favCustom`,`community_userprofile`.`wforGame`,`community_userprofile`.`wforHardware`,`community_userprofile`.`wforMovie`,`community_userprofile`.`wforIdea`,`community_userprofile`.`PCPicture`,`community_userprofile`.`PCCPU`,`community_userprofile`.`PCRAM`,`community_userprofile`.`PCHDD`,`community_userprofile`.`PCGPU`,`community_userprofile`.`PCSPU`,`community_userprofile`.`PCMonitor`,`community_userprofile`.`PCPSU`,`community_userprofile`.`PCMB`,`community_userprofile`.`PCProvider`,`community_userprofile`.`PCConnection`,`community_userprofile`.`PCCustom`,`community_userprofile`.`PCMouse`,`community_userprofile`.`PCPad`,`community_userprofile`.`PCHeadset`,`community_userprofile`.`PCBungee`,`community_userprofile`.`PCSkates`,`community_userprofile`.`PCKeyboard`,`community_userprofile`.`PCOther`,`community_userprofile`.`gallery_id`,`community_userprofile`.`adminComments_id`,`community_userprofile`.`user_id`,`community_userprofile`.`betsWon`,`community_userprofile`.`betsLost`,`community_userprofile`.`hitCount`,`community_userprofile`.`showLastname`,`community_userprofile`.`showTFC`,`community_userprofile`.`showPFC`,`auth_user`.`id`,`auth_user`.`username`,`auth_user`.`first_name`,`auth_user`.`last_name`,`auth_user`.`email`,`auth_user`.`password`,`auth_user`.`is_staff`,`auth_user`.`is_active`,`auth_user`.`is_superuser`,`auth_user`.`last_login`,`auth_user`.`date_joined` 
FROM `forum_thread` INNER JOIN `forum_forum` AS `forum_thread__forum` ON `forum_thread`.`forum_id` = `forum_thread__forum`.`id` , `forum_forum`, `community_userprofile`, `auth_user` 
WHERE ((NOT (`forum_thread__forum`.`type` = fcin)) 
AND (NOT (`forum_thread__forum`.`type` = stin)) 
AND (NOT (`forum_thread__forum`.`type` = suin)) 
AND (NOT (`forum_thread__forum`.`type` = fc))) 
AND `forum_thread`.`forum_id` = `forum_forum`.`id` 
AND `forum_thread`.`author_id` = `community_userprofile`.`id` 
AND `community_userprofile`.`user_id` = `auth_user`.`id` 
ORDER BY `forum_thread`.`creationDate` DESC LIMIT 8 '

resulting in NO results

If you need additional info about the Models, please say so.

[Malcolm Tredinnick]

Fixed description.