id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
17541	Unexpected ForeignKey Behavior with self.pk == None	Peter Sheats	anonymous	"I'm not sure if this is technically a bug but I wanted to report it because it really surprised me today.

{{{
class Manufacturer(models.Model):
    name = models.CharField(blank=True, max_length=100)

class Car(models.Model):
    manufacturer = models.ForeignKey(Manufacturer, blank=True, null=True)
    name = models.CharField(blank=True, max_length=100)


Car.objects.create(name='Accord')
Car.objects.create(name='Civic')

print Manufacturer().car_set.all().count()    
>>> 2
}}}

Even though neither Car is related to a Manufacturer, they are both returned through the related qs.  I'm assuming this is because the query looks something like this:

{{{
manufacturer = Manufacturer()
Car.objects.filter(manufacturer=manufacturer.id)
}}}

I would say it is incorrect behavior to return anything through that related queryset that is not explicitly related.  
"	Bug	closed	Database layer (models, ORM)	1.3	Release blocker	fixed		anssi.kaariainen@…	Accepted	1	0	0	0	0	0