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
25882	Deletion on ForeignKey raises TypeError	Markus Gerards	Simon Charette	"Consider following model constellation:


{{{
class Catalog(models.Model):
	name = models.CharField(max_length=255)
	...

class Reader(models.Model):
	name = models.CharField(max_length=255)
	catalog = models.ForeignKey(Catalog)
	...

class ReaderHasMedia(models.Model):
	reader = models.ForeignKey(Reader)
	...
}}}

Now in some cases I need to perform following command


{{{
ReaderHasMedia.objects.filter(catalog=Catalog.objects.get(pk=123)).delete()
}}}

With this command, I get following TypeError:


{{{
Traceback (most recent call last):
  File ""<console>"", line 1, in <module>
  File ""/usr/local/lib/python2.7/site-packages/django/db/models/query.py"", line 600, in delete
    deleted, _rows_count = collector.delete()
  File ""/usr/local/lib/python2.7/site-packages/django/db/models/deletion.py"", line 293, in delete
    deleted_counter[qs.model._meta.label] += count
TypeError: unsupported operand type(s) for +=: 'int' and 'NoneType'
}}}

With Django 1.8.7 there wasn't a count variable in deletion.py and so I believe, this is a fresh bug with Django 1.9... "	Bug	closed	Database layer (models, ORM)	1.9	Release blocker	fixed	mysql	raphael.merx@…	Ready for checkin	1	0	0	0	0	0