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
13534	m2m_changed signal doesn't call receiver	Chris Targett <chris@…>	nobody	"For some reason or another the m2m_changed signal does not call the receiver.

A rough models.py similar to my code:
{{{
#!python

class SomeContent(models.Model):
  sites = models.ForeignKey(Site)

def m2m_handler(sender, instance, action, reverse, model, pk_set, **kwargs):
  raise NotImplementedError
models.signals.m2m_changed.connect(m2m_handler, SomeContent)


>>> sc = SomeContent()
>>> sc.save()
>>> sc.sites.add(Site.objects.get_current()) # Here you would expect a ""NotImplementedError""
>>>
}}}

It seems the signal loses all receivers in `django.dispatch.dispatcher.Signal._line_receivers` line 215.
"		closed	Database layer (models, ORM)	1.2-beta		invalid	m2m_save, dispatch, signal		Unreviewed	0	0	0	0	0	0