Turning arround m2m_changed bug in admin from Django 1.8

views.py

'''
  Obs1: m2m_changed never trigger the remove signal (pre_remove, post_remove) when deleted, so this ways you can force he do it
  obs2: Since the pre_clear data will be removed anyways to new valuei n post_add add it again and when you fully remove data
  the add events wont be trigger, so this solution will simule the exacly action the m2m_changed should do
'''
class OtherModel(model.Models)
  pass

class MyModel(model.Models): 
    m2m_attribute = models.ManyToManyField(OtherModel,related_name='other_model', blank=True)
    
# SIGNALS
from django.db.models.signals import m2m_changed
from django.dispatch import receiver

@receiver(m2m_changed, sender=MyModel.m2m_attribute.through)
def mymodel_m2m_attribute_changed(sender, **kwargs):
    action = kwargs.pop('action', None)
    pk_set = kwargs.pop('pk_set', None)
    instance = kwargs.pop('instance', None)
    
    if action == "pre_clear":
        #Here we do the trick
        instance_m2m_attributes = instance.m2m_attribute.all()
        if instance_m2m_attributes:
            for one_m2m in instance_m2m_attributes:
                instance.m2m_attribute.remove(one_m2m)
            instance.save()   
   
    if action == "post_add" and pk_set:
        #Do Your Stuff