ManyToManyField passes ModelBase to router.db_for_write

[craig.kimerer@…]

When using a ManyToMany field without the through parameter, the incorrect model type is passed into the router functions.

Consider the following example:

Models:

from django.db import models

class A(models.Model):
  asdf = models.CharField(max_length=10)
  
class B(models.Model):
  b = models.CharField(max_length=10)
  asdfs = models.ManyToManyField('A')

Router:

class MyRouter(object):
  
  def db_for_write(self, model, **hints):
    if model._meta.app_label == 'model_app_label':
      return 'not_default'
  
  def db_for_read(self, model, **hints):
    if model._meta.app_label == 'model_app_label'
      return 'not_default'
      
  def allow_relation(self, obj1, obj2, **hints):
    return obj1._state.db == obj2._state.db
      
  def allow_syncdb(self, db, model):
    if db == 'not_default' and model._meta.app_label == 'model_app_label':
      return True
    if db == 'default' and model._meta.app_label == 'model_app_label':
      return False
    return None

Running the following bit of code:

      aa = A.objects.create(asdf='1')
      bb = B.objects.create(b='asdf')
      bb.asdfs.add(aa)

I get an error about how the intermediary table model_app_label_b_asdfs on the default database does not exist

[Malcolm Tredinnick]

Looks good to me. Thanks.

[Ramiro Morales]

(In [15185]) Fixed #13668 -- Corrected database router methods invocation for ManyToMany fields without through models. Thanks craig.kimerer for the report and David Gouldin for the fix.

This also adds tests for r14857.

[Ramiro Morales]

(In [15186]) [1.2.X] Fixed #13668 -- Corrected database router methods invocation for ManyToMany fields without through models. Thanks craig.kimerer for the report and David Gouldin for the fix.

This also adds tests for r14857.

Backport of [15185] from trunk.

[Jacob]

Milestone 1.3 deleted