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
16920	Models with GenericRelation are unnecessarily validated for clashes in reverse manager accessor	Ricky Rosario	nobody	"GenericRelation fields don't add a reverse manager to the related model. However, the model validation verifies that there are no collisions forcing the use of an unused related_name parameter (which then can cause issues such as #16913).

'''To reproduce:'''

Create a model with a GenericForeignKey and a related model with a GenericRelation. testapp1/models.py:
{{{
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes import generic
from django.db import models


class Topic(models.Model):
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = generic.GenericForeignKey('content_type', 'object_id')


class Post(models.Model):
    topic = generic.GenericRelation(Topic)
}}}


In a different app, create another related model with the same name. testapp2/models.py:
{{{
from django.contrib.contenttypes import generic
from django.db import models

from testapp1.models import Topic

class Post(models.Model):
    topic = generic.GenericRelation(Topic)
}}}


Now run syncdb:
{{{
$ ./manage.py syncdb

Error: One or more models did not validate:
testapp2.post: Accessor for m2m field 'topic' clashes with related m2m field 'Topic.post_set'. Add a related_name argument to the definition for 'topic'.
testapp1.post: Accessor for m2m field 'topic' clashes with related m2m field 'Topic.post_set'. Add a related_name argument to the definition for 'topic'.
}}}"	Bug	new	contrib.contenttypes	1.3	Normal			james@… 4glitch@…	Accepted	1	0	0	1	0	0