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
16509	init test db: try insert a existing permission (django.db.utils.IntegrityError: columns content_type_id, codename are not unique)	rogeliomita@…	Tobias McNulty	"I have a problem with django 1.3, south 0.7.3, not which of them ocacion the problem, but I tell that happens to me:
debuging I see that the problem is that in a migration try add the permission 'Can add profile' again and the table constraint auth_permission does not allow it and raise.
Viewing source for south found nothing, and seeing the source of django I found this fragment in which I found a problem, but I not know his reason

-django/contrib/auth/management/__init__.py
{{{
def create_permissions(app, created_models, verbosity, **kwargs):
    from django.contrib.contenttypes.models import ContentType

    app_models = get_models(app)

    # This will hold the permissions we're looking for as
    # (content_type, (codename, name))
    searched_perms = list()
    # The codenames and ctypes that should exist.
    ctypes = set()
    for klass in app_models:
        ctype = ContentType.objects.get_for_model(klass)
        ctypes.add(ctype)
        for perm in _get_all_permissions(klass._meta):
            searched_perms.append((ctype, perm))

    # Find all the Permissions that have a context_type for a model we're
    # looking for.  We don't need to check for codenames since we already have
    # a list of the ones we're going to create.
    all_perms = set(auth_app.Permission.objects.filter(
        content_type__in=ctypes,
    ).values_list(
        ""content_type"", ""codename""
    ))

    for ctype, (codename, name) in searched_perms:
        # If the permissions exists, move on.
        if (ctype.pk, codename) in all_perms:
            continue
        p = auth_app.Permission.objects.create(
            codename=codename,
            name=name,
            content_type=ctype
        )
        if verbosity >= 2:
            print ""Adding permission '%s'"" % p
}}}

Looking at the result of searched_perms variable, I found repeated permissions

searched_perms: [(<ContentType: profile>, (u'add_profile', u'Can add profile')), (<ContentType: profile>, (u'change_profile', u'Can change profile')), (<ContentType: profile>, (u'delete_profile', u'Can delete profile')), (<ContentType: profile>, ('add_profile', 'Can add profile')), (<ContentType: profile>, ('change_profile', 'Can change profile')), (<ContentType: profile>, ('delete_profile', 'Can delete profile')), (<ContentType: profile>, ('view_profile', 'Can view profile'))].

Converting searched_perms to a set and solve the problem by eliminating repetitions, but completely ignores the cause. (sorry for my bad English)

{{{
for ctype, (codename, name) in searched_perms: -------> for ctype, (codename, name) in set(searched_perms):
}}}"	Bug	closed	contrib.contenttypes	1.4	Release blocker	needsinfo	not unique, permission, auth	patrick.craston@…	Accepted	0	0	0	0	0	0