divio/django-cms — pull request #1448 by ojii (2012-09-26 13:26:14+00:00)
Title: No longer allow '+' as related_name in PlaceholderField

Setting the related_name in a models.fields.PlaceholderField to '+'
causes the permission checks on models.Placeholder to fail because
models.Placeholder._get_attached_fields which is used by the permission
system will not find the attached model.

This patch prevents this by simply raising a ValueError if a developer
attempts to create a models.fields.PlaceholderField with '+' as
related_name. This is documented in extending_cms/placeholders.rst and
tested in PlaceholderTestCase.test_placeholder_field_no_related_name.