Documentation of FormView.form_class produces warning

[timobrembeck]

The documentation of the attribute form_class in views which inherit from Django's FormView produces the following warning when executing sphinx-build:

WARNING: :1: (WARNING/2) Bullet list ends without a blank line; unexpected unindent.

It took me a while to figure out what the problem is, because there is no reference to the source code which produced this warning.
Looking at the verbose debug output of sphinx-build, I noticed the following:

   .. py:attribute:: CustomView.form_class
      :module: app.views

      Docstring for this attribute

      **Form fields:**

      * ``field1``: Field1 (:class:`~django.forms.fields.CharField`)
      alias of :class:`CustomForm`

So the form fields are appended to the docstring by sphinxcontrib-django and the "alias" is appended because the value of the field in a class. The missing new line between the bullet list and the "alias"-line causes the warning.

[timobrembeck]

This was not a problem of this extension, but of Sphinx itself and was fixed in version 3.3.0: sphinx-doc/sphinx#8190