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
29238	psycopg2.InterfaceError in sequential tests after HTTP 404	alubbock	nobody	"I'm getting a curious error, where if I have two test methods, one using a force_login after a test with an HTTP 404, the second one fails. I've added a minimal reproducible example below. If the first method instead returns an HTTP 200, no error arises. If I use SQLite instead of Postgres, no error arises. 

I'm using a custom user model with the custom_user package, with email instead of username, in case that's relevant.

Key package versions:
django 1.11.10, python 3.6.4, postgres 9.6, custom_user 0.7, django allauth 0.35.0

{{{
from django.test import TestCase
from django.contrib.auth import get_user_model


class TestViews(TestCase):
    @classmethod
    def setUpTestData(cls):
        cls.user = get_user_model().objects.create(email='test@example.com')

    def test_404(self):
        resp = self.client.get('_non_existent_URL')
        self.assertEquals(resp.status_code, 404)

    def test_login(self):
        # fails with postgres
        self.client.force_login(self.user)
}}}

Here's the traceback:

{{{
Traceback (most recent call last):
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/backends/base/base.py"", line 231, in _cursor
    return self._prepare_cursor(self.create_cursor(name))
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/backends/postgresql/base.py"", line 220, in create_cursor
    cursor = self.connection.cursor()
psycopg2.InterfaceError: connection already closed

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File ""/Users/alex/git/VU/myproj-web/myprojweb/tests/test_logins.py"", line 16, in test_login
    self.client.force_login(self.user)
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/test/client.py"", line 645, in force_login
    self._login(user, backend)
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/test/client.py"", line 654, in _login
    if self.session:
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/test/client.py"", line 459, in session
    session.save()
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/contrib/sessions/backends/db.py"", line 81, in save
    return self.create()
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/contrib/sessions/backends/db.py"", line 50, in create
    self._session_key = self._get_new_session_key()
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/contrib/sessions/backends/base.py"", line 164, in _get_new_session_key
    if not self.exists(session_key):
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/contrib/sessions/backends/db.py"", line 46, in exists
    return self.model.objects.filter(session_key=session_key).exists()
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/models/query.py"", line 670, in exists
    return self.query.has_results(using=self.db)
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/models/sql/query.py"", line 517, in has_results
    return compiler.has_results()
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/models/sql/compiler.py"", line 858, in has_results
    return bool(self.execute_sql(SINGLE))
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/models/sql/compiler.py"", line 887, in execute_sql
    cursor = self.connection.cursor()
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/backends/base/base.py"", line 254, in cursor
    return self._cursor()
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/backends/base/base.py"", line 231, in _cursor
    return self._prepare_cursor(self.create_cursor(name))
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/utils.py"", line 94, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/utils/six.py"", line 685, in reraise
    raise value.with_traceback(tb)
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/backends/base/base.py"", line 231, in _cursor
    return self._prepare_cursor(self.create_cursor(name))
  File ""/Users/alex/miniconda3/envs/myproj/lib/python3.6/site-packages/django/db/backends/postgresql/base.py"", line 220, in create_cursor
    cursor = self.connection.cursor()
django.db.utils.InterfaceError: connection already closed
}}}
"	Bug	closed	Testing framework	1.11	Normal	invalid		alubbock	Unreviewed	0	0	0	0	0	0