Stores don't rollback correctly in Django

[Anthony Lenton]

When using storm as a Django db backend, if you have to rollback a store due to a database disconnection, the connection isn't set up again properly. Here's a short example using Django's interactive shell:

$ python manage.py shell
Python 2.6.4 (r264:75706, Nov 2 2009, 14:38:03)
[GCC 4.4.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> # My STORM_STORES is {'data': 'postgres://postgres@localhost/foobar'}
>>> from django.db import connection
>>> cur = connection.cursor()
>>> # Before continuing, restart the database so that the connection is stale
>>> cur.execute('select true')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "(...)/django/db/backends/util.py", line 19, in execute
    return self.cursor.execute(sql, params)
OperationalError: terminating connection due to administrator command
server closed the connection unexpectedly
 This probably means the server terminated abnormally
 before or while processing the request.

>>> # As expected, that failed. So let's rollback...
>>> connection._store.rollback()
>>> cur = connection.cursor()
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "(...)/django/db/backends/__init__.py", line 56, in cursor
    cursor = self._cursor(settings)
  File "(...)/storm/django/backend/base.py", line 30, in _cursor
    cursor = super(StormDatabaseWrapperMixin, self)._cursor(*args)
  File "(...)/django/db/backends/postgresql_psycopg2/base.py", line 84, in _cursor
    self.connection = Database.connect(conn_string, **self.options)
OperationalError: FATAL: database "data" does not exist

At this point it shouldn't be trying to connect in line 84 of django/db/backends/postgresql_psycopg2/base.py, as storm should already have set up a connection for it when it reaches line 70. The code on line 84 of base.py should never be run while using the storm backend, as it uses the DATABASE_* settings that storm replaces with STORM_STORES.

Or am I doing it wrong? :)

[James Henstridge (jamesh)]

Looks like StormDatabaseWrapperMixin._get_connection() should include a call to self._store._connection._ensure_connected().