Using a Postgres database with TIME_ZONE set to None and USE_TZ set to False causes an exception

[Jensen Cochran]

You are supposed to be able to set TIME_ZONE = None and USE_TZ = False in order to the use the system time (if you are not on Windows). When using a Postgres database, this functionality is broken in 1.8 onward and causes an exception to occur when the development server is started.

The bottom part of the stack trace looks like this:

File "/usr/lib64/python2.7/site-packages/django/db/backends/base/base.py", line 121, in connect
    self.init_connection_state()
File "/usr/lib64/python2.7/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 204, in init_connection_state
    cursor.execute(self.ops.set_time_zone_sql(), [tz])
django.db.utils.ProgrammingError: syntax error at or near "NULL"

What is happening is that self.init_connection_state() is not checking whether or not the tz setting is None, so None is being formatted into the SQL string inside of self.ops.set_time_zone_sql() to get "SET TIME ZONE NULL".

Before 1.8, there was a check in place to make sure that tz was truthy before proceeding, but it was removed in ​this commit.

You can reproduce this bug simply by making a new Django project and setting TIME_ZONE = None, USE_TZ = False, and setting the default database to a postgres database.

Tested on Django 1.8.0, 1.8.9, and 1.9.2 using PostgreSQL 9.2.9 and Python 2.7.3 on CentOS 6.5

[Tim Graham]

​PR

[Tim Graham <timograham@…>]

In 97eb3356:

Fixed #26177 -- Fixed a PostgreSQL crash with TIME_ZONE=None and USE_TZ=False.

[Tim Graham <timograham@…>]

In 6b689a50:

[1.9.x] Fixed #26177 -- Fixed a PostgreSQL crash with TIME_ZONE=None and USE_TZ=False.

Backport of 97eb3356b2a7488c8d0ca0e47ef3e538852d44a2 from master

[Tim Graham <timograham@…>]

In 2f0de9b:

[1.8.x] Fixed #26177 -- Fixed a PostgreSQL crash with TIME_ZONE=None and USE_TZ=False.

Backport of 97eb3356b2a7488c8d0ca0e47ef3e538852d44a2 from master