Commit 7c31e195 authored by Aymeric Augustin's avatar Aymeric Augustin
Browse files

[1.6.x] Fixed #18766 -- Pointed to pytz when LocalTimezone fails. 

Thanks void for the report.

Backport of ded11aa6 from master.
parent c03848b5

django/utils/timezone.py

+23 −2
Original line number Diff line number Diff line 
"""Timezone helper functions.

"""

Timezone-related classes and functions.



This module uses pytz when it's available and fallbacks when it isn't.

"""



from datetime import datetime, timedelta, tzinfo

from threading import local

import sys

import time as _time



try:
@@ -45,12 +47,14 @@ class UTC(tzinfo): 
    def dst(self, dt):

        return ZERO



class LocalTimezone(tzinfo):

class ReferenceLocalTimezone(tzinfo):

    """

    Local time implementation taken from Python's docs.



    Used only when pytz isn't available, and most likely inaccurate. If you're

    having trouble with this class, don't waste your time, just install pytz.



    Kept identical to the reference version. Subclasses contain improvements.

    """



    def __init__(self):
@@ -91,6 +95,23 @@ class LocalTimezone(tzinfo): 
        tt = _time.localtime(stamp)

        return tt.tm_isdst > 0



class LocalTimezone(ReferenceLocalTimezone):

    """

    Slightly improved local time implementation focusing on correctness.



    It still crashes on dates before 1970 or after 2038, but at least the

    error message is helpful.

    """



    def _isdst(self, dt):

        try:

            return super(LocalTimezone, self)._isdst(dt)

        except (OverflowError, ValueError) as exc:

            exc_type = type(exc)

            exc_value = exc_type(

                    "Unsupported value: %r. You should install pytz." % dt)

            exc_value.__cause__ = exc

            six.reraise(exc_type, exc_value, sys.exc_info()[2])



utc = pytz.utc if pytz else UTC()

"""UTC time zone as a tzinfo instance."""

tests/utils_tests/test_timezone.py

+7 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ import copy 
import datetime

import pickle

from django.test.utils import override_settings

from django.utils import six

from django.utils import timezone

from django.utils.tzinfo import FixedOffset

from django.utils import unittest
@@ -19,6 +20,12 @@ class TimezoneTests(unittest.TestCase): 
        local_now = timezone.localtime(now, local_tz)

        self.assertEqual(local_now.tzinfo, local_tz)



    def test_localtime_out_of_range(self):

        local_tz = timezone.LocalTimezone()

        long_ago = datetime.datetime(1900, 1, 1, tzinfo=timezone.utc)

        with six.assertRaisesRegex(self, OverflowError, "install pytz"):

            timezone.localtime(long_ago, local_tz)



    def test_now(self):

        with override_settings(USE_TZ=True):

            self.assertTrue(timezone.is_aware(timezone.now()))