timeuntil doesn't work with datetime.date objects

[dmitry.guyvoronsky@…]

It seems a bug exists in several django.utils.timezone methods, is_aware() and is_native(). This leads to error "AttributeError: 'datetime.date' object has no attribute 'tzinfo'" when timesince filter is applied to date object in Django template. Proof code

import time
from datetime import date
today = date.today()

from django.template import Context, Template
c = Context({"today": today})
t = Template("{{ today|timeuntil }}")

print t.render(c)

Error trace:

Traceback (most recent call last):
  File "test.py", line 9, in <module>
    print t.render(c)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/template/base.py", line 140, in render
    return self._render(context)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/template/base.py", line 134, in _render
    return self.nodelist.render(context)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/template/base.py", line 823, in render
    bit = self.render_node(node, context)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/template/base.py", line 837, in render_node
    return node.render(context)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/template/base.py", line 874, in render
    output = self.filter_expression.resolve(context)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/template/base.py", line 599, in resolve
    new_obj = func(obj, *arg_vals)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/template/defaultfilters.py", line 755, in timeuntil_filter
    return timeuntil(value, arg)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/utils/timesince.py", line 61, in timeuntil
    now = datetime.datetime.now(utc if is_aware(d) else None)
  File "/cygdrive/c/Users/dmitryg/.virtualenvs/feedback/lib/python2.6/site-packages/django/utils/timezone.py", line 243, in is_aware
    return value.tzinfo is not None and value.tzinfo.utcoffset(value) is not None
AttributeError: 'datetime.date' object has no attribute 'tzinfo'

[Aymeric Augustin]

Indeed, the ​docs clearly mean that timesince accepts either a date or a datetime.

[dmitry.guyvoronsky@…]

Objects of date class should be always naive according to python docs

[Aymeric Augustin]

The patch is at the wrong layer -- is_aware and is_naive are only intended to receive datetime objects (or subclasses, or API-compatible classes).

The check should be in timesince instead.

The same bug probably exists in timeuntil and possibly in other filters.

[dreamiurg]

Replying to aaugustin:

Thanks for the patch. Unfortunately, I think it puts the check in the wrong layer -- is_aware and is_naive are only intended to receive datetime objects (or subclasses, or API-compatible classes).

The check should be in timesince instead.

The same bug probably exists in timeuntil and possibly in other filters.

'Yes, I was thinking about patching at timesince/timeuntil level, however, after considerations it seemed more logical to make changes at the bottom level instead.

[dreamiurg]

Replying to aaugustin:

Thanks for the patch. Unfortunately, I think it puts the check in the wrong layer -- is_aware and is_naive are only intended to receive datetime objects (or subclasses, or API-compatible classes).

The check should be in timesince instead.

The same bug probably exists in timeuntil and possibly in other filters.

Please see second version of the patch, this one fixes problem on timeuntil() level + adds unittests.

[Aymeric Augustin]

In fact, this problem only affects timeuntil, not timesince — there are tests checking that timeuntil accepts date objects.

It's a little bit hard to explain the problem in English but the patch is self-explanatory. It just avoids duplicating the preprocessing of parguments that is done correctly in timesince and incorrectly in timeuntil.

[Aymeric Augustin]

In [17774]:

Fixed #17937 -- Avoided an error in the timeuntil filter when it receives a date object. Thanks Dmitry Guyvoronsky for the report.