AttributeError: 'NoneType' object has no attribute 'tzinfo'

[Christian Boos]

How to Reproduce

While doing a GET operation on /prefs/datetime, Trac issued an internal error.

After installing pytz and restarting the server, changing one's timezone works but leads to the following traceback when visiting the preferences Date & Time panel (not only after the redirect, also afterwards).

Request parameters:

{'panel_id': u'datetime'}

User Agent was: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US) AppleWebKit/533.2 (KHTML, like Gecko) Chrome/5.0.342.8 Safari/533.2

System Information

Trac	0.12dev-r9404
Docutils	0.6
Genshi	0.6dev-r1096
psycopg2	2.0.8
Pygments	1.2.2dev-20100224
Python	2.5.2 (r252:60911, Oct 5 2008, 19:29:17) [GCC 4.3.2]
pytz	2010g
setuptools	0.6c9
Subversion	1.5.1 (r32289)
jQuery	1.4.2

Enabled Plugins

StatusFixer	r6326
TracSpamFilter	0.2.1dev-r8929
TracVote	0.1

Python Traceback

Traceback (most recent call last):
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 514, in _dispatch_request
    dispatcher.dispatch(req)
  File "build/bdist.linux-x86_64/egg/trac/web/main.py", line 257, in dispatch
    content_type)
  File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 862, in render_template
    stream.render(method, doctype=doctype, out=buffer)
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 183, in render
    return encode(generator, method=method, encoding=encoding, out=out)
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 58, in encode
    for chunk in iterator:
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 339, in __call__
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 826, in __call__
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 670, in __call__
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 771, in __call__
    for kind, data, pos in chain(stream, [(None, None, None)]):
  File "build/bdist.linux-x86_64/egg/genshi/output.py", line 586, in __call__
    for ev in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 966, in _strip_accesskeys
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/trac/web/chrome.py", line 955, in _generate
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 381, in _match
    ctxt, start=idx + 1, **vars):
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 381, in _match
    ctxt, start=idx + 1, **vars):
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 381, in _match
    ctxt, start=idx + 1, **vars):
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 381, in _match
    ctxt, start=idx + 1, **vars):
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 330, in _match
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 532, in _flatten
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/path.py", line 588, in _generate
    subevent = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 330, in _match
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 319, in _strip
    event = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 532, in _flatten
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/path.py", line 588, in _generate
    subevent = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 319, in _strip
    event = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 532, in _flatten
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/path.py", line 588, in _generate
    subevent = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 319, in _strip
    event = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 532, in _flatten
    for kind, data, pos in stream:
  File "build/bdist.linux-x86_64/egg/genshi/core.py", line 288, in _ensure
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/path.py", line 588, in _generate
    subevent = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 592, in _include
    for event in stream:
  File "build/bdist.linux-x86_64/egg/genshi/template/markup.py", line 319, in _strip
    event = next()
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 552, in _flatten
    result = _eval_expr(data, ctxt, vars)
  File "build/bdist.linux-x86_64/egg/genshi/template/base.py", line 277, in _eval_expr
    retval = expr.evaluate(ctxt)
  File "build/bdist.linux-x86_64/egg/genshi/template/eval.py", line 178, in evaluate
    return eval(self.code, _globals, {'__data__': data})
  File "/tmp/.lighttpd-egg-cache-trunk/Trac-0.12dev_r9404-py2.5.egg-tmp/trac/prefs/templates/prefs_datetime.html", line 35, in <Expression u'selected_tz.tzname(None)'>
    In your time zone ${selected_tz.tzname(None)}, this would be displayed as
  File "/usr/local/virtualenv/trunk/lib/python2.5/site-packages/pytz-2010g-py2.5.egg/pytz/tzinfo.py", line 431, in tzname
    if dt.tzinfo is not self:
AttributeError: 'NoneType' object has no attribute 'tzinfo'

[Christian Boos]

Seems to be a problem with newer pytz (2010g here), for my version 2009g it's working fine.

The doc for tzname says:

A tzinfo subclass's methods should therefore be prepared to accept a dt argument of None, or of class datetime. - ​datetime.tzinfo.tzname

So pytz seems at fault here (​http://bazaar.launchpad.net/~stub/pytz/devel/revision/214).

[Christian Boos]

So… [9413] was not enough, now we get:

ValueError: Not naive datetime (tzinfo is already set)

Fichier « /tmp/.lighttpd-egg-cache-trunk/Trac-0.12dev_r9418-py2.5.egg-tmp/trac/prefs/templates/prefs_datetime.html », ligne 35, dans <Expression u'selected_tz.tzname(now)'>
  In your time zone ${selected_tz.tzname(now)}, this would be displayed as
Fichier « /usr/local/virtualenv/trunk/lib/python2.5/site-packages/pytz-2010g-py2.5.egg/pytz/tzinfo.py », ligne 432, dans tznameFichier « /usr/local/virtualenv/trunk/lib/python2.5/site-packages/pytz-2010g-py2.5.egg/pytz/tzinfo.py », ligne 263, dans localize

[Christian Boos]

Fixed for good with r9419. I just verified that the problem also happened on 0.11-stable, so I backported the fix in r9420.