In Django 2.3.3 the CMSSitemap doesn't work anymore if there are cms_page records with publication_date that have a NULL value

[googol7]

Django==1.4.2
django-cms==2.3.3

Environment:

Request Method: GET
Request URL: http://dev.carusocarsharing.com/sitemap.xml

Django Version: 1.4.2
Python Version: 2.7.3
Installed Applications:
('django_extensions',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.gis',
'django.contrib.admin',
'django.contrib.sitemaps',
'django.contrib.staticfiles',
'menus',
'sorl.thumbnail',
'cms',
'mptt',
'south',
'appmedia',
'cms.plugins.text',
'cms.plugins.picture',
'cms.plugins.link',
'cms.plugins.file',
'cms.plugins.snippet',
'cms.plugins.googlemap',
'main',
'marketplace',
'convadis',
'smart_selects',
'server',
'rpc4django',
'cmsplugin_news',
'cmsplugin_mediaelements',
'cmsplugin_faq',
'cmsplugin_textwithimage',
'cmsplugin_galleria',
'contact_form',
'djangocms_utils',
'treemenus',
'sekizai',
'reversion',
'workflows',
'permissions',
'tinymce',
'cronjobs',
'compressor')
Installed Middleware:
('django.middleware.cache.UpdateCacheMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.transaction.TransactionMiddleware',
'django.middleware.cache.FetchFromCacheMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.middleware.locale.LocaleMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'cms.middleware.page.CurrentPageMiddleware',
'cms.middleware.user.CurrentUserMiddleware')

Traceback:
File "/home/django/.virtualenvs/django14-dev/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response

1.                     response = callback(request, _callback_args, *_callback_kwargs)
   

   File "/home/django/.virtualenvs/django14-dev/lib/python2.7/site-packages/django/contrib/sitemaps/views.py" in sitemap

2.                                   protocol=req_protocol))
   

   File "/home/django/.virtualenvs/django14-dev/lib/python2.7/site-packages/django/contrib/sitemaps/init.py" in get_urls

3.             'lastmod':    self.**get('lastmod', item, None),
   

   File "/home/django/.virtualenvs/django14-dev/lib/python2.7/site-packages/django/contrib/sitemaps/__init**.py" in __get

4.         return attr(obj)
   

   File "/home/django/.virtualenvs/django14-dev/lib/python2.7/site-packages/cms/sitemaps/cms_sitemap.py" in lastmod

5.     return max(modification_dates)
   

Exception Type: TypeError at /sitemap.xml
Exception Value: can't compare datetime.datetime to NoneType

[dbartenstein]

This problem occurs when a Page is in the 'published'-state but does not have a publication_date set. How can that happen as in the save-Method of class Page publication_date is set when state is 'published'?

[dbartenstein]

This issue might have to do with data not migrated from django-cms 2.0.2
Back then the publication_date was set to NULL on published pages in some cases:

# Drafts should not, unless they have been set to the future
if self.published:
        if settings.CMS_SHOW_START_DATE:
            if self.publication_date and self.publication_date <= datetime.now():
                self.publication_date = None
        else:
            self.publication_date = None

For me the solution was to set publication_date to all published pages:

orm['cms.page'].objects.filter(published=True, publication_date=None).update(publication_date=timezone.now()) 

[digi604]

pages that get published will set the publication_date. This is probably only a upgrade issue.