[Django] #36397: Server ignores 'Last-Modified' date (Debian#926074)

[Django]

#36397: Server ignores 'Last-Modified' date (Debian#926074)
-----------------------+-----------------------------------------
Reporter: buhtz | Type: Uncategorized
Status: new | Component: Uncategorized
Version: | Severity: Normal
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-----------------------+-----------------------------------------
Hello,
First please take my apologize for writing such a broad ticket. But
others, with more intel, I asked, didn't.

This is related to a (6 year old) Debian bug ticket:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=926074
In short: The modified date is ignored by the server.

The Debian folks telling me that Django is somehow involved and there
should go a bug ticket and fix.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=926074#10

I can not tell because I lack of deeper understanding of the underlying
technology.

I do have minimal working example demonstrating the problem with the
Debian server.

>>> url = 'https://tracker.debian.org/pkg/feedparser/rss'
>>> import feedparser as fp
>>> a = fp.parse(url)
>>> import json
>>> print(json.dumps(a.headers, indent=4))
{
"X-Clacks-Overhead": "GNU Terry Pratchett",
"X-Xss-Protection": "1",
"Transfer-Encoding": "chunked",
"Last-Modified": "Sat, 30 Mar 2019 13:06:51 GMT",
"Public-Key-Pins": "pin-
sha256=\"M9Wyk2x6hLne/VkyJWFx33+LB8s+kAaMbO49fnm5fEY=\"; pin-
sha256=\"ZsBWn0bekrum/1CJtBlg5yZ2eqRywN6YwGeBS31nH+s=\"; max-age=5184000",
"Strict-Transport-Security": "max-age=15552000",
"Content-Type": "application/rss+xml; charset=utf-8",
"X-Content-Type-Options": "nosniff",
"Connection": "close",
"Referrer-Policy": "same-origin",
"Content-Encoding": "gzip",
"X-Frame-Options": "sameorigin",
"Server": "Apache",
"Vary": "Cookie,Accept-Encoding",
"Date": "Sun, 31 Mar 2019 11:11:03 GMT"
}
>>> a.modified
'Sat, 30 Mar 2019 13:06:51 GMT'
>>> b = fp.parse(url, modified=a.modified)
>>> len(a.entries)
30
>>> len(b.entries)
30

I would expect "b.entries" should be (near) 0.

I also can not tell wich version of Django is used by Debian.

Maybe you can give some comments in the Debian ticket?

Regards,
Christian
--
Ticket URL: <https://code.djangoproject.com/ticket/36397>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

[Django]

#36397: Server ignores 'Last-Modified' date (Debian#926074)

-------------------------------+--------------------------------------
Reporter: buhtz | Owner: (none)

Type: Uncategorized | Status: new
Component: Uncategorized | Version:

Severity: Normal | Resolution:

Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

-------------------------------+--------------------------------------
Comment (by buhtz):

Your platform broke my plaintext python-repl-code. Sorry. Can you edit
that?
--
Ticket URL: <https://code.djangoproject.com/ticket/36397#comment:1>

[Django]

#36397: Server ignores 'Last-Modified' date (Debian#926074)
-------------------------------+--------------------------------------
Reporter: buhtz | Owner: (none)
Type: Uncategorized | Status: new
Component: Uncategorized | Version:
Severity: Normal | Resolution:
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------+--------------------------------------

Description changed by buhtz:

Old description:

New description:

--
Ticket URL: <https://code.djangoproject.com/ticket/36397#comment:2>

[Django]

#36397: Server ignores 'Last-Modified' date (Debian#926074)

-------------------------------------+-------------------------------------
Reporter: Christian Buhtz | Owner: (none)
Type: Bug | Status: closed
Component: contrib.syndication | Version: 4.2
Severity: Normal | Resolution: invalid

Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0

-------------------------------------+-------------------------------------
Changes (by Natalia Bidart):

* cc: Colin Watson (added)
* component: Uncategorized => contrib.syndication
* resolution: => invalid
* status: new => closed
* type: Uncategorized => Bug
* version: => 4.2

Comment:

Hello Christian Buhtz, thank you for taking the time to create this
ticket. I see from the messages in the Debian mailing list that you care
deeply about this issue. Still, this is not an issue in Django: the `Feed`
implementation from the syndication framework does handle item publication
as shown in the Django source code. See the `class Feed` implementation at
[https://github.com/django/django/blob/main/django/contrib/syndication/views.py#L35-L49
these relevant lines]. This behavior is enabled via
`ConditionalGetMiddleware` (which I'm not sure if the Debian tracker
uses).

The issue you're experiencing could be caused by a variety of factors,
including (but not limited to) the `PackageNewsFeed` view (from the
[https://salsa.debian.org/qa/distro-
tracker/-/blob/master/distro_tracker/core/news_feed.py?ref_type=heads#L101-106
Debian source code that defines item_pubdate()]) returning timezone-naive
datetimes or `None`.

Considering that this issue tracker is meant to track confirmed bugs in
Django itself, and since this report seems to stem from application-
specific code in the Debian project, I’ll close this ticket as `invalid`
per our [https://docs.djangoproject.com/en/dev/internals/contributing
/triaging-tickets/#closing-tickets ticket triaging process]. The best
place to get further help would be one of the support forums listed at
[https://docs.djangoproject.com/en/dev/faq/help/#how-do-i-do-x-why-
doesn-t-y-work-where-can-i-go-to-get-help this link]. If after debugging,
you (or someone else) find that the problem lies in Django itself, please
reopen the ticket with specific details and, ideally, a minimal Django
project or failing test case that demonstrates the issue (using Django
code only, we're not able to debug arbitrary third-party services).
--
Ticket URL: <https://code.djangoproject.com/ticket/36397#comment:3>