No updates for one specific feed

[syranez]

nextcloud/news initially fetches and parses https://www.bpb.de/rss-feed/62409.rss correctly, but cannot update it.

W3C-Validator reports currently a duplicate guid error
https://validator.w3.org/feed/check.cgi?url=https%3A%2F%2Fwww.bpb.de%2Frss-feed%2F62409.rss+
I do not think a duplicate guid error should fail the update.

Feed-IO can handle the feed:

require 'vendor/autoload.php';

use \FeedIo\Factory;

$feedIo = Factory::create()->getFeedIo();
$result = $feedIo->read('https://www.bpb.de/rss-feed/62409.rss');

echo "feed title : {$result->getFeed()->getTitle()} \n";
foreach ($result->getFeed() as $item) {
    echo "{$item->getLastModified()->format(\DateTime::ATOM)} : {$item->getTitle()} \n";
    echo "{$item->getDescription()} \n";
}

curl -I https://www.bpb.de/rss-feed/62409.rss
HTTP/1.1 200 OK
Server: nginx/1.18.0 (Ubuntu)
Date: Sat, 20 Feb 2021 18:20:01 GMT
Content-Type: text/xml; charset=utf-8
Content-Length: 22054
Connection: keep-alive
X-Drupal-Cache: MISS
Cache-Control: public, max-age=240, s-maxage=240
X-Content-Type-Options: nosniff
X-Cache-Control: public, max-age=240, s-maxage=240
X-Date: Sat, 20 Feb 2021 16:29:11 GMT
X-Varnish: 112368839 111859268
Via: 1.1 varnish (Varnish/6.2)
age: 0
X-RCache: Sat, 20 Feb 2021 18:20:01 GMT
Accept-Ranges: bytes

Thank you for looking into this.

[Grotax]

News can't handle duplicate guids it's the unique identifier for the item.

[syranez]

I am okay with not seeing some entrys who use the same guid. That is an error by the feed creator.

But i do not understand why the feed as a whole does not get updates. Precisely: Why do not i see new entrys of the feed which indeed have a really unique guid?

[Grotax]

Because the logic of the code can't take that. It's not skipping the entry.

In theory that would be possible but requires a careful implementation and tests.
If you feel like it you can write down a feature suggestion in https://github.com/nextcloud/news/discussions/categories/features
Describing how news should handle duplicate guids and such things keeping in mind that a confused user might miss a certain item from his feed that he can see on the website, he subscribed to.