Infinite loop when RSS is not available - crashing server

[anonymized_13628566]

Putting up a widget loading local rss feed (via FQDN, not localhost ofc).
For some reason my RSS is not available (unrelated), so it redirects to a 404 page when trying to access the feed.
On the 404 page, the same widget is displayed again, trying to load the same RSS.
This generates an infinite loop.

Crashed my server for 2 days over and over again until I found out.

Should add a check whether already tried to load the feed and maybe a Timeout. Or even better, use Javascript RSS processing instead of serverside.

[stevenkword]

@DanFromGermany -- Could you please list steps to reproduce? I have been unsuccessful thus far.

[stevenkword]

Relates to #13049

[stevenkword]

This would benefit from the solution proposed in #11585