Last Modified header issue in support RSS feed

[Rarst]

From personal experience support feeds work horribly in feed reader services. I discovered the reply from week (!) ago still hadn't appeared in feedly for me (just as it was often stuck for days in google reader in the past) and looked at feed more closely.

As of now my feed ​http://wordpress.org/support/rss/view/plugin-contributor/Rarst

Has header Last-Modified: Wed, 17 Jul 2013 16:41:02 GMT

While actual last message in it was at Mon, 29 Jul 2013 14:20:26 +0000 and the date from header corresponds to four messages earlier.

This is very likely to cause incorrect 304 Not Modified responses to feed readers and have them stuck if they are not refreshing aggressively.

[daveshine]

+1
What @Rarst said!
I had this very often already, with old Google Reader it was a desaster, "feedly" now is a bit better but it depends, sometimes a few hours sometimes a few days (about a week).
Any fix or help would be highly appreciated.

[Otto42]

This appears to only be the case on the plugin-contributor and plugin-committer views. It was due to the way those views were overridden to show all posts instead of just the first posts in the topic (like a normal view would). I've added code to override the headers and send the same date as the most recent post for those two views.

[helen]

Guess that also fixes ​#WP22506.

[nacin]

Reopening to point miqrogroove over here from ​#WP22506.

[miqrogroove]

Repost:

The HTTP header is still wrong. (or the RSS header is) One of these servers is living 5 minutes in the future perhaps?

​http://wordpress.org/support/rss/view/plugin-contributor/TigrouMeow

Last-Modified: Wed, 31 Jul 2013 18:51:33 GMT

<pubDate>Wed, 31 Jul 2013 18:57:04 +0000</pubDate>

[Otto42]

No, the header is correct. Last-Modified date is set to the time of the most recent post. Look lower in the feed at the actual post and it shows that the post "skonsult on [Plugin: WP Retina 2x].." made that post at the time being used for the last modified header.

The pubDate of the feed as-a-whole is always "now" because that's how bbPress generates feeds. Setting the last-modified header to "now" makes no sense if the content has not been actually modified in a significant way.