New filter request in feed.php

[mogman1]

When writing a plugin that works with the URLs in the RSS feeds, I noticed that one of the functions used by the RSS feed generator, "self_link" in wp-includes/feed.php does not have a filter associated with it. I had to manually modify the function in order to get the behaviour I desired.

The other functions used by the feed generator (the_permalink_rss, comments_link, the_guid, etc) all have filters associated with them either directly or indirectly and it would be nice for this one to have a filter placed on it as well.

Only feed_link I found was in get_feed_link(), and it has a filter. Please re-open with feedback if this is still current in trunk.

The self_link() function is used in feed-atom.php, feed-rss2-comments.php, feed-rss2.php for the self item in the feed. What I'm seeing with the PuSHPress plugin (for PubSubHubbub) is that the inclusion of $_SERVER['REQUEST_URI'] is triggering some odd looking self URLs in some cases. I've seen URLs for do_wp_cron, /wp-admin/, etc. Those are clearly not the self reference link for the feed.

Adding a filter would allow the PuSHPress plugin to ensure that the self link is set to the correct feed URL. I'm including a simple patch that applies a 'self_link' filter to the value, then escapes it, then outputs the value.

This has been soaking on wordpress.com for 5 weeks.

In 23521:

Add self_link filter to self_link(). props josephscott. fixes #10434.