Index: feed.php
===================================================================
--- feed.php	(revision 12162)
+++ feed.php	(working copy)
@@ -522,7 +522,8 @@
 	$feed->set_feed_url($url);
 	$feed->set_cache_class('WP_Feed_Cache');
 	$feed->set_file_class('WP_SimplePie_File');
-	$feed->set_cache_duration(apply_filters('wp_feed_cache_transient_lifetime', 43200));
+	$feed->set_cache_duration(apply_filters('wp_feed_cache_transient_lifetime', 43200, $url));
+	do_action('wp_feed_options', $feed, $url);
 	$feed->init();
 	$feed->handle_content_type();