Feeds: `<comments>` is optional in RSS2, so don't include it when comments aren't present or open. Same for `<wfw:commentRss>` and `<slash:comments>`

Adds unit test.

Props swissspidy, realloc, hakre, sivel.
Fixes #9134.


git-svn-id: https://develop.svn.wordpress.org/trunk@35506 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/feed-atom.php

@@ -78,10 +78,13 @@ do_action( 'rss_tag_pre', 'atom' );
 	 * @since 2.0.0
 	 */
 	do_action( 'atom_entry' );
+
+	if ( get_comments_number() || comments_open() ) :
 		?>
 		<link rel="replies" type="<?php bloginfo_rss('html_type'); ?>" href="<?php the_permalink_rss() ?>#comments" thr:count="<?php echo get_comments_number()?>"/>
 		<link rel="replies" type="application/atom+xml" href="<?php echo esc_url( get_post_comments_feed_link(0, 'atom') ); ?>" thr:count="<?php echo get_comments_number()?>"/>
 		<thr:total><?php echo get_comments_number()?></thr:total>
+	<?php endif; ?>
 	</entry>
 	<?php endwhile ; ?>
 </feed>

src/wp-includes/feed-rss2.php

@@ -83,7 +83,9 @@ do_action( 'rss_tag_pre', 'rss2' );
 	<item>
 		<title><?php the_title_rss() ?></title>
 		<link><?php the_permalink_rss() ?></link>
+<?php if ( get_comments_number() || comments_open() ) : ?>
 		<comments><?php comments_link_feed(); ?></comments>
+<?php endif; ?>
 		<pubDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_post_time('Y-m-d H:i:s', true), false); ?></pubDate>
 		<dc:creator><![CDATA[<?php the_author() ?>]]></dc:creator>
 		<?php the_category_rss('rss2') ?>
@@ -100,8 +102,10 @@ do_action( 'rss_tag_pre', 'rss2' );
 		<content:encoded><![CDATA[<?php the_excerpt_rss(); ?>]]></content:encoded>
 	<?php endif; ?>
 <?php endif; ?>
+<?php if ( get_comments_number() || comments_open() ) : ?>
 		<wfw:commentRss><?php echo esc_url( get_post_comments_feed_link(null, 'rss2') ); ?></wfw:commentRss>
 		<slash:comments><?php echo get_comments_number(); ?></slash:comments>
+<?php endif; ?>
 <?php rss_enclosure(); ?>
 	<?php
 	/**

tests/phpunit/tests/feed/rss2.php

@@ -102,8 +102,7 @@ class Tests_Feed_RSS2 extends WP_UnitTestCase {
 		$xml = xml_to_array($feed);
 
 		// get all the rss -> channel -> item elements
-		$items = xml_find($xml, 'rss', 'channel', 'item');
-		$posts = get_posts('numberposts='.$this->post_count);
+		$items = xml_find( $xml, 'rss', 'channel', 'item' );
 
 		// check each of the items against the known post data
 		foreach ( $items as $key => $item ) {
@@ -178,4 +177,36 @@ class Tests_Feed_RSS2 extends WP_UnitTestCase {
 			$this->assertEquals( html_entity_decode( get_post_comments_feed_link( $post->ID) ), $comment_rss[0]['content'] );
 		}
 	}
+
+	/**
+	 * @ticket 9134
+	 */
+	function test_items_comments_closed() {
+		add_filter( 'comments_open', '__return_false' );
+
+		$this->go_to( '/?feed=rss2' );
+		$feed = $this->do_rss2();
+		$xml = xml_to_array($feed);
+
+		// get all the rss -> channel -> item elements
+		$items = xml_find( $xml, 'rss', 'channel', 'item' );
+
+		// check each of the items against the known post data
+		foreach ( $items as $key => $item ) {
+			// Get post for comparison
+			$guid = xml_find( $items[$key]['child'], 'guid' );
+			preg_match( '/\?p=(\d+)/', $guid[0]['content'], $matches );
+			$post = get_post( $matches[1] );
+
+			// comment link
+			$comments_link = xml_find( $items[ $key ]['child'], 'comments' );
+			$this->assertEmpty( $comments_link );
+
+			// comment rss
+			$comment_rss = xml_find( $items[ $key ]['child'], 'wfw:commentRss' );
+			$this->assertEmpty( $comment_rss );
+		}
+
+		remove_filter( 'comments_open', '__return_false' );
+	}
 }