Changeset 38925

Timestamp:

10/25/2016 08:47:06 PM (8 years ago)

Author:

rachelbaker

Message:

Feeds: Always return a valid timestamp for the Last-Modified header of comment or post feeds.

Fixes bug where an invalid Last-Modified value would be returned in feed requests for sites that had 0 items to return. Comment or post feeds will now return the current timestamp as the Last-Modified header value. Example: a request for the comments feed for a site without any comments.

Replaced use of the local static variable $cache_lastcommentmodified to store the modified date in get_lastcommentmodified() with the Object Cache API. The get_lastcommentmodified() function returns early if there is a cached value and returns false if there where no comments found. Introduced _clear_modified_cache_on_transition_comment_status() to flush the lastcommentmodified cache key when a comment enters or leaves approval status. In get_lastpostmodified() return early if there is a cached value and return false if there are no posts found.

Props swissspidy, rachelbaker, dllh, leobaiano.
Fixes #38027.

Location:

trunk

Files:

• src/wp-includes/class-wp.php (modified) (1 diff)
• src/wp-includes/comment.php (modified) (3 diffs)
• src/wp-includes/default-filters.php (modified) (1 diff)
• src/wp-includes/feed-atom-comments.php (modified) (1 diff)
• src/wp-includes/feed-atom.php (modified) (1 diff)
• src/wp-includes/feed-rdf.php (modified) (1 diff)
• src/wp-includes/feed-rss.php (modified) (1 diff)
• src/wp-includes/feed-rss2-comments.php (modified) (1 diff)
• src/wp-includes/feed-rss2.php (modified) (1 diff)
• src/wp-includes/post.php (modified) (1 diff)
• tests/phpunit/tests/comment/lastCommentModified.php (added)

trunk/src/wp-includes/class-wp.php

@@ -423 +423 @@
             $headers['Content-Type'] = feed_content_type( $type ) . '; charset=' . get_option( 'blog_charset' );
 
-            // We're showing a feed, so WP is indeed the only thing that last changed
-            if ( !empty($this->query_vars['withcomments'])
-                || false !== strpos( $this->query_vars['feed'], 'comments-' )
-                || ( empty($this->query_vars['withoutcomments'])
-                    && ( !empty($this->query_vars['p'])
-                        || !empty($this->query_vars['name'])
-                        || !empty($this->query_vars['page_id'])
-                        || !empty($this->query_vars['pagename'])
-                        || !empty($this->query_vars['attachment'])
-                        || !empty($this->query_vars['attachment_id'])
-                    )
-                )
-            )
-                $wp_last_modified = mysql2date('D, d M Y H:i:s', get_lastcommentmodified('GMT'), 0).' GMT';
-            else
-                $wp_last_modified = mysql2date('D, d M Y H:i:s', get_lastpostmodified('GMT'), 0).' GMT';
+            // We're showing a feed, so WP is indeed the only thing that last changed.
+            if ( ! empty( $this->query_vars['withcomments'] )
+                 || false !== strpos( $this->query_vars['feed'], 'comments-' )
+                 || ( empty( $this->query_vars['withoutcomments'] )
+                      && ( ! empty( $this->query_vars['p'] )
+                           || ! empty( $this->query_vars['name'] )
+                           || ! empty( $this->query_vars['page_id'] )
+                           || ! empty( $this->query_vars['pagename'] )
+                           || ! empty( $this->query_vars['attachment'] )
+                           || ! empty( $this->query_vars['attachment_id'] )
+                      )
+                 )
+            ) {
+                $wp_last_modified = mysql2date( 'D, d M Y H:i:s', get_lastcommentmodified( 'GMT' ), false );
+            } else {
+                $wp_last_modified = mysql2date( 'D, d M Y H:i:s', get_lastpostmodified( 'GMT' ), false );
+            }
+
+            if ( ! $wp_last_modified ) {
+                $wp_last_modified = date( 'D, d M Y H:i:s' );
+            }
+
+            $wp_last_modified .= ' GMT';
+
             $wp_etag = '"' . md5($wp_last_modified) . '"';
             $headers['Last-Modified'] = $wp_last_modified;

trunk/src/wp-includes/comment.php

@@ -294 +294 @@
  *
  * @since 1.5.0
+ * @since 4.7.0 Replaced caching the modified date in a local static variable
+ *              with the Object Cache API.
  *
  * @global wpdb $wpdb WordPress database abstraction object.
- * @staticvar array $cache_lastcommentmodified
- *
- * @param string $timezone Which timezone to use in reference to 'gmt', 'blog',
- *      or 'server' locations.
- * @return string Last comment modified date.
- */
-function get_lastcommentmodified($timezone = 'server') {
+ *
+ * @param string $timezone Which timezone to use in reference to 'gmt', 'blog', or 'server' locations.
+ * @return string|false Last comment modified date on success, false on failure.
+ */
+function get_lastcommentmodified( $timezone = 'server' ) {
     global $wpdb;
-    static $cache_lastcommentmodified = array();
-
-    if ( isset($cache_lastcommentmodified[$timezone]) )
-        return $cache_lastcommentmodified[$timezone];
-
-    $add_seconds_server = date('Z');
-
-    switch ( strtolower($timezone)) {
+
+    $timezone = strtolower( $timezone );
+    $key = "lastcommentmodified:$timezone";
+
+    $comment_modified_date = wp_cache_get( $key, 'timeinfo' );
+    if ( false !== $comment_modified_date ) {
+        return $comment_modified_date;
+    }
+
+    switch ( $timezone ) {
         case 'gmt':
-            $lastcommentmodified = $wpdb->get_var("SELECT comment_date_gmt FROM $wpdb->comments WHERE comment_approved = '1' ORDER BY comment_date_gmt DESC LIMIT 1");
+            $comment_modified_date = $wpdb->get_var( "SELECT comment_date_gmt FROM $wpdb->comments WHERE comment_approved = '1' ORDER BY comment_date_gmt DESC LIMIT 1" );
             break;
         case 'blog':
-            $lastcommentmodified = $wpdb->get_var("SELECT comment_date FROM $wpdb->comments WHERE comment_approved = '1' ORDER BY comment_date_gmt DESC LIMIT 1");
+            $comment_modified_date = $wpdb->get_var( "SELECT comment_date FROM $wpdb->comments WHERE comment_approved = '1' ORDER BY comment_date_gmt DESC LIMIT 1" );
             break;
         case 'server':
-            $lastcommentmodified = $wpdb->get_var($wpdb->prepare("SELECT DATE_ADD(comment_date_gmt, INTERVAL %s SECOND) FROM $wpdb->comments WHERE comment_approved = '1' ORDER BY comment_date_gmt DESC LIMIT 1", $add_seconds_server));
+            $add_seconds_server = date( 'Z' );
+
+            $comment_modified_date = $wpdb->get_var( $wpdb->prepare( "SELECT DATE_ADD(comment_date_gmt, INTERVAL %s SECOND) FROM $wpdb->comments WHERE comment_approved = '1' ORDER BY comment_date_gmt DESC LIMIT 1", $add_seconds_server ) );
             break;
     }
 
-    $cache_lastcommentmodified[$timezone] = $lastcommentmodified;
-
-    return $lastcommentmodified;
+    if ( $comment_modified_date ) {
+        wp_cache_set( $key, $comment_modified_date, 'timeinfo' );
+
+        return $comment_modified_date;
+    }
+
+    return false;
 }
 
@@ -1574 +1582 @@
 
 /**
+ * Clear the lastcommentmodified cached value when a comment status is changed.
+ *
+ * Deletes the lastcommentmodified cache key when a comment enters or leaves
+ * 'approved' status.
+ *
+ * @since 4.7.0
+ * @access private
+ *
+ * @param string $new_status The new comment status.
+ * @param string $old_status The old comment status.
+ */
+function _clear_modified_cache_on_transition_comment_status( $new_status, $old_status ) {
+    if ( 'approved' === $new_status || 'approved' === $old_status ) {
+        foreach ( array( 'server', 'gmt', 'blog' ) as $timezone ) {
+            wp_cache_delete( "lastcommentmodified:$timezone", 'timeinfo' );
+        }
+    }
+}
+
+/**
  * Get current commenter's name, email, and URL.
  *
@@ -1682 +1710 @@
     if ( $comment_approved == 1 ) {
         wp_update_comment_count( $comment_post_ID );
+
+        foreach ( array( 'server', 'gmt', 'blog' ) as $timezone ) {
+            wp_cache_delete( "lastcommentmodified:$timezone", 'timeinfo' );
+        }
     }
 

trunk/src/wp-includes/default-filters.php

@@ -214 +214 @@
 add_filter( 'xmlrpc_pingback_error',    'xmlrpc_pingback_error'               );
 add_filter( 'title_save_pre',           'trim'                                );
+
+add_action( 'transition_comment_status', '_clear_modified_cache_on_transition_comment_status', 10, 2 );
 
 add_filter( 'http_request_host_is_external',    'allowed_http_request_hosts', 10, 2 );

trunk/src/wp-includes/feed-atom-comments.php

@@ -38 +38 @@
     <subtitle type="text"><?php bloginfo_rss('description'); ?></subtitle>
 
-    <updated><?php echo mysql2date('Y-m-d\TH:i:s\Z', get_lastcommentmodified('GMT'), false); ?></updated>
+    <updated><?php
+        $date = get_lastcommentmodified( 'GMT' );
+        echo $date ? mysql2date( 'Y-m-d\TH:i:s\Z', $date ) : date( 'Y-m-d\TH:i:s\Z' );
+    ?></updated>
 
 <?php if ( is_singular() ) { ?>

trunk/src/wp-includes/feed-atom.php

@@ -31 +31 @@
     <subtitle type="text"><?php bloginfo_rss("description") ?></subtitle>
 
-    <updated><?php echo mysql2date('Y-m-d\TH:i:s\Z', get_lastpostmodified('GMT'), false); ?></updated>
+    <updated><?php
+        $date = get_lastpostmodified( 'GMT' );
+        echo $date ? mysql2date( 'Y-m-d\TH:i:s\Z', $date ) : date( 'Y-m-d\TH:i:s\Z' );
+    ?></updated>
 
     <link rel="alternate" type="<?php bloginfo_rss('html_type'); ?>" href="<?php bloginfo_rss('url') ?>" />

trunk/src/wp-includes/feed-rdf.php

@@ -34 +34 @@
     <link><?php bloginfo_rss('url') ?></link>
     <description><?php bloginfo_rss('description') ?></description>
-    <dc:date><?php echo mysql2date('Y-m-d\TH:i:s\Z', get_lastpostmodified('GMT'), false); ?></dc:date>
+    <dc:date><?php
+        $date = get_lastpostmodified( 'GMT' );
+        echo $date ? mysql2date( 'Y-m-d\TH:i:s\Z', $date ) : date( 'Y-m-d\TH:i:s\Z' );
+    ?></dc:date>
     <sy:updatePeriod><?php
         /** This filter is documented in wp-includes/feed-rss2.php */

trunk/src/wp-includes/feed-rss.php

@@ -15 +15 @@
     <link><?php bloginfo_rss('url') ?></link>
     <description><?php bloginfo_rss('description') ?></description>
-    <lastBuildDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></lastBuildDate>
+    <lastBuildDate><?php
+        $date = get_lastpostmodified( 'GMT' );
+        echo $date ? mysql2date( 'D, d M Y H:i:s +0000', $date ) : date( 'D, d M Y H:i:s +0000' );
+    ?></lastBuildDate>
     <docs>http://backend.userland.com/rss092</docs>
     <language><?php bloginfo_rss( 'language' ); ?></language>

trunk/src/wp-includes/feed-rss2-comments.php

@@ -44 +44 @@
     <link><?php (is_single()) ? the_permalink_rss() : bloginfo_rss("url") ?></link>
     <description><?php bloginfo_rss("description") ?></description>
-    <lastBuildDate><?php echo mysql2date('r', get_lastcommentmodified('GMT')); ?></lastBuildDate>
+    <lastBuildDate><?php
+        $date = get_lastcommentmodified( 'GMT' );
+        echo $date ? mysql2date( 'r', $date ) : date( 'r' );
+    ?></lastBuildDate>
     <sy:updatePeriod><?php
         /** This filter is documented in wp-includes/feed-rss2.php */

trunk/src/wp-includes/feed-rss2.php

@@ -43 +43 @@
     <link><?php bloginfo_rss('url') ?></link>
     <description><?php bloginfo_rss("description") ?></description>
-    <lastBuildDate><?php echo mysql2date('D, d M Y H:i:s +0000', get_lastpostmodified('GMT'), false); ?></lastBuildDate>
+    <lastBuildDate><?php
+        $date = get_lastpostmodified( 'GMT' );
+        echo $date ? mysql2date( 'D, d M Y H:i:s +0000', $date ) : date( 'D, d M Y H:i:s +0000' );
+    ?></lastBuildDate>
     <language><?php bloginfo_rss( 'language' ); ?></language>
     <sy:updatePeriod><?php

trunk/src/wp-includes/post.php

@@ -5613 +5613 @@
 
     $date = wp_cache_get( $key, 'timeinfo' );
-
-    if ( ! $date ) {
-        if ( 'any' === $post_type ) {
-            $post_types = get_post_types( array( 'public' => true ) );
-            array_walk( $post_types, array( $wpdb, 'escape_by_ref' ) );
-            $post_types = "'" . implode( "', '", $post_types ) . "'";
-        } else {
-            $post_types = "'" . sanitize_key( $post_type ) . "'";
-        }
-
-        switch ( $timezone ) {
-            case 'gmt':
-                $date = $wpdb->get_var("SELECT post_{$field}_gmt FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
-                break;
-            case 'blog':
-                $date = $wpdb->get_var("SELECT post_{$field} FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
-                break;
-            case 'server':
-                $add_seconds_server = date( 'Z' );
-                $date = $wpdb->get_var("SELECT DATE_ADD(post_{$field}_gmt, INTERVAL '$add_seconds_server' SECOND) FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
-                break;
-        }
-
-        if ( $date ) {
-            wp_cache_set( $key, $date, 'timeinfo' );
-        }
-    }
-
-    return $date;
+    if ( false !== $date ) {
+        return $date;
+    }
+
+    if ( 'any' === $post_type ) {
+        $post_types = get_post_types( array( 'public' => true ) );
+        array_walk( $post_types, array( $wpdb, 'escape_by_ref' ) );
+        $post_types = "'" . implode( "', '", $post_types ) . "'";
+    } else {
+        $post_types = "'" . sanitize_key( $post_type ) . "'";
+    }
+
+    switch ( $timezone ) {
+        case 'gmt':
+            $date = $wpdb->get_var("SELECT post_{$field}_gmt FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
+            break;
+        case 'blog':
+            $date = $wpdb->get_var("SELECT post_{$field} FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
+            break;
+        case 'server':
+            $add_seconds_server = date( 'Z' );
+            $date = $wpdb->get_var("SELECT DATE_ADD(post_{$field}_gmt, INTERVAL '$add_seconds_server' SECOND) FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
+            break;
+    }
+
+    if ( $date ) {
+        wp_cache_set( $key, $date, 'timeinfo' );
+
+        return $date;
+    }
+
+    return false;
 }