Ticket #21665: 21665-v1.diff

Index: wp-admin/includes/class-wp-posts-list-table.php
===================================================================
--- wp-admin/includes/class-wp-posts-list-table.php     (revision 21596)
+++ wp-admin/includes/class-wp-posts-list-table.php     (working copy)
@@ -45,6 +45,15 @@
         */
        var $sticky_posts_count = 0;
 
+       /**
+        * Holds the number of pages designated as System Pages.
+        *
+        * @since 3.5.0
+        * @var int
+        * @access private
+        */
+       var $system_pages_count = 0;
+
        function __construct() {
                global $post_type_object, $wpdb;
 
@@ -67,6 +76,11 @@
                        $this->sticky_posts_count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT( 1 ) FROM $wpdb->posts WHERE post_type = %s AND post_status != 'trash' AND ID IN ($sticky_posts)", $post_type ) );
                }
 
+               if ( 'page' == $post_type && $system_pages = get_option( 'system_pages' ) ) {
+                       $system_pages = implode( ', ', array_map( 'absint', (array) $system_pages ) );
+                       $this->system_pages_count = $wpdb->get_var( $wpdb->prepare( "SELECT COUNT( 1 ) FROM $wpdb->posts WHERE post_type = %s AND post_status != 'trash' AND ID IN ($system_pages)", $post_type ) );
+               }
+
                parent::__construct( array(
                        'plural' => 'posts',
                ) );
@@ -178,6 +192,15 @@
                        $status_links = array_merge( array_slice( $status_links, 0, $split ), $sticky_link, array_slice( $status_links, $split ) );
                }
 
+               if ( ! empty( $this->system_pages_count ) ) {
+                       $class = ! empty( $_REQUEST['show_system'] ) ? ' class="current"' : '';
+
+                       $system_link = array( 'system' => "<a href='edit.php?post_type=$post_type&amp;show_system=1'$class>" . sprintf( _nx( 'System <span class="count">(%s)</span>', 'System <span class="count">(%s)</span>', $this->system_pages_count, 'posts' ), number_format_i18n( $this->system_pages_count ) ) . '</a>' );
+
+                       $split = 1 + array_search( ( isset( $status_links['publish'] ) ? 'publish' : 'all' ), array_keys( $status_links ) );
+                       $status_links = array_merge( array_slice( $status_links, 0, $split ), $system_link, array_slice( $status_links, $split ) );
+               }
+
                return $status_links;
        }
 
Index: wp-admin/includes/post.php
===================================================================
--- wp-admin/includes/post.php  (revision 21596)
+++ wp-admin/includes/post.php  (working copy)
@@ -887,6 +887,9 @@
        if ( ! empty( $q['show_sticky'] ) )
                $query['post__in'] = (array) get_option( 'sticky_posts' );
 
+       if ( ! empty( $q['show_system'] ) )
+               $query['post__in'] = (array) get_option( 'system_pages' );
+
        wp( $query );
 
        return $avail_post_stati;
Index: wp-admin/options-reading.php
===================================================================
--- wp-admin/options-reading.php        (revision 21596)
+++ wp-admin/options-reading.php        (working copy)
@@ -90,6 +90,25 @@
        if ( 'page' == get_option( 'show_on_front' ) && ! get_option( 'page_on_front' ) && ! get_option( 'page_for_posts' ) )
                update_option( 'show_on_front', 'posts' );
 ?>
+
+<?php
+       if ( get_option('page_for_posts') != '0' ) :
+
+               make_system_page( get_option('page_for_posts') );
+
+               if ( get_option('page_for_posts') != get_option('page_for_posts_last') ) :
+                       undo_system_page( get_option('page_for_posts_last') );
+               endif;
+               
+               update_option('page_for_posts_last', get_option('page_for_posts') );
+
+       else:
+               undo_system_page( get_option('page_for_posts_last') );
+               update_option('page_for_posts_last', '0');
+
+       endif;
+?>
+
 <table class="form-table">
 <tr valign="top">
 <th scope="row"><?php _e( 'Front page displays' ); ?></th>
Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php        (revision 21596)
+++ wp-includes/post.php        (working copy)
@@ -1946,6 +1946,52 @@
 }
 
 /**
+ * Classify a page as a System Page.
+ *
+ * @since 3.5.0
+ *
+ * @param int $post_id Post ID.
+ */
+function make_system_page($post_id) {
+       $system_pages = get_option('system_pages');
+       $post_id = (int) $post_id;
+
+       if ( !is_array($system_pages) )
+               $system_pages = array($post_id);
+
+       if ( ! in_array($post_id, $system_pages) )
+               $system_pages[] = $post_id;
+
+       update_option('system_pages', $system_pages);
+}
+
+/**
+ * De-Classify a page as a System Page.
+ *
+ * @since 3.5.0
+ *
+ * @param int $post_id Post ID.
+ */
+function undo_system_page($post_id) {
+       $system_pages = get_option('system_pages');
+       $post_id = (int) $post_id;
+
+       if ( !is_array($system_pages) )
+               return;
+
+       if ( ! in_array($post_id, $system_pages) )
+               return;
+
+       $offset = array_search($post_id, $system_pages);
+       if ( false === $offset )
+               return;
+
+       array_splice($system_pages, $offset, 1);
+
+       update_option('system_pages', $system_pages);
+}
+
+/**
  * Count number of posts of a post type and is user has permissions to view.
  *
  * This function provides an efficient method of finding the amount of post's