Ticket #22176: 22176.diff

wp-includes/post.php

@@ -4507 +4507 @@
                 wp_cache_delete( 'all_page_ids', 'posts' );
                 do_action( 'clean_page_cache', $post->ID );
         }
+
+        if ( function_exists( 'wp_cache_incr' ) ) {
+                wp_cache_incr( 'last_changed', 1, 'posts' );
+        } else {
+                $last_changed = wp_cache_get( 'last_changed', 'posts' );
+                wp_cache_set( 'last_changed', $last_changed + 1, 'posts' );
+        }
 }
 
 /**

wp-includes/query.php

@@ -2661 +2661 @@
 
                         $this->request = apply_filters( 'posts_request_ids', $this->request, $this );
 
-                        $ids = $wpdb->get_col( $this->request );
+                        $last_changed = wp_cache_get( 'last_changed', 'posts' );
+                        if ( ! $last_changed )
+                                $last_changed = wp_cache_set( 'last_changed', 1, 'posts' );
+                        $this->cache_key = md5( $this->request ) . $last_changed;
 
+                        if ( ! $ids = wp_cache_get( $this->cache_key, 'posts' ) ) {
+                                $ids = $wpdb->get_col( $this->request );
+                                wp_cache_set( $this->cache_key, $ids, 'posts' );
+                        }
+
                         if ( $ids ) {
                                 $this->posts = $ids;
                                 $this->set_found_posts( $q, $limits );