Ticket #27003: 27003.23.diff

src/wp-includes/ms-settings.php

@@ -124 +124 @@
                 if ( $current_blog && $current_blog->domain === $current_site->domain && $current_blog->path === $current_site->path ) {
                         $current_site->blog_id = $current_blog->blog_id;
                 } else {
-                        // @todo we should be able to cache the blog ID of a network's main site easily.
-                        $current_site->blog_id = $wpdb->get_var( $wpdb->prepare( "SELECT blog_id FROM $wpdb->blogs WHERE domain = %s AND path = %s",
-                                $current_site->domain, $current_site->path ) );
+                        if ( ! $current_site->blog_id = wp_cache_get( 'network_' . $current_site->id . '_blog_id', 'site-options' ) ) {
+                                $current_site->blog_id = $wpdb->get_var( $wpdb->prepare( "SELECT blog_id FROM $wpdb->blogs WHERE domain = %s AND path = %s",
+                                        $current_site->domain, $current_site->path ) );
+                                wp_cache_add( 'network_' . $current_site->id . '_blog_id', $current_site->blog_id, 'site-options' );
+                        }
                 }
         }