Index: src/wp-admin/admin-ajax.php
===================================================================
--- src/wp-admin/admin-ajax.php	(revision 35482)
+++ src/wp-admin/admin-ajax.php	(working copy)
@@ -25,8 +25,9 @@
 send_origin_headers();
 
 // Require an action parameter
-if ( empty( $_REQUEST['action'] ) )
+if ( empty( $_REQUEST['action'] ) ) {
 	die( '0' );
+}
 
 /** Load WordPress Administration APIs */
 require_once( ABSPATH . 'wp-admin/includes/admin.php' );
@@ -69,11 +70,13 @@
 $core_actions_post[] = 'wp-fullscreen-save-post';
 
 // Register core Ajax calls.
-if ( ! empty( $_GET['action'] ) && in_array( $_GET['action'], $core_actions_get ) )
+if ( ! empty( $_GET['action'] ) && in_array( $_GET['action'], $core_actions_get ) ) {
 	add_action( 'wp_ajax_' . $_GET['action'], 'wp_ajax_' . str_replace( '-', '_', $_GET['action'] ), 1 );
+}
 
-if ( ! empty( $_POST['action'] ) && in_array( $_POST['action'], $core_actions_post ) )
+if ( ! empty( $_POST['action'] ) && in_array( $_POST['action'], $core_actions_post ) ) {
 	add_action( 'wp_ajax_' . $_POST['action'], 'wp_ajax_' . str_replace( '-', '_', $_POST['action'] ), 1 );
+}
 
 add_action( 'wp_ajax_nopriv_heartbeat', 'wp_ajax_nopriv_heartbeat', 1 );