Make sure we are using the admin-ajax handler when we call wp_die() for WP_Ajax_Response. see #20024.

git-svn-id: http://svn.automattic.com/wordpress/trunk@19911 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-ajax-response.php

@@ -131,6 +131,9 @@ class WP_Ajax_Response {
 		foreach ( (array) $this->responses as $response )
 			echo $response;
 		echo '</wp_ajax>';
-		wp_die();
+		if ( defined( 'DOING_AJAX' ) && DOING_AJAX )
+			wp_die();
+		else
+			die();
 	}
 }