commit b814a7ce20f73cc46efda8bb15f14ef709ecd061
Author: Brückner Tamás <tamas.bruckner@integralvision.hu>
Date:   Mon Sep 22 16:36:04 2014 +0200

    No error on intersect

diff --git a/commerce_email.module b/commerce_email.module
index 87401d0..7e055e9 100755
--- a/commerce_email.module
+++ b/commerce_email.module
@@ -117,7 +117,11 @@ function commerce_email_settings_form() {
 }
 
 function commerce_email_preprocess_token_tree(&$variables) {
-  if (array_intersect(array('node', 'user'), $variables['token_types'])) {
+  if (
+      isset($variables['token_types'])
+      && is_array($variables['token_types'])
+      && array_intersect(array('node', 'user'), $variables['token_types'])
+  ) {
     $variables['recursion_limit'] = 2;
   }
 }