diff -r 07239de796bb -r e756a8c72c3d cms/drupal/modules/simpletest/tests/upgrade/drupal-6.duplicate-permission.database.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cms/drupal/modules/simpletest/tests/upgrade/drupal-6.duplicate-permission.database.php	Fri Sep 08 12:04:06 2017 +0200
@@ -0,0 +1,8 @@
+<?php
+
+// Simulate duplicated permission condition.
+db_update('permission')->fields(array(
+  'perm' => 'access content, access content',
+))
+->condition('pid', 1)
+->execute();