- Modified patch #256509 by dropcube: report when an invalid cron key is used.

cron.php

@@ -10,4 +10,7 @@
 drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
 if (isset($_GET['cron_key']) && variable_get('cron_key', 'drupal') == $_GET['cron_key']) {
   drupal_cron_run();
-}
\ No newline at end of file
+}
+else {
+  watchdog('cron', 'Cron did not run because an invalid key used.', array(), WATCHDOG_NOTICE);
+}