Hmm, that's the following (highlighted) line in /includes/functions/functions_lookups.php:
Code:
function zen_run_normal() {
$zc_run = false;
switch (true) {
case (strstr(EXCLUDE_ADMIN_IP_FOR_MAINTENANCE, $_SERVER['REMOTE_ADDR'])):
// down for maintenance not for ADMIN
$zc_run = true;
break;
The PHP warning is that the $_SERVER['REMOTE_ADDR'] portion is null/empty. While it shouldn't be empty, if you've got someone pounding on your site it's quite possible that they've got a mechanism to obfuscate that value. A possible solution for this case would be to change the line to read:
Code:
case (!empty ($_SERVER['REMOTE_ADDR']) && strstr(EXCLUDE_ADMIN_IP_FOR_MAINTENANCE, $_SERVER['REMOTE_ADDR'])):
The strstr case in the functions_lookups module is the tip of the proverbial iceberg; using the DTK in a v1.5.3 test site's admin to search for $_SESSION['REMOTE_ADDR'] yields 55 matches, most of them similar to the function's usage.