Would you mind do some test?
In QueryString.php, find:
// Looks like this is an IPv4 address
if (strpos($part[1][1], '.') !== false)
{
and replace it with:
if (!isset($part[1][1]))
log_error('Original address: ' . $addr);
// Looks like this is an IPv4 address
if (!isset($part[1][1]) || strpos($part[1][1], '.') !== false)
{
Then cleanup the error log and keep a eye on it to see if any error that looks like:
Original address: 123.123.123
appears.