IIS Fast-CGI HTTPS

$_SERVER['HTTPS']

Set to a non-empty value if the script was queried through the HTTPS protocol.
Note:Note that when using ISAPI with IIS, the value will be off if the request was not made through the HTTPS protocol.

上面這段文字來源是官方說明文件。而本篇文章的重點是
當PHP在IIS透過FastCGI執行的時候，$_SERVER['HTTPS']的值也是off，而不是empty value

所以因此產生了一個問題：isset($_SERVER['HTTPS'])
在這種環境下，測試isset()是沒有意義的，只會回傳TRUE
應該改為類似這種判斷式
if($_SERVER['HTTPS'] == 'off')

註：Gallery 1就有上述的問題。詳細說明點此