$_SERVER['PHP_SELF'] intermittently returning two leading forward slashes
<p>Why would $_SERVER['PHP_SELF'] return a filename in one instance as /test/foo.bar and another instance (executed from the same php script) as //test/foo.bar (with double leading forward slashes)?</p>

<p>form.php sends $_GET to login.php. login.php redirects to</p>

<pre><code>header ('Location: test/foo.bar')
</code></pre>

<p>foo.bar includes: </p>

<pre><code>$page = filter_var($_SERVER['SCRIPT_NAME'], FILTER_SANITIZE_STRING);
</code></pre>

<p>(<em>Additionally, I cannot replicate it on demand.</em> )</p>
