Include File Vulnerability
<p>I try to read Claroline source code to learn from their coding.<br>
In index.php file, at the first line of code, they write</p>

<pre><code>unset($includePath); // prevent hacking
</code></pre>

<p>You can see full claroline source code from <a href="http://phpxref.free.fr/claroline/nav.html?index.php.source.html" rel="nofollow">here</a>.</p>

<p>They commented that the line is used to prevent hacking..<br>
I have no idea why should they unset <code>$includePath</code> while the variable is never defined before that line..   </p>

<p>What is the purpose of that line of code do actually, and what hacking type that they means?</p>
