/undefined appearing lots of time in my 404 error log
<p>Basically in my error log i see lots of:</p>

<pre><code>mysite.com/undefined (with referer coming from random pages of the website)

User-Agent: Mozilla/5.0 (Windows NT 6.0) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1
</code></pre>

<p>(and some other user agent)</p>

<p>I have of course checked HTML or DOM for links with <code>/undefined</code> or something like that and there is just nothing. I have checked network tab with developer tools and on those page nothing requests <code>/undefined</code> (with my chrome).</p>

<p>I have then setted a <a href="http://stackoverflow.com/a/11168326/496223">javascript logger</a> to save any error that come up. And in the log there isn't nothing that throws undefined or something like that... </p>

<p>This is driving me crazy. Of course if i go on tihs page with my chrome, javascript doesn't print any error</p>

<p>Notice: i have read everything <a href="http://stackoverflow.com/questions/11017609/undefined-randomly-appended-in-1-of-requested-urls-on-my-website-since-12-jun">here</a></p>

<h2>Edit</h2>

<p>Notice2: Beside that javascript error logger I have added an eventlistener (as explained in the answer linked)</p>

<pre><code>$("body").on("click", "a[href$='undefined']", function() {
    window.onerror('Bad link: ' + $(this).html()); //alert home base
});
</code></pre>

<p>And this never get triggered. (I have tested it with a manual /undefined link and the logger works)</p>

<p>Also I found <a href="http://productforums.google.com/forum/#!topic/chrome/G1snYHaHSOc" rel="nofollow">this topic</a> on google groups. Webmaster there are experiencing the same problem but no one has managed to nail down to the cause.</p>

<p>Maybe it's some <strong>extension</strong> on chrome or any other browser that causes this requests.</p>
