Breaking Change in .net 4.5 Callcontext when doing a HTTP Post to an ashx?
<p>I've just installed .Net 4.5 and noticed that an existing web application, that is still running under .Net 4, is failing when I'm trying to retrieve an item from the CallContext, when before the install was working perfectly and has done for the last year.</p>

<p>On the AuthenticateRequest event of the application, we use the Identity of the user to load more security information about the user. This is then added to the CallContext for later use.</p>

<p>e.g.</p>

<pre><code> protected void Application_AuthenticateRequest(object sender, EventArgs e)
    {
        if (HttpContext.Current.User != null &amp;&amp; HttpContext.Current.User.Identity.IsAuthenticated)
        { 
             // set someValue 
            CallContext.SetData(ContextIdentifier, someValue);
        }
    }
</code></pre>

<p>The value in the callcontext is retrieved at later points in the lifecycle. e.g 
    CallContext.GetData(ContextIdentifier)</p>

<p>However, when requesting an .ashx from a http "POST" request, the value is now null but on a "GET" request the value is correct.</p>

<p>I can't find an documented reason why this has suddenly changed or whether this is now by design and why it would affect existing .Net 4 applications?</p>

<p>My obvious fix is to also put the data on the HTTPContext, yet without understanding the reason why I'm unsure if using the CallContext will cause issues elsewhere!</p>

<p>Any help / understanding would be gratefully recieved</p>
