WWW.responseHeader["STATUS"] does not exists - windows-phone-8

Question

I already asked on answers.unity3d but as there is no response I'll ask on SO too..
I'm not able to retrieve the http status of a response on the WWW object on Windows Phone 8 and Windows RT 8.1 (while it's ok on IOS/Android).
www.responseHeader["STATUS"] does not exists and the hidden field _responseHeaderString does not contain as first line
HTTP/1.1 200 OK
responseHeaderString :
Server: nginx
Date: Wed, 21 Oct 2015 07:44:36 GMT
Last-Modified: Mon, 07 Sep 2015 11:43:46 GMT
Connection: keep-alive
Expires: Fri, 20 Nov 2015 07:44:36 GMT
Cache-Control: max-age=2592000
Cache-Control: public
responseHeader :
{
"SERVER" : "nginx"
"DATE" : "Wed, 21 Oct 2015 07:44:36 GMT"
"LAST-MODIFIED": "Mon, 07 Sep 2015 11:43:46 GMT"
"CONNECTION" : "keep-alive"
"EXPIRES" : "Fri, 20 Nov 2015 07:44:36 GMT"
"CACHE-CONTROL": "public"
}
Sample code to reproduce : (tested on an empty new project)
WWW www = new WWW("http://www.google.com");
yield return www;
Debug.Log("Google Status : " + www.responseHeaders.ContainsKey("STATUS")); // False
Debug.Log(www.text); // <doctype ...
Debug.Log(www.responseHeaders["STATUS"]); // KeyError
Am I missing something or is there someone that can confirm this as a bug ?
Edit:
Still not able to retrieve the http status with the latest 5.3

Answer 1

Your network server is probably responding with a different (unexpected) response to each device. For various reasons such as the user agent string, which could lead the WWW class to not get the STATUS.
Firstly, I would install a proxy so you can see exactly what the phone sends and what the server raw response is. Either Charles Proxy (mac/windows) or Fiddler (windows) are great.
Here is the actual code that Unity WWW class is using to generate status:
if (num++ == 0 && text.StartsWith("HTTP"))
{
dictionary["STATUS"] = text;
}
Ref: https://github.com/MattRix/UnityDecompiled/blob/master/UnityEngine/UnityEngine/WWW.cs#L483
From the proxy it should be clear what is happening. If not, post the request and response here (as raw).

Answer 2

Try reading the www.error before looking for the STATUS header.
// Construct the response object
string error = www.error;
if (error == null) {
if (www.responseHeaders.ContainsKey("STATUS")) {
string [] status=www.responseHeaders["STATUS"].Split(' ');
if (status.Length>2 && status[2] != "OK") {
error = www.responseHeaders["STATUS"];
}
}
}