Description:
------------
On php.net Doc sites (e.g. http://php.net/print_r) the scripts return a HTTP/1.1 header even if the client requested HTTP/1.0

This leads to Content-Transfer-Encoding metadata being inserted into the websites body.

Reproduce code:
---------------
  $ telnet php3.de 80
  Trying 217.160.72.57...
  Connected to php3.de.
  Escape character is '^]'.
  HEAD /print_r HTTP/1.0
  Connection: close
  Host: de3.php.net

  HTTP/1.1 200 OK
  [..]

Expected result:
----------------
HTTP/1.0 200 OK

Actual result:
--------------
The header is generated at this point:

== schnipp == 
// Send out a proper status header
function status_header($num)
{
    // Set status text
    switch ($num) {
        case 200: $status = "OK"; break;
        case 301: $status = "Moved Permanently"; break;
        case 302: $status = "Found"; break;
        case 404: $status = "Not Found"; break;
        default: return FALSE;
    }

    // BC code for PHP < 4.3.0
    @header("HTTP/1.1 $num $status");
    @header("Status: $num $status", TRUE, $num);

    return TRUE;
}
== schnapp ==

See http://trac.wordpress.org/ticket/3886 for the exact same problem including a patch for older wordpress versions.

Here is a screenshot of the website with garbage in it when requested via squid proxy server with HTTP/1.0:

  http://test.thermoman.de/images/php_net_chunked_error.png

Please cross-reference bug #42402.

Credits to Timm Friebe for the deeper look inside.