Description:
------------
When multiple response headers with the same name are set using header(..., false), only the last value is returned by apache_response_headers().

apache_response_headers() returns an associative array, so it cannot have multiple entries for the same header name. However, according to section 4.2 of RFC 2616, multiple headers with the same name may be combined into one comma-separated header.

    It MUST be possible to combine the multiple header fields into
    one "field-name: field-value" pair, without changing the semantics
    of the message, by appending each subsequent field-value to the
    first, each separated by a comma.

I suggest that apache_response_headers() does this, i.e. combines multiple headers with comma.


Reproduce code:
---------------
header('Foo: 1');
header('Foo: 2', false);
header('Foo: 3', false);
var_dump(apache_response_headers());


Expected result:
----------------
array(2) {
  ["X-Powered-By"]=>
  string(9) "PHP/5.2.5"
  ["Foo"]=>
  string(1) "1,2,3"
}

Actual result:
--------------
array(2) {
  ["X-Powered-By"]=>
  string(9) "PHP/5.2.5"
  ["Foo"]=>
  string(1) "3"
}