Description:
------------
With php 5.2.8 and curlwrapper option, after calling fopen() on a remote url, a call to stream_get_meta_data() returns an empty header list.
If a call to fread() is inserted between fopen() and stream_get_meta_data(), the headers are presents.

The problem appears during a migration from 5.0 without curl, to 5.2 with curl, so it seems curl related.

Calling the test script via strace shows that the socket is opened, but there's no call to read() syscall before the stream_get_meta_data is called.

The problem is not systematically reproduced (certainly due to response latencies), but appears very often.

Reproduce code:
---------------
this version fails :

$src = fopen("http://www.perdu.com", 'r');
$meta = stream_get_meta_data($src);
var_dump($meta);
var_dump($http_response_header);
$data= fread($src, 500);
echo $data."\n\n";

this one works (just call fread before get_meta) :

$src = fopen("http://www.perdu.com", 'r');
$data= fread($src, 500);
$meta = stream_get_meta_data($src);
var_dump($meta);
var_dump($http_response_header);
echo $data."\n\n";


Expected result:
----------------
array(10) {
  ["wrapper_data"]=>
  array(2) {
    ["headers"]=>
    array(8) {
      [0]=>
      string(15) "HTTP/1.1 200 OK"
      [1]=>
      string(35) "Date: Thu, 18 Dec 2008 10:15:19 GMT"
      [2]=>
      string(14) "Server: Apache"
      [3]=> ....

Actual result:
--------------
array(10) {
  ["wrapper_data"]=>
  array(2) {
    ["headers"]=>
    array(0) {
    }
...