Description:
------------
cURL 1.15.5, 1.16.0 and 1.16.1

Got many error in log if request site with empty body.

Sample:
http://bar-navig.yandex.ru/u?sample=test

HTTP/1.1 200 Ok
Connection: close
Cache-control: no-cache, max-age=0
Expires: Thu, 01 Jan 1970 00:00:01 GMT
Content-Type: text/html; charset=windows-1251

and no body.

Reproduce code:
---------------
<?php
$curl = curl_init();
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_HEADER, 0);
curl_setopt($curl, CURLOPT_TIMEOUT, 30);
curl_setopt($curl, CURLOPT_USERAGENT, '');
curl_setopt($curl, CURLOPT_URL, 'http://bar-navig.yandex.ru/u?sample=test');
$return = curl_exec($curl);

echo (curl_errno($this->Curl) == 0) ? 'ok' : 'error';
?>

Expected result:
----------------
error.log

many lines with
httpd in free(): warning: page is already free
httpd in free(): warning: chunk is already free
and
Integer overflow in memory_limit check detected

Actual result:
--------------
Zero page.