Description:
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PHP is compiled with option "--with-curlwrappers". Whenever a HEAD request issued with "file_get_contents", "$http_response_header" is not filled-up but upon calling "get_headers()", variable "$http_response_header" auto-magically filled up.

Test script:
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$url = 'http://www.google.com';
$ctx = stream_context_create();

stream_context_set_option($ctx, array('http' => array('method' => 'HEAD','timeout' => 60)));

$res = file_get_contents($url, false, $ctx);
var_dump($http_response_header); // NULL
get_headers($url);
var_dump($http_response_header); // filled up correctly

Expected result:
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"$http_response_header" filled-up correctly

Actual result:
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"$http_response_header" is always NULL