Description:
------------
when you call get_headers function with unresolved url (url has dns and ip but is not responding) within script codes running script will be finished without any warning after a short timeout less that one minutes. there is not any warning or return value! running it alone did not raise this error.
pay attention : url must has valid dns ip but has not any response to requests like http://www.sport.ir

Test script:
---------------
ini_set("max_execution_time", "0");
ini_set("max_input_time", "0");
set_time_limit(0);

//  TEST ZONE START
error_reporting(E_ALL);
var_dump(get_headers('http://www.sport.ir'));
echo 'finished';
die;
//  TEST ZONE END

Expected result:
----------------
<br />
<b>Warning</b>:  get_headers(): php_network_getaddresses: getaddrinfo failed: Name or service not known in <b>[SCRIPT-PATH]/[SCRIPT-NAME]</b> on line <b>7</b><br />
<br />
<b>Warning</b>:  get_headers(http://www.sport.ir): failed to open stream: php_network_getaddresses: getaddrinfo failed: Name or service not known in <b>[SCRIPT-PATH]/[SCRIPT-NAME]</b> on line <b>7</b><br />
bool(false)
finished