Description:
------------
When a couple of cURL options are set in a specific and valid way, curl_exec() never returns and PHP does not throw any exception, causing indefinite hang.

Same code in php 5.6.x (in each x32/x64 ts/nts) worked as expected.

In php 7.0.3 (x32/x64 nts, ts not tried) hang occurs.



Test script:
---------------
<?php
repo();
function repo() {
	$location = 'https://mail.microsoft.com/ews/exchange.asmx';
	$request = "01234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234";

	$ch = curl_init($location);
	curl_setopt($ch, CURLOPT_POSTFIELDS, $request);
	curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC | CURLAUTH_NTLM);
	curl_setopt($ch, CURLOPT_USERPWD, ' ');

	$response = curl_exec($ch);
}

Expected result:
----------------
Call to curl_exec($ch) returns.



Actual result:
--------------
Call to curl_exec($ch) never returns.

However....

If you change $location to an invalid endpoint or one that does not require NTLM, curl_exec() returns.

If you remove the 'CURLAUTH_BASIC' leaving only 'CURLAUTH_NTLM', curl_exec() returns;

If you remove 'CURLAUTH_NTLM' leaving only 'CURLAUTH_BASIC', curl_exec() returns;

If you set an empty string ('') instead of one with one or more characters to CURLOPT_USERPWD, curl_exec() returns.

$request is a string with 1025 characters. If you remove one character, leaving a (suspiciously sized) 1024 character length $request, curl_exec($ch) returns.