Fix 76480: Use curl_multi_wait() so that timeouts are respected

[adoy]

Bug #76480

libcurl 7.28 introduced curl_multi_wait(), which is a select() wrapper that respects configured timeouts.

This patch will change the implementation of php curl_multi_select to use curl_multi_wait instead of curl_multi_fdset and select. It will fix #76480 but also unliked behaviour like #63411.

Unless anyone have any objection, I plan to commit it on PHP-7.1 since there should not be any BC.

[adoy]

FYI, HPHP is already using curl_multi_wait when available as a replacement for curl_multi_fdset + select

[staabm]

I guess this should be covered by a unit test

[php-pulls]

Comment on behalf of carusogabriel at php.net:

Labelling

[adoy]

Merged

[xPaw]

Looks like this PR changed return values of curl_multi_select so upgrading to 7.2.11 makes my code run into infinite loops sometimes.

Code I'm running is here: https://github.com/xPaw/Crimp.php/blob/master/Crimp.php

However upon further inspection, I'm not entirely sure why it's doing that.