[php-src] Issue #13711: Infinite waiting for CURLOPT_WRITEFUNCTION in case of no response

Issue: https://github.com/php/php-src/issues/13711 Author: accountnujen ### Description To reach an address that responds every 5 seconds, I use CURLOPT_WRITEFUNCTION. Since I want to maintain an infinite connection, I have CURLOPT_TIMEOUT => 0. ```php function writer($ch, $data) { handler($data); return strlen($data); } $ch = curl_init("$urlcam/cgi-bin/eventManager.cgi?action=attach&codes=[NewFile]&heartbeat=5"); curl_setopt_array($ch, [ CURLOPT_CONNECTTIMEOUT => 20, CURLOPT_TIMEOUT => 0, CURLOPT_RETURNTRANSFER => 1, CURLOPT_WRITEFUNCTION => 'writer' ]); $result = curl_exec($ch); curl_close($ch); ``` The response looks like this: ``` --myboundary Content-Type: text/plain Content-Length: 9 Heartbeat --myboundary Content-Type: text/plain Content-Length: 9 Heartbeat ... ``` Everything works as long as there is a response from the url. However, if the url stops responding, nothing happens. No error or warning. The PHP script will stay inside the "writer" function and never leave it. For example, if you implement this functionality using fopen: ```php $resource = fopen("http://".$host.$uri, 'r', false, $context); while (!feof($resource)) { print_r(date("d-m-Y H:i:s")); $line = fgets($resource); if (str_contains($line,"--myboundary")) { handler($response); $response = ''; } else { $response.=$line; } } ``` Then the print_r function will be called every minute. Yes, if the url is restored, the fopen connection will not be restored, but at least we can handle the error/state to restart the script. In the case of CURL, this cannot be done as nothing happens. We need to add functionality to leave the function specified in CURLOPT_WRITEFUNCTION. I suppose you could take CURLOPT_CONNECTTIMEOUT and display an error if the WRITEFUNCTION has not received a response within that time. ### PHP Version 8.1.23 ### Operating System Ubuntu 20.04