cURL incompatibility with Kaspersky (kesl)

[mircobabini]

Summary

I'm facing an issue with some servers having kesl service (Kaspersky) installed and running.

Sometimes wp_remote_* calls fails with error:

Scaricamento del pacchetto di installazione da https://downloads.wordpress.org/plugin/jetpack.10.1.zip...
Warning: Il download non è andato a buon fine. "cURL error 18: transfer closed with 332690 bytes remaining to read"

The number of bytes is completely randomic.
Since it's not consistent, I've prepared this script to be run over and over (without wp-cli cache of course):

while :; do  wp plugin install jetpack && wp plugin delete jetpack && rm -rf /root/.wp-cli/cache/*; done

After digging a lot into WpOrg\Requests\Transport\cURL implementation I've found these lines being the cause of the issue:

<?php
// Force closing the connection for old versions of cURL (<7.22).
if (!isset($headers['Connection'])) {
        $headers['Connection'] = 'close';
}

Disabling these lines, the issue disappear. Why aren't we checking the cURL version here?
I would then suggest these changes:

1. Add a new const const CURL_7_22_0 = 0x071600
2. Check the version and add that header only if needed

Your environment

Environment	Answer
Operating system and version (e.g. Ubuntu 20.04, CentOS, tried both)
PHP version	7.4 (tried others as well)
Requests version	provided with WordPress latest
Autoloader used	WordPress
Link to your project	into a vpn, not accessible through the internet

Tested against develop branch?

• I have verified the issue still exists in the develop branch of Requests.

[mircobabini]

As reported here: https://core.trac.wordpress.org/ticket/54588

[jrfnl]

FYI: A patch for this issue was included in the Requests 2.0.8 release and reverted in Requests 2.0.9 due to it causing problems with Curl 7.29.0 (and possibly others). See #838

Re-opening this issue as it is now unsolved again. This will need further investigation in conjunction with #838.