False WARNING "PHP cli binary is not available in the jail" when PHP is present via global jailkit_c

Hi,
I'd like to report a bug I found in ISPConfig's Jailkit handling. I searched the forum but couldn't find an existing report for this specific scenario.

Environment:

• Debian 13
• ISPConfig 3.3.1p1 (latest stable)
• Apache + PHP-FPM
• PHP 8.4 / 8.5

Problem:
When a website has PHP disabled (php = no) or no explicit PHP version assigned (server_php_id = 0), but an SSH/SFTP jail user is configured, ISPConfig sends a false warning email:

WARNING - The PHP cli binary is not available in the jail of the web example.de / SSH/SFTP user: username. Check your Jailkit setup!
This warning is incorrect when PHP binaries have been added to all jails via the global Jailkit chroot app sections setting under System → Server Config → Jailkit.

Steps to reproduce:

1. Add php8_4 to System → Server Config → Jailkit → Jailkit chroot app sections
2. Create a website with PHP disabled (php = no) – leave server_php_id = 0
3. Create an SSH/SFTP jail user for that website
4. Receive the WARNING email despite PHP being fully functional in the jail

Proof that PHP works fine in the jail:

Code:

chroot /var/www/clients/clientX/webY /usr/bin/php --version
PHP 8.4.22 (cli) (built: Jun  6 2026 06:50:35) (NTS)
Copyright (c) The PHP Group
Built by Debian
Zend Engine v4.4.22, Copyright (c) Zend Technologies

Root cause:
In shelluser_jailkit_plugin.inc.php, function _setup_shell_php(), around line 825:

PHP:

if(!file_exists($php_binary_path)) {
    $app->log("The PHP cli binary " . $this->web['php_cli_binary'] .
              " is not available in the jail...", LOGLEVEL_WARN);

The check relies solely on php_cli_binary from the server_php join, which is empty when server_php_id = 0. It does not check whether a PHP binary is actually present in the jail via the global app sections.

Suggested fix:
Before logging the warning, additionally verify whether any PHP binary exists in the jail:

PHP:

$jail_has_php = !empty(glob($web_docroot . '/usr/bin/php*'));
if(!file_exists($php_binary_path) && !$jail_has_php) {
    $app->log("The PHP cli binary...", LOGLEVEL_WARN);

This way the warning is only triggered when PHP is genuinely missing from the jail, not when it was installed via the global Jailkit sections.

Thanks for looking into this!