[php-src] Issue #13926: File system group permission with is_readable and is_writable is not being honored

Issue: https://github.com/php/php-src/issues/13926 Author: SirLouen ### Description # Server Context - Operating system: Fedora 38 - Web server: nginx 1.24.0 - Database version: MariaDB 10.5.23 - PHP version: PHP 8.2.17 - phpMyAdmin version: phpMyAdmin 5.2.1-1.fc38 # The following code: Script in /var/www/test/info.php: ```php <?php echo exec('whoami') . PHP_EOL; if (is_readable('/var/www/test/check.php')) echo "OK"; else echo "KO"; echo PHP_EOL; if(!is_dir('/var/www/test/test_dir')) { echo 'Nope. Nothing!'.PHP_EOL; } else { echo 'Found it!'.PHP_EOL; } ``` With the following filesystems permissions: ```bash # ll -a drwxr-xr-x. 3 alcudia alcudia 4096 Apr 9 14:42 . drwxr-xr-x. 7 root root 4096 Apr 9 01:40 .. -rw-r-----. 1 nginx nginx 21 Apr 9 01:42 check.php -rwxrwxrwx. 1 root root 252 Apr 9 14:42 info.php dr-xr-x---. 2 nginx nginx 4096 Apr 9 14:42 test_dir ``` ``` # lid -g nginx nginx(uid=992) alcudia(uid=1000) ``` # Resulted in this output: Check the video: https://github.com/php/php-src/assets/224787/704bfa51-ad06-454b-95b5-83cf562b8809 Every time I press F5, the result changes # But I expected this output instead: Just this exclusively: ``` alcudia OK Found it! ``` # Extra information: It's interesting because I first discovered this while I was setting phpMyAdmin and raised this issue: https://github.com/phpmyadmin/phpmyadmin/issues/19106 ### PHP Version 8.2.17 ### Operating System Fedora 38