[php-src] Issue #12032: PDO::getAttribute() behaves differently than document

Issue: https://github.com/php/php-src/issues/12032 Author: SakiTakamachi ### Description The following code: ```php <?php // PDO::ERRMODE_SILENT $pdo = new PDO('mysql:host=mysql;dbname=test;', 'root', '', [PDO::ATTR_ERRMODE => PDO::ERRMODE_SILENT]); // my env var_dump($pdo->getAttribute(PDO::ATTR_TIMEOUT)); // PDO::ERRMODE_EXCEPTION $pdo = new PDO('mysql:host=mysql;dbname=test;', 'root', ''); // my env var_dump($pdo->getAttribute(PDO::ATTR_TIMEOUT)); ``` Resulted in this output: ``` Warning: PDO::getAttribute(): SQLSTATE[IM001]: Driver does not support this function: driver does not support that attribute in /var/www/html/test/test_mysql.php on line 5 bool(false) Fatal error: Uncaught PDOException: SQLSTATE[IM001]: Driver does not support this function: driver does not support that attribute in /var/www/html/test/test_mysql.php:9 Stack trace: #0 /var/www/html/test/test_mysql.php(9): PDO->getAttribute(2) #1 {main} thrown in /var/www/html/test/test_mysql.php on line 9 ``` But I expected this output instead: ``` bool(null) bool(null) ``` https://www.php.net/manual/en/pdo.getattribute.php#refsect1-pdo.getattribute-returnvalues I suspect that the error/warning and returning false instead of null is probably just outdated documentation. Even so, it is strange that warning is output with PDO::ERRMODE_SILENT. I don't know if the documentation and the implementation need to be fixed, and if so, what should be fixed, so I would like your opinion. ### PHP Version PHP 8.1.22 ### Operating System _No response_