Description:
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Using PDOStatement::fetch() or PDOStatement::fetachAll() after a query without resulting data (INSERT, DELETE and so on) results in throw of PDOException.

2 problems:

1.: Before PHP 7.4.13 fetch(All) returned false. Throwing an exception here seems wrong to me.

2.: Exception text is misleading. It says that there are other unbuffered queries even when there are no queries made before.

Exception text: "Uncaught PDOException: SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active.  Consider using PDOStatement::fetchAll().  Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute"

Test script:
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error_reporting(E_ALL);
ini_set('display_errors', '1');

// Connect
$pdoLink = new PDO("mysql:dbname=test;host=localhost;charset=UTF8", 'root', 'root');
$pdoLink->setAttribute(PDO::ATTR_CASE, PDO::CASE_NATURAL);
$pdoLink->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdoLink->setAttribute(PDO::ATTR_ORACLE_NULLS, PDO::NULL_NATURAL);
$pdoLink->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
$pdoLink->setAttribute(PDO::ATTR_STRINGIFY_FETCHES, false);
$pdoLink->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
$pdoLink->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

// Query
$stmt = 'INSERT INTO `pdotest_user` (`username`) VALUES (:username)';
$pdoStmt = $pdoLink->prepare($stmt);
$pdoStmt->execute([':username' => 'Testman']);

// Result
$resArr = [];
while (($row = $pdoStmt->fetch(PDO::FETCH_ASSOC)) !== false)   // Exception thrown here
	$resArr[] = $row;

// Cleanup
$pdoStmt->closeCursor();

print_r($resArr);

Expected result:
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fetch/fetchAll should return false if there is no data for the query