Description:
------------
An exception is thrown in the test case below.

 - Emulated prepares must be OFF

 - "LOCK TABLE" triggers the error, eg "set @foo='bar'" does NOT

I see no reason why the error occurs in this case.

Test script:
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// Please fill in

$host = '';
$db = '';
$user = '';
$pass = '';

$options = [];
$options[PDO::ATTR_EMULATE_PREPARES] = false; /* required */
$options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;

$PDO = new PDO   ( "mysql:host=$host;dbname=$db;charset=utf8mb4", $user, $pass, $options );

$PDO->exec ('create temporary table foo (bar int)');

$PDO->query ('lock table foo write');

Expected result:
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No exception thrown.

Actual result:
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Exception thrown.

SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOState ment::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.