Description:
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PHP displays some UTF-8 strings wrongly. E.g. "????????" is rendered as "????????". 

Reproduce code:
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First Oracle db insert:
insert into temp values (convert('????????','UTF8'));

$pdo = new PDO('oci:dbname=//localhost/ora','user','pass');
$sth = $pdo->prepare("select * from temp");
$sth->execute();
$sth->fetchAll(PDO::FETCH_ASSOC);
echo $sth[0]['TEXT'];





Expected result:
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????????


Actual result:
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????????