Description:
------------
When using a prepared statement with a like clause with '%?%' the pdo driver segfaults. This should either work or throw an error.

Using it in the syntax of "fname like ?" and having the variable be "%Lud%" works as intended. This is minor but it should not be crashing.

Reproduce code:
---------------
<?

putenv("INFORMIXDIR=/opt/informix");
putenv("INFORMIXSERVER=llama");
$dbh = new PDO("informix:host=server; service=1516; database=stores_demo; server=server; protocol=onsoctcp;EnableScrollableCursors=1", "informix", "password");
$sqlline = "select fname from customer where fname like '%?%'";
$val = "Lud";
$sth = $dbh->prepare($sqlline);
$sth->execute(array($val));
$row = $sth->fetch();
print_r($row);


Expected result:
----------------
Array
(
    [FNAME] => Ludwig
    [0] => Ludwig
)


Actual result:
--------------
llama:/www/fht # php test.php
Segmentation fault