From: uwendel at mysql dot com
Operating system:
PHP version: 5.3CVS-2008-03-11 (CVS)
PHP Bug Type: PDO related
Bug description: PDO::FETCH_SERIALIZE calls __construct()
Description:
------------
There seems to be very few documentation about PDO::FETCH_SERIALIZE in the
PHP manual but playing the guessing game from the code it seems that this
feature aims to support SPL/Serialize interface. As I'm not sure about the
purpose of PDO::FETCH_SERIALIZE I'm not sure if the following is a bug or
not. However, it seems to me that PDO::FETCH_SERIALIZE unintentionally
calls __construct().
One of the main ideas behind SPL/Serialize interface seems to be that for
unserialization the constructor of a class does not get called. The
constructor of a class has a different meaning than a helper function like
unserialize() and thus should not be called automatically. Let's check:
class myclass implements Serialize {
public function __construct() {
printf("%s()\n", __METHOD__);
}
public function serialize() {
printf("%s()\n", __METHOD__);
return "any data from serialize()";
}
public function unserialize($dat) {
printf("%s(%s)\n", __METHOD__, var_export($dat, true));
}
}
$obj1 = new myclass()
---> myclass::__construct()
$tmp = serialize($obj1)
$obj2 = unserialize($tmp)
---> myclass::unserialize('any data from serizalize()')
__construct() gets called only once for object creation but not again
during unserialization. Let's try that with PDO:
[...]
$stmt = $db->query("SELECT dat FROM test");
$rows = $stmt->fetchAll(PDO::FETCH_CLASS|PDO::FETCH_SERIZALIZE,
"myclass");
--> myclass::unserialize("data from DB")
--> myclass::__construct()
[...]
PDO first calls unserialize() as its supposed to do. But then it also
calls __construct() which is against the idea of the Serialize interface
not to call the constructor automatically during unserialization.
Reproduce code:
---------------
sapi/cli/php -r '$db = new PDO("sqlite:/tmp/foo"); $db->exec("DROP TABLE
test"); $db->exec("CREATE TABLE test(dat VARCHAR(100))"); $db->exec("INSERT
INTO test(dat) VALUES (\"Data from DB\")"); class myclass implements
Serializable { public function __construct() { printf("%s()\n",
__METHOD__); } public function serialize() { return "any data from
serizalize()"; } public function unserialize($dat) { printf("%s(%s)\n",
__METHOD__, var_export($dat, true)); }} $stmt = $db->query("SELECT * FROM
test"); var_dump($stmt->fetchAll(PDO::FETCH_CLASS|PDO::FETCH_SERIALIZE,
"myclass")); $obj = new myclass();
var_dump(unserialize(serialize($obj)));'
myclass::unserialize('Data from DB')
myclass::__construct()
array(1) {
[0]=>
object(myclass)#3 (0) {
}
}
myclass::__construct()
myclass::unserialize('any data from serizalize()')
object(myclass)#4 (0) {
}
--
Edit bug report at http://bugs.php.net/?id=44409&edit=1
--
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=44409&r=trysnapshot52
Try a CVS snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=44409&r=trysnapshot53
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=44409&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=44409&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=44409&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=44409&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=44409&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=44409&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=44409&r=support
Expected behavior: http://bugs.php.net/fix.php?id=44409&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=44409&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=44409&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=44409&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=44409&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=44409&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=44409&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=44409&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=44409&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=44409&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=44409&r=mysqlcfg
