#36424 [NEW]: Serializable interface breaks object references

From: mastabog at hotmail dot com Operating system: *nix, win32 PHP version: 5.1.2 PHP Bug Type: SPL related Bug description: Serializable interface breaks object references Description: ------------ First of all, I know this is very new and undocumented. The Serializable interface serialize() method breaks reference of objects that are properties of the serialized object and that they themselves implement the Serializable interface. See the reproduceable code below. an echo over $ser yields: C:1:"C":85:{a:2:{s:1:"A";C:1:"A":6:{a:0:{}}s:1:"B";C:1:"B":32:{a:1:{s:1:"A";C:1:"A":6:{a:0:{}}}}}} It's visible that the last A is not a reference but a new class instance. I know that Serializable::unserialize() acts as a constructor, but shouldn't object references be honored by Serializable::serialize() the same way unserialize() does when the class does not implement the Serializable interface. If we remove the Serializable interface from class A and leave it like this: class A {} then $ser looks like the following: O:1:"C":2:{s:1:"A";O:1:"A":0:{}s:1:"B";O:1:"B":1:{s:1:"A";r:2;}} And it's visible that the last A is a reference. If this is all intended behavior for the Serializable interface to break object references then you can ignore this bug report. I hope it's not though, because it would have provided a better alternative to the __sleep() and __wakeup() (e.g. classes extending the PDO class cannot be serialized using __sleep() and __wakeup(), neither by overloading nor by default) Reproduce code: --------------- class A implements Serializable { public function serialize () { $serialized = array(); foreach($this as $prop => $val) { $serialized[$prop] = $val; } return serialize($serialized); //return serialize(get_object_vars($this)); } function unserialize($serialized) { foreach(unserialize($serialized) as $prop => $val) { $this->$prop = $val; } return true; } } class B extends A { public $A; } class C extends A { public $A; public $B; } $oC = new C(); $oC->A = new A(); $oC->B = new B(); $oC->B->A = $oC->A; echo $oC->A === $oC->B->A ? "yes" : "no", "\n"; $ser = serialize($oC); $new_oC = unserialize($ser); echo $new_oC->A === $new_oC->B->A ? "yes" : "no", "\n"; Expected result: ---------------- yes yes Actual result: -------------- yes no -- Edit bug report at http://bugs.php.net/?id=36424&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=36424&r=trysnapshot44 Try a CVS snapshot (PHP 5.1): http://bugs.php.net/fix.php?id=36424&r=trysnapshot51 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=36424&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=36424&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=36424&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=36424&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=36424&r=needscript Try newer version: http://bugs.php.net/fix.php?id=36424&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=36424&r=support Expected behavior: http://bugs.php.net/fix.php?id=36424&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=36424&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=36424&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=36424&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=36424&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=36424&r=dst IIS Stability: http://bugs.php.net/fix.php?id=36424&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=36424&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=36424&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=36424&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=36424&r=mysqlcfg