#19243 [Fbk->Opn]: Seg Fault Restoring Session Variables with References to Objects

ID: 19243 User updated by: fdruseikis@sc.rr.com Reported By: fdruseikis@sc.rr.com -Status: Feedback +Status: Open Bug Type: Session related Operating System: Linux RH 7.0 PHP Version: 4.2.2 New Comment: I tried the script on this build: php4-200209060300 (linux) No segfault. However, both variables $o1 and $o2 are saved (and restored) as null. This results in a "Fatal Error: Call to a member function on a non-object in ..." Both $o1 and $o2 should refer to the original (singleton) object instance. Previous Comments: ------------------------------------------------------------------------ [2002-09-05 16:48:14] kalowsky@php.net keeping set as feedback ------------------------------------------------------------------------ [2002-09-05 16:41:24] fdruseikis@sc.rr.com I'll give it a try. ------------------------------------------------------------------------ [2002-09-05 15:48:06] sniper@php.net Please try using this CVS snapshot: http://snaps.php.net/php4-latest.tar.gz For Windows: http://snaps.php.net/win32/php4-win32-latest.zip ------------------------------------------------------------------------ [2002-09-05 15:04:16] kalowsky@php.net Can you try one of the new snapshots please? There has been some work on the way sessions are delt with, and while I don't think it fixes this problem... hey it's worth a shot. Regardless, I don't think what you're doing is really going to ever work. I agree with yohgaki that we should throw some warnings or something. ------------------------------------------------------------------------ [2002-09-05 08:05:00] fdruseikis@sc.rr.com BTW this is not a problem if the references are not global, for example, interior variables in an array instead. For example, $x = array(9,8,7); $o1 = array(1,2,3,null,null); $o1[2] =& $x; $o1[3] =& $x; This array clearly has references within it and shares the array named by $x. Conclusion: It would seem to have something to do with restoring a reference to something that is already global. IMO the serialization formats clearly intend to support serializing/deserializing of references. The system provided deserializer needs to restore references correctly by implementing the inverse of the process that the serializer performed, which appearantly is not working correctly. All the information you need is in the session file. It also means that the closure of all references implict in an object (or array) need to be captured, which is clearly being done in the array example above. Not to put too fine a point on it: "This kind of thing is done in Java all the time." If your recommendation is taken, then you need to clarify the restriction in the documentation on references and in the session functions. You're talking about a rat's nest of exceptions here. Sometimes works for arrays, don't work for globals, etc. It would be easier to make it work. Give me a hint - where is the de/serializer implemented? ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/19243 -- Edit this bug report at http://bugs.php.net/?id=19243&edit=1