# PHP 5.3.1 reference parameter regression - Thread: https://externals.io/message/46389 - Original archive: https://news-web.php.net/php.internals/46389 - Started by Tim Starling on 2009-12-09T22:43:11+00:00 - Messages: 11 - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #46389 — Tim Starling — 2009-12-09T22:43:11+00:00 URL: https://externals.io/message/46389#46389 Since 5.3.1 it's impossible to have a reference parameter passed to a __call() function. This is apparently due to the bugfix committed by stas as shown here: Test cases can be found here: . It seems to me that a special case would be needed to restore the behaviour seen in PHP 5.3.0. This change causes bugs in MediaWiki, where an attempt by a proxy object to pass a call through to a function that accepts reference parameters will always fail, due to the exacerbating change made to reference argument semantics in PHP 5.3.0. If we want MediaWiki to support PHP 5.3.1, we'll have to do some major changes, like abandoning __call entirely, or rewriting all the relevant interfaces to not use reference parameters. I'm not too keen about doing this without getting some indication from the PHP dev team as to whether this change is permanent or whether it will be fixed in an imminent PHP 5.3.2 release. If it's going to be fixed soon, we can just blacklist PHP 5.3.1 in our installer. I've tried emailing stas but I didn't get a reply. -- Tim Starling --- ## #46392 — Stanislav Malyshev — 2009-12-09T23:12:32+00:00 URL: https://externals.io/message/46389#46392 · In reply to: #46389 Hi! > Test cases can be found here:. It > seems to me that a special case would be needed to restore the behaviour > seen in PHP 5.3.0. I'll check it out, seems to be valid use case, we should find some solution for that. > I've tried emailing stas but I didn't get a reply. Sorry, I didn't see any email from you. -- Stanislav Malyshev, Zend Software Architect stas@zend.com http://www.zend.com/ (408)253-8829 MSN: stas@zend.com --- ## #46403 — Keisial — 2009-12-12T17:08:44+00:00 URL: https://externals.io/message/46389#46403 · In reply to: #46389 Tim Starling wrote: > Since 5.3.1 it's impossible to have a reference parameter passed to a > __call() function. > This change causes bugs in MediaWiki, where an attempt by a proxy object > to pass a call through to a function that accepts reference parameters > will always fail, due to the exacerbating change made to reference > argument semantics in PHP 5.3.0. > > If we want MediaWiki to support PHP 5.3.1, we'll have to do some major > changes, like abandoning __call entirely, or rewriting all the relevant > interfaces to not use reference parameters. I'm not too keen about doing > this without getting some indication from the PHP dev team as to whether > this change is permanent or whether it will be fixed in an imminent PHP > 5.3.2 release. If it's going to be fixed soon, we can just blacklist PHP > 5.3.1 in our installer. > > I've tried emailing stas but I didn't get a reply. > > -- Tim Starling It's also broken in PHP 5.2.11 and 5.2.12 RC4. Works in 5.2.10 and 5.2.11RC1. Whatever change broke it, was backported and got into 5.2.11RC2. PS: Did mediawiki opt-out for release candidate announcements? It didn't receive emails about RCs for 5.2.12 branch. --- ## #46453 — Tim Starling — 2009-12-17T02:46:47+00:00 URL: https://externals.io/message/46389#46453 · In reply to: #46392 Stanislav Malyshev wrote: > Hi! > > > […] > > I'll check it out, seems to be valid use case, we should find some > solution for that. > There seems to have been no progress on this. Is there anything I can do to help? -- Tim Starling --- ## #46454 — Stefan Esser — 2009-12-17T06:37:43+00:00 URL: https://externals.io/message/46389#46454 · In reply to: #46453 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello Tim, > > […] just for the record: why does MediaWiki rely on a feature "Call-Time-Pass-By-Reference" that is deprecated since PHP 4.0.0 <- Yes exactly 4.0.0 What happened between 5.3.0 and 5.3.1 is that stas killed that feature for internal functions to work around a big security problem in the design of the Zend Engine. Considering the fact that the feature is DEPRECATED since 4.0.0 it would even be okay to kill it for all functions. Stefan Esser - -- SektionEins GmbH stefan.esser@sektioneins.de Eupener Straße 150 Tel: 0221 / 29282931 50933 Köln Fax: 0221 / 29282935 http://SektionEins.de/ Firmensitz Eupener Straße 150 50933 Köln Registergericht Amtsgericht Köln HRB 59950 Geschäftsführer Johann-Peter Hartmann -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAksp0bcACgkQSuF5XhWr2nhdwQCggzxIUz8N7ZlRLWWklTqJBnPO BSoAniiOqs2JXyh4iNwRtp9FiGRIy/16 =q9+2 -----END PGP SIGNATURE --- ## #46455 — Ferenc Kovacs — 2009-12-17T08:44:29+00:00 URL: https://externals.io/message/46389#46455 · In reply to: #46454 I agree that this feature should be avoided in userland, but I think that it would be terrible, if this "bugfix" would stay this way, because this breaks backward compatibility -without notification- with a minor version update both in 5.3 and 5.2 branch. Tyrael On Thu, Dec 17, 2009 at 7:37 AM, Stefan Esser wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Hello Tim, > > […] > just for the record: why does MediaWiki rely on a feature > "Call-Time-Pass-By-Reference" that is deprecated since PHP 4.0.0 <- > Yes exactly 4.0.0 > > What happened between 5.3.0 and 5.3.1 is that stas killed that feature > for internal functions to work around a big security problem in the > design of the Zend Engine. > Considering the fact that the feature is DEPRECATED since 4.0.0 it > would even be okay to kill it for all functions. > > Stefan Esser > > - -- > SektionEins GmbH                      stefan.esser@sektioneins.de > Eupener Straße 150                           Tel: 0221 / 29282931 > 50933 Köln                                   Fax: 0221 / 29282935 > http://SektionEins.de/ > > Firmensitz          Eupener Straße 150       50933 Köln > Registergericht     Amtsgericht Köln         HRB 59950 > Geschäftsführer     Johann-Peter Hartmann > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.8 (Darwin) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iEYEARECAAYFAksp0bcACgkQSuF5XhWr2nhdwQCggzxIUz8N7ZlRLWWklTqJBnPO > BSoAniiOqs2JXyh4iNwRtp9FiGRIy/16 > =q9+2 > -----END PGP SIGNATURE --- ## #46456 — Stefan Esser — 2009-12-17T08:54:49+00:00 URL: https://externals.io/message/46389#46456 · In reply to: #46455 Hi, > because this breaks backward compatibility -without notification- with > a minor version update both in 5.3 and 5.2 branch. well actually the bug was that `call_user_func_array()` did not trigger the "what you do is deprecated warning". Calling the function directly would have resulted in a "this is deprecated" warning anyway. Stefan Esser -- SektionEins GmbH stefan.esser@sektioneins.de Eupener Straße 150 Tel: 0221 / 29282931 50933 Köln Fax: 0221 / 29282935 http://SektionEins.de/ Firmensitz Eupener Straße 150 50933 Köln Registergericht Amtsgericht Köln HRB 59950 Geschäftsführer Johann-Peter Hartmann --- ## #46457 — Ferenc Kovacs — 2009-12-17T09:00:32+00:00 URL: https://externals.io/message/46389#46457 · In reply to: #46456 As tsarling stated in the bugreport: http://bugs.php.net/bug.php?id=50394 "I'm not complaining about the warning, which I just added to demonstrate the problem. I'm not complaining about the new behaviour of zend_call_function() as of PHP 5.3.0, I'm complaining about the lost reference in __call in PHP 5.3.1." Tyrael On Thu, Dec 17, 2009 at 9:54 AM, Stefan Esser wrote: > Hi, > > > […] > well actually the bug was that `call_user_func_array()` did not trigger > the "what you do is deprecated warning". > Calling the function directly would have resulted in a "this is > deprecated" warning anyway. > > Stefan Esser > > -- > SektionEins GmbH                      stefan.esser@sektioneins.de > Eupener Straße 150                           Tel: 0221 / 29282931 > 50933 Köln                                   Fax: 0221 / 29282935 > http://SektionEins.de/ > > Firmensitz          Eupener Straße 150       50933 Köln > Registergericht     Amtsgericht Köln         HRB 59950 > Geschäftsführer     Johann-Peter Hartmann --- ## #46462 — Stanislav Malyshev — 2009-12-17T19:28:29+00:00 URL: https://externals.io/message/46389#46462 · In reply to: #46453 Hi! > > […] > > There seems to have been no progress on this. Is there anything I can do > to help? Tim, could you check if the attached patch solves your problem? -- Stanislav Malyshev, Zend Software Architect stas@zend.com http://www.zend.com/ (408)253-8829 MSN: stas@zend.com --- ## #46465 — Tim Starling — 2009-12-18T01:50:26+00:00 URL: https://externals.io/message/46389#46465 · In reply to: #46462 Stanislav Malyshev wrote: > > Tim, could you check if the attached patch solves your problem? > Yes, it works for me, in both the isolated test case and the original MW bug. MW's parser test suite shows 4 failing tests in 5.3.1, all fixed with this patch and no new regressions. Stefan Esser wrote: > just for the record: why does MediaWiki rely on a feature > "Call-Time-Pass-By-Reference" that is deprecated since PHP 4.0.0 <- > Yes exactly 4.0.0 The underlying functions are declared with reference parameters, and we call them with `call_user_func_array()` so explicitly creating references on the caller side is required. If you have a better method for calling arbitrary functions that accept reference parameters, let me know. Lots of MediaWiki functions are declared with reference parameters for objects when they aren't really needed, because that was the required convention in PHP 4, and we never made a concerted effort to remove all the ampersands. It's too late to fix it now, in many cases, because many extensions declare hook functions with reference parameters, following the caller and documentation that dates from PHP 4, and so we have to keep passing them reference parameters to avoid breaking them in PHP 5.3+. So the window for easy migration to value parameters has closed. -- Tim Starling --- ## #46466 — Stanislav Malyshev — 2009-12-18T02:01:07+00:00 URL: https://externals.io/message/46389#46466 · In reply to: #46465 Hi! > Yes, it works for me, in both the isolated test case and the original MW > bug. > > MW's parser test suite shows 4 failing tests in 5.3.1, all fixed with > this patch and no new regressions. Great, will commit the patch tomorrow then to all branches. > The underlying functions are declared with reference parameters, and we > call them with `call_user_func_array()` so explicitly creating references > on the caller side is required. If you have a better method for calling > arbitrary functions that accept reference parameters, let me know. `call_user_func_array()` wasn't a problem in this particular case, __call was (see the bug), because internally it's user function call simulated by internal function call, so it needed some special check. > Lots of MediaWiki functions are declared with reference parameters for > objects when they aren't really needed, because that was the required Entirely unrelated to this bug, passing objects by-ref is not the best idea in PHP 5. -- Stanislav Malyshev, Zend Software Architect stas@zend.com http://www.zend.com/ (408)253-8829 MSN: stas@zend.com