Bug #70289 [Csd]: Different sort in php7 (and hhvm) compared to php5

Edit report at https://bugs.php.net/bug.php?id=70289&edit=1 ID: 70289 Updated by: rasmus@php.net Reported by: kjarli at gmail dot com Summary: Different sort in php7 (and hhvm) compared to php5 Status: Closed Type: Bug Package: Arrays related Operating System: Ubuntu 14.04 PHP Version: 7.0.0beta3 Assigned To: cmb Block user comment: N Private report: N New Comment: nazar, actually those are the same. You are comparing integer 0 to string "is" there which means PHP will cast "is" to int which is 0. 0==0. You can prove this to yourself by forcing a string sort: ksort($array, SORT_STRING); Previous Comments: ------------------------------------------------------------------------ [2015-08-29 05:48:26] nazar at mokrynskyi dot com Here is live example with this bug: https://3v4l.org/AErRF Neither values nor keys are the same. Here is example: <?php $array = array( 'is' => 'a', 'b' ); ksort($array); var_dump($array); ------------------------------------------------------------------------ [2015-08-18 11:44:44] cmb@php.net Automatic comment on behalf of cmb Revision: http://git.php.net/?p=php-src.git;a=commit;h=1b5e87a579080da1452e173981b7d8a6814f15c0 Log: Fix #70289: Different sort in php7 (and hhvm) compared to php5 ------------------------------------------------------------------------ [2015-08-18 11:31:08] cmb@php.net I agree that a note in UPGRADING is appropriate, event though the documentation (e.g. for usort()) already states: | If two members compare as equal, their relative order in the | sorted array is undefined. See also the related internal discussion <http://markmail.org/thread/trb3g4o6vqccitpd>. ------------------------------------------------------------------------ [2015-08-18 08:22:39] kjarli at gmail dot com This report seems related: https://bugs.php.net/bug.php?id=40888 If it's not a bug and indeed related to small arrays in php7, I would rather see a small notice in the upgrade guide than to have people "waste" time on such a trivial "issue" as it's much better to rely on defined behavior by the developer. ------------------------------------------------------------------------ [2015-08-18 08:19:51] requinix@php.net Thank you for this bug report. To properly diagnose the problem, we need a short but complete example script to be able to reproduce this bug ourselves. A proper reproducing script starts with <?php and ends with ?>, is max. 10-20 lines long and does not require any external resources such as databases, etc. If the script requires a database to demonstrate the issue, please make sure it creates all necessary tables, stored procedures etc. Please avoid embedding huge scripts into the report. Sounds like cweiske's right. PHP's sorting has never promised that equal elements will appear in any particular order. Also know that PHP 7 uses a different sorting algorithm for small arrays than it does larger arrays. ------------------------------------------------------------------------ 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 https://bugs.php.net/bug.php?id=70289 -- Edit this bug report at https://bugs.php.net/bug.php?id=70289&edit=1