Bug #71334 [Asn]: Cannot access array keys while uksort()

Edit report at https://bugs.php.net/bug.php?id=71334&edit=1 ID: 71334 Updated by: nikic@php.net Reported by: alex dot schneider at sevenval dot com Summary: Cannot access array keys while uksort() Status: Assigned Type: Bug Package: Arrays related Operating System: Linux Mint 17.3 PHP Version: 7.0.2 Assigned To: laruence Block user comment: N Private report: N New Comment: New patch that resolves the ArrayObject issue: https://github.com/nikic/php-src/commit/73e6c257abc9ad5a5aef6b91a2238e941b2045d5 Previous Comments: ------------------------------------------------------------------------ [2016-01-13 16:15:11] jsgoupil at gmail dot com I have the same problem, I am able to access the values, but the sorting is not correct. <?php function cmp($a, $b) { $x = $GLOBALS['x']; $v1 = $x[$a]; $v2 = $x[$b]; if ($v1 < $v2) { return -1; } elseif ($v1 > $v2) { return 1; } else { // Would then sort by key, irrelevant here. } } $x = array(1 => 1, 2 => 3, 3 => 2); uksort($x, 'cmp'); var_dump($x); // PHP5 array(3) { [1]=> int(1) [3]=> int(2) [2]=> int(3) } // PHP7 array(3) { [3]=> int(2) [2]=> int(3) [1]=> int(1) } Let me know if you want me to open another bug instead. ------------------------------------------------------------------------ [2016-01-13 06:36:55] laruence@php.net hmm, we could also adjust arHash after swap, but it must not be a simple patch.. thanks ------------------------------------------------------------------------ [2016-01-12 16:36:08] nikic@php.net It looks like ArrayObject relies on sorting functions not to duplicate the array for the rc=1 case, so this will need some more work :( ------------------------------------------------------------------------ [2016-01-12 15:37:35] nikic@php.net The problem is that we're doing the sort in-place, so any access to the array during the sort will see it in an inconsistent state. I don't see any way to solve this problem without requiring the array to always be duplicated before sorts with user-defined callbacks. Here's a patch to implement this: https://github.com/nikic/php-src/commit/703fed650319f9e2d78e2dc2cafb422e558c5841 It also removes the array modification check, as it's no longer relevant after this change. @laruence: You worked on the sorting functionality, do you see a way to fix this in any other way? ------------------------------------------------------------------------ [2016-01-11 11:03:05] alex dot schneider at sevenval dot com Description: ------------ Cannot access array keys while uksort(). Sorry for my English... Test script: --------------- <?php class myClass { private $a = [ 'foo-test' => [1], '-' => [2], 'bar-test' => [3] ]; private function _mySort($x, $y) { if (!isset($this->a[$x])) { throw new Exception('Missing X: "' . $x . '"'); } if (!isset($this->a[$y])) { throw new Exception('Missing Y: "' . $y . '"'); } return $x < $y; } public function __construct() { uksort($this->a, [$this, '_mySort']); } } new myClass(); Expected result: ---------------- No Exceptions Actual result: -------------- Exception: PHP Fatal error: Uncaught Exception: Missing Y: "bar-test" in ... ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=71334&edit=1