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?

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 :(

hmm, we could also adjust arHash after swap, but it must not be a simple patch..

thanks

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.

New patch that resolves the ArrayObject issue: https://github.com/nikic/php-src/commit/73e6c257abc9ad5a5aef6b91a2238e941b2045d5