Bug #79404 [Com]: Referencing to SplFixedArray interrupts foreach loop

Edit report at https://bugs.php.net/bug.php?id=79404&edit=1 ID: 79404 Comment by: alexinbeijing at gmail dot com Reported by: vlad dot turchinskiy at yandex dot ru Summary: Referencing to SplFixedArray interrupts foreach loop Status: Verified Type: Bug Package: SPL related Operating System: all PHP Version: 5.4.0 - 7.4.4 Block user comment: N Private report: N New Comment: I have a patch which "fixes" get_iterator() without converting SplFixedArray to an IteratorAggregate. It's a pretty dubious idea. Still, I may push it to GH for review and comments. Previous Comments: ------------------------------------------------------------------------ [2020-04-10 14:31:39] requinix@php.net > Nikita, I don't understand how SplFixedArray could possibly support multiple > parallel get_iterator()s while still following the contract of the Iterator > interface. Could you explain what you mean? To make sure that all the Traversables returned by multiple calls to getIterator() won't conflict with each other. ------------------------------------------------------------------------ [2020-04-10 08:41:30] alexinbeijing at gmail dot com > I do think we should ensure that multiple parallel get_iterator()s are supported independently > of that. Nikita, I don't understand how SplFixedArray could possibly support multiple parallel get_iterator()s while still following the contract of the Iterator interface. Could you explain what you mean? ------------------------------------------------------------------------ [2020-03-23 14:04:26] nikic@php.net SplFixedArray should probably be IteratorAggregate rather than Iterator... I do think we should ensure that multiple parallel get_iterator()s are supported independently of that. ------------------------------------------------------------------------ [2020-03-23 11:03:27] cmb@php.net Yes, a single foreach loop works certainly as expected; the problem is *nesting* of foreach loops: <?php $spl = SplFixedArray::fromArray([0, 1]); foreach ($spl as $el1) { foreach ($spl as $el2) { echo "$el1.$el2\n"; } } ?> outputs 0.0 0.1 while you want to get 0.0 0.1 1.0 1.1 It seems to me that this behavior is correct for Iterators; maybe not for IteratorAggregates. ------------------------------------------------------------------------ [2020-03-23 01:51:35] vlad dot turchinskiy at yandex dot ru cmb@php.net, as far as SPLFixedArray implements Traversable, it is expected to support foreach. I updated code, to make the difference more obvious: https://3v4l.org/N9k7P Please, note, that in the test code i provided, unless we use $collection->getSum() inside the loop - it works as expected. ------------------------------------------------------------------------ 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=79404 -- Edit this bug report at https://bugs.php.net/bug.php?id=79404&edit=1