Bug #70246 [Opn]: ArrayIterator skips next element when current element is unset in foreach.
Edit report at https://bugs.php.net/bug.php?id=70246&edit=1
ID: 70246
Updated by: derick@php.net
Reported by: arjen at react dot com
Summary: ArrayIterator skips next element when current
element is unset in foreach.
Status: Open
Type: Bug
Package: SPL related
Operating System: Linux
PHP Version: 7.0.0beta3
Block user comment: N
Private report: N
New Comment:
This bug is still being encountered in the wild, and it cost us considerable time to figure out what
was wrong: https://github.com/mongodb/mongo-php-library/pull/544/files#diff-d4c8c6dc8769324fc27cfdac19f05cafR88
Previous Comments:
------------------------------------------------------------------------
[2016-03-18 11:45:14] david at grudl dot com
Similar bug with stdClass and ArrayIterator: https://3v4l.org/2A1pf
------------------------------------------------------------------------
[2015-09-19 18:55:50] j dot tvr at centrum dot cz
This is probably not a bug. When you unset current element, the internal array pointer moves to the
next element. Therefore what you're doing is essentially equivalent to https://3v4l.org/rWQq8:
<?php
$ar = [1, 2, 3, 4, 5];
$it = new ArrayIterator($ar);
foreach ($it as $k => $v) {
if ($k === 0) $it->next(); // eq. to unset($it[0]);
echo "\$ar[$k] = $v;\n";
}
echo "\n";
print_r(iterator_to_array($it));
------------------------------------------------------------------------
[2015-08-18 11:56:39] arjen at react dot com
Expected and actual result are swapped, my mistake..
Expected result:
--------------
int(1)
int(2)
int(3)
int(4)
int(5)
---------
int(1)
int(3)
int(4)
int(5)
Actual result:
----------------
int(1)
int(2)
int(4)
int(5)
---------
int(1)
int(3)
int(4)
int(5)
------------------------------------------------------------------------
[2015-08-12 12:34:15] arjen at react dot com
Description:
------------
ArrayIterator skips next element when current element is unset in foreach.
http://3v4l.org/uUoaH
Test script:
---------------
<?php
$ar = [1,2,3,4,5];
$i = new ArrayIterator($ar);
foreach ($i as $k => $e) {
var_dump($e);
if ($k === 1) {
unset($i[$k]);
}
}
echo '---------' . PHP_EOL;
foreach ($i as $e) {
var_dump($e);
}
Expected result:
----------------
int(1)
int(2)
int(4)
int(5)
---------
int(1)
int(3)
int(4)
int(5)
Actual result:
--------------
int(1)
int(2)
int(3)
int(4)
int(5)
---------
int(1)
int(3)
int(4)
int(5)
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=70246&edit=1
Thread (6 messages)