Bug #70387 [Opn->Nab]: Array corruption after iteration with a &pointer

Edit report at https://bugs.php.net/bug.php?id=70387&edit=1 ID: 70387 Updated by: rasmus@php.net Reported by: oleg dot nucer at gmail dot com Summary: Array corruption after iteration with a &pointer -Status: Open +Status: Not a bug Type: Bug Package: Scripting Engine problem Operating System: Windows 8.1 x64 PHP Version: 5.6.12 Block user comment: N Private report: N New Comment: And this is not a bug. Think about what the code would look like if you unrolled your loops and manually assigned each element to $s by reference and then started using $s as a non-reference suddenly. Obviously the last thing $s is referencing will now be modified by that assignment unless you clear it. Previous Comments: ------------------------------------------------------------------------ [2015-08-30 23:24:52] mark at lange dot demon dot co dot uk This is documented behaviour with an explanation on the [foreach PHP docs page](http://php.net/manual/en/control-structures.foreach.php) and a description of how to avoid it > Warning > Reference of a $value and the last array element remain even after the foreach loop. It is > recommended to destroy it by unset(). ------------------------------------------------------------------------ [2015-08-29 11:39:03] oleg dot nucer at gmail dot com Description: ------------ I've found a realy strange bug .. Just look to the script and to the output! I've killed a half of our to understand what's going on in my script... After iterating over array with a pointer variable the array becomes corrupted for next time iteration... Look at the last element in foreach loop, it's the same with previous!! Test script: --------------- <? $sample = [ [ "first", 1 ], [ "second", 2 ], [ "third", 3 ] ]; foreach ( $sample AS &$s ) { } echo "Array: <pre>".print_r( $sample, 1 )."</pre><br/>"; foreach ( $sample AS $s ) { echo "Element: <pre>".print_r( $s, 1 )."</pre>"; } ?> Expected result: ---------------- Array: Array ( [0] => Array ( [0] => first [1] => 1 ) [1] => Array ( [0] => second [1] => 2 ) [2] => Array ( [0] => third [1] => 3 ) ) Element: Array ( [0] => first [1] => 1 ) Element: Array ( [0] => second [1] => 2 ) Element: Array ( [0] => third [1] => 3 ) Actual result: -------------- Array: Array ( [0] => Array ( [0] => first [1] => 1 ) [1] => Array ( [0] => second [1] => 2 ) [2] => Array ( [0] => third [1] => 3 ) ) Element: Array ( [0] => first [1] => 1 ) Element: Array ( [0] => second [1] => 2 ) Element: Array ( [0] => second [1] => 2 ) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=70387&edit=1