Bug #71215 [Opn->Csd]: foreach() with inline assignment doesn't keep references

[email protected] ("bugs dot php dot net at ss dot st dot tc")
Newsgroups php.bugs
Message-ID <[email protected]>
Edit report at https://bugs.php.net/bug.php?id=71215&edit=1

 ID:                 71215
 User updated by:    bugs dot php dot net at ss dot st dot tc
 Reported by:        bugs dot php dot net at ss dot st dot tc
 Summary:            foreach() with inline assignment doesn't keep
                     references
-Status:             Open
+Status:             Closed
 Type:               Bug
 Package:            Scripting Engine problem
 Operating System:   Linux, OSX
 PHP Version:        7.0.1
 Block user comment: N
 Private report:     N

 New Comment:

(closing, sorry, typo in test script (I wish I could edit it after the ticked has already been submitted!))


Previous Comments:
------------------------------------------------------------------------
[2015-12-24 19:58:42] bugs dot php dot net at ss dot st dot tc

Description:
------------
When an inline assignment of array_expression is done right in foreach() statement, all further references to iterated array items seem to become their copies.

I believe both PHP 5.6 and 7 are affected, yet still they behave differently.
Tested on PHP 5.6.12, 5.6.16, 7.0.0, 7.0.1.


Test script:
---------------
<?php

# source array
$source = [ 'subarray' => ['item' => 'old value ---'] ];


# $ref1 is assigned to $source right in the foreach()
foreach ( $ref1 = $source as &$subarray ) {
	$subarray['item'] = 'NEW value';
	echo $subarray['item'], PHP_EOL;
	echo $ref1['subarray']['item'], PHP_EOL;
}
echo PHP_EOL;


# $ref1 is assigned to $source normally, as a separate operation
$ref2 = $source;
foreach ( $ref2 as &$subarray ) {
	$subarray['item'] = 'NEW value';
	echo $subarray['item'], PHP_EOL;
	echo $ref2['subarray']['item'], PHP_EOL;
}
echo PHP_EOL;


########################################

# similar to $source array, but implemented using a function
function getSource() {
	return [ 'subarray' => ['item' => 'old value ---'] ];
}


# $ref1 is assigned to return value of getSource() right in the foreach()
foreach ( $ref3 = getSource() as &$subarray ) {
	$subarray['item'] = 'NEW value';
	echo $subarray['item'], PHP_EOL;
	echo $ref3['subarray']['item'], PHP_EOL;
}
echo PHP_EOL;


# $ref4 is a "normal" reference to a result of getSource()
$ref4 = getSource();
foreach ( $ref4 as &$subarray ) {
	$subarray['item'] = 'NEW value';
	echo $subarray['item'], PHP_EOL;
	echo $ref3['subarray']['item'], PHP_EOL;
}

Expected result:
----------------
both PHP 5 and 7:

NEW value
NEW value

NEW value
NEW value

NEW value
NEW value

NEW value
NEW value

Actual result:
--------------
PHP 7: 

NEW value
old value ---

NEW value
NEW value

NEW value
old value ---

NEW value
old value ---


PHP 5:

NEW value
old value ---

NEW value
NEW value

NEW value
NEW value

NEW value
NEW value


------------------------------------------------------------------------



--
Edit this bug report at https://bugs.php.net/bug.php?id=71215&edit=1
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.