Bug #70910 [Fbk->Asn]: extract() breaks variable references
Edit report at https://bugs.php.net/bug.php?id=70910&edit=1
ID: 70910
User updated by: php at maisqi dot com
Reported by: php at maisqi dot com
Summary: extract() breaks variable references
-Status: Feedback
+Status: Assigned
Type: Bug
Package: Scripting Engine problem
Operating System: Windows 8
PHP Version: 7.0.0RC7
Assigned To: laruence
Block user comment: N
Private report: N
New Comment:
I agree with nikic. It should do the same as doing it manually.
Previous Comments:
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[2015-11-13 16:24:30] nikic@php.net
@laruence: My intuition would say that extract() without EXTR_REFS should behave the same was as
manually doing the assignments, i.e.:
extract(['a' => 'b', 'c' => 'd']);
// should be the same as writing
$a = 'b';
$c = 'd';
So in this case the equivalent code without extract() would be:
$var = 'original value';
$ref =& $var;
$var = 'new value';
In which case the result that PHP 5.6 provides is correct.
If EXTR_REFS is specified then all assignments should happen with =&, which breaks references.
In this case the current behavior matches the previous one already.
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[2015-11-13 15:39:21] laruence@php.net
actually, I think previously behavior seems bug... current behavior is more reasonable, "it
overwrite the old value".
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[2015-11-13 10:57:46] php at maisqi dot com
Description:
------------
extract() sets the values of variables that reference variables, instead of changing the variables
that they point to.
For example, say $ref is a reference to $var; if extract() has a "ref" var to inject in
the current scope, it changes $ref and does nothing to $var -- it breaks the reference.
NOTE: My tests was on PHP 7RC7 64 bits on Windows, though this probably isn't relevant.
Test script:
---------------
<?php
$var = 'original value';
$ref =& $var;
$hash = ['var' => 'new value'];
extract($hash);
echo 'ref: ', $ref, ' var: ', $var;
Expected result:
----------------
ref: new value var: new value
(This is what happens on PHP 5.6/64 bits)
Actual result:
--------------
ref: original value var: new value
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