#44181 [Opn->Bgs]: extract($a, EXTR_OVERWRITE|EXTR_REFS) can fail to create references to $a
| From: | jani@php.net | Date: | Sat, 25 Oct 2008 13:26:21 +0000 |
| Subject: | #44181 [Opn->Bgs]: extract($a, EXTR_OVERWRITE|EXTR_REFS) can fail to create references to $a | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-130092@lists.php.net to get a copy of this message | ||
ID: 44181
Updated by: jani@php.net
Reported By: robin_fernandes at uk dot ibm dot com
-Status: Open
+Status: Bogus
Bug Type: Arrays related
-Operating System: Windows
+Operating System: *
PHP Version: 5.2CVS-2008-02-20 (snap)
New Comment:
No need for several open reports about this issue.
Previous Comments:
------------------------------------------------------------------------
[2008-02-20 09:30:23] robin_fernandes at uk dot ibm dot com
I think this is because $a is passed by value, and the call to
SEPARATE_ZVAL_TO_MAKE_IS_REF(entry) below splits the array element from
the original array.
The reference is therefore created to the element of the argument array
which, after the split, is not the same as the element of the original
array.
From array.c:
...
if (zend_u_hash_find(EG(active_symbol_table), Z_TYPE(final_name),
Z_UNIVAL(final_name), Z_UNILEN(final_name) + 1, (void **) &orig_var) ==
SUCCESS) {
SEPARATE_ZVAL_TO_MAKE_IS_REF(entry); // <-- Split! entry no longer
refers to element of $a.
zval_add_ref(entry);
zval_ptr_dtor(orig_var);
*orig_var = *entry;
} else {
...
I believe the root cause for this bug is the same as bug
http://bugs.php.net/44182.
I have submitted a patch for that bug which fixes this one too.
------------------------------------------------------------------------
[2008-02-20 09:25:43] robin_fernandes at uk dot ibm dot com
Description:
------------
Using extract() with EXTR_OVERWRITE|EXTR_REFS does not create
references to the array elements if the following conditions are true:
- $a is referenced by some other variable (its is_ref flag is true).
- A variable already exists in the current scope with a name matching
the key.
This is reproducible on 5.2, 5.3 and 6.0 snaps.
Reproduce code:
---------------
<?php
$a = array('foo' => 'original.foo');
$foo = 'test';
$ref = &$a;
extract($a, EXTR_OVERWRITE|EXTR_REFS);
$foo = 'changed.foo';
var_dump($a['foo']); //expecting changed.foo
?>
Expected result:
----------------
string(11) "changed.foo"
Actual result:
--------------
string(12) "original.foo"
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=44181&edit=1