From:             devik at cdi dot cz
Operating system: Linux
PHP version:      5.0.4
PHP Bug Type:     Scripting Engine problem
Bug description:  Reference is killed by unset but not by other =&

Description:
------------
This is variation on #15025. But I accept the bug is feature and I show
other bug it triggers.

Basic problem is that when you take ref of array item then the item will
turn into reference (which will survive even array copy). I don't see it
as too big problem as long as I can get rid of the reference.
"unset" does the trick as expected:
$r =& $A[0]; 
unset($r); - $A[0] is not reference any more

But something like:
$r =& $othervar;

doesn't kill reference - you see zval with is_ref=1 and refcount=1.

It prevents you from writing handy code:
$c = &$c[$i] when traversing complex structures.

Reproduce code:
---------------
<?
$a = array(1,2);
$b =& $a[0];
echo "Now a[0] is reference, no problem\n";
debug_zval_dump($a);

$b =& $a[1];
echo "Now a[0] has no reason to be reference any longer, but a[1] is\n";
debug_zval_dump($a);

unset($b);
echo "Now a[1] reference is gone too BUT WAIT, a[0] is still a ref !\n";
debug_zval_dump($a);
?>


Expected result:
----------------
I expect $a without references.

Actual result:
--------------
$a[0] is reference with refcount(1).

-- 
Edit bug report at http://bugs.php.net/?id=33282&edit=1
-- 
Try a CVS snapshot (php4):   http://bugs.php.net/fix.php?id=33282&r=trysnapshot4
Try a CVS snapshot (php5.0): 
http://bugs.php.net/fix.php?id=33282&r=trysnapshot50
Try a CVS snapshot (php5.1): 
http://bugs.php.net/fix.php?id=33282&r=trysnapshot51
Fixed in CVS:                http://bugs.php.net/fix.php?id=33282&r=fixedcvs
Fixed in release:            http://bugs.php.net/fix.php?id=33282&r=alreadyfixed
Need backtrace:              http://bugs.php.net/fix.php?id=33282&r=needtrace
Need Reproduce Script:       http://bugs.php.net/fix.php?id=33282&r=needscript
Try newer version:           http://bugs.php.net/fix.php?id=33282&r=oldversion
Not developer issue:         http://bugs.php.net/fix.php?id=33282&r=support
Expected behavior:           http://bugs.php.net/fix.php?id=33282&r=notwrong
Not enough info:             
http://bugs.php.net/fix.php?id=33282&r=notenoughinfo
Submitted twice:             
http://bugs.php.net/fix.php?id=33282&r=submittedtwice
register_globals:            http://bugs.php.net/fix.php?id=33282&r=globals
PHP 3 support discontinued:  http://bugs.php.net/fix.php?id=33282&r=php3
Daylight Savings:            http://bugs.php.net/fix.php?id=33282&r=dst
IIS Stability:               http://bugs.php.net/fix.php?id=33282&r=isapi
Install GNU Sed:             http://bugs.php.net/fix.php?id=33282&r=gnused
Floating point limitations:  http://bugs.php.net/fix.php?id=33282&r=float
No Zend Extensions:          http://bugs.php.net/fix.php?id=33282&r=nozend
MySQL Configuration Error:   http://bugs.php.net/fix.php?id=33282&r=mysqlcfg

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