ID: 30076
User updated by: daphp at mcbf dot net
-Summary: PHP fails to copy an array of objects when using
assignment
Reported By: daphp at mcbf dot net
Status: Open
Bug Type: Arrays related
Operating System: Linux Debian unstable 2.6.8.1
PHP Version: 4CVS-2004-09-13 (stable)
New Comment:
Fixed bad english in the summary.
Previous Comments:
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[2004-09-13 17:58:44] daphp at mcbf dot net
Description:
------------
When copying an array of objects using the assignment operator '=' in
some circumstances not a copy but a reference is created.
I discovered this when I used a function that had a reference to an
object in the array passed modified the object and all over sudden the
source of the copy got modified as well.
However, it seems this is not the only way to trigger this behavior, as
you can see in the URL provided with the code. It also happens when you
use a member function of the object after it got copied.
Please contact me if you need any more information.
Reproduce code:
---------------
<?
class urlfreq {
var $freq; // frequency count
}
function upd(&$uf)
{
$uf->freq++;
}
/********** init *********/
$urls[0][] = new urlfreq();
$urls[0][] = new urlfreq();
$urls[1][] = new urlfreq();
$urls[1][] = new urlfreq();
print("****** Incorrect output, using upd() ********\n");
$std[0][0] = $urls[0][0];
upd($std[0][0]);
$std[0][1] = $urls[0][1];
upd($std[0][1]);
$std[1] = $std[0];
upd($std[1][0]);
print($std[0][0]->freq." < ".$std[1][0]->freq."\n");
unset($std);
print("****** Correct output, using urlfreq::freq++ ********\n");
$std[0][0] = $urls[0][0];
$std[0][0]->freq++;
$std[0][1] = $urls[0][1];
$std[0][1]->freq++;
$std[1] = $std[0];
$std[1][0]->freq++;
print($std[0][0]->freq." < ".$std[1][0]->freq."\n");
// more examples can be found at
http://sun.mcbf.net/~squisher/phpbug.phps
?>
Expected result:
----------------
****** Incorrect output, using upd() ********
1 < 2
****** Correct output, using urlfreq::freq++ ********
1 < 2
Actual result:
--------------
****** Incorrect output, using upd() ********
2 < 2
****** Correct output, using urlfreq::freq++ ********
1 < 2
------------------------------------------------------------------------
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Edit this bug report at http://bugs.php.net/?id=30076&edit=1
