From: xris at siliconmechanics dot com
Operating system: redhat 7.3, 8 and 9
PHP version: Irrelevant
PHP Bug Type: Reproducible crash
Bug description: recursive data structures issue
Description:
------------
Can't upgrade, production environment. Happens on 4.2.2 and earlier, and
I'm forced to assume that it's still happening on more modern versions.
Ran into this problem with a much more complicated piece of code.
Basically, I have an array nested in an object. The array contains other
objects that then reference the parent object ala circular linked-list.
The provided example uses print_r to create an overflow, though my actual
code the overflow happens elsewhere (I can't figure out where in my code
the overflow is being generated, since I never actually traversed the
list, as print_r does). I know that it's the same problem because both
print_r and my code stabilize the instant I remove the recursive entry
from the second object (luckily for me, it wasn't needed).
Reproduce code:
---------------
class a {
var $items = array();
function a() {
}
}
class b {
var $a;
function b(&$a) {
$this->a = &$a;
}
}
$a = new a();
$a->items[] = new b($a);
$a->items[] = new b($a);
$a->items[] = new b($a); # this much is ok
$a->items[] = new b($a); # the proverbial straw
print_r($a);
Expected result:
----------------
get a printout from print_r where all recursive entries are marked:
a Object
(
[items] => Array
(
[0] => b Object
(#
[a] => *RECURSION*
)
[1] => b Object
(
[a] => *RECURSION*
)
)
)
Actual result:
--------------
With fewer items, the recursion is not properly detected, leading to an
overflow as more items are added.
With too many items in the array, nothing. php dies, or something like
that. IE produces a "page not found" error, and gecko just redisplays
whatever page was previously loaded, with no error returned (I expected a
"document contains no data" error, but never got it).
--
Edit bug report at http://bugs.php.net/?id=24811&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=24811&r=trysnapshot4
Try a CVS snapshot (php5): http://bugs.php.net/fix.php?id=24811&r=trysnapshot5
Fixed in CVS: http://bugs.php.net/fix.php?id=24811&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=24811&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=24811&r=needtrace
Try newer version: http://bugs.php.net/fix.php?id=24811&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=24811&r=support
Expected behavior: http://bugs.php.net/fix.php?id=24811&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=24811&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=24811&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=24811&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=24811&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=24811&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=24811&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=24811&r=gnused
