From: cetra3 at hotmaill dot com
Operating system: Windows XP
PHP version: 5.2.4
PHP Bug Type: *Math Functions
Bug description: rand generates predictable results
Description:
------------
The function Rand will produce predictable results.
Reproduce code:
---------------
<?php
$array_random = array_fill(1,10,1);
for($i=0;$i<100000000;$i++) {
$array_random[rand(1,10)]++;
}
print_r($array_random);
?>
Expected result:
----------------
This should produce an array which counts how many times each number is
picked at random. It should return a different result each time.
Actual result:
--------------
Instead of getting purely random responses, we get predictable ones, in
this example there will be tainted results, with numbers 5 and 10 producing
lower counts:
Array
(
[1] => 10000594
[2] => 10000610
[3] => 10000633
[4] => 10000589
[5] => 9997562
[6] => 10000606
[7] => 10000568
[8] => 10000620
[9] => 10000645
[10] => 9997583
)
You will always see these types of return values.
--
Edit bug report at http://bugs.php.net/?id=43108&edit=1
--
Try a CVS snapshot (PHP 4.4):
http://bugs.php.net/fix.php?id=43108&r=trysnapshot44
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=43108&r=trysnapshot52
Try a CVS snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=43108&r=trysnapshot53
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=43108&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=43108&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=43108&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=43108&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=43108&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=43108&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=43108&r=support
Expected behavior: http://bugs.php.net/fix.php?id=43108&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=43108&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=43108&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=43108&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=43108&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=43108&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=43108&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=43108&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=43108&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=43108&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=43108&r=mysqlcfg
