From:             wglynn at freedomhealthcare dot org
Operating system: Linux
PHP version:      4.3.11
PHP Bug Type:     Session related
Bug description:  Session cookies are set only once

Description:
------------
After switching webservers (and upgrading PHP) over the weekend for an
internal application, our users began reporting that they were getting
logged out randomly. After triple-checking our code and web server setup,
we started digging through the PHP source, and eventually discovered the
issue.

In PHP 4.3.4 (and versions before and after 4.3.4), setting a nonzero
value of session.cookie_lifetime either via php.ini or
session_set_cookie_params() resulted in a cookie that expires a certain
number of seconds after the current page load. This has the net effect of
session.cookie_lifetime setting an inactivity timeout.

In PHP 4.3.11, session_start() sends Set-Cookie: once, with an expiration
time governed by session.cookie_lifetime. (I believe this behavior changed
for PHP 4.3.9.) So, if session.cookie_lifetime is 20 minutes, the cookie
will expire and destroy the session 20 minutes after login, regardless of
any activity.

Bug #30232 attempted to change this behavior and got a patch committed,
but it was ripped out, saying that the behavior of setting the cookie once
is intentional and correct. I feel that this behavior is completely wrong
for cases where session.cookie_lifetime is nonzero; there is no situation
where sessions should expire a fixed time after setting them, but many
situations where sessions should expire a fixed time after a call to
session_start().

My proposed fix is to always send cookies if session.cookie_lifetime is
nonzero.

Reproduce code:
---------------
<?php

header('Refresh: 10');
session_set_cookie_params(15);
session_start();

if (!isset($_SESSION['i'])) {
  $_SESSION['i'] = 1;
  echo 'Started session.';

} else {
  $_SESSION['i']++;
  echo "Page load number {$_SESSION['i']}.";
}


Expected result:
----------------
"Page load number" should keep incrementing for as long as the browser
keeps refreshing the page within the cookie lifetime.

Actual result:
--------------
The cookie expires 15 seconds after the first page load, destroying the
session.

-- 
Edit bug report at http://bugs.php.net/?id=33868&edit=1
-- 
Try a CVS snapshot (php4):   http://bugs.php.net/fix.php?id=33868&r=trysnapshot4
Try a CVS snapshot (php5.0): 
http://bugs.php.net/fix.php?id=33868&r=trysnapshot50
Try a CVS snapshot (php5.1): 
http://bugs.php.net/fix.php?id=33868&r=trysnapshot51
Fixed in CVS:                http://bugs.php.net/fix.php?id=33868&r=fixedcvs
Fixed in release:            http://bugs.php.net/fix.php?id=33868&r=alreadyfixed
Need backtrace:              http://bugs.php.net/fix.php?id=33868&r=needtrace
Need Reproduce Script:       http://bugs.php.net/fix.php?id=33868&r=needscript
Try newer version:           http://bugs.php.net/fix.php?id=33868&r=oldversion
Not developer issue:         http://bugs.php.net/fix.php?id=33868&r=support
Expected behavior:           http://bugs.php.net/fix.php?id=33868&r=notwrong
Not enough info:             
http://bugs.php.net/fix.php?id=33868&r=notenoughinfo
Submitted twice:             
http://bugs.php.net/fix.php?id=33868&r=submittedtwice
register_globals:            http://bugs.php.net/fix.php?id=33868&r=globals
PHP 3 support discontinued:  http://bugs.php.net/fix.php?id=33868&r=php3
Daylight Savings:            http://bugs.php.net/fix.php?id=33868&r=dst
IIS Stability:               http://bugs.php.net/fix.php?id=33868&r=isapi
Install GNU Sed:             http://bugs.php.net/fix.php?id=33868&r=gnused
Floating point limitations:  http://bugs.php.net/fix.php?id=33868&r=float
No Zend Extensions:          http://bugs.php.net/fix.php?id=33868&r=nozend
MySQL Configuration Error:   http://bugs.php.net/fix.php?id=33868&r=mysqlcfg

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