Wordpress inclusion in CodeIgniter leads to destroyed sessions - wordpress

Question

I had to add a WordPress installation to my CodeIgniter system, so I've put it in a submap called blog and excepted that folder in my .htaccess. All good and well.
I've put the all WordPress tables together with in my CodeIgniter databases with prefix _wp.
I've now loaded the WordPress blog header file into the index.php of CodeIgniter, like so;
require('blog/wp-blog-header.php');
add_filter('site_url', 'ci_site_url', 1);
function ci_site_url() {
include(FCPATH.'/application/config/config.php');
return $config['base_url'];
}
And made a registration method in my Account controller to make an actual link to my Customers. I do this because I want to make the WordPress login/registration obsolete and solely control that from the CodeIgniter login page;
protected function register_wp($email_address = FALSE) {
if ($email_address !== FALSE) {
if (username_exists( $email_address ) == NULL) {
$password = wp_generate_password(12, TRUE);
$user_id = wp_create_user($email_address, $password, $email_address);
wp_update_user(array(
'ID' => $user_id,
'nickname' => $email_address
));
$user = new WP_User($user_id);
$user->set_role('subscriber');
$login_data = array(
'user_id' => $user_id,
'password' => $password,
);
return $login_data;
}
else {
// User already exists with that email address
return FALSE;
}
}
else {
// No email_address given
return FALSE;
}
}
And the login method, to give an idea;
protected function login_wp($user_id = FALSE) {
if ($user_id !== FALSE) {
$user_login = 'admin';
$user = get_userdatabylogin($user_login);
$user_id = $user->ID;
wp_set_current_user($user_id, $user_login);
wp_set_auth_cookie($user_id);
do_action('wp_login', $user_login);
}
else {
// No user_id given
return FALSE;
}
}
All still going well. But here comes the clash; something I was very sad about because everything worked very well up until now:
WordPress overtakes the session and kills CodeIgniter's session.
I already tried tons of things;
session_rename('PHPSESSIDWP'); and then starting another session (with another name) for CodeIgniter after WordPress was loaded
COOKIE path (I'm not 100% sure if I done this right, as it didn't change at all. Read some things online it doesn't work well in all browsers either)
COOKIE domain (seemed to have no effect)
The problem is I can't load the require('blog/wp-blog-header.php'); only in the controller method, as I need to be able to control the logged in state of the WordPress part. Besides that I will get complaints about the site_url() function, that's already claimed by the URL helper.
I think the problem is mainly because both CodeIgniter and WordPress use their own unique way of handling Sessions (CI in the Database and WordPress in "super globals") which probably only makes them use the cookie to remember a "state".
My whole CodeIgniter system already runs on the Database-driven Session models so that's an absolute no-go to make a switch. For WordPress it seems it can't even work with session anymore with it's code features (I know session "do" work, but that doesn't seem to count in any way for the WP core system).
Also I quoted out wp_unregister_GLOBALS(); in the wp-settings.php file.
Plus that I also tried to rename my session COOKIE name in CodeIgniter to use something like session_ci
I really hope someone knows a way to being able to tell CodeIgniter or WordPress to only update their values and don't kill the whole session each time. I also read something about splitting up cookies with .htaccess but can't find good resources on it. So if anyone knows how to do that, I would be eternally grateful.
I'm in despair. Finishing it for 98% and then getting such a letdown in the end :(..
Update
Maybe I can do something in the WordPress section that handles the cookies?
http://codex.wordpress.org/Function_Reference/wp_set_auth_cookie
Sadly I'm not really home in the WordPress world. I solely have to use it this one time due to the bought template that the people really wanted to use in the blog.
Also this page states the following;
WordPress uses the two cookies to bypass the password entry portion of wp-login.php. If WordPress recognizes that you have valid, non-expired cookies, you go directly to the WordPress Administration interface. If you don't have the cookies, or they're expired, or in some other way invalid (like you edited them manually for some reason), WordPress will require you to log in again, in order to obtain new cookies.
I wonder tho, how to bypass that "invalid" check, which probably is the reason it kills the CodeIgniter cookie(s)? Weirdly enough tho, it seems the session_ci value stays, although the session still seems killed.

Answer 1

You need to put your session start at the very top of config.php.
This is the only place a session will not be destroyed by WordPress.
if (!session_id())
session_start();
If your PHP installation does not have register_global enabled, the
above code should allow you to use session, however, if it does, you
will not be able to get the data that was set in previous request.
This is because WordPress will destroy all data contained inside
session variable when it does the initialization.
Here's why and troubleshooting on this -> kanasolution.com
EXPANDED ANSWERS:
Source: http://codex.wordpress.org/WordPress_Cookies
On login, wordpress uses the wordpress_[hash] cookie to store your
authentication details. Its use is limited to the admin console area,
/wp-admin/
After login, wordpress sets the wordpress_logged_in_[hash] cookie, which indicates when you're logged in, and who you are, for
most interface use.
So WordPress clearly dislikes the way that you're writing cookies, maybe their lack of 8 pass MD5 hash etc? WordPress encryption methods
The WordPress Environment
The next thing I would try is integrating your custom login page into the WordPress environment instead of just requiring the header. (lets stay away from editing core)
From WordPress & AJAX by Ronald Huereca page 78 explains manually loading the WordPress environment.
The use of the dirname functions depend on the hierarchy of your file. Adjust them as needed. Code should be used before the tag of your file.
$root = dirname(dirname(dirname(dirname(dirname(__FILE__)))));
if (file_exists($root.'/wp-load.php')) {
require_once($root.'/wp-load.php');
/*Run custom WordPress stuff here */
//Output header HTML, queue scripts and styles, and include BODY content
wp_enqueue_script('my_script', get_stylesheet_directory_uri() . '/my_script.js', array('jquery'), '1.0.0');
wp_print_scripts(array('my_script'));
}