Patch to allow anonymous users (uid = 0) have favorites on their own

When your site is used by a majority of anonymous users you will notice that the favorite nodes block will overflow because all anonymous users count as one, the user with uid 0. So every guest will see every favorite set by every other guest.

The solution ist just a small patch that keeps track of favorites in the session of a guest user.

1. Function favorite_nodes_add

After the db querys add the following code

	if ($user->uid == 0) {
		$data->nid = $nid;
		$data->title = $node->title;
		$data->uid = $user->uid;
		$data->last = time();

		$sess_favorites = unserialize($_SESSION['sess_favorites']);
		$sess_favorites[$nid] = $data;
		$_SESSION['sess_favorites'] = serialize($sess_favorites);
	}

2. function favorite_nodes_delete

After the db query add the following code

	if ($user->uid == 0) {
		$sess_favorites = unserialize($_SESSION['sess_favorites']);
		if (isset($sess_favorites[$nid])) { 
			unset($sess_favorites[$nid]); 
		}
		$_SESSION['sess_favorites'] = serialize($sess_favorites);
	}

3. function favorite_nodes_get

After the following lines

      while ($data = db_fetch_object($result)) {
        $row[$data->nid] = $data;
      }

just add

	if ($user->uid == 0) {
		$sess_favorites = unserialize($_SESSION['sess_favorites']);
		foreach($row as $nid => $data) {
			if ($sess_favorites[$nid] == $data) {
				$filtered_row[$nid] = $data;
			}
		}
		$row = $filtered_row;
	}

This solution keeps the basic functionality unchanged - only the output for the guest user will be filtered to his own favorites set during his visit.