githubFork/roundcubemail.git

			@@ -5,15 +5,15 @@
			\| program/include/rcube_imap.php \|
			\| \|
			\| This file is part of the RoundCube Webmail client \|
			\| Copyright (C) 2005-2009, RoundCube Dev. - Switzerland \|
			\| Copyright (C) 2005-2010, RoundCube Dev. - Switzerland \|
			\| Licensed under the GNU GPL \|
			\| \|
			\| PURPOSE: \|
			\| IMAP wrapper that implements the Iloha IMAP Library (IIL) \|
			\| See http://ilohamail.org/ for details \|
			\| IMAP Engine \|
			\| \|
			+-----------------------------------------------------------------------+
			\| Author: Thomas Bruederli <roundcube@gmail.com> \|
			\| Author: Aleksander Machniak <alec@alec.pl> \|
			+-----------------------------------------------------------------------+

			$Id$
			@@ -21,3145 +21,3795 @@
			*/


			/*
			* Obtain classes from the Iloha IMAP library
			*/
			require_once('lib/imap.inc');
			require_once('lib/mime.inc');
			require_once('lib/tnef_decoder.inc');


			/**
			* Interface class for accessing an IMAP server
			*
			* This is a wrapper that implements the Iloha IMAP Library (IIL)
			*
			* @package Mail
			* @author Thomas Bruederli <roundcube@gmail.com>
			* @version 1.5
			* @link http://ilohamail.org
			* @author Aleksander Machniak <alec@alec.pl>
			* @version 2.0
			*/
			class rcube_imap
			{
			var $db;
			var $conn;
			var $root_ns = '';
			var $root_dir = '';
			var $mailbox = 'INBOX';
			var $list_page = 1;
			var $page_size = 10;
			var $sort_field = 'date';
			var $sort_order = 'DESC';
			var $index_sort = true;
			var $delimiter = NULL;
			var $caching_enabled = FALSE;
			var $default_charset = 'ISO-8859-1';
			var $struct_charset = NULL;
			var $default_folders = array('INBOX');
			var $default_folders_lc = array('inbox');
			var $fetch_add_headers = '';
			var $cache = array();
			var $cache_keys = array();
			var $cache_changes = array();
			var $uid_id_map = array();
			var $msg_headers = array();
			var $skip_deleted = FALSE;
			var $search_set = NULL;
			var $search_string = '';
			var $search_charset = '';
			var $search_sort_field = '';
			var $debug_level = 1;
			var $error_code = 0;
			var $options = array('auth_method' => 'check');

			private $host, $user, $pass, $port, $ssl;
			public $debug_level = 1;
			public $error_code = 0;
			public $skip_deleted = false;
			public $root_dir = '';
			public $page_size = 10;
			public $list_page = 1;
			public $delimiter = NULL;
			public $threading = false;
			public $fetch_add_headers = '';
			public $conn; // rcube_imap_generic object

			private $db;
			private $root_ns = '';
			private $mailbox = 'INBOX';
			private $sort_field = '';
			private $sort_order = 'DESC';
			private $caching_enabled = false;
			private $default_charset = 'ISO-8859-1';
			private $struct_charset = NULL;
			private $default_folders = array('INBOX');
			private $icache = array();
			private $cache = array();
			private $cache_keys = array();
			private $cache_changes = array();
			private $uid_id_map = array();
			private $msg_headers = array();
			public $search_set = NULL;
			public $search_string = '';
			private $search_charset = '';
			private $search_sort_field = '';
			private $search_threads = false;
			private $db_header_fields = array('idx', 'uid', 'subject', 'from', 'to', 'cc', 'date', 'size');
			private $options = array('auth_method' => 'check');
			private $host, $user, $pass, $port, $ssl;


			/**
			* Object constructor
			*
			* @param object DB Database connection
			*/
			function __construct($db_conn)
			/**
			* Object constructor
			*
			* @param object DB Database connection
			*/
			function __construct($db_conn)
			{
			$this->db = $db_conn;
			$this->db = $db_conn;
			$this->conn = new rcube_imap_generic();
			}


			/**
			* Connect to an IMAP server
			*
			* @param string Host to connect
			* @param string Username for IMAP account
			* @param string Password for IMAP account
			* @param number Port to connect to
			* @param string SSL schema (either ssl or tls) or null if plain connection
			* @return boolean TRUE on success, FALSE on failure
			* @access public
			*/
			function connect($host, $user, $pass, $port=143, $use_ssl=null)
			/**
			* Connect to an IMAP server
			*
			* @param string Host to connect
			* @param string Username for IMAP account
			* @param string Password for IMAP account
			* @param number Port to connect to
			* @param string SSL schema (either ssl or tls) or null if plain connection
			* @return boolean TRUE on success, FALSE on failure
			* @access public
			*/
			function connect($host, $user, $pass, $port=143, $use_ssl=null)
			{
			global $ICL_SSL, $ICL_PORT, $IMAP_USE_INTERNAL_DATE;

			// check for Open-SSL support in PHP build
			if ($use_ssl && extension_loaded('openssl'))
			$ICL_SSL = $use_ssl == 'imaps' ? 'ssl' : $use_ssl;
			else if ($use_ssl) {
			raise_error(array('code' => 403, 'type' => 'imap',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "Open SSL not available"), TRUE, FALSE);
			$port = 143;
			}

			$ICL_PORT = $port;
			$IMAP_USE_INTERNAL_DATE = false;

			$attempt = 0;
			do {
			$data = rcmail::get_instance()->plugins->exec_hook('imap_connect', array('host' => $host, 'user' => $user, 'attempt' => ++$attempt));
			if (!empty($data['pass']))
			$pass = $data['pass'];

			$this->conn = iil_Connect($data['host'], $data['user'], $pass, $this->options);
			} while(!$this->conn && $data['retry']);

			$this->host = $data['host'];
			$this->user = $data['user'];
			$this->pass = $pass;
			$this->port = $port;
			$this->ssl = $use_ssl;

			// print trace messages
			if ($this->conn && ($this->debug_level & 8))
			console($this->conn->message);

			// write error log
			else if (!$this->conn && $GLOBALS['iil_error'])
			{
			$this->error_code = $GLOBALS['iil_errornum'];
			raise_error(array('code' => 403, 'type' => 'imap',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => $GLOBALS['iil_error']), TRUE, FALSE);
			}

			// get server properties
			if ($this->conn)
			{
			if (!empty($this->conn->rootdir))
			{
			$this->set_rootdir($this->conn->rootdir);
			$this->root_ns = preg_replace('/[.\/]$/', '', $this->conn->rootdir);
			// check for OpenSSL support in PHP build
			if ($use_ssl && extension_loaded('openssl'))
			$this->options['ssl_mode'] = $use_ssl == 'imaps' ? 'ssl' : $use_ssl;
			else if ($use_ssl) {
			raise_error(array('code' => 403, 'type' => 'imap',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => "OpenSSL not available"), true, false);
			$port = 143;
			}
			if (empty($this->delimiter))
			$this->get_hierarchy_delimiter();
			}

			return $this->conn ? TRUE : FALSE;
			$this->options['port'] = $port;

			$attempt = 0;
			do {
			$data = rcmail::get_instance()->plugins->exec_hook('imap_connect',
			array('host' => $host, 'user' => $user, 'attempt' => ++$attempt));

			if (!empty($data['pass']))
			$pass = $data['pass'];

			$this->conn->connect($data['host'], $data['user'], $pass, $this->options);
			} while(!$this->conn->connected() && $data['retry']);

			$this->host = $data['host'];
			$this->user = $data['user'];
			$this->pass = $pass;
			$this->port = $port;
			$this->ssl = $use_ssl;

			// print trace messages
			if ($this->conn->connected()) {
			if ($this->conn->message && ($this->debug_level & 8)) {
			console($this->conn->message);
			}

			// get server properties
			if (!empty($this->conn->rootdir))
			$this->set_rootdir($this->conn->rootdir);
			if (empty($this->delimiter))
			$this->get_hierarchy_delimiter();

			return true;
			}
			// write error log
			else if ($this->conn->error) {
			$this->error_code = $this->conn->errornum;
			raise_error(array('code' => 403, 'type' => 'imap',
			'file' => __FILE__, 'line' => __LINE__,
			'message' => $this->conn->error), true, false);
			}

			return false;
			}


			/**
			* Close IMAP connection
			* Usually done on script shutdown
			*
			* @access public
			*/
			function close()
			{
			if ($this->conn)
			iil_Close($this->conn);
			}


			/**
			* Close IMAP connection and re-connect
			* This is used to avoid some strange socket errors when talking to Courier IMAP
			*
			* @access public
			*/
			function reconnect()
			/**
			* Close IMAP connection
			* Usually done on script shutdown
			*
			* @access public
			*/
			function close()
			{
			$this->close();
			$this->connect($this->host, $this->user, $this->pass, $this->port, $this->ssl);

			// issue SELECT command to restore connection status
			if ($this->mailbox)
			iil_C_Select($this->conn, $this->mailbox);
			if ($this->conn && $this->conn->connected())
			$this->conn->close();
			$this->write_cache();
			}

			/**
			* Set options to be used in iil_Connect()
			*/
			function set_options($opt)
			{
			$this->options = array_merge($this->options, (array)$opt);
			}

			/**
			* Set a root folder for the IMAP connection.
			*
			* Only folders within this root folder will be displayed
			* and all folder paths will be translated using this folder name
			*
			* @param string Root folder
			* @access public
			*/
			function set_rootdir($root)
			/**
			* Close IMAP connection and re-connect
			* This is used to avoid some strange socket errors when talking to Courier IMAP
			*
			* @access public
			*/
			function reconnect()
			{
			if (preg_match('/[.\/]$/', $root)) //(substr($root, -1, 1)==='/')
			$root = substr($root, 0, -1);
			$this->close();
			$this->connect($this->host, $this->user, $this->pass, $this->port, $this->ssl);

			$this->root_dir = $root;
			$this->options['rootdir'] = $root;

			if (empty($this->delimiter))
			$this->get_hierarchy_delimiter();
			// issue SELECT command to restore connection status
			if ($this->mailbox)
			$this->conn->select($this->mailbox);
			}


			/**
			* Set default message charset
			*
			* This will be used for message decoding if a charset specification is not available
			*
			* @param string Charset string
			* @access public
			*/
			function set_charset($cs)
			/**
			* Set options to be used in rcube_imap_generic::connect()
			*/
			function set_options($opt)
			{
			$this->default_charset = $cs;
			$this->options = array_merge($this->options, (array)$opt);
			}


			/**
			* This list of folders will be listed above all other folders
			*
			* @param array Indexed list of folder names
			* @access public
			*/
			function set_default_mailboxes($arr)
			/**
			* Set a root folder for the IMAP connection.
			*
			* Only folders within this root folder will be displayed
			* and all folder paths will be translated using this folder name
			*
			* @param string Root folder
			* @access public
			*/
			function set_rootdir($root)
			{
			if (is_array($arr))
			{
			$this->default_folders = $arr;
			$this->default_folders_lc = array();
			if (preg_match('/[.\/]$/', $root)) //(substr($root, -1, 1)==='/')
			$root = substr($root, 0, -1);

			// add inbox if not included
			if (!in_array_nocase('INBOX', $this->default_folders))
			array_unshift($this->default_folders, 'INBOX');
			$this->root_dir = $root;
			$this->options['rootdir'] = $root;

			// create a second list with lower cased names
			foreach ($this->default_folders as $mbox)
			$this->default_folders_lc[] = strtolower($mbox);
			}
			if (empty($this->delimiter))
			$this->get_hierarchy_delimiter();
			}


			/**
			* Set internal mailbox reference.
			*
			* All operations will be perfomed on this mailbox/folder
			*
			* @param string Mailbox/Folder name
			* @access public
			*/
			function set_mailbox($new_mbox)
			/**
			* Set default message charset
			*
			* This will be used for message decoding if a charset specification is not available
			*
			* @param string Charset string
			* @access public
			*/
			function set_charset($cs)
			{
			$mailbox = $this->mod_mailbox($new_mbox);

			if ($this->mailbox == $mailbox)
			return;

			$this->mailbox = $mailbox;

			// clear messagecount cache for this mailbox
			$this->_clear_messagecount($mailbox);
			$this->default_charset = $cs;
			}


			/**
			* Set internal list page
			*
			* @param number Page number to list
			* @access public
			*/
			function set_page($page)
			/**
			* This list of folders will be listed above all other folders
			*
			* @param array Indexed list of folder names
			* @access public
			*/
			function set_default_mailboxes($arr)
			{
			$this->list_page = (int)$page;
			if (is_array($arr)) {
			$this->default_folders = $arr;

			// add inbox if not included
			if (!in_array('INBOX', $this->default_folders))
			array_unshift($this->default_folders, 'INBOX');
			}
			}


			/**
			* Set internal page size
			*
			* @param number Number of messages to display on one page
			* @access public
			*/
			function set_pagesize($size)
			/**
			* Set internal mailbox reference.
			*
			* All operations will be perfomed on this mailbox/folder
			*
			* @param string Mailbox/Folder name
			* @access public
			*/
			function set_mailbox($new_mbox)
			{
			$this->page_size = (int)$size;
			}

			$mailbox = $this->mod_mailbox($new_mbox);

			/**
			* Save a set of message ids for future message listing methods
			*
			* @param string IMAP Search query
			* @param array List of message ids or NULL if empty
			* @param string Charset of search string
			* @param string Sorting field
			*/
			function set_search_set($str=null, $msgs=null, $charset=null, $sort_field=null)
			if ($this->mailbox == $mailbox)
			return;

			$this->mailbox = $mailbox;

			// clear messagecount cache for this mailbox
			$this->_clear_messagecount($mailbox);
			}


			/**
			* Set internal list page
			*
			* @param number Page number to list
			* @access public
			*/
			function set_page($page)
			{
			if (is_array($str) && $msgs == null)
			list($str, $msgs, $charset, $sort_field) = $str;
			if ($msgs != null && !is_array($msgs))
			$msgs = explode(',', $msgs);

			$this->search_string = $str;
			$this->search_set = $msgs;
			$this->search_charset = $charset;
			$this->search_sort_field = $sort_field;
			$this->list_page = (int)$page;
			}


			/**
			* Return the saved search set as hash array
			* @return array Search set
			*/
			function get_search_set()
			/**
			* Set internal page size
			*
			* @param number Number of messages to display on one page
			* @access public
			*/
			function set_pagesize($size)
			{
			return array($this->search_string, $this->search_set, $this->search_charset, $this->search_sort_field);
			$this->page_size = (int)$size;
			}


			/**
			* Returns the currently used mailbox name
			*
			* @return string Name of the mailbox/folder
			* @access public
			*/
			function get_mailbox_name()
			/**
			* Save a set of message ids for future message listing methods
			*
			* @param string IMAP Search query
			* @param array List of message ids or NULL if empty
			* @param string Charset of search string
			* @param string Sorting field
			*/
			function set_search_set($str=null, $msgs=null, $charset=null, $sort_field=null, $threads=false)
			{
			return $this->conn ? $this->mod_mailbox($this->mailbox, 'out') : '';
			if (is_array($str) && $msgs == null)
			list($str, $msgs, $charset, $sort_field, $threads) = $str;
			if ($msgs != null && !is_array($msgs))
			$msgs = explode(',', $msgs);

			$this->search_string = $str;
			$this->search_set = $msgs;
			$this->search_charset = $charset;
			$this->search_sort_field = $sort_field;
			$this->search_threads = $threads;
			}


			/**
			* Returns the IMAP server's capability
			*
			* @param string Capability name
			* @return mixed Capability value or TRUE if supported, FALSE if not
			* @access public
			*/
			function get_capability($cap)
			/**
			* Return the saved search set as hash array
			* @return array Search set
			*/
			function get_search_set()
			{
			return iil_C_GetCapability($this->conn, strtoupper($cap));
			return array($this->search_string,
			$this->search_set,
			$this->search_charset,
			$this->search_sort_field,
			$this->search_threads,
			);
			}


			/**
			* Checks the PERMANENTFLAGS capability of the current mailbox
			* and returns true if the given flag is supported by the IMAP server
			*
			* @param string Permanentflag name
			* @return mixed True if this flag is supported
			* @access public
			*/
			function check_permflag($flag)
			/**
			* Returns the currently used mailbox name
			*
			* @return string Name of the mailbox/folder
			* @access public
			*/
			function get_mailbox_name()
			{
			$flag = strtoupper($flag);
			$imap_flag = $GLOBALS['IMAP_FLAGS'][$flag];
			return (in_array_nocase($imap_flag, $this->conn->permanentflags));
			return $this->conn->connected() ? $this->mod_mailbox($this->mailbox, 'out') : '';
			}


			/**
			* Returns the delimiter that is used by the IMAP server for folder separation
			*
			* @return string Delimiter string
			* @access public
			*/
			function get_hierarchy_delimiter()
			/**
			* Returns the IMAP server's capability
			*
			* @param string Capability name
			* @return mixed Capability value or TRUE if supported, FALSE if not
			* @access public
			*/
			function get_capability($cap)
			{
			if ($this->conn && empty($this->delimiter))
			$this->delimiter = iil_C_GetHierarchyDelimiter($this->conn);

			if (empty($this->delimiter))
			$this->delimiter = '/';

			return $this->delimiter;
			return $this->conn->getCapability(strtoupper($cap));
			}


			/**
			* Public method for mailbox listing.
			*
			* Converts mailbox name with root dir first
			*
			* @param string Optional root folder
			* @param string Optional filter for mailbox listing
			* @return array List of mailboxes/folders
			* @access public
			*/
			function list_mailboxes($root='', $filter='*')
			/**
			* Sets threading flag to the best supported THREAD algorithm
			*
			* @param boolean TRUE to enable and FALSE
			* @return string Algorithm or false if THREAD is not supported
			* @access public
			*/
			function set_threading($enable=false)
			{
			$a_out = array();
			$a_mboxes = $this->_list_mailboxes($root, $filter);
			$this->threading = false;

			foreach ($a_mboxes as $mbox_row)
			{
			$name = $this->mod_mailbox($mbox_row, 'out');
			if (strlen($name))
			$a_out[] = $name;
			}
			if ($enable) {
			if ($this->get_capability('THREAD=REFS'))
			$this->threading = 'REFS';
			else if ($this->get_capability('THREAD=REFERENCES'))
			$this->threading = 'REFERENCES';
			else if ($this->get_capability('THREAD=ORDEREDSUBJECT'))
			$this->threading = 'ORDEREDSUBJECT';
			}

			// INBOX should always be available
			if (!in_array_nocase('INBOX', $a_out))
			array_unshift($a_out, 'INBOX');

			// sort mailboxes
			$a_out = $this->_sort_mailbox_list($a_out);

			return $a_out;
			return $this->threading;
			}


			/**
			* Private method for mailbox listing
			*
			* @return array List of mailboxes/folders
			* @see rcube_imap::list_mailboxes()
			* @access private
			*/
			private function _list_mailboxes($root='', $filter='*')
			/**
			* Checks the PERMANENTFLAGS capability of the current mailbox
			* and returns true if the given flag is supported by the IMAP server
			*
			* @param string Permanentflag name
			* @return mixed True if this flag is supported
			* @access public
			*/
			function check_permflag($flag)
			{
			$a_defaults = $a_out = array();

			// get cached folder list
			$a_mboxes = $this->get_cache('mailboxes');
			if (is_array($a_mboxes))
			return $a_mboxes;

			// Give plugins a chance to provide a list of mailboxes
			$data = rcmail::get_instance()->plugins->exec_hook('list_mailboxes',array('root'=>$root,'filter'=>$filter));
			if (isset($data['folders'])) {
			$a_folders = $data['folders'];
			}
			else{
			// retrieve list of folders from IMAP server
			$a_folders = iil_C_ListSubscribed($this->conn, $this->mod_mailbox($root), $filter);
			}


			if (!is_array($a_folders) \|\| !sizeof($a_folders))
			$a_folders = array();

			// write mailboxlist to cache
			$this->update_cache('mailboxes', $a_folders);

			return $a_folders;
			$flag = strtoupper($flag);
			$imap_flag = $this->conn->flags[$flag];
			return (in_array_nocase($imap_flag, $this->conn->permanentflags));
			}


			/**
			* Get message count for a specific mailbox
			*
			* @param string Mailbox/folder name
			* @param string Mode for count [ALL\|UNSEEN\|RECENT]
			* @param boolean Force reading from server and update cache
			* @return int Number of messages
			* @access public
			*/
			function messagecount($mbox_name='', $mode='ALL', $force=FALSE)
			/**
			* Returns the delimiter that is used by the IMAP server for folder separation
			*
			* @return string Delimiter string
			* @access public
			*/
			function get_hierarchy_delimiter()
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_messagecount($mailbox, $mode, $force);
			if ($this->conn && empty($this->delimiter))
			$this->delimiter = $this->conn->getHierarchyDelimiter();

			if (empty($this->delimiter))
			$this->delimiter = '/';

			return $this->delimiter;
			}


			/**
			* Private method for getting nr of messages
			*
			* @access private
			* @see rcube_imap::messagecount()
			*/
			private function _messagecount($mailbox='', $mode='ALL', $force=FALSE)
			/**
			* Get message count for a specific mailbox
			*
			* @param string Mailbox/folder name
			* @param string Mode for count [ALL\|THREADS\|UNSEEN\|RECENT]
			* @param boolean Force reading from server and update cache
			* @param boolean Enables storing folder status info (max UID/count),
			* required for mailbox_status()
			* @return int Number of messages
			* @access public
			*/
			function messagecount($mbox_name='', $mode='ALL', $force=false, $status=true)
			{
			$mode = strtoupper($mode);

			if (empty($mailbox))
			$mailbox = $this->mailbox;

			// count search set
			if ($this->search_string && $mailbox == $this->mailbox && $mode == 'ALL' && !$force)
			return count((array)$this->search_set);

			$a_mailbox_cache = $this->get_cache('messagecount');

			// return cached value
			if (!$force && is_array($a_mailbox_cache[$mailbox]) && isset($a_mailbox_cache[$mailbox][$mode]))
			return $a_mailbox_cache[$mailbox][$mode];

			// RECENT count is fetched a bit different
			if ($mode == 'RECENT')
			$count = iil_C_CheckForRecent($this->conn, $mailbox);

			// use SEARCH for message counting
			else if ($this->skip_deleted)
			{
			$search_str = "ALL UNDELETED";

			// get message count and store in cache
			if ($mode == 'UNSEEN')
			$search_str .= " UNSEEN";

			// get message count using SEARCH
			// not very performant but more precise (using UNDELETED)
			$index = $this->_search_index($mailbox, $search_str);
			$count = is_array($index) ? count($index) : 0;
			}
			else
			{
			if ($mode == 'UNSEEN')
			$count = iil_C_CountUnseen($this->conn, $mailbox);
			else
			$count = iil_C_CountMessages($this->conn, $mailbox);
			}

			if (!is_array($a_mailbox_cache[$mailbox]))
			$a_mailbox_cache[$mailbox] = array();

			$a_mailbox_cache[$mailbox][$mode] = (int)$count;

			// write back to cache
			$this->update_cache('messagecount', $a_mailbox_cache);

			return (int)$count;
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_messagecount($mailbox, $mode, $force, $status);
			}


			/**
			* Public method for listing headers
			* convert mailbox name with root dir first
			*
			* @param string Mailbox/folder name
			* @param int Current page to list
			* @param string Header field to sort by
			* @param string Sort order [ASC\|DESC]
			* @param boolean Number of slice items to extract from result array
			* @return array Indexed array with message header objects
			* @access public
			*/
			function list_headers($mbox_name='', $page=NULL, $sort_field=NULL, $sort_order=NULL, $slice=0)
			/**
			* Private method for getting nr of messages
			*
			* @access private
			* @see rcube_imap::messagecount()
			*/
			private function _messagecount($mailbox='', $mode='ALL', $force=false, $status=true)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_list_headers($mailbox, $page, $sort_field, $sort_order, false, $slice);
			$mode = strtoupper($mode);

			if (empty($mailbox))
			$mailbox = $this->mailbox;

			// count search set
			if ($this->search_string && $mailbox == $this->mailbox && ($mode == 'ALL' \|\| $mode == 'THREADS') && !$force) {
			if ($this->search_threads)
			return $mode == 'ALL' ? count((array)$this->search_set['depth']) : count((array)$this->search_set['tree']);
			else
			return count((array)$this->search_set);
			}

			$a_mailbox_cache = $this->get_cache('messagecount');

			// return cached value
			if (!$force && is_array($a_mailbox_cache[$mailbox]) && isset($a_mailbox_cache[$mailbox][$mode]))
			return $a_mailbox_cache[$mailbox][$mode];

			if (!is_array($a_mailbox_cache[$mailbox]))
			$a_mailbox_cache[$mailbox] = array();

			if ($mode == 'THREADS') {
			$count = $this->_threadcount($mailbox, $msg_count);
			if ($status) {
			$this->set_folder_stats($mailbox, 'cnt', $msg_count);
			$this->set_folder_stats($mailbox, 'maxuid', $msg_count ? $this->_id2uid($msg_count, $mailbox) : 0);
			}
			}
			// RECENT count is fetched a bit different
			else if ($mode == 'RECENT') {
			$count = $this->conn->checkForRecent($mailbox);
			}
			// use SEARCH for message counting
			else if ($this->skip_deleted) {
			$search_str = "ALL UNDELETED";

			// get message count and store in cache
			if ($mode == 'UNSEEN')
			$search_str .= " UNSEEN";

			// get message count using SEARCH
			// not very performant but more precise (using UNDELETED)
			// disable THREADS for this request
			$threads = $this->threading;
			$this->threading = false;
			$index = $this->_search_index($mailbox, $search_str);
			$this->threading = $threads;

			$count = is_array($index) ? count($index) : 0;

			if ($mode == 'ALL' && $status) {
			$this->set_folder_stats($mailbox, 'cnt', $count);
			$this->set_folder_stats($mailbox, 'maxuid', $index ? $this->_id2uid(max($index), $mailbox) : 0);
			}
			}
			else {
			if ($mode == 'UNSEEN')
			$count = $this->conn->countUnseen($mailbox);
			else {
			$count = $this->conn->countMessages($mailbox);
			if ($status) {
			$this->set_folder_stats($mailbox,'cnt', $count);
			$this->set_folder_stats($mailbox, 'maxuid', $count ? $this->_id2uid($count, $mailbox) : 0);
			}
			}
			}

			$a_mailbox_cache[$mailbox][$mode] = (int)$count;

			// write back to cache
			$this->update_cache('messagecount', $a_mailbox_cache);

			return (int)$count;
			}


			/**
			* Private method for listing message headers
			*
			* @access private
			* @see rcube_imap::list_headers
			*/
			private function _list_headers($mailbox='', $page=NULL, $sort_field=NULL, $sort_order=NULL, $recursive=FALSE, $slice=0)
			/**
			* Private method for getting nr of threads
			*
			* @access private
			* @see rcube_imap::messagecount()
			*/
			private function _threadcount($mailbox, &$msg_count)
			{
			if (!strlen($mailbox))
			return array();
			if (!empty($this->icache['threads']))
			return count($this->icache['threads']['tree']);

			// use saved message set
			if ($this->search_string && $mailbox == $this->mailbox)
			return $this->_list_header_set($mailbox, $page, $sort_field, $sort_order, $slice);
			list ($thread_tree, $msg_depth, $has_children) = $this->_fetch_threads($mailbox);

			$this->_set_sort_order($sort_field, $sort_order);
			$msg_count = count($msg_depth);

			$page = $page ? $page : $this->list_page;
			$cache_key = $mailbox.'.msg';
			$cache_status = $this->check_cache_status($mailbox, $cache_key);
			// $this->update_thread_cache($mailbox, $thread_tree, $msg_depth, $has_children);
			return count($thread_tree);
			}

			// cache is OK, we can get all messages from local cache
			if ($cache_status>0)
			{
			$start_msg = ($page-1) * $this->page_size;
			$a_msg_headers = $this->get_message_cache($cache_key, $start_msg, $start_msg+$this->page_size, $this->sort_field, $this->sort_order);
			$result = array_values($a_msg_headers);
			if ($slice)
			$result = array_slice($result, -$slice, $slice);
			return $result;
			}
			// cache is dirty, sync it
			else if ($this->caching_enabled && $cache_status==-1 && !$recursive)
			{
			$this->sync_header_index($mailbox);
			return $this->_list_headers($mailbox, $page, $this->sort_field, $this->sort_order, TRUE, $slice);
			}

			// retrieve headers from IMAP
			$a_msg_headers = array();
			/**
			* Public method for listing headers
			* convert mailbox name with root dir first
			*
			* @param string Mailbox/folder name
			* @param int Current page to list
			* @param string Header field to sort by
			* @param string Sort order [ASC\|DESC]
			* @param boolean Number of slice items to extract from result array
			* @return array Indexed array with message header objects
			* @access public
			*/
			function list_headers($mbox_name='', $page=NULL, $sort_field=NULL, $sort_order=NULL, $slice=0)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_list_headers($mailbox, $page, $sort_field, $sort_order, false, $slice);
			}

			// use message index sort for sorting by Date (for better performance)
			if ($this->index_sort && $this->sort_field == 'date')
			{
			if ($this->skip_deleted) {
			// @TODO: this could be cached
			if ($msg_index = $this->_search_index($mailbox, 'ALL UNDELETED')) {

			/**
			* Private method for listing message headers
			*
			* @access private
			* @see rcube_imap::list_headers
			*/
			private function _list_headers($mailbox='', $page=NULL, $sort_field=NULL, $sort_order=NULL, $recursive=false, $slice=0)
			{
			if (!strlen($mailbox))
			return array();

			// use saved message set
			if ($this->search_string && $mailbox == $this->mailbox)
			return $this->_list_header_set($mailbox, $page, $sort_field, $sort_order, $slice);

			if ($this->threading)
			return $this->_list_thread_headers($mailbox, $page, $sort_field, $sort_order, $recursive, $slice);

			$this->_set_sort_order($sort_field, $sort_order);

			$page = $page ? $page : $this->list_page;
			$cache_key = $mailbox.'.msg';
			$cache_status = $this->check_cache_status($mailbox, $cache_key);

			// cache is OK, we can get all messages from local cache
			if ($cache_status>0) {
			$start_msg = ($page-1) * $this->page_size;
			$a_msg_headers = $this->get_message_cache($cache_key, $start_msg,
			$start_msg+$this->page_size, $this->sort_field, $this->sort_order);
			$result = array_values($a_msg_headers);
			if ($slice)
			$result = array_slice($result, -$slice, $slice);
			return $result;
			}
			// cache is dirty, sync it
			else if ($this->caching_enabled && $cache_status==-1 && !$recursive) {
			$this->sync_header_index($mailbox);
			return $this->_list_headers($mailbox, $page, $this->sort_field, $this->sort_order, true, $slice);
			}

			// retrieve headers from IMAP
			$a_msg_headers = array();

			// use message index sort as default sorting (for better performance)
			if (!$this->sort_field) {
			if ($this->skip_deleted) {
			// @TODO: this could be cached
			if ($msg_index = $this->_search_index($mailbox, 'ALL UNDELETED')) {
			$max = max($msg_index);
			list($begin, $end) = $this->_get_message_range(count($msg_index), $page);
			$msg_index = array_slice($msg_index, $begin, $end-$begin);
			}
			}
			else if ($max = $this->conn->countMessages($mailbox)) {
			list($begin, $end) = $this->_get_message_range($max, $page);
			$msg_index = range($begin+1, $end);
			}
			else
			$msg_index = array();

			if ($slice)
			$msg_index = array_slice($msg_index, ($this->sort_order == 'DESC' ? 0 : -$slice), $slice);

			// fetch reqested headers from server
			if ($msg_index)
			$this->_fetch_headers($mailbox, join(",", $msg_index), $a_msg_headers, $cache_key);
			}
			// use SORT command
			else if ($this->get_capability('SORT')) {
			if ($msg_index = $this->conn->sort($mailbox, $this->sort_field, $this->skip_deleted ? 'UNDELETED' : '')) {
			list($begin, $end) = $this->_get_message_range(count($msg_index), $page);
			$max = max($msg_index);
			$msg_index = array_slice($msg_index, $begin, $end-$begin);

			if ($slice)
			$msg_index = array_slice($msg_index, ($this->sort_order == 'DESC' ? 0 : -$slice), $slice);

			// fetch reqested headers from server
			$this->_fetch_headers($mailbox, join(',', $msg_index), $a_msg_headers, $cache_key);
			}
			}
			// fetch specified header for all messages and sort
			else if ($a_index = $this->conn->fetchHeaderIndex($mailbox, "1:*", $this->sort_field, $this->skip_deleted)) {
			asort($a_index); // ASC
			$msg_index = array_keys($a_index);
			$max = max($msg_index);
			list($begin, $end) = $this->_get_message_range(count($msg_index), $page);
			$msg_index = array_slice($msg_index, $begin, $end-$begin);
			}
			} else if ($max = iil_C_CountMessages($this->conn, $mailbox)) {
			list($begin, $end) = $this->_get_message_range($max, $page);
			$msg_index = range($begin+1, $end);
			} else
			$msg_index = array();

			if ($slice)
			$msg_index = array_slice($msg_index, ($this->sort_order == 'DESC' ? 0 : -$slice), $slice);
			if ($slice)
			$msg_index = array_slice($msg_index, ($this->sort_order == 'DESC' ? 0 : -$slice), $slice);

			// fetch reqested headers from server
			if ($msg_index)
			$this->_fetch_headers($mailbox, join(",", $msg_index), $a_msg_headers, $cache_key);
			}
			// use SORT command
			else if ($this->get_capability('sort') && ($msg_index = iil_C_Sort($this->conn, $mailbox, $this->sort_field, $this->skip_deleted ? 'UNDELETED' : '')))
			{
			list($begin, $end) = $this->_get_message_range(count($msg_index), $page);
			$max = max($msg_index);
			$msg_index = array_slice($msg_index, $begin, $end-$begin);
			// fetch reqested headers from server
			$this->_fetch_headers($mailbox, join(",", $msg_index), $a_msg_headers, $cache_key);
			}

			if ($slice)
			$msg_index = array_slice($msg_index, ($this->sort_order == 'DESC' ? 0 : -$slice), $slice);
			// delete cached messages with a higher index than $max+1
			// Changed $max to $max+1 to fix this bug : #1484295
			$this->clear_message_cache($cache_key, $max + 1);

			// fetch reqested headers from server
			$this->_fetch_headers($mailbox, join(',', $msg_index), $a_msg_headers, $cache_key);
			}
			// fetch specified header for all messages and sort
			else if ($a_index = iil_C_FetchHeaderIndex($this->conn, $mailbox, "1:*", $this->sort_field, $this->skip_deleted))
			{
			asort($a_index); // ASC
			$msg_index = array_keys($a_index);
			$max = max($msg_index);
			list($begin, $end) = $this->_get_message_range(count($msg_index), $page);
			$msg_index = array_slice($msg_index, $begin, $end-$begin);

			if ($slice)
			$msg_index = array_slice($msg_index, ($this->sort_order == 'DESC' ? 0 : -$slice), $slice);

			// fetch reqested headers from server
			$this->_fetch_headers($mailbox, join(",", $msg_index), $a_msg_headers, $cache_key);
			}

			// delete cached messages with a higher index than $max+1
			// Changed $max to $max+1 to fix this bug : #1484295
			$this->clear_message_cache($cache_key, $max + 1);

			// kick child process to sync cache
			// ...

			// return empty array if no messages found
			if (!is_array($a_msg_headers) \|\| empty($a_msg_headers))
			return array();

			// use this class for message sorting
			$sorter = new rcube_header_sorter();
			$sorter->set_sequence_numbers($msg_index);
			$sorter->sort_headers($a_msg_headers);

			if ($this->sort_order == 'DESC')
			$a_msg_headers = array_reverse($a_msg_headers);

			return array_values($a_msg_headers);
			}


			/**
			* Private method for listing a set of message headers (search results)
			*
			* @param string Mailbox/folder name
			* @param int Current page to list
			* @param string Header field to sort by
			* @param string Sort order [ASC\|DESC]
			* @param boolean Number of slice items to extract from result array
			* @return array Indexed array with message header objects
			* @access private
			* @see rcube_imap::list_header_set()
			*/
			private function _list_header_set($mailbox, $page=NULL, $sort_field=NULL, $sort_order=NULL, $slice=0)
			{
			if (!strlen($mailbox) \|\| empty($this->search_set))
			return array();

			$msgs = $this->search_set;
			$a_msg_headers = array();
			$page = $page ? $page : $this->list_page;
			$start_msg = ($page-1) * $this->page_size;

			$this->_set_sort_order($sort_field, $sort_order);

			// quickest method
			if ($this->index_sort && $this->search_sort_field == 'date' && $this->sort_field == 'date')
			{
			if ($sort_order == 'DESC')
			$msgs = array_reverse($msgs);

			// get messages uids for one page
			$msgs = array_slice(array_values($msgs), $start_msg, min(count($msgs)-$start_msg, $this->page_size));

			if ($slice)
			$msgs = array_slice($msgs, -$slice, $slice);

			// fetch headers
			$this->_fetch_headers($mailbox, join(',',$msgs), $a_msg_headers, NULL);

			// I didn't found in RFC that FETCH always returns messages sorted by index
			$sorter = new rcube_header_sorter();
			$sorter->set_sequence_numbers($msgs);
			$sorter->sort_headers($a_msg_headers);

			return array_values($a_msg_headers);
			}
			// sorted messages, so we can first slice array and then fetch only wanted headers
			if ($this->get_capability('sort') && (!$this->index_sort \|\| $this->sort_field != 'date')) // SORT searching result
			{
			// reset search set if sorting field has been changed
			if ($this->sort_field && $this->search_sort_field != $this->sort_field)
			$msgs = $this->search('', $this->search_string, $this->search_charset, $this->sort_field);

			// return empty array if no messages found
			if (empty($msgs))
			return array();

			if ($sort_order == 'DESC')
			$msgs = array_reverse($msgs);

			// get messages uids for one page
			$msgs = array_slice(array_values($msgs), $start_msg, min(count($msgs)-$start_msg, $this->page_size));

			if ($slice)
			$msgs = array_slice($msgs, -$slice, $slice);

			// fetch headers
			$this->_fetch_headers($mailbox, join(',',$msgs), $a_msg_headers, NULL);

			$sorter = new rcube_header_sorter();
			$sorter->set_sequence_numbers($msgs);
			$sorter->sort_headers($a_msg_headers);

			return array_values($a_msg_headers);
			}
			else { // SEARCH searching result, need sorting
			$cnt = count($msgs);
			// 300: experimantal value for best result
			if (($cnt > 300 && $cnt > $this->page_size) \|\| ($this->index_sort && $this->sort_field == 'date')) {
			// use memory less expensive (and quick) method for big result set
			$a_index = $this->message_index('', $this->sort_field, $this->sort_order);
			// get messages uids for one page...
			$msgs = array_slice($a_index, $start_msg, min($cnt-$start_msg, $this->page_size));
			if ($slice)
			$msgs = array_slice($msgs, -$slice, $slice);
			// ...and fetch headers
			$this->_fetch_headers($mailbox, join(',', $msgs), $a_msg_headers, NULL);
			// kick child process to sync cache
			// ...

			// return empty array if no messages found
			if (!is_array($a_msg_headers) \|\| empty($a_msg_headers))
			return array();
			return array();

			// use this class for message sorting
			$sorter = new rcube_header_sorter();
			$sorter->set_sequence_numbers($msgs);
			$sorter->set_sequence_numbers($msg_index);
			$sorter->sort_headers($a_msg_headers);

			if ($this->sort_order == 'DESC')
			$a_msg_headers = array_reverse($a_msg_headers);

			return array_values($a_msg_headers);
			}


			/**
			* Private method for listing message headers using threads
			*
			* @access private
			* @see rcube_imap::list_headers
			*/
			private function _list_thread_headers($mailbox, $page=NULL, $sort_field=NULL, $sort_order=NULL, $recursive=false, $slice=0)
			{
			$this->_set_sort_order($sort_field, $sort_order);

			$page = $page ? $page : $this->list_page;
			// $cache_key = $mailbox.'.msg';
			// $cache_status = $this->check_cache_status($mailbox, $cache_key);

			// get all threads (default sort order)
			list ($thread_tree, $msg_depth, $has_children) = $this->_fetch_threads($mailbox);

			if (empty($thread_tree))
			return array();

			$msg_index = $this->_sort_threads($mailbox, $thread_tree);

			return $this->_fetch_thread_headers($mailbox,
			$thread_tree, $msg_depth, $has_children, $msg_index, $page, $slice);
			}


			/**
			* Private method for fetching threads data
			*
			* @param string Mailbox/folder name
			* @return array Array with thread data
			* @access private
			*/
			private function _fetch_threads($mailbox)
			{
			if (empty($this->icache['threads'])) {
			// get all threads
			list ($thread_tree, $msg_depth, $has_children) = $this->conn->thread(
			$mailbox, $this->threading, $this->skip_deleted ? 'UNDELETED' : '');

			// add to internal (fast) cache
			$this->icache['threads'] = array();
			$this->icache['threads']['tree'] = $thread_tree;
			$this->icache['threads']['depth'] = $msg_depth;
			$this->icache['threads']['has_children'] = $has_children;
			}
			else {
			// for small result set we can fetch all messages headers
			$this->_fetch_headers($mailbox, join(',', $msgs), $a_msg_headers, NULL);


			return array(
			$this->icache['threads']['tree'],
			$this->icache['threads']['depth'],
			$this->icache['threads']['has_children'],
			);
			}


			/**
			* Private method for fetching threaded messages headers
			*
			* @access private
			*/
			private function _fetch_thread_headers($mailbox, $thread_tree, $msg_depth, $has_children, $msg_index, $page, $slice=0)
			{
			$cache_key = $mailbox.'.msg';
			// now get IDs for current page
			list($begin, $end) = $this->_get_message_range(count($msg_index), $page);
			$msg_index = array_slice($msg_index, $begin, $end-$begin);

			if ($slice)
			$msg_index = array_slice($msg_index, ($this->sort_order == 'DESC' ? 0 : -$slice), $slice);

			if ($this->sort_order == 'DESC')
			$msg_index = array_reverse($msg_index);

			// flatten threads array
			// @TODO: fetch children only in expanded mode (?)
			$all_ids = array();
			foreach($msg_index as $root) {
			$all_ids[] = $root;
			if (!empty($thread_tree[$root]))
			$all_ids = array_merge($all_ids, array_keys_recursive($thread_tree[$root]));
			}

			// fetch reqested headers from server
			$this->_fetch_headers($mailbox, $all_ids, $a_msg_headers, $cache_key);

			// return empty array if no messages found
			if (!is_array($a_msg_headers) \|\| empty($a_msg_headers))
			return array();
			return array();

			// if not already sorted
			$a_msg_headers = iil_SortHeaders($a_msg_headers, $this->sort_field, $this->sort_order);

			// only return the requested part of the set
			$a_msg_headers = array_slice(array_values($a_msg_headers), $start_msg, min($cnt-$start_msg, $this->page_size));
			if ($slice)
			$a_msg_headers = array_slice($a_msg_headers, -$slice, $slice);
			// use this class for message sorting
			$sorter = new rcube_header_sorter();
			$sorter->set_sequence_numbers($all_ids);
			$sorter->sort_headers($a_msg_headers);

			return $a_msg_headers;
			}
			}
			// Set depth, has_children and unread_children fields in headers
			$this->_set_thread_flags($a_msg_headers, $msg_depth, $has_children);

			return array_values($a_msg_headers);
			}


			/**
			* Helper function to get first and last index of the requested set
			*
			* @param int message count
			* @param mixed page number to show, or string 'all'
			* @return array array with two values: first index, last index
			* @access private
			*/
			private function _get_message_range($max, $page)
			/**
			* Private method for setting threaded messages flags:
			* depth, has_children and unread_children
			*
			* @param array Reference to headers array indexed by message ID
			* @param array Array of messages depth indexed by message ID
			* @param array Array of messages children flags indexed by message ID
			* @return array Message headers array indexed by message ID
			* @access private
			*/
			private function _set_thread_flags(&$headers, $msg_depth, $msg_children)
			{
			$start_msg = ($page-1) * $this->page_size;

			if ($page=='all')
			{
			$begin = 0;
			$end = $max;
			}
			else if ($this->sort_order=='DESC')
			{
			$begin = $max - $this->page_size - $start_msg;
			$end = $max - $start_msg;
			}
			else
			{
			$begin = $start_msg;
			$end = $start_msg + $this->page_size;
			}
			$parents = array();

			if ($begin < 0) $begin = 0;
			if ($end < 0) $end = $max;
			if ($end > $max) $end = $max;

			return array($begin, $end);
			}

			foreach ($headers as $idx => $header) {
			$id = $header->id;
			$depth = $msg_depth[$id];
			$parents = array_slice($parents, 0, $depth);

			/**
			* Fetches message headers
			* Used for loop
			*
			* @param string Mailbox name
			* @param string Message index to fetch
			* @param array Reference to message headers array
			* @param array Array with cache index
			* @return int Messages count
			* @access private
			*/
			private function _fetch_headers($mailbox, $msgs, &$a_msg_headers, $cache_key)
			{
			// fetch reqested headers from server
			$a_header_index = iil_C_FetchHeaders($this->conn, $mailbox, $msgs, false, false, $this->fetch_add_headers);

			if (!empty($a_header_index))
			{
			// cache is incomplete
			$cache_index = $this->get_message_cache_index($cache_key);

			foreach ($a_header_index as $i => $headers) {
			if ($this->caching_enabled && $cache_index[$headers->id] != $headers->uid) {
			// prevent index duplicates
			if ($cache_index[$headers->id]) {
			$this->remove_message_cache($cache_key, $headers->id, true);
			unset($cache_index[$headers->id]);
			}
			// add message to cache
			$this->add_message_cache($cache_key, $headers->id, $headers, NULL,
			!in_array($headers->uid, $cache_index));
			}

			$a_msg_headers[$headers->uid] = $headers;
			}
			}

			return count($a_msg_headers);
			}


			/**
			* Return sorted array of message IDs (not UIDs)
			*
			* @param string Mailbox to get index from
			* @param string Sort column
			* @param string Sort order [ASC, DESC]
			* @return array Indexed array with message ids
			*/
			function message_index($mbox_name='', $sort_field=NULL, $sort_order=NULL)
			{
			$this->_set_sort_order($sort_field, $sort_order);

			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			$key = "{$mailbox}:{$this->sort_field}:{$this->sort_order}:{$this->search_string}.msgi";

			// we have a saved search result, get index from there
			if (!isset($this->cache[$key]) && $this->search_string && $mailbox == $this->mailbox)
			{
			$this->cache[$key] = array();

			// use message index sort for sorting by Date
			if ($this->index_sort && $this->sort_field == 'date')
			{
			$msgs = $this->search_set;

			if ($this->search_sort_field != 'date')
			sort($msgs);

			if ($this->sort_order == 'DESC')
			$this->cache[$key] = array_reverse($msgs);
			else
			$this->cache[$key] = $msgs;
			}
			// sort with SORT command
			else if ($this->get_capability('sort'))
			{
			if ($this->sort_field && $this->search_sort_field != $this->sort_field)
			$this->search('', $this->search_string, $this->search_charset, $this->sort_field);

			if ($this->sort_order == 'DESC')
			$this->cache[$key] = array_reverse($this->search_set);
			else
			$this->cache[$key] = $this->search_set;
			}
			else
			{
			$a_index = iil_C_FetchHeaderIndex($this->conn, $mailbox, join(',', $this->search_set), $this->sort_field, $this->skip_deleted);

			if ($this->sort_order=="ASC")
			asort($a_index);
			else if ($this->sort_order=="DESC")
			arsort($a_index);

			$this->cache[$key] = array_keys($a_index);
			}
			}

			// have stored it in RAM
			if (isset($this->cache[$key]))
			return $this->cache[$key];

			// check local cache
			$cache_key = $mailbox.'.msg';
			$cache_status = $this->check_cache_status($mailbox, $cache_key);

			// cache is OK
			if ($cache_status>0)
			{
			$a_index = $this->get_message_cache_index($cache_key, TRUE, $this->sort_field, $this->sort_order);
			return array_keys($a_index);
			}

			// use message index sort for sorting by Date
			if ($this->index_sort && $this->sort_field == 'date')
			{
			if ($this->skip_deleted) {
			$a_index = $this->_search_index($mailbox, 'ALL');
			} else if ($max = $this->_messagecount($mailbox)) {
			$a_index = range(1, $max);
			}

			if ($this->sort_order == 'DESC')
			$a_index = array_reverse($a_index);

			$this->cache[$key] = $a_index;
			}
			// fetch complete message index
			else if ($this->get_capability('sort') && ($a_index = iil_C_Sort($this->conn, $mailbox, $this->sort_field, $this->skip_deleted ? 'UNDELETED' : '')))
			{
			if ($this->sort_order == 'DESC')
			$a_index = array_reverse($a_index);

			$this->cache[$key] = $a_index;
			}
			else
			{
			$a_index = iil_C_FetchHeaderIndex($this->conn, $mailbox, "1:*", $this->sort_field, $this->skip_deleted);

			if ($this->sort_order=="ASC")
			asort($a_index);
			else if ($this->sort_order=="DESC")
			arsort($a_index);

			$this->cache[$key] = array_keys($a_index);
			}

			return $this->cache[$key];
			}


			/**
			* @access private
			*/
			function sync_header_index($mailbox)
			{
			$cache_key = $mailbox.'.msg';
			$cache_index = $this->get_message_cache_index($cache_key);

			// fetch complete message index
			$a_message_index = iil_C_FetchHeaderIndex($this->conn, $mailbox, "1:*", 'UID', $this->skip_deleted);

			if ($a_message_index === false)
			return false;

			foreach ($a_message_index as $id => $uid)
			{
			// message in cache at correct position
			if ($cache_index[$id] == $uid)
			{
			unset($cache_index[$id]);
			continue;
			}

			// message in cache but in wrong position
			if (in_array((string)$uid, $cache_index, TRUE))
			{
			unset($cache_index[$id]);
			}

			// other message at this position
			if (isset($cache_index[$id]))
			{
			$for_remove[] = $cache_index[$id];
			unset($cache_index[$id]);
			}

			$for_update[] = $id;
			}

			// clear messages at wrong positions and those deleted that are still in cache_index
			if (!empty($for_remove))
			$cache_index = array_merge($cache_index, $for_remove);

			if (!empty($cache_index))
			$this->remove_message_cache($cache_key, $cache_index);

			// fetch complete headers and add to cache
			if (!empty($for_update)) {
			if ($headers = iil_C_FetchHeader($this->conn, $mailbox, join(',', $for_update), false, $this->fetch_add_headers))
			foreach ($headers as $header)
			$this->add_message_cache($cache_key, $header->id, $header, NULL,
			in_array($header->uid, (array)$for_remove));
			}
			}


			/**
			* Invoke search request to IMAP server
			*
			* @param string mailbox name to search in
			* @param string search string
			* @param string search string charset
			* @param string header field to sort by
			* @return array search results as list of message ids
			* @access public
			*/
			function search($mbox_name='', $str=NULL, $charset=NULL, $sort_field=NULL)
			{
			if (!$str)
			return false;

			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;

			$results = $this->_search_index($mailbox, $str, $charset, $sort_field);

			// try search with US-ASCII charset (should be supported by server)
			// only if UTF-8 search is not supported
			if (empty($results) && !is_array($results) && !empty($charset) && $charset != 'US-ASCII')
			{
			// convert strings to US_ASCII
			if(preg_match_all('/\{([0-9]+)\}\r\n/', $str, $matches, PREG_OFFSET_CAPTURE))
			{
			$last = 0; $res = '';
			foreach($matches[1] as $m)
			{
			$string_offset = $m[1] + strlen($m[0]) + 4; // {}\r\n
			$string = substr($str, $string_offset - 1, $m[0]);
			$string = rcube_charset_convert($string, $charset, 'US-ASCII');
			if (!$string) continue;
			$res .= sprintf("%s{%d}\r\n%s", substr($str, $last, $m[1] - $last - 1), strlen($string), $string);
			$last = $m[0] + $string_offset - 1;
			}
			if ($last < strlen($str))
			$res .= substr($str, $last, strlen($str)-$last);
			}
			else // strings for conversion not found
			$res = $str;

			$results = $this->search($mbox_name, $res, NULL, $sort_field);
			}

			$this->set_search_set($str, $results, $charset, $sort_field);

			return $results;
			}


			/**
			* Private search method
			*
			* @return array search results as list of message ids
			* @access private
			* @see rcube_imap::search()
			*/
			private function _search_index($mailbox, $criteria='ALL', $charset=NULL, $sort_field=NULL)
			{
			$orig_criteria = $criteria;

			if ($this->skip_deleted && !preg_match('/UNDELETED/', $criteria))
			$criteria = 'UNDELETED '.$criteria;

			if ($sort_field && $this->get_capability('sort') && (!$this->index_sort \|\| $sort_field != 'date')) {
			$charset = $charset ? $charset : $this->default_charset;
			$a_messages = iil_C_Sort($this->conn, $mailbox, $sort_field, $criteria, FALSE, $charset);
			}
			else {
			if ($orig_criteria == 'ALL') {
			$max = $this->_messagecount($mailbox);
			$a_messages = $max ? range(1, $max) : array();
			}
			else {
			$a_messages = iil_C_Search($this->conn, $mailbox, ($charset ? "CHARSET $charset " : '') . $criteria);

			// I didn't found that SEARCH always returns sorted IDs
			if ($this->index_sort && $this->sort_field == 'date')
			sort($a_messages);
			}
			}
			// update messagecount cache ?
			// $a_mailbox_cache = get_cache('messagecount');
			// $a_mailbox_cache[$mailbox][$criteria] = sizeof($a_messages);
			// $this->update_cache('messagecount', $a_mailbox_cache);

			return $a_messages;
			}


			/**
			* Refresh saved search set
			*
			* @return array Current search set
			*/
			function refresh_search()
			{
			if (!empty($this->search_string))
			$this->search_set = $this->search('', $this->search_string, $this->search_charset, $this->search_sort_field);

			return $this->get_search_set();
			}


			/**
			* Check if the given message ID is part of the current search set
			*
			* @return boolean True on match or if no search request is stored
			*/
			function in_searchset($msgid)
			{
			if (!empty($this->search_string))
			return in_array("$msgid", (array)$this->search_set, true);
			else
			return true;
			}


			/**
			* Return message headers object of a specific message
			*
			* @param int Message ID
			* @param string Mailbox to read from
			* @param boolean True if $id is the message UID
			* @param boolean True if we need also BODYSTRUCTURE in headers
			* @return object Message headers representation
			*/
			function get_headers($id, $mbox_name=NULL, $is_uid=TRUE, $bodystr=FALSE)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			$uid = $is_uid ? $id : $this->_id2uid($id);

			// get cached headers
			if ($uid && ($headers = &$this->get_cached_message($mailbox.'.msg', $uid)))
			return $headers;

			$headers = iil_C_FetchHeader($this->conn, $mailbox, $id, $is_uid, $bodystr, $this->fetch_add_headers);

			// write headers cache
			if ($headers)
			{
			if ($headers->uid && $headers->id)
			$this->uid_id_map[$mailbox][$headers->uid] = $headers->id;

			$this->add_message_cache($mailbox.'.msg', $headers->id, $headers, NULL, true);
			}

			return $headers;
			}


			/**
			* Fetch body structure from the IMAP server and build
			* an object structure similar to the one generated by PEAR::Mail_mimeDecode
			*
			* @param int Message UID to fetch
			* @param string Message BODYSTRUCTURE string (optional)
			* @return object rcube_message_part Message part tree or False on failure
			*/
			function &get_structure($uid, $structure_str='')
			{
			$cache_key = $this->mailbox.'.msg';
			$headers = &$this->get_cached_message($cache_key, $uid);

			// return cached message structure
			if (is_object($headers) && is_object($headers->structure)) {
			return $headers->structure;
			}

			if (!$structure_str)
			$structure_str = iil_C_FetchStructureString($this->conn, $this->mailbox, $uid, true);
			$structure = iml_GetRawStructureArray($structure_str);
			$struct = false;

			// parse structure and add headers
			if (!empty($structure))
			{
			$headers = $this->get_headers($uid);
			$this->_msg_id = $headers->id;

			// set message charset from message headers
			if ($headers->charset)
			$this->struct_charset = $headers->charset;
			else
			$this->struct_charset = $this->_structure_charset($structure);

			// Here we can recognize malformed BODYSTRUCTURE and
			// 1. [@TODO] parse the message in other way to create our own message structure
			// 2. or just show the raw message body.
			// Example of structure for malformed MIME message:
			// ("text" "plain" ("charset" "us-ascii") NIL NIL "7bit" 2154 70 NIL NIL NIL)
			if ($headers->ctype && $headers->ctype != 'text/plain'
			&& $structure[0] == 'text' && $structure[1] == 'plain') {
			return false;
			}

			$struct = &$this->_structure_part($structure);
			$struct->headers = get_object_vars($headers);

			// don't trust given content-type
			if (empty($struct->parts) && !empty($struct->headers['ctype']))
			{
			$struct->mime_id = '1';
			$struct->mimetype = strtolower($struct->headers['ctype']);
			list($struct->ctype_primary, $struct->ctype_secondary) = explode('/', $struct->mimetype);
			}

			// write structure to cache
			if ($this->caching_enabled)
			$this->add_message_cache($cache_key, $this->_msg_id, $headers, $struct);
			}

			return $struct;
			}


			/**
			* Build message part object
			*
			* @access private
			*/
			function &_structure_part($part, $count=0, $parent='', $mime_headers=null, $raw_headers=null)
			{
			$struct = new rcube_message_part;
			$struct->mime_id = empty($parent) ? (string)$count : "$parent.$count";

			// multipart
			if (is_array($part[0]))
			{
			$struct->ctype_primary = 'multipart';

			// find first non-array entry
			for ($i=1; $i<count($part); $i++)
			if (!is_array($part[$i]))
			{
			$struct->ctype_secondary = strtolower($part[$i]);
			break;
			}

			$struct->mimetype = 'multipart/'.$struct->ctype_secondary;

			// build parts list for headers pre-fetching
			for ($i=0, $count=0; $i<count($part); $i++)
			if (is_array($part[$i]) && count($part[$i]) > 3) {
			// fetch message headers if message/rfc822 or named part (could contain Content-Location header)
			if (!is_array($part[$i][0])) {
			$tmp_part_id = $struct->mime_id ? $struct->mime_id.'.'.($i+1) : $i+1;
			if (strtolower($part[$i][0]) == 'message' && strtolower($part[$i][1]) == 'rfc822') {
			$raw_part_headers[] = $tmp_part_id;
			$mime_part_headers[] = $tmp_part_id;
			}
			else if (in_array('name', (array)$part[$i][2]) && (empty($part[$i][3]) \|\| $part[$i][3]=='NIL')) {
			$mime_part_headers[] = $tmp_part_id;
			}
			if (!empty($parents)) {
			$headers[$idx]->parent_uid = end($parents);
			if (!$header->seen)
			$headers[$parents[0]]->unread_children++;
			}
			}

			// pre-fetch headers of all parts (in one command for better performance)
			// @TODO: we could do this before _structure_part() call, to fetch
			// headers for parts on all levels
			if ($mime_part_headers)
			$mime_part_headers = iil_C_FetchMIMEHeaders($this->conn, $this->mailbox,
			$this->_msg_id, $mime_part_headers);
			// we'll need a real content-type of message/rfc822 part
			if ($raw_part_headers)
			$raw_part_headers = iil_C_FetchMIMEHeaders($this->conn, $this->mailbox,
			$this->_msg_id, $raw_part_headers, false);
			array_push($parents, $header->uid);

			$struct->parts = array();
			for ($i=0, $count=0; $i<count($part); $i++)
			if (is_array($part[$i]) && count($part[$i]) > 3) {
			$tmp_part_id = $struct->mime_id ? $struct->mime_id.'.'.($i+1) : $i+1;
			$struct->parts[] = $this->_structure_part($part[$i], ++$count, $struct->mime_id,
			$mime_part_headers[$tmp_part_id], $raw_part_headers[$tmp_part_id]);
			}

			return $struct;
			}


			// regular part
			$struct->ctype_primary = strtolower($part[0]);
			$struct->ctype_secondary = strtolower($part[1]);
			$struct->mimetype = $struct->ctype_primary.'/'.$struct->ctype_secondary;

			// read content type parameters
			if (is_array($part[2]))
			{
			$struct->ctype_parameters = array();
			for ($i=0; $i<count($part[2]); $i+=2)
			$struct->ctype_parameters[strtolower($part[2][$i])] = $part[2][$i+1];

			if (isset($struct->ctype_parameters['charset']))
			$struct->charset = $struct->ctype_parameters['charset'];
			}

			// read content encoding
			if (!empty($part[5]) && $part[5]!='NIL')
			{
			$struct->encoding = strtolower($part[5]);
			$struct->headers['content-transfer-encoding'] = $struct->encoding;
			}

			// get part size
			if (!empty($part[6]) && $part[6]!='NIL')
			$struct->size = intval($part[6]);

			// read part disposition
			$di = count($part) - 2;
			if ((is_array($part[$di]) && count($part[$di]) == 2 && is_array($part[$di][1])) \|\|
			(is_array($part[--$di]) && count($part[$di]) == 2))
			{
			$struct->disposition = strtolower($part[$di][0]);

			if (is_array($part[$di][1]))
			for ($n=0; $n<count($part[$di][1]); $n+=2)
			$struct->d_parameters[strtolower($part[$di][1][$n])] = $part[$di][1][$n+1];
			}

			// get child parts
			if (is_array($part[8]) && $di != 8)
			{
			$struct->parts = array();
			for ($i=0, $count=0; $i<count($part[8]); $i++)
			if (is_array($part[8][$i]) && count($part[8][$i]) > 5)
			$struct->parts[] = $this->_structure_part($part[8][$i], ++$count, $struct->mime_id);
			}

			// get part ID
			if (!empty($part[3]) && $part[3]!='NIL')
			{
			$struct->content_id = $part[3];
			$struct->headers['content-id'] = $part[3];

			if (empty($struct->disposition))
			$struct->disposition = 'inline';
			}

			// fetch message headers if message/rfc822 or named part (could contain Content-Location header)
			if ($struct->ctype_primary == 'message' \|\| ($struct->ctype_parameters['name'] && !$struct->content_id)) {
			if (empty($mime_headers))
			$mime_headers = iil_C_FetchPartHeader($this->conn, $this->mailbox, $this->_msg_id, false, $struct->mime_id);
			$struct->headers = $this->_parse_headers($mime_headers) + $struct->headers;

			// get real headers for message of type 'message/rfc822'
			if ($struct->mimetype == 'message/rfc822') {
			if (empty($raw_headers))
			$raw_headers = iil_C_FetchMIMEHeaders($this->conn, $this->mailbox, $this->_msg_id, (array)$struct->mime_id, false);
			$struct->real_headers = $this->_parse_headers($raw_headers);

			// get real content-type of message/rfc822
			if (preg_match('/^([a-z0-9_\/-]+)/i', $struct->real_headers['content-type'], $matches)) {
			$struct->real_mimetype = strtolower($matches[1]);
			}
			$headers[$idx]->depth = $depth;
			$headers[$idx]->has_children = $msg_children[$id];
			}
			}

			if ($struct->ctype_primary=='message') {
			if (is_array($part[8]) && $di != 8 && empty($struct->parts))
			$struct->parts[] = $this->_structure_part($part[8], ++$count, $struct->mime_id);
			}

			// normalize filename property
			$this->_set_part_filename($struct, $mime_headers);

			return $struct;
			}


			/**
			* Set attachment filename from message part structure
			*
			* @access private
			* @param object rcube_message_part Part object
			* @param string Part's raw headers
			*/
			private function _set_part_filename(&$part, $headers=null)

			/**
			* Private method for listing a set of message headers (search results)
			*
			* @param string Mailbox/folder name
			* @param int Current page to list
			* @param string Header field to sort by
			* @param string Sort order [ASC\|DESC]
			* @param boolean Number of slice items to extract from result array
			* @return array Indexed array with message header objects
			* @access private
			* @see rcube_imap::list_header_set()
			*/
			private function _list_header_set($mailbox, $page=NULL, $sort_field=NULL, $sort_order=NULL, $slice=0)
			{
			if (!empty($part->d_parameters['filename']))
			$filename_mime = $part->d_parameters['filename'];
			else if (!empty($part->d_parameters['filename*']))
			$filename_encoded = $part->d_parameters['filename*'];
			else if (!empty($part->ctype_parameters['name*']))
			$filename_encoded = $part->ctype_parameters['name*'];
			// RFC2231 value continuations
			// TODO: this should be rewrited to support RFC2231 4.1 combinations
			else if (!empty($part->d_parameters['filename*0'])) {
			$i = 0;
			while (isset($part->d_parameters['filename*'.$i])) {
			$filename_mime .= $part->d_parameters['filename*'.$i];
			$i++;
			}
			// some servers (eg. dovecot-1.x) have no support for parameter value continuations
			// we must fetch and parse headers "manually"
			if ($i<2) {
			if (!$headers)
			$headers = iil_C_FetchPartHeader($this->conn, $this->mailbox, $this->_msg_id, false, $part->mime_id);
			$filename_mime = '';
			$i = 0;
			while (preg_match('/filename\'.$i.'\s=\s"([^"\n;]+)[";]*/', $headers, $matches)) {
			$filename_mime .= $matches[1];
			$i++;
			}
			}
			}
			else if (!empty($part->d_parameters['filename0'])) {
			$i = 0;
			while (isset($part->d_parameters['filename'.$i.''])) {
			$filename_encoded .= $part->d_parameters['filename'.$i.''];
			$i++;
			}
			if ($i<2) {
			if (!$headers)
			$headers = iil_C_FetchPartHeader($this->conn, $this->mailbox, $this->_msg_id, false, $part->mime_id);
			$filename_encoded = '';
			$i = 0; $matches = array();
			while (preg_match('/filename\'.$i.'\\s=\s"([^"\n;]+)[";]/', $headers, $matches)) {
			$filename_encoded .= $matches[1];
			$i++;
			}
			}
			}
			else if (!empty($part->ctype_parameters['name*0'])) {
			$i = 0;
			while (isset($part->ctype_parameters['name*'.$i])) {
			$filename_mime .= $part->ctype_parameters['name*'.$i];
			$i++;
			}
			if ($i<2) {
			if (!$headers)
			$headers = iil_C_FetchPartHeader($this->conn, $this->mailbox, $this->_msg_id, false, $part->mime_id);
			$filename_mime = '';
			$i = 0; $matches = array();
			while (preg_match('/\s+name\'.$i.'\s=\s"([^"\n;]+)[";]*/', $headers, $matches)) {
			$filename_mime .= $matches[1];
			$i++;
			}
			}
			}
			else if (!empty($part->ctype_parameters['name0'])) {
			$i = 0;
			while (isset($part->ctype_parameters['name'.$i.''])) {
			$filename_encoded .= $part->ctype_parameters['name'.$i.''];
			$i++;
			}
			if ($i<2) {
			if (!$headers)
			$headers = iil_C_FetchPartHeader($this->conn, $this->mailbox, $this->_msg_id, false, $part->mime_id);
			$filename_encoded = '';
			$i = 0; $matches = array();
			while (preg_match('/\s+name\'.$i.'\\s=\s"([^"\n;]+)[";]/', $headers, $matches)) {
			$filename_encoded .= $matches[1];
			$i++;
			}
			}
			}
			// read 'name' after rfc2231 parameters as it may contains truncated filename (from Thunderbird)
			else if (!empty($part->ctype_parameters['name']))
			$filename_mime = $part->ctype_parameters['name'];
			// Content-Disposition
			else if (!empty($part->headers['content-description']))
			$filename_mime = $part->headers['content-description'];
			else
			return;
			if (!strlen($mailbox) \|\| empty($this->search_set))
			return array();

			// decode filename
			if (!empty($filename_mime)) {
			$part->filename = rcube_imap::decode_mime_string($filename_mime,
			$part->charset ? $part->charset : $this->struct_charset ? $this->struct_charset :
			rc_detect_encoding($filename_mime, $this->default_charset));
			}
			else if (!empty($filename_encoded)) {
			// decode filename according to RFC 2231, Section 4
			if (preg_match("/^([^'])'[^']'(.*)$/", $filename_encoded, $fmatches)) {
			$filename_charset = $fmatches[1];
			$filename_encoded = $fmatches[2];
			}
			$part->filename = rcube_charset_convert(urldecode($filename_encoded), $filename_charset);
			}
			}
			// use saved messages from searching
			if ($this->threading)
			return $this->_list_thread_header_set($mailbox, $page, $sort_field, $sort_order, $slice);

			// search set is threaded, we need a new one
			if ($this->search_threads)
			$this->search('', $this->search_string, $this->search_charset, $sort_field);

			/**
			* Get charset name from message structure (first part)
			*
			* @access private
			* @param array Message structure
			* @return string Charset name
			*/
			function _structure_charset($structure)
			{
			while (is_array($structure)) {
			if (is_array($structure[2]) && $structure[2][0] == 'charset')
			return $structure[2][1];
			$structure = $structure[0];
			}
			}
			$msgs = $this->search_set;
			$a_msg_headers = array();
			$page = $page ? $page : $this->list_page;
			$start_msg = ($page-1) * $this->page_size;

			$this->_set_sort_order($sort_field, $sort_order);

			/**
			* Fetch message body of a specific message from the server
			*
			* @param int Message UID
			* @param string Part number
			* @param object rcube_message_part Part object created by get_structure()
			* @param mixed True to print part, ressource to write part contents in
			* @param resource File pointer to save the message part
			* @return string Message/part body if not printed
			*/
			function &get_message_part($uid, $part=1, $o_part=NULL, $print=NULL, $fp=NULL)
			{
			// get part encoding if not provided
			if (!is_object($o_part))
			{
			$structure_str = iil_C_FetchStructureString($this->conn, $this->mailbox, $uid, true);
			$structure = iml_GetRawStructureArray($structure_str);
			// error or message not found
			if (empty($structure))
			return false;
			// quickest method (default sorting)
			if (!$this->search_sort_field && !$this->sort_field) {
			if ($sort_order == 'DESC')
			$msgs = array_reverse($msgs);

			$part_type = iml_GetPartTypeCode($structure, $part);
			$o_part = new rcube_message_part;
			$o_part->ctype_primary = $part_type==0 ? 'text' : ($part_type==2 ? 'message' : 'other');
			$o_part->encoding = strtolower(iml_GetPartEncodingString($structure, $part));
			$o_part->charset = iml_GetPartCharset($structure, $part);
			}

			// TODO: Add caching for message parts
			// get messages uids for one page
			$msgs = array_slice(array_values($msgs), $start_msg, min(count($msgs)-$start_msg, $this->page_size));

			if (!$part) $part = 'TEXT';
			if ($slice)
			$msgs = array_slice($msgs, -$slice, $slice);

			$body = iil_C_HandlePartBody($this->conn, $this->mailbox, $uid, true, $part,
			$o_part->encoding, $print, $fp);
			// fetch headers
			$this->_fetch_headers($mailbox, join(',',$msgs), $a_msg_headers, NULL);

			if ($fp \|\| $print)
			return true;
			// I didn't found in RFC that FETCH always returns messages sorted by index
			$sorter = new rcube_header_sorter();
			$sorter->set_sequence_numbers($msgs);
			$sorter->sort_headers($a_msg_headers);

			// convert charset (if text or message part)
			if ($o_part->ctype_primary=='text' \|\| $o_part->ctype_primary=='message') {
			// assume default if no charset specified
			if (empty($o_part->charset) \|\| strtolower($o_part->charset) == 'us-ascii')
			$o_part->charset = $this->default_charset;

			$body = rcube_charset_convert($body, $o_part->charset);
			}

			return $body;
			}


			/**
			* Fetch message body of a specific message from the server
			*
			* @param int Message UID
			* @return string Message/part body
			* @see rcube_imap::get_message_part()
			*/
			function &get_body($uid, $part=1)
			{
			$headers = $this->get_headers($uid);
			return rcube_charset_convert($this->get_message_part($uid, $part, NULL),
			$headers->charset ? $headers->charset : $this->default_charset);
			}


			/**
			* Returns the whole message source as string
			*
			* @param int Message UID
			* @return string Message source string
			*/
			function &get_raw_body($uid)
			{
			return iil_C_HandlePartBody($this->conn, $this->mailbox, $uid, true);
			}


			/**
			* Returns the message headers as string
			*
			* @param int Message UID
			* @return string Message headers string
			*/
			function &get_raw_headers($uid)
			{
			return iil_C_FetchPartHeader($this->conn, $this->mailbox, $uid, true);
			}


			/**
			* Sends the whole message source to stdout
			*
			* @param int Message UID
			*/
			function print_raw_body($uid)
			{
			iil_C_HandlePartBody($this->conn, $this->mailbox, $uid, true, NULL, NULL, true);
			}


			/**
			* Set message flag to one or several messages
			*
			* @param mixed Message UIDs as array or as comma-separated string
			* @param string Flag to set: SEEN, UNDELETED, DELETED, RECENT, ANSWERED, DRAFT, MDNSENT
			* @param string Folder name
			* @param boolean True to skip message cache clean up
			* @return boolean True on success, False on failure
			*/
			function set_flag($uids, $flag, $mbox_name=NULL, $skip_cache=false)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;

			$flag = strtoupper($flag);
			if (!is_array($uids))
			$uids = explode(',',$uids);

			if (strpos($flag, 'UN') === 0)
			$result = iil_C_UnFlag($this->conn, $mailbox, join(',', $uids), substr($flag, 2));
			else
			$result = iil_C_Flag($this->conn, $mailbox, join(',', $uids), $flag);

			// reload message headers if cached
			if ($this->caching_enabled && !$skip_cache) {
			$cache_key = $mailbox.'.msg';
			$this->remove_message_cache($cache_key, $uids);
			}

			// set nr of messages that were flaged
			$count = count($uids);

			// clear message count cache
			if ($result && $flag=='SEEN')
			$this->_set_messagecount($mailbox, 'UNSEEN', $count*(-1));
			else if ($result && $flag=='UNSEEN')
			$this->_set_messagecount($mailbox, 'UNSEEN', $count);
			else if ($result && $flag=='DELETED')
			$this->_set_messagecount($mailbox, 'ALL', $count*(-1));

			return $result;
			}


			/**
			* Remove message flag for one or several messages
			*
			* @param mixed Message UIDs as array or as comma-separated string
			* @param string Flag to unset: SEEN, DELETED, RECENT, ANSWERED, DRAFT, MDNSENT
			* @param string Folder name
			* @return boolean True on success, False on failure
			* @see set_flag
			*/
			function unset_flag($uids, $flag, $mbox_name=NULL)
			{
			return $this->set_flag($uids, 'UN'.$flag, $mbox_name);
			}


			/**
			* Append a mail message (source) to a specific mailbox
			*
			* @param string Target mailbox
			* @param string Message source
			* @return boolean True on success, False on error
			*/
			function save_message($mbox_name, &$message)
			{
			$mailbox = $this->mod_mailbox($mbox_name);

			// make sure mailbox exists
			if (($mailbox == 'INBOX') \|\| in_array($mailbox, $this->_list_mailboxes()))
			$saved = iil_C_Append($this->conn, $mailbox, $message);

			if ($saved)
			{
			// increase messagecount of the target mailbox
			$this->_set_messagecount($mailbox, 'ALL', 1);
			}

			return $saved;
			}


			/**
			* Move a message from one mailbox to another
			*
			* @param string List of UIDs to move, separated by comma
			* @param string Target mailbox
			* @param string Source mailbox
			* @return boolean True on success, False on error
			*/
			function move_message($uids, $to_mbox, $from_mbox='')
			{
			$fbox = $from_mbox;
			$tbox = $to_mbox;
			$to_mbox = $this->mod_mailbox($to_mbox);
			$from_mbox = $from_mbox ? $this->mod_mailbox($from_mbox) : $this->mailbox;

			// make sure mailbox exists
			if ($to_mbox != 'INBOX' && !in_array($to_mbox, $this->_list_mailboxes()))
			{
			if (in_array($tbox, $this->default_folders))
			$this->create_mailbox($tbox, TRUE);
			else
			return FALSE;
			}

			// convert the list of uids to array
			$a_uids = is_string($uids) ? explode(',', $uids) : (is_array($uids) ? $uids : NULL);

			// exit if no message uids are specified
			if (!is_array($a_uids) \|\| empty($a_uids))
			return false;

			// flag messages as read before moving them
			$config = rcmail::get_instance()->config;
			if ($config->get('read_when_deleted') && $tbox == $config->get('trash_mbox')) {
			// don't flush cache (4th argument)
			$this->set_flag($uids, 'SEEN', $fbox, true);
			}

			// move messages
			$iil_move = iil_C_Move($this->conn, join(',', $a_uids), $from_mbox, $to_mbox);
			$moved = !($iil_move === false \|\| $iil_move < 0);

			// send expunge command in order to have the moved message
			// really deleted from the source mailbox
			if ($moved) {
			$this->_expunge($from_mbox, FALSE, $a_uids);
			$this->_clear_messagecount($from_mbox);
			$this->_clear_messagecount($to_mbox);
			}
			// moving failed
			else if (rcmail::get_instance()->config->get('delete_always', false)) {
			return iil_C_Delete($this->conn, $from_mbox, join(',', $a_uids));
			}

			// remove message ids from search set
			if ($moved && $this->search_set && $from_mbox == $this->mailbox) {
			foreach ($a_uids as $uid)
			$a_mids[] = $this->_uid2id($uid, $from_mbox);
			$this->search_set = array_diff($this->search_set, $a_mids);
			}

			// update cached message headers
			$cache_key = $from_mbox.'.msg';
			if ($moved && $start_index = $this->get_message_cache_index_min($cache_key, $a_uids)) {
			// clear cache from the lowest index on
			$this->clear_message_cache($cache_key, $start_index);
			}

			return $moved;
			}


			/**
			* Mark messages as deleted and expunge mailbox
			*
			* @param string List of UIDs to move, separated by comma
			* @param string Source mailbox
			* @return boolean True on success, False on error
			*/
			function delete_message($uids, $mbox_name='')
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;

			// convert the list of uids to array
			$a_uids = is_string($uids) ? explode(',', $uids) : (is_array($uids) ? $uids : NULL);

			// exit if no message uids are specified
			if (!is_array($a_uids) \|\| empty($a_uids))
			return false;

			$deleted = iil_C_Delete($this->conn, $mailbox, join(',', $a_uids));

			// send expunge command in order to have the deleted message
			// really deleted from the mailbox
			if ($deleted)
			{
			$this->_expunge($mailbox, FALSE, $a_uids);
			$this->_clear_messagecount($mailbox);
			unset($this->uid_id_map[$mailbox]);
			}

			// remove message ids from search set
			if ($deleted && $this->search_set && $mailbox == $this->mailbox) {
			foreach ($a_uids as $uid)
			$a_mids[] = $this->_uid2id($uid, $mailbox);
			$this->search_set = array_diff($this->search_set, $a_mids);
			}

			// remove deleted messages from cache
			$cache_key = $mailbox.'.msg';
			if ($deleted && $start_index = $this->get_message_cache_index_min($cache_key, $a_uids)) {
			// clear cache from the lowest index on
			$this->clear_message_cache($cache_key, $start_index);
			}

			return $deleted;
			}


			/**
			* Clear all messages in a specific mailbox
			*
			* @param string Mailbox name
			* @return int Above 0 on success
			*/
			function clear_mailbox($mbox_name=NULL)
			{
			$mailbox = !empty($mbox_name) ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			$msg_count = $this->_messagecount($mailbox, 'ALL');

			if ($msg_count>0)
			{
			$cleared = iil_C_ClearFolder($this->conn, $mailbox);

			// make sure the message count cache is cleared as well
			if ($cleared)
			{
			$this->clear_message_cache($mailbox.'.msg');
			$a_mailbox_cache = $this->get_cache('messagecount');
			unset($a_mailbox_cache[$mailbox]);
			$this->update_cache('messagecount', $a_mailbox_cache);
			}

			return $cleared;
			}
			else
			return 0;
			}


			/**
			* Send IMAP expunge command and clear cache
			*
			* @param string Mailbox name
			* @param boolean False if cache should not be cleared
			* @return boolean True on success
			*/
			function expunge($mbox_name='', $clear_cache=TRUE)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_expunge($mailbox, $clear_cache);
			}


			/**
			* Send IMAP expunge command and clear cache
			*
			* @see rcube_imap::expunge()
			* @param string Mailbox name
			* @param boolean False if cache should not be cleared
			* @param string List of UIDs to remove, separated by comma
			* @return boolean True on success
			* @access private
			*/
			private function _expunge($mailbox, $clear_cache=TRUE, $uids=NULL)
			{
			if ($uids && $this->get_capability('UIDPLUS'))
			$a_uids = is_array($uids) ? join(',', $uids) : $uids;
			else
			$a_uids = NULL;

			$result = iil_C_Expunge($this->conn, $mailbox, $a_uids);

			if ($result>=0 && $clear_cache)
			{
			$this->clear_message_cache($mailbox.'.msg');
			$this->_clear_messagecount($mailbox);
			}

			return $result;
			}


			/* --------------------------------
			* folder managment
			* --------------------------------*/


			/**
			* Get a list of all folders available on the IMAP server
			*
			* @param string IMAP root dir
			* @return array Indexed array with folder names
			*/
			function list_unsubscribed($root='')
			{
			static $sa_unsubscribed;

			if (is_array($sa_unsubscribed))
			return $sa_unsubscribed;

			// retrieve list of folders from IMAP server
			$a_mboxes = iil_C_ListMailboxes($this->conn, $this->mod_mailbox($root), '*');

			// modify names with root dir
			foreach ($a_mboxes as $mbox_name)
			{
			$name = $this->mod_mailbox($mbox_name, 'out');
			if (strlen($name))
			$a_folders[] = $name;
			}

			// filter folders and sort them
			$sa_unsubscribed = $this->_sort_mailbox_list($a_folders);
			return $sa_unsubscribed;
			}


			/**
			* Get mailbox quota information
			* added by Nuny
			*
			* @return mixed Quota info or False if not supported
			*/
			function get_quota()
			{
			if ($this->get_capability('QUOTA'))
			return iil_C_GetQuota($this->conn);

			return FALSE;
			}


			/**
			* Subscribe to a specific mailbox(es)
			*
			* @param array Mailbox name(s)
			* @return boolean True on success
			*/
			function subscribe($a_mboxes)
			{
			if (!is_array($a_mboxes))
			$a_mboxes = array($a_mboxes);

			// let this common function do the main work
			return $this->_change_subscription($a_mboxes, 'subscribe');
			}


			/**
			* Unsubscribe mailboxes
			*
			* @param array Mailbox name(s)
			* @return boolean True on success
			*/
			function unsubscribe($a_mboxes)
			{
			if (!is_array($a_mboxes))
			$a_mboxes = array($a_mboxes);

			// let this common function do the main work
			return $this->_change_subscription($a_mboxes, 'unsubscribe');
			}


			/**
			* Create a new mailbox on the server and register it in local cache
			*
			* @param string New mailbox name (as utf-7 string)
			* @param boolean True if the new mailbox should be subscribed
			* @param string Name of the created mailbox, false on error
			*/
			function create_mailbox($name, $subscribe=FALSE)
			{
			$result = FALSE;

			// reduce mailbox name to 100 chars
			$name = substr($name, 0, 100);

			$abs_name = $this->mod_mailbox($name);
			$a_mailbox_cache = $this->get_cache('mailboxes');

			if (strlen($abs_name) && (!is_array($a_mailbox_cache) \|\| !in_array($abs_name, $a_mailbox_cache)))
			$result = iil_C_CreateFolder($this->conn, $abs_name);

			// try to subscribe it
			if ($result && $subscribe)
			$this->subscribe($name);

			return $result ? $name : FALSE;
			}


			/**
			* Set a new name to an existing mailbox
			*
			* @param string Mailbox to rename (as utf-7 string)
			* @param string New mailbox name (as utf-7 string)
			* @return string Name of the renames mailbox, False on error
			*/
			function rename_mailbox($mbox_name, $new_name)
			{
			$result = FALSE;

			// encode mailbox name and reduce it to 100 chars
			$name = substr($new_name, 0, 100);

			// make absolute path
			$mailbox = $this->mod_mailbox($mbox_name);
			$abs_name = $this->mod_mailbox($name);

			// check if mailbox is subscribed
			$a_subscribed = $this->_list_mailboxes();
			$subscribed = in_array($mailbox, $a_subscribed);

			// unsubscribe folder
			if ($subscribed)
			iil_C_UnSubscribe($this->conn, $mailbox);

			if (strlen($abs_name))
			$result = iil_C_RenameFolder($this->conn, $mailbox, $abs_name);

			if ($result)
			{
			$delm = $this->get_hierarchy_delimiter();

			// check if mailbox children are subscribed
			foreach ($a_subscribed as $c_subscribed)
			if (preg_match('/^'.preg_quote($mailbox.$delm, '/').'/', $c_subscribed))
			{
			iil_C_UnSubscribe($this->conn, $c_subscribed);
			iil_C_Subscribe($this->conn, preg_replace('/^'.preg_quote($mailbox, '/').'/', $abs_name, $c_subscribed));
			}

			// clear cache
			$this->clear_message_cache($mailbox.'.msg');
			$this->clear_cache('mailboxes');
			}

			// try to subscribe it
			if ($result && $subscribed)
			iil_C_Subscribe($this->conn, $abs_name);

			return $result ? $name : FALSE;
			}


			/**
			* Remove mailboxes from server
			*
			* @param string Mailbox name(s) string/array
			* @return boolean True on success
			*/
			function delete_mailbox($mbox_name)
			{
			$deleted = FALSE;

			if (is_array($mbox_name))
			$a_mboxes = $mbox_name;
			else if (is_string($mbox_name) && strlen($mbox_name))
			$a_mboxes = explode(',', $mbox_name);

			$all_mboxes = iil_C_ListMailboxes($this->conn, $this->mod_mailbox($root), '*');

			if (is_array($a_mboxes))
			foreach ($a_mboxes as $mbox_name)
			{
			$mailbox = $this->mod_mailbox($mbox_name);

			// unsubscribe mailbox before deleting
			iil_C_UnSubscribe($this->conn, $mailbox);

			// send delete command to server
			$result = iil_C_DeleteFolder($this->conn, $mailbox);
			if ($result >= 0) {
			$deleted = TRUE;
			$this->clear_message_cache($mailbox.'.msg');
			}

			foreach ($all_mboxes as $c_mbox)
			{
			$regex = preg_quote($mailbox . $this->delimiter, '/');
			$regex = '/^' . $regex . '/';
			if (preg_match($regex, $c_mbox))
			{
			iil_C_UnSubscribe($this->conn, $c_mbox);
			$result = iil_C_DeleteFolder($this->conn, $c_mbox);
			if ($result >= 0) {
			$deleted = TRUE;
			$this->clear_message_cache($c_mbox.'.msg');
			}
			}
			}
			return array_values($a_msg_headers);
			}

			// clear mailboxlist cache
			if ($deleted)
			$this->clear_cache('mailboxes');
			// sorted messages, so we can first slice array and then fetch only wanted headers
			if ($this->get_capability('SORT')) { // SORT searching result
			// reset search set if sorting field has been changed
			if ($this->sort_field && $this->search_sort_field != $this->sort_field)
			$msgs = $this->search('', $this->search_string, $this->search_charset, $this->sort_field);

			return $deleted;
			}
			// return empty array if no messages found
			if (empty($msgs))
			return array();

			if ($sort_order == 'DESC')
			$msgs = array_reverse($msgs);

			/**
			* Create all folders specified as default
			*/
			function create_default_folders()
			{
			$a_folders = iil_C_ListMailboxes($this->conn, $this->mod_mailbox(''), '*');
			$a_subscribed = iil_C_ListSubscribed($this->conn, $this->mod_mailbox(''), '*');

			// create default folders if they do not exist
			foreach ($this->default_folders as $folder)
			{
			$abs_name = $this->mod_mailbox($folder);
			if (!in_array_nocase($abs_name, $a_folders))
			$this->create_mailbox($folder, TRUE);
			else if (!in_array_nocase($abs_name, $a_subscribed))
			$this->subscribe($folder);
			}
			}
			// get messages uids for one page
			$msgs = array_slice(array_values($msgs), $start_msg, min(count($msgs)-$start_msg, $this->page_size));

			if ($slice)
			$msgs = array_slice($msgs, -$slice, $slice);

			// fetch headers
			$this->_fetch_headers($mailbox, join(',',$msgs), $a_msg_headers, NULL);

			/* --------------------------------
			* internal caching methods
			* --------------------------------*/
			$sorter = new rcube_header_sorter();
			$sorter->set_sequence_numbers($msgs);
			$sorter->sort_headers($a_msg_headers);

			/**
			* @access private
			*/
			function set_caching($set)
			{
			if ($set && is_object($this->db))
			$this->caching_enabled = TRUE;
			else
			$this->caching_enabled = FALSE;
			}

			/**
			* @access private
			*/
			function get_cache($key)
			{
			// read cache (if it was not read before)
			if (!count($this->cache) && $this->caching_enabled)
			{
			return $this->_read_cache_record($key);
			}

			return $this->cache[$key];
			}

			/**
			* @access private
			*/
			function update_cache($key, $data)
			{
			$this->cache[$key] = $data;
			$this->cache_changed = TRUE;
			$this->cache_changes[$key] = TRUE;
			}

			/**
			* @access private
			*/
			function write_cache()
			{
			if ($this->caching_enabled && $this->cache_changed)
			{
			foreach ($this->cache as $key => $data)
			{
			if ($this->cache_changes[$key])
			$this->_write_cache_record($key, serialize($data));
			return array_values($a_msg_headers);
			}
			}
			}
			else { // SEARCH result, need sorting
			$cnt = count($msgs);
			// 300: experimantal value for best result
			if (($cnt > 300 && $cnt > $this->page_size) \|\| !$this->sort_field) {
			// use memory less expensive (and quick) method for big result set
			$a_index = $this->message_index('', $this->sort_field, $this->sort_order);
			// get messages uids for one page...
			$msgs = array_slice($a_index, $start_msg, min($cnt-$start_msg, $this->page_size));
			if ($slice)
			$msgs = array_slice($msgs, -$slice, $slice);
			// ...and fetch headers
			$this->_fetch_headers($mailbox, join(',', $msgs), $a_msg_headers, NULL);

			/**
			* @access private
			*/
			function clear_cache($key=NULL)
			{
			if (!$this->caching_enabled)
			return;

			if ($key===NULL)
			{
			foreach ($this->cache as $key => $data)
			$this->_clear_cache_record($key);
			// return empty array if no messages found
			if (!is_array($a_msg_headers) \|\| empty($a_msg_headers))
			return array();

			$this->cache = array();
			$this->cache_changed = FALSE;
			$this->cache_changes = array();
			}
			else
			{
			$this->_clear_cache_record($key);
			$this->cache_changes[$key] = FALSE;
			unset($this->cache[$key]);
			}
			}
			$sorter = new rcube_header_sorter();
			$sorter->set_sequence_numbers($msgs);
			$sorter->sort_headers($a_msg_headers);

			/**
			* @access private
			*/
			private function _read_cache_record($key)
			{
			if ($this->db)
			{
			// get cached data from DB
			$sql_result = $this->db->query(
			"SELECT cache_id, data, cache_key
			FROM ".get_table_name('cache')."
			WHERE user_id=?
			AND cache_key LIKE 'IMAP.%'",
			$_SESSION['user_id']);
			return array_values($a_msg_headers);
			}
			else {
			// for small result set we can fetch all messages headers
			$this->_fetch_headers($mailbox, join(',', $msgs), $a_msg_headers, NULL);

			while ($sql_arr = $this->db->fetch_assoc($sql_result))
			{
			$sql_key = preg_replace('/^IMAP\./', '', $sql_arr['cache_key']);
			$this->cache_keys[$sql_key] = $sql_arr['cache_id'];
			if (!isset($this->cache[$sql_key]))
			$this->cache[$sql_key] = $sql_arr['data'] ? unserialize($sql_arr['data']) : FALSE;
			// return empty array if no messages found
			if (!is_array($a_msg_headers) \|\| empty($a_msg_headers))
			return array();

			// if not already sorted
			$a_msg_headers = $this->conn->sortHeaders(
			$a_msg_headers, $this->sort_field, $this->sort_order);

			// only return the requested part of the set
			$a_msg_headers = array_slice(array_values($a_msg_headers),
			$start_msg, min($cnt-$start_msg, $this->page_size));

			if ($slice)
			$a_msg_headers = array_slice($a_msg_headers, -$slice, $slice);

			return $a_msg_headers;
			}
			}
			}

			return $this->cache[$key];
			}

			/**
			* @access private
			*/
			private function _write_cache_record($key, $data)

			/**
			* Private method for listing a set of threaded message headers (search results)
			*
			* @param string Mailbox/folder name
			* @param int Current page to list
			* @param string Header field to sort by
			* @param string Sort order [ASC\|DESC]
			* @param boolean Number of slice items to extract from result array
			* @return array Indexed array with message header objects
			* @access private
			* @see rcube_imap::list_header_set()
			*/
			private function _list_thread_header_set($mailbox, $page=NULL, $sort_field=NULL, $sort_order=NULL, $slice=0)
			{
			if (!$this->db)
			return FALSE;
			// update search_set if previous data was fetched with disabled threading
			if (!$this->search_threads)
			$this->search('', $this->search_string, $this->search_charset, $sort_field);

			// update existing cache record
			if ($this->cache_keys[$key])
			{
			$this->db->query(
			"UPDATE ".get_table_name('cache')."
			SET created=". $this->db->now().", data=?
			WHERE user_id=?
			AND cache_key=?",
			$data,
			$_SESSION['user_id'],
			'IMAP.'.$key);
			}
			// add new cache record
			else
			{
			$this->db->query(
			"INSERT INTO ".get_table_name('cache')."
			(created, user_id, cache_key, data)
			VALUES (".$this->db->now().", ?, ?, ?)",
			$_SESSION['user_id'],
			'IMAP.'.$key,
			$data);
			$thread_tree = $this->search_set['tree'];
			$msg_depth = $this->search_set['depth'];
			$has_children = $this->search_set['children'];
			$a_msg_headers = array();

			// get cache entry ID for this key
			$sql_result = $this->db->query(
			"SELECT cache_id
			FROM ".get_table_name('cache')."
			WHERE user_id=?
			AND cache_key=?",
			$_SESSION['user_id'],
			'IMAP.'.$key);

			if ($sql_arr = $this->db->fetch_assoc($sql_result))
			$this->cache_keys[$key] = $sql_arr['cache_id'];
			}
			$page = $page ? $page : $this->list_page;
			$start_msg = ($page-1) * $this->page_size;

			$this->_set_sort_order($sort_field, $sort_order);

			$msg_index = $this->_sort_threads($mailbox, $thread_tree, array_keys($msg_depth));

			return $this->_fetch_thread_headers($mailbox,
			$thread_tree, $msg_depth, $has_children, $msg_index, $page, $slice=0);
			}

			/**
			* @access private
			*/
			private function _clear_cache_record($key)

			/**
			* Helper function to get first and last index of the requested set
			*
			* @param int message count
			* @param mixed page number to show, or string 'all'
			* @return array array with two values: first index, last index
			* @access private
			*/
			private function _get_message_range($max, $page)
			{
			$this->db->query(
			"DELETE FROM ".get_table_name('cache')."
			WHERE user_id=?
			AND cache_key=?",
			$_SESSION['user_id'],
			'IMAP.'.$key);

			unset($this->cache_keys[$key]);
			}
			$start_msg = ($page-1) * $this->page_size;



			/* --------------------------------
			* message caching methods
			* --------------------------------*/


			/**
			* Checks if the cache is up-to-date
			*
			* @param string Mailbox name
			* @param string Internal cache key
			* @return int Cache status: -3 = off, -2 = incomplete, -1 = dirty
			*/
			private function check_cache_status($mailbox, $cache_key)
			{
			if (!$this->caching_enabled)
			return -3;

			$cache_index = $this->get_message_cache_index($cache_key);
			$msg_count = $this->_messagecount($mailbox);
			$cache_count = count($cache_index);

			// empty mailbox
			if (!$msg_count)
			return $cache_count ? -2 : 1;

			// @TODO: We've got one big performance problem in cache status checking method
			// E.g. mailbox contains 1000 messages, in cache table we've got first 100
			// of them. Now if we want to display only that 100 (which we've got)
			// check_cache_status returns 'incomplete' and messages are fetched
			// from IMAP instead of DB.

			if ($cache_count==$msg_count) {
			if ($this->skip_deleted) {
			$h_index = iil_C_FetchHeaderIndex($this->conn, $mailbox, "1:*", 'UID', $this->skip_deleted);

			if (sizeof($h_index) == $cache_count) {
			$cache_index = array_flip($cache_index);
			foreach ($h_index as $idx => $uid)
			unset($cache_index[$uid]);

			if (empty($cache_index))
			return 1;
			}
			return -2;
			} else {
			// get UID of message with highest index
			$uid = iil_C_ID2UID($this->conn, $mailbox, $msg_count);
			$cache_uid = array_pop($cache_index);

			// uids of highest message matches -> cache seems OK
			if ($cache_uid == $uid)
			return 1;
			}
			// cache is dirty
			return -1;
			}
			// if cache count differs less than 10% report as dirty
			else if (abs($msg_count - $cache_count) < $msg_count/10)
			return -1;
			else
			return -2;
			}

			/**
			* @access private
			*/
			private function get_message_cache($key, $from, $to, $sort_field, $sort_order)
			{
			$cache_key = "$key:$from:$to:$sort_field:$sort_order";
			$db_header_fields = array('idx', 'uid', 'subject', 'from', 'to', 'cc', 'date', 'size');

			$config = rcmail::get_instance()->config;

			// use idx sort for sorting by Date with index_sort=true or for unknown field
			if (($sort_field == 'date' && $this->index_sort)
			\|\| !in_array($sort_field, $db_header_fields)) {
			$sort_field = 'idx';
			}

			if ($this->caching_enabled && !isset($this->cache[$cache_key]))
			{
			$this->cache[$cache_key] = array();
			$sql_result = $this->db->limitquery(
			"SELECT idx, uid, headers
			FROM ".get_table_name('messages')."
			WHERE user_id=?
			AND cache_key=?
			ORDER BY ".$this->db->quoteIdentifier($sort_field)." ".strtoupper($sort_order),
			$from,
			$to-$from,
			$_SESSION['user_id'],
			$key);

			while ($sql_arr = $this->db->fetch_assoc($sql_result))
			{
			$uid = $sql_arr['uid'];
			$this->cache[$cache_key][$uid] = $this->db->decode(unserialize($sql_arr['headers']));

			// featch headers if unserialize failed
			if (empty($this->cache[$cache_key][$uid]))
			$this->cache[$cache_key][$uid] = iil_C_FetchHeader($this->conn, preg_replace('/.msg$/', '', $key), $uid, true, $this->fetch_add_headers);
			if ($page=='all') {
			$begin = 0;
			$end = $max;
			}
			}

			return $this->cache[$cache_key];
			}

			/**
			* @access private
			*/
			private function &get_cached_message($key, $uid)
			{
			$internal_key = '__single_msg';

			if ($this->caching_enabled && !isset($this->cache[$internal_key][$uid]))
			{
			$sql_result = $this->db->query(
			"SELECT idx, headers, structure
			FROM ".get_table_name('messages')."
			WHERE user_id=?
			AND cache_key=?
			AND uid=?",
			$_SESSION['user_id'],
			$key,
			$uid);

			if ($sql_arr = $this->db->fetch_assoc($sql_result))
			{
			$this->uid_id_map[preg_replace('/\.msg$/', '', $key)][$uid] = $sql_arr['idx'];
			$this->cache[$internal_key][$uid] = $this->db->decode(unserialize($sql_arr['headers']));
			if (is_object($this->cache[$internal_key][$uid]) && !empty($sql_arr['structure']))
			$this->cache[$internal_key][$uid]->structure = $this->db->decode(unserialize($sql_arr['structure']));
			else if ($this->sort_order=='DESC') {
			$begin = $max - $this->page_size - $start_msg;
			$end = $max - $start_msg;
			}
			}

			return $this->cache[$internal_key][$uid];
			}

			/**
			* @access private
			*/
			private function get_message_cache_index($key, $force=FALSE, $sort_field='idx', $sort_order='ASC')
			{
			static $sa_message_index = array();

			// empty key -> empty array
			if (!$this->caching_enabled \|\| empty($key))
			return array();

			if (!empty($sa_message_index[$key]) && !$force)
			return $sa_message_index[$key];

			// use idx sort for sorting by Date with index_sort=true
			if ($sort_field == 'date' && $this->index_sort)
			$sort_field = 'idx';

			$sa_message_index[$key] = array();
			$sql_result = $this->db->query(
			"SELECT idx, uid
			FROM ".get_table_name('messages')."
			WHERE user_id=?
			AND cache_key=?
			ORDER BY ".$this->db->quote_identifier($sort_field)." ".$sort_order,
			$_SESSION['user_id'],
			$key);

			while ($sql_arr = $this->db->fetch_assoc($sql_result))
			$sa_message_index[$key][$sql_arr['idx']] = $sql_arr['uid'];

			return $sa_message_index[$key];
			}

			/**
			* @access private
			*/
			private function add_message_cache($key, $index, $headers, $struct=null, $force=false)
			{
			if (empty($key) \|\| !is_object($headers) \|\| empty($headers->uid))
			return;

			// add to internal (fast) cache
			$this->cache['__single_msg'][$headers->uid] = clone $headers;
			$this->cache['__single_msg'][$headers->uid]->structure = $struct;

			// no further caching
			if (!$this->caching_enabled)
			return;

			// check for an existing record (probly headers are cached but structure not)
			if (!$force) {
			$sql_result = $this->db->query(
			"SELECT message_id
			FROM ".get_table_name('messages')."
			WHERE user_id=?
			AND cache_key=?
			AND uid=?",
			$_SESSION['user_id'],
			$key,
			$headers->uid);
			if ($sql_arr = $this->db->fetch_assoc($sql_result))
			$message_id = $sql_arr['message_id'];
			}

			// update cache record
			if ($message_id)
			{
			$this->db->query(
			"UPDATE ".get_table_name('messages')."
			SET idx=?, headers=?, structure=?
			WHERE message_id=?",
			$index,
			serialize($this->db->encode(clone $headers)),
			is_object($struct) ? serialize($this->db->encode(clone $struct)) : NULL,
			$message_id
			);
			}
			else // insert new record
			{
			$this->db->query(
			"INSERT INTO ".get_table_name('messages')."
			(user_id, del, cache_key, created, idx, uid, subject, ".$this->db->quoteIdentifier('from').", ".$this->db->quoteIdentifier('to').", cc, date, size, headers, structure)
			VALUES (?, 0, ?, ".$this->db->now().", ?, ?, ?, ?, ?, ?, ".$this->db->fromunixtime($headers->timestamp).", ?, ?, ?)",
			$_SESSION['user_id'],
			$key,
			$index,
			$headers->uid,
			(string)mb_substr($this->db->encode($this->decode_header($headers->subject, TRUE)), 0, 128),
			(string)mb_substr($this->db->encode($this->decode_header($headers->from, TRUE)), 0, 128),
			(string)mb_substr($this->db->encode($this->decode_header($headers->to, TRUE)), 0, 128),
			(string)mb_substr($this->db->encode($this->decode_header($headers->cc, TRUE)), 0, 128),
			(int)$headers->size,
			serialize($this->db->encode(clone $headers)),
			is_object($struct) ? serialize($this->db->encode(clone $struct)) : NULL
			);
			}
			}

			/**
			* @access private
			*/
			private function remove_message_cache($key, $ids, $idx=false)
			{
			if (!$this->caching_enabled)
			return;

			$this->db->query(
			"DELETE FROM ".get_table_name('messages')."
			WHERE user_id=?
			AND cache_key=?
			AND ".($idx ? "idx" : "uid")." IN (".$this->db->array2list($ids, 'integer').")",
			$_SESSION['user_id'],
			$key);
			}

			/**
			* @access private
			*/
			private function clear_message_cache($key, $start_index=1)
			{
			if (!$this->caching_enabled)
			return;

			$this->db->query(
			"DELETE FROM ".get_table_name('messages')."
			WHERE user_id=?
			AND cache_key=?
			AND idx>=?",
			$_SESSION['user_id'], $key, $start_index);
			}

			/**
			* @access private
			*/
			private function get_message_cache_index_min($key, $uids=NULL)
			{
			if (!$this->caching_enabled)
			return;

			$sql_result = $this->db->query(
			"SELECT MIN(idx) AS minidx
			FROM ".get_table_name('messages')."
			WHERE user_id=?
			AND cache_key=?"
			.(!empty($uids) ? " AND uid IN (".$this->db->array2list($uids, 'integer').")" : ''),
			$_SESSION['user_id'],
			$key);

			if ($sql_arr = $this->db->fetch_assoc($sql_result))
			return $sql_arr['minidx'];
			else
			return 0;
			}


			/* --------------------------------
			* encoding/decoding methods
			* --------------------------------*/

			/**
			* Split an address list into a structured array list
			*
			* @param string Input string
			* @param int List only this number of addresses
			* @param boolean Decode address strings
			* @return array Indexed list of addresses
			*/
			function decode_address_list($input, $max=null, $decode=true)
			{
			$a = $this->_parse_address_list($input, $decode);
			$out = array();
			// Special chars as defined by RFC 822 need to in quoted string (or escaped).
			$special_chars = '[\<\>\\\.\[\]@,;:"]';

			if (!is_array($a))
			return $out;

			$c = count($a);
			$j = 0;

			foreach ($a as $val)
			{
			$j++;
			$address = $val['address'];
			$name = preg_replace(array('/^[\'"]/', '/[\'"]$/'), '', trim($val['name']));
			if ($name && $address && $name != $address)
			$string = sprintf('%s <%s>', preg_match("/$special_chars/", $name) ? '"'.addcslashes($name, '"').'"' : $name, $address);
			else if ($address)
			$string = $address;
			else if ($name)
			$string = $name;

			$out[$j] = array('name' => $name,
			'mailto' => $address,
			'string' => $string);

			if ($max && $j==$max)
			break;
			}

			return $out;
			}


			/**
			* Decode a Microsoft Outlook TNEF part (winmail.dat)
			*
			* @param object rcube_message_part Message part to decode
			* @param string UID of the message
			* @return array List of rcube_message_parts extracted from windmail.dat
			*/
			function tnef_decode(&$part, $uid)
			{
			if (!isset($part->body))
			$part->body = $this->get_message_part($uid, $part->mime_id, $part);

			$pid = 0;
			$tnef_parts = array();
			$tnef_arr = tnef_decode($part->body);
			foreach ($tnef_arr as $winatt) {
			$tpart = new rcube_message_part;
			$tpart->filename = $winatt["name"];
			$tpart->encoding = 'stream';
			$tpart->ctype_primary = $winatt["type0"];
			$tpart->ctype_secondary = $winatt["type1"];
			$tpart->mimetype = strtolower($winatt["type0"] . "/" . $winatt["type1"]);
			$tpart->mime_id = "winmail." . $part->mime_id . ".$pid";
			$tpart->size = $winatt["size"];
			$tpart->body = $winatt['stream'];

			$tnef_parts[] = $tpart;
			$pid++;
			}

			return $tnef_parts;
			}


			/**
			* Decode a message header value
			*
			* @param string Header value
			* @param boolean Remove quotes if necessary
			* @return string Decoded string
			*/
			function decode_header($input, $remove_quotes=FALSE)
			{
			$str = rcube_imap::decode_mime_string((string)$input, $this->default_charset);
			if ($str{0}=='"' && $remove_quotes)
			$str = str_replace('"', '', $str);

			return $str;
			}


			/**
			* Decode a mime-encoded string to internal charset
			*
			* @param string $input Header value
			* @param string $fallback Fallback charset if none specified
			*
			* @return string Decoded string
			* @static
			*/
			public static function decode_mime_string($input, $fallback=null)
			{
			// Initialize variable
			$out = '';

			// Iterate instead of recursing, this way if there are too many values we don't have stack overflows
			// rfc: all line breaks or other characters not found
			// in the Base64 Alphabet must be ignored by decoding software
			// delete all blanks between MIME-lines, differently we can
			// receive unnecessary blanks and broken utf-8 symbols
			$input = preg_replace("/\?=\s+=\?/", '?==?', $input);

			// Check if there is stuff to decode
			if (strpos($input, '=?') !== false) {
			// Loop through the string to decode all occurences of =? ?= into the variable $out
			while(($pos = strpos($input, '=?')) !== false) {
			// Append everything that is before the text to be decoded
			$out .= substr($input, 0, $pos);

			// Get the location of the text to decode
			$end_cs_pos = strpos($input, "?", $pos+2);
			$end_en_pos = strpos($input, "?", $end_cs_pos+1);
			$end_pos = strpos($input, "?=", $end_en_pos+1);

			// Extract the encoded string
			$encstr = substr($input, $pos+2, ($end_pos-$pos-2));
			// Extract the remaining string
			$input = substr($input, $end_pos+2);

			// Decode the string fragement
			$out .= rcube_imap::_decode_mime_string_part($encstr);
			}

			// Deocde the rest (if any)
			if (strlen($input) != 0)
			$out .= rcube_imap::decode_mime_string($input, $fallback);

			// return the results
			return $out;
			}

			// no encoding information, use fallback
			return rcube_charset_convert($input,
			!empty($fallback) ? $fallback : rcmail::get_instance()->config->get('default_charset', 'ISO-8859-1'));
			}


			/**
			* Decode a part of a mime-encoded string
			*
			* @access private
			*/
			private function _decode_mime_string_part($str)
			{
			$a = explode('?', $str);
			$count = count($a);

			// should be in format "charset?encoding?base64_string"
			if ($count >= 3)
			{
			for ($i=2; $i<$count; $i++)
			$rest.=$a[$i];

			if (($a[1]=="B")\|\|($a[1]=="b"))
			$rest = base64_decode($rest);
			else if (($a[1]=="Q")\|\|($a[1]=="q"))
			{
			$rest = str_replace("_", " ", $rest);
			$rest = quoted_printable_decode($rest);
			else {
			$begin = $start_msg;
			$end = $start_msg + $this->page_size;
			}

			return rcube_charset_convert($rest, $a[0]);
			}
			else
			return $str; // we dont' know what to do with this
			if ($begin < 0) $begin = 0;
			if ($end < 0) $end = $max;
			if ($end > $max) $end = $max;

			return array($begin, $end);
			}


			/**
			* Decode a mime part
			*
			* @param string Input string
			* @param string Part encoding
			* @return string Decoded string
			*/
			function mime_decode($input, $encoding='7bit')
			/**
			* Fetches message headers
			* Used for loop
			*
			* @param string Mailbox name
			* @param string Message index to fetch
			* @param array Reference to message headers array
			* @param array Array with cache index
			* @return int Messages count
			* @access private
			*/
			private function _fetch_headers($mailbox, $msgs, &$a_msg_headers, $cache_key)
			{
			switch (strtolower($encoding))
			{
			case 'quoted-printable':
			return quoted_printable_decode($input);
			break;

			case 'base64':
			return base64_decode($input);
			break;
			// fetch reqested headers from server
			$a_header_index = $this->conn->fetchHeaders(
			$mailbox, $msgs, false, false, $this->fetch_add_headers);

			case 'x-uuencode':
			case 'x-uue':
			case 'uue':
			case 'uuencode':
			return convert_uudecode($input);
			break;

			case '7bit':
			default:
			return $input;
			}
			}
			if (empty($a_header_index))
			return 0;

			// cache is incomplete
			$cache_index = $this->get_message_cache_index($cache_key);

			/**
			* Convert body charset to RCMAIL_CHARSET according to the ctype_parameters
			*
			* @param string Part body to decode
			* @param string Charset to convert from
			* @return string Content converted to internal charset
			*/
			function charset_decode($body, $ctype_param)
			{
			if (is_array($ctype_param) && !empty($ctype_param['charset']))
			return rcube_charset_convert($body, $ctype_param['charset']);
			foreach ($a_header_index as $i => $headers) {
			if ($this->caching_enabled && $cache_index[$headers->id] != $headers->uid) {
			// prevent index duplicates
			if ($cache_index[$headers->id]) {
			$this->remove_message_cache($cache_key, $headers->id, true);
			unset($cache_index[$headers->id]);
			}
			// add message to cache
			$this->add_message_cache($cache_key, $headers->id, $headers, NULL,
			!in_array($headers->uid, $cache_index));
			}

			// defaults to what is specified in the class header
			return rcube_charset_convert($body, $this->default_charset);
			}


			/**
			* Translate UID to message ID
			*
			* @param int Message UID
			* @param string Mailbox name
			* @return int Message ID
			*/
			function get_id($uid, $mbox_name=NULL)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_uid2id($uid, $mailbox);
			}


			/**
			* Translate message number to UID
			*
			* @param int Message ID
			* @param string Mailbox name
			* @return int Message UID
			*/
			function get_uid($id,$mbox_name=NULL)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_id2uid($id, $mailbox);
			}


			/**
			* Modify folder name for input/output according to root dir and namespace
			*
			* @param string Folder name
			* @param string Mode
			* @return string Folder name
			*/
			function mod_mailbox($mbox_name, $mode='in')
			{
			if ((!empty($this->root_ns) && $this->root_ns == $mbox_name) \|\| $mbox_name == 'INBOX')
			return $mbox_name;

			if (!empty($this->root_dir)) {
			if ($mode=='in')
			$mbox_name = $this->root_dir.$this->delimiter.$mbox_name;
			else if (!empty($mbox_name)) // $mode=='out'
			$mbox_name = substr($mbox_name, strlen($this->root_dir)+1);
			}

			return $mbox_name;
			}


			/* --------------------------------
			* private methods
			* --------------------------------*/

			/**
			* Validate the given input and save to local properties
			* @access private
			*/
			private function _set_sort_order($sort_field, $sort_order)
			{
			if ($sort_field != null)
			$this->sort_field = asciiwords($sort_field);
			if ($sort_order != null)
			$this->sort_order = strtoupper($sort_order) == 'DESC' ? 'DESC' : 'ASC';
			}

			/**
			* Sort mailboxes first by default folders and then in alphabethical order
			* @access private
			*/
			private function _sort_mailbox_list($a_folders)
			{
			$a_out = $a_defaults = $folders = array();

			$delimiter = $this->get_hierarchy_delimiter();

			// find default folders and skip folders starting with '.'
			foreach ($a_folders as $i => $folder)
			{
			if ($folder{0}=='.')
			continue;

			if (($p = array_search(strtolower($folder), $this->default_folders_lc)) !== false && !$a_defaults[$p])
			$a_defaults[$p] = $folder;
			else
			$folders[$folder] = mb_strtolower(rcube_charset_convert($folder, 'UTF7-IMAP'));
			}

			// sort folders and place defaults on the top
			asort($folders, SORT_LOCALE_STRING);
			ksort($a_defaults);
			$folders = array_merge($a_defaults, array_keys($folders));

			// finally we must rebuild the list to move
			// subfolders of default folders to their place...
			// ...also do this for the rest of folders because
			// asort() is not properly sorting case sensitive names
			while (list($key, $folder) = each($folders)) {
			// set the type of folder name variable (#1485527)
			$a_out[] = (string) $folder;
			unset($folders[$key]);
			$this->_rsort($folder, $delimiter, $folders, $a_out);
			}

			return $a_out;
			}


			/**
			* @access private
			*/
			private function _rsort($folder, $delimiter, &$list, &$out)
			{
			while (list($key, $name) = each($list)) {
			if (strpos($name, $folder.$delimiter) === 0) {
			// set the type of folder name variable (#1485527)
			$out[] = (string) $name;
			unset($list[$key]);
			$this->_rsort($name, $delimiter, $list, $out);
			}
			}
			reset($list);
			}


			/**
			* @access private
			*/
			private function _uid2id($uid, $mbox_name=NULL)
			{
			if (!$mbox_name)
			$mbox_name = $this->mailbox;

			if (!isset($this->uid_id_map[$mbox_name][$uid]))
			$this->uid_id_map[$mbox_name][$uid] = iil_C_UID2ID($this->conn, $mbox_name, $uid);

			return $this->uid_id_map[$mbox_name][$uid];
			}

			/**
			* @access private
			*/
			private function _id2uid($id, $mbox_name=NULL)
			{
			if (!$mbox_name)
			$mbox_name = $this->mailbox;

			$index = array_flip((array)$this->uid_id_map[$mbox_name]);
			if (isset($index[$id]))
			$uid = $index[$id];
			else
			{
			$uid = iil_C_ID2UID($this->conn, $mbox_name, $id);
			$this->uid_id_map[$mbox_name][$uid] = $id;
			}

			return $uid;
			}


			/**
			* Subscribe/unsubscribe a list of mailboxes and update local cache
			* @access private
			*/
			private function _change_subscription($a_mboxes, $mode)
			{
			$updated = FALSE;

			if (is_array($a_mboxes))
			foreach ($a_mboxes as $i => $mbox_name)
			{
			$mailbox = $this->mod_mailbox($mbox_name);
			$a_mboxes[$i] = $mailbox;

			if ($mode=='subscribe')
			$updated = iil_C_Subscribe($this->conn, $mailbox);
			else if ($mode=='unsubscribe')
			$updated = iil_C_UnSubscribe($this->conn, $mailbox);
			$a_msg_headers[$headers->uid] = $headers;
			}

			// get cached mailbox list
			if ($updated)
			{
			$a_mailbox_cache = $this->get_cache('mailboxes');
			if (!is_array($a_mailbox_cache))
			return $updated;

			// modify cached list
			if ($mode=='subscribe')
			$a_mailbox_cache = array_merge($a_mailbox_cache, $a_mboxes);
			else if ($mode=='unsubscribe')
			$a_mailbox_cache = array_diff($a_mailbox_cache, $a_mboxes);

			// write mailboxlist to cache
			$this->update_cache('mailboxes', $this->_sort_mailbox_list($a_mailbox_cache));
			}

			return $updated;
			return count($a_msg_headers);
			}


			/**
			* Increde/decrese messagecount for a specific mailbox
			* @access private
			*/
			private function _set_messagecount($mbox_name, $mode, $increment)
			/**
			* Returns current status of mailbox
			*
			* We compare the maximum UID to determine the number of
			* new messages because the RECENT flag is not reliable.
			*
			* @param string Mailbox/folder name
			* @return int Folder status
			*/
			function mailbox_status($mbox_name = null)
			{
			$a_mailbox_cache = FALSE;
			$mailbox = $mbox_name ? $mbox_name : $this->mailbox;
			$mode = strtoupper($mode);
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			$old = $this->get_folder_stats($mailbox);

			$a_mailbox_cache = $this->get_cache('messagecount');

			if (!is_array($a_mailbox_cache[$mailbox]) \|\| !isset($a_mailbox_cache[$mailbox][$mode]) \|\| !is_numeric($increment))
			return FALSE;

			// add incremental value to messagecount
			$a_mailbox_cache[$mailbox][$mode] += $increment;

			// there's something wrong, delete from cache
			if ($a_mailbox_cache[$mailbox][$mode] < 0)
			unset($a_mailbox_cache[$mailbox][$mode]);
			// refresh message count -> will update
			$this->_messagecount($mailbox, 'ALL', true);

			// write back to cache
			$this->update_cache('messagecount', $a_mailbox_cache);

			return TRUE;
			$result = 0;
			$new = $this->get_folder_stats($mailbox);

			// got new messages
			if ($new['maxuid'] > $old['maxuid'])
			$result += 1;
			// some messages has been deleted
			if ($new['cnt'] < $old['cnt'])
			$result += 2;

			// @TODO: optional checking for messages flags changes (?)
			// @TODO: UIDVALIDITY checking

			return $result;
			}


			/**
			* Remove messagecount of a specific mailbox from cache
			* @access private
			*/
			private function _clear_messagecount($mbox_name='')
			/**
			* Stores folder statistic data in session
			* @TODO: move to separate DB table (cache?)
			*
			* @param string Mailbox name
			* @param string Data name
			* @param mixed Data value
			*/
			private function set_folder_stats($mbox_name, $name, $data)
			{
			$a_mailbox_cache = FALSE;
			$mailbox = $mbox_name ? $mbox_name : $this->mailbox;

			$a_mailbox_cache = $this->get_cache('messagecount');

			if (is_array($a_mailbox_cache[$mailbox]))
			{
			unset($a_mailbox_cache[$mailbox]);
			$this->update_cache('messagecount', $a_mailbox_cache);
			}
			$_SESSION['folders'][$mbox_name][$name] = $data;
			}


			/**
			* Split RFC822 header string into an associative array
			* @access private
			*/
			private function _parse_headers($headers)
			/**
			* Gets folder statistic data
			*
			* @param string Mailbox name
			* @return array Stats data
			*/
			private function get_folder_stats($mbox_name)
			{
			$a_headers = array();
			$headers = preg_replace('/\r?\n(\t\| )+/', ' ', $headers);
			$lines = explode("\n", $headers);
			$c = count($lines);
			for ($i=0; $i<$c; $i++)
			{
			if ($p = strpos($lines[$i], ': '))
			{
			$field = strtolower(substr($lines[$i], 0, $p));
			$value = trim(substr($lines[$i], $p+1));
			if (!empty($value))
			$a_headers[$field] = $value;
			}
			}

			return $a_headers;
			}


			/**
			* @access private
			*/
			private function _parse_address_list($str, $decode=true)
			{
			// remove any newlines and carriage returns before
			$a = rcube_explode_quoted_string('[,;]', preg_replace( "/[\r\n]/", " ", $str));
			$result = array();

			foreach ($a as $key => $val)
			{
			$val = preg_replace("/([\"\w])</", "$1 <", $val);
			$sub_a = rcube_explode_quoted_string(' ', $decode ? $this->decode_header($val) : $val);
			$result[$key]['name'] = '';

			foreach ($sub_a as $k => $v)
			{
			// use angle brackets in regexp to not handle names with @ sign
			if (preg_match('/^<\S+@\S+>$/', $v))
			$result[$key]['address'] = trim($v, '<>');
			if ($_SESSION['folders'][$mbox_name])
			return (array) $_SESSION['folders'][$mbox_name];
			else
			$result[$key]['name'] .= (empty($result[$key]['name'])?'':' ').str_replace("\"",'',stripslashes($v));
			return array();
			}


			/**
			* Return sorted array of message IDs (not UIDs)
			*
			* @param string Mailbox to get index from
			* @param string Sort column
			* @param string Sort order [ASC, DESC]
			* @return array Indexed array with message ids
			*/
			function message_index($mbox_name='', $sort_field=NULL, $sort_order=NULL)
			{
			if ($this->threading)
			return $this->thread_index($mbox_name, $sort_field, $sort_order);

			$this->_set_sort_order($sort_field, $sort_order);

			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			$key = "{$mailbox}:{$this->sort_field}:{$this->sort_order}:{$this->search_string}.msgi";

			// we have a saved search result, get index from there
			if (!isset($this->cache[$key]) && $this->search_string
			&& !$this->search_threads && $mailbox == $this->mailbox) {
			// use message index sort as default sorting
			if (!$this->sort_field) {
			$msgs = $this->search_set;

			if ($this->search_sort_field != 'date')
			sort($msgs);

			if ($this->sort_order == 'DESC')
			$this->cache[$key] = array_reverse($msgs);
			else
			$this->cache[$key] = $msgs;
			}
			// sort with SORT command
			else if ($this->get_capability('SORT')) {
			if ($this->sort_field && $this->search_sort_field != $this->sort_field)
			$this->search('', $this->search_string, $this->search_charset, $this->sort_field);

			if ($this->sort_order == 'DESC')
			$this->cache[$key] = array_reverse($this->search_set);
			else
			$this->cache[$key] = $this->search_set;
			}
			else {
			$a_index = $this->conn->fetchHeaderIndex($mailbox,
			join(',', $this->search_set), $this->sort_field, $this->skip_deleted);

			if (is_array($a_index)) {
			if ($this->sort_order=="ASC")
			asort($a_index);
			else if ($this->sort_order=="DESC")
			arsort($a_index);

			$this->cache[$key] = array_keys($a_index);
			}
			else {
			$this->cache[$key] = array();
			}
			}
			}

			// have stored it in RAM
			if (isset($this->cache[$key]))
			return $this->cache[$key];

			// check local cache
			$cache_key = $mailbox.'.msg';
			$cache_status = $this->check_cache_status($mailbox, $cache_key);

			// cache is OK
			if ($cache_status>0) {
			$a_index = $this->get_message_cache_index($cache_key,
			true, $this->sort_field, $this->sort_order);
			return array_keys($a_index);
			}

			// use message index sort as default sorting
			if (!$this->sort_field) {
			if ($this->skip_deleted) {
			$a_index = $this->_search_index($mailbox, 'ALL');
			} else if ($max = $this->_messagecount($mailbox)) {
			$a_index = range(1, $max);
			}

			if ($this->sort_order == 'DESC')
			$a_index = array_reverse($a_index);

			$this->cache[$key] = $a_index;
			}
			// fetch complete message index
			else if ($this->get_capability('SORT')) {
			if ($a_index = $this->conn->sort($mailbox,
			$this->sort_field, $this->skip_deleted ? 'UNDELETED' : '')) {
			if ($this->sort_order == 'DESC')
			$a_index = array_reverse($a_index);

			$this->cache[$key] = $a_index;
			}
			}
			else if ($a_index = $this->conn->fetchHeaderIndex(
			$mailbox, "1:*", $this->sort_field, $this->skip_deleted)) {
			if ($this->sort_order=="ASC")
			asort($a_index);
			else if ($this->sort_order=="DESC")
			arsort($a_index);

			$this->cache[$key] = array_keys($a_index);
			}

			return $this->cache[$key];
			}


			/**
			* Return sorted array of threaded message IDs (not UIDs)
			*
			* @param string Mailbox to get index from
			* @param string Sort column
			* @param string Sort order [ASC, DESC]
			* @return array Indexed array with message IDs
			*/
			function thread_index($mbox_name='', $sort_field=NULL, $sort_order=NULL)
			{
			$this->_set_sort_order($sort_field, $sort_order);

			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			$key = "{$mailbox}:{$this->sort_field}:{$this->sort_order}:{$this->search_string}.thi";

			// we have a saved search result, get index from there
			if (!isset($this->cache[$key]) && $this->search_string
			&& $this->search_threads && $mailbox == $this->mailbox) {
			// use message IDs for better performance
			$ids = array_keys_recursive($this->search_set['tree']);
			$this->cache[$key] = $this->_flatten_threads($mailbox, $this->search_set['tree'], $ids);
			}

			// have stored it in RAM
			if (isset($this->cache[$key]))
			return $this->cache[$key];
			/*
			// check local cache
			$cache_key = $mailbox.'.msg';
			$cache_status = $this->check_cache_status($mailbox, $cache_key);

			// cache is OK
			if ($cache_status>0) {
			$a_index = $this->get_message_cache_index($cache_key, true, $this->sort_field, $this->sort_order);
			return array_keys($a_index);
			}
			*/
			// get all threads (default sort order)
			list ($thread_tree) = $this->_fetch_threads($mailbox);

			$this->cache[$key] = $this->_flatten_threads($mailbox, $thread_tree);

			return $this->cache[$key];
			}


			/**
			* Return array of threaded messages (all, not only roots)
			*
			* @param string Mailbox to get index from
			* @param array Threaded messages array (see _fetch_threads())
			* @param array Message IDs if we know what we need (e.g. search result)
			* for better performance
			* @return array Indexed array with message IDs
			*
			* @access private
			*/
			private function _flatten_threads($mailbox, $thread_tree, $ids=null)
			{
			if (empty($thread_tree))
			return array();

			$msg_index = $this->_sort_threads($mailbox, $thread_tree, $ids);

			if ($this->sort_order == 'DESC')
			$msg_index = array_reverse($msg_index);

			// flatten threads array
			$all_ids = array();
			foreach($msg_index as $root) {
			$all_ids[] = $root;
			if (!empty($thread_tree[$root]))
			$all_ids = array_merge($all_ids, array_keys_recursive($thread_tree[$root]));
			}

			return $all_ids;
			}


			/**
			* @access private
			*/
			private function sync_header_index($mailbox)
			{
			$cache_key = $mailbox.'.msg';
			$cache_index = $this->get_message_cache_index($cache_key);

			// fetch complete message index
			$a_message_index = $this->conn->fetchHeaderIndex($mailbox, "1:*", 'UID', $this->skip_deleted);

			if ($a_message_index === false)
			return false;

			foreach ($a_message_index as $id => $uid) {
			// message in cache at correct position
			if ($cache_index[$id] == $uid) {
			unset($cache_index[$id]);
			continue;
			}

			// message in cache but in wrong position
			if (in_array((string)$uid, $cache_index, true)) {
			unset($cache_index[$id]);
			}

			// other message at this position
			if (isset($cache_index[$id])) {
			$for_remove[] = $cache_index[$id];
			unset($cache_index[$id]);
			}

			$for_update[] = $id;
			}

			// clear messages at wrong positions and those deleted that are still in cache_index
			if (!empty($for_remove))
			$cache_index = array_merge($cache_index, $for_remove);

			if (!empty($cache_index))
			$this->remove_message_cache($cache_key, $cache_index);

			// fetch complete headers and add to cache
			if (!empty($for_update)) {
			if ($headers = $this->conn->fetchHeader($mailbox,
			join(',', $for_update), false, $this->fetch_add_headers)) {
			foreach ($headers as $header) {
			$this->add_message_cache($cache_key, $header->id, $header, NULL,
			in_array($header->uid, (array)$for_remove));
			}
			}
			}
			}


			/**
			* Invoke search request to IMAP server
			*
			* @param string mailbox name to search in
			* @param string search string
			* @param string search string charset
			* @param string header field to sort by
			* @return array search results as list of message ids
			* @access public
			*/
			function search($mbox_name='', $str=NULL, $charset=NULL, $sort_field=NULL)
			{
			if (!$str)
			return false;

			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;

			$results = $this->_search_index($mailbox, $str, $charset, $sort_field);

			// try search with US-ASCII charset (should be supported by server)
			// only if UTF-8 search is not supported
			if (empty($results) && !is_array($results) && !empty($charset) && $charset != 'US-ASCII')
			{
			// convert strings to US_ASCII
			if(preg_match_all('/\{([0-9]+)\}\r\n/', $str, $matches, PREG_OFFSET_CAPTURE)) {
			$last = 0; $res = '';
			foreach($matches[1] as $m)
			{
			$string_offset = $m[1] + strlen($m[0]) + 4; // {}\r\n
			$string = substr($str, $string_offset - 1, $m[0]);
			$string = rcube_charset_convert($string, $charset, 'US-ASCII');
			if (!$string)
			continue;
			$res .= sprintf("%s{%d}\r\n%s", substr($str, $last, $m[1] - $last - 1), strlen($string), $string);
			$last = $m[0] + $string_offset - 1;
			}
			if ($last < strlen($str))
			$res .= substr($str, $last, strlen($str)-$last);
			}
			else // strings for conversion not found
			$res = $str;

			$results = $this->search($mbox_name, $res, NULL, $sort_field);
			}

			$this->set_search_set($str, $results, $charset, $sort_field, (bool)$this->threading);

			return $results;
			}


			/**
			* Private search method
			*
			* @return array search results as list of message ids
			* @access private
			* @see rcube_imap::search()
			*/
			private function _search_index($mailbox, $criteria='ALL', $charset=NULL, $sort_field=NULL)
			{
			$orig_criteria = $criteria;

			if ($this->skip_deleted && !preg_match('/UNDELETED/', $criteria))
			$criteria = 'UNDELETED '.$criteria;

			if ($this->threading) {
			list ($thread_tree, $msg_depth, $has_children) = $this->conn->thread(
			$mailbox, $this->threading, $criteria, $charset);

			$a_messages = array(
			'tree' => $thread_tree,
			'depth' => $msg_depth,
			'children' => $has_children
			);
			}
			else if ($sort_field && $this->get_capability('SORT')) {
			$charset = $charset ? $charset : $this->default_charset;
			$a_messages = $this->conn->sort($mailbox, $sort_field, $criteria, false, $charset);

			if (!$a_messages)
			return array();
			}
			else {
			if ($orig_criteria == 'ALL') {
			$max = $this->_messagecount($mailbox);
			$a_messages = $max ? range(1, $max) : array();
			}
			else {
			$a_messages = $this->conn->search($mailbox,
			($charset ? "CHARSET $charset " : '') . $criteria);

			if (!$a_messages)
			return array();

			// I didn't found that SEARCH always returns sorted IDs
			if (!$this->sort_field)
			sort($a_messages);
			}
			}

			// update messagecount cache ?
			// $a_mailbox_cache = get_cache('messagecount');
			// $a_mailbox_cache[$mailbox][$criteria] = sizeof($a_messages);
			// $this->update_cache('messagecount', $a_mailbox_cache);

			return $a_messages;
			}


			/**
			* Direct (real and simple) SEARCH request to IMAP server,
			* without result sorting and caching
			*
			* @param string Mailbox name to search in
			* @param string Search string
			* @param boolean True if UIDs should be returned
			* @return array Search results as list of message IDs or UIDs
			* @access public
			*/
			function search_once($mbox_name='', $str=NULL, $ret_uid=false)
			{
			if (!$str)
			return false;

			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;

			return $this->conn->search($mailbox, $str, $ret_uid);
			}


			/**
			* Sort thread
			*
			* @param string Mailbox name
			* @param array Unsorted thread tree (rcube_imap_generic::thread() result)
			* @param array Message IDs if we know what we need (e.g. search result)
			* @return array Sorted roots IDs
			* @access private
			*/
			private function _sort_threads($mailbox, $thread_tree, $ids=NULL)
			{
			// THREAD=ORDEREDSUBJECT: sorting by sent date of root message
			// THREAD=REFERENCES: sorting by sent date of root message
			// THREAD=REFS: sorting by the most recent date in each thread
			// default sorting
			if (!$this->sort_field \|\| ($this->sort_field == 'date' && $this->threading == 'REFS')) {
			return array_keys((array)$thread_tree);
			}
			// here we'll implement REFS sorting, for performance reason
			else { // ($sort_field == 'date' && $this->threading != 'REFS')
			// use SORT command
			if ($this->get_capability('SORT')) {
			$a_index = $this->conn->sort($mailbox, $this->sort_field,
			!empty($ids) ? $ids : ($this->skip_deleted ? 'UNDELETED' : ''));

			// return unsorted tree if we've got no index data
			if (!$a_index)
			return array_keys((array)$thread_tree);
			}
			else {
			// fetch specified headers for all messages and sort them
			$a_index = $this->conn->fetchHeaderIndex($mailbox, !empty($ids) ? $ids : "1:*",
			$this->sort_field, $this->skip_deleted);

			// return unsorted tree if we've got no index data
			if (!$a_index)
			return array_keys((array)$thread_tree);

			asort($a_index); // ASC
			$a_index = array_values($a_index);
			}

			return $this->_sort_thread_refs($thread_tree, $a_index);
			}
			}


			/**
			* THREAD=REFS sorting implementation
			*
			* @param array Thread tree array (message identifiers as keys)
			* @param array Array of sorted message identifiers
			* @return array Array of sorted roots messages
			* @access private
			*/
			private function _sort_thread_refs($tree, $index)
			{
			if (empty($tree))
			return array();

			$index = array_combine(array_values($index), $index);

			// assign roots
			foreach ($tree as $idx => $val) {
			$index[$idx] = $idx;
			if (!empty($val)) {
			$idx_arr = array_keys_recursive($tree[$idx]);
			foreach ($idx_arr as $subidx)
			$index[$subidx] = $idx;
			}
			}

			$index = array_values($index);

			// create sorted array of roots
			$msg_index = array();
			if ($this->sort_order != 'DESC') {
			foreach ($index as $idx)
			if (!isset($msg_index[$idx]))
			$msg_index[$idx] = $idx;
			$msg_index = array_values($msg_index);
			}
			else {
			for ($x=count($index)-1; $x>=0; $x--)
			if (!isset($msg_index[$index[$x]]))
			$msg_index[$index[$x]] = $index[$x];
			$msg_index = array_reverse($msg_index);
			}

			return $msg_index;
			}


			/**
			* Refresh saved search set
			*
			* @return array Current search set
			*/
			function refresh_search()
			{
			if (!empty($this->search_string))
			$this->search_set = $this->search('', $this->search_string, $this->search_charset,
			$this->search_sort_field, $this->search_threads);

			return $this->get_search_set();
			}


			/**
			* Check if the given message ID is part of the current search set
			*
			* @return boolean True on match or if no search request is stored
			*/
			function in_searchset($msgid)
			{
			if (!empty($this->search_string)) {
			if ($this->search_threads)
			return isset($this->search_set['depth']["$msgid"]);
			else
			return in_array("$msgid", (array)$this->search_set, true);
			}
			else
			return true;
			}


			/**
			* Return message headers object of a specific message
			*
			* @param int Message ID
			* @param string Mailbox to read from
			* @param boolean True if $id is the message UID
			* @param boolean True if we need also BODYSTRUCTURE in headers
			* @return object Message headers representation
			*/
			function get_headers($id, $mbox_name=NULL, $is_uid=true, $bodystr=false)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			$uid = $is_uid ? $id : $this->_id2uid($id, $mailbox);

			// get cached headers
			if ($uid && ($headers = &$this->get_cached_message($mailbox.'.msg', $uid)))
			return $headers;

			$headers = $this->conn->fetchHeader(
			$mailbox, $id, $is_uid, $bodystr, $this->fetch_add_headers);

			// write headers cache
			if ($headers) {
			if ($headers->uid && $headers->id)
			$this->uid_id_map[$mailbox][$headers->uid] = $headers->id;

			$this->add_message_cache($mailbox.'.msg', $headers->id, $headers, NULL);
			}

			return $headers;
			}


			/**
			* Fetch body structure from the IMAP server and build
			* an object structure similar to the one generated by PEAR::Mail_mimeDecode
			*
			* @param int Message UID to fetch
			* @param string Message BODYSTRUCTURE string (optional)
			* @return object rcube_message_part Message part tree or False on failure
			*/
			function &get_structure($uid, $structure_str='')
			{
			$cache_key = $this->mailbox.'.msg';
			$headers = &$this->get_cached_message($cache_key, $uid);

			// return cached message structure
			if (is_object($headers) && is_object($headers->structure)) {
			return $headers->structure;
			}

			if (!$structure_str) {
			$structure_str = $this->conn->fetchStructureString($this->mailbox, $uid, true);
			}
			$structure = rcube_mime_struct::parseStructure($structure_str);
			$struct = false;

			// parse structure and add headers
			if (!empty($structure)) {
			$headers = $this->get_headers($uid);
			$this->_msg_id = $headers->id;

			// set message charset from message headers
			if ($headers->charset)
			$this->struct_charset = $headers->charset;
			else
			$this->struct_charset = $this->_structure_charset($structure);

			// Here we can recognize malformed BODYSTRUCTURE and
			// 1. [@TODO] parse the message in other way to create our own message structure
			// 2. or just show the raw message body.
			// Example of structure for malformed MIME message:
			// ("text" "plain" ("charset" "us-ascii") NIL NIL "7bit" 2154 70 NIL NIL NIL)
			if ($headers->ctype && $headers->ctype != 'text/plain'
			&& $structure[0] == 'text' && $structure[1] == 'plain') {
			return false;
			}

			$struct = &$this->_structure_part($structure);
			$struct->headers = get_object_vars($headers);

			// don't trust given content-type
			if (empty($struct->parts) && !empty($struct->headers['ctype'])) {
			$struct->mime_id = '1';
			$struct->mimetype = strtolower($struct->headers['ctype']);
			list($struct->ctype_primary, $struct->ctype_secondary) = explode('/', $struct->mimetype);
			}

			// write structure to cache
			if ($this->caching_enabled)
			$this->add_message_cache($cache_key, $this->_msg_id, $headers, $struct);
			}

			return $struct;
			}


			/**
			* Build message part object
			*
			* @access private
			*/
			function &_structure_part($part, $count=0, $parent='', $mime_headers=null, $raw_headers=null)
			{
			$struct = new rcube_message_part;
			$struct->mime_id = empty($parent) ? (string)$count : "$parent.$count";

			// multipart
			if (is_array($part[0])) {
			$struct->ctype_primary = 'multipart';

			// find first non-array entry
			for ($i=1; $i<count($part); $i++) {
			if (!is_array($part[$i])) {
			$struct->ctype_secondary = strtolower($part[$i]);
			break;
			}
			}

			$struct->mimetype = 'multipart/'.$struct->ctype_secondary;

			// build parts list for headers pre-fetching
			for ($i=0, $count=0; $i<count($part); $i++) {
			if (is_array($part[$i]) && count($part[$i]) > 3) {
			// fetch message headers if message/rfc822
			// or named part (could contain Content-Location header)
			if (!is_array($part[$i][0])) {
			$tmp_part_id = $struct->mime_id ? $struct->mime_id.'.'.($i+1) : $i+1;
			if (strtolower($part[$i][0]) == 'message' && strtolower($part[$i][1]) == 'rfc822') {
			$raw_part_headers[] = $tmp_part_id;
			$mime_part_headers[] = $tmp_part_id;
			}
			else if (in_array('name', (array)$part[$i][2]) && (empty($part[$i][3]) \|\| $part[$i][3]=='NIL')) {
			$mime_part_headers[] = $tmp_part_id;
			}
			}
			}
			}

			// pre-fetch headers of all parts (in one command for better performance)
			// @TODO: we could do this before _structure_part() call, to fetch
			// headers for parts on all levels
			if ($mime_part_headers) {
			$mime_part_headers = $this->conn->fetchMIMEHeaders($this->mailbox,
			$this->_msg_id, $mime_part_headers);
			}
			// we'll need a real content-type of message/rfc822 part
			if ($raw_part_headers) {
			$raw_part_headers = $this->conn->fetchMIMEHeaders($this->mailbox,
			$this->_msg_id, $raw_part_headers, false);
			}
			$struct->parts = array();
			for ($i=0, $count=0; $i<count($part); $i++) {
			if (is_array($part[$i]) && count($part[$i]) > 3) {
			$tmp_part_id = $struct->mime_id ? $struct->mime_id.'.'.($i+1) : $i+1;
			$struct->parts[] = $this->_structure_part($part[$i], ++$count, $struct->mime_id,
			$mime_part_headers[$tmp_part_id], $raw_part_headers[$tmp_part_id]);
			}
			}

			return $struct;
			}

			// regular part
			$struct->ctype_primary = strtolower($part[0]);
			$struct->ctype_secondary = strtolower($part[1]);
			$struct->mimetype = $struct->ctype_primary.'/'.$struct->ctype_secondary;

			// read content type parameters
			if (is_array($part[2])) {
			$struct->ctype_parameters = array();
			for ($i=0; $i<count($part[2]); $i+=2)
			$struct->ctype_parameters[strtolower($part[2][$i])] = $part[2][$i+1];

			if (isset($struct->ctype_parameters['charset']))
			$struct->charset = $struct->ctype_parameters['charset'];
			}

			// read content encoding
			if (!empty($part[5]) && $part[5]!='NIL') {
			$struct->encoding = strtolower($part[5]);
			$struct->headers['content-transfer-encoding'] = $struct->encoding;
			}

			// get part size
			if (!empty($part[6]) && $part[6]!='NIL')
			$struct->size = intval($part[6]);

			// read part disposition
			$di = count($part) - 2;
			if ((is_array($part[$di]) && count($part[$di]) == 2 && is_array($part[$di][1])) \|\|
			(is_array($part[--$di]) && count($part[$di]) == 2)) {
			$struct->disposition = strtolower($part[$di][0]);

			if (is_array($part[$di][1]))
			for ($n=0; $n<count($part[$di][1]); $n+=2)
			$struct->d_parameters[strtolower($part[$di][1][$n])] = $part[$di][1][$n+1];
			}

			// get child parts
			if (is_array($part[8]) && $di != 8) {
			$struct->parts = array();
			for ($i=0, $count=0; $i<count($part[8]); $i++)
			if (is_array($part[8][$i]) && count($part[8][$i]) > 5)
			$struct->parts[] = $this->_structure_part($part[8][$i], ++$count, $struct->mime_id);
			}

			// get part ID
			if (!empty($part[3]) && $part[3]!='NIL') {
			$struct->content_id = $part[3];
			$struct->headers['content-id'] = $part[3];

			if (empty($struct->disposition))
			$struct->disposition = 'inline';
			}

			// fetch message headers if message/rfc822 or named part (could contain Content-Location header)
			if ($struct->ctype_primary == 'message' \|\| ($struct->ctype_parameters['name'] && !$struct->content_id)) {
			if (empty($mime_headers)) {
			$mime_headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $struct->mime_id);
			}
			$struct->headers = $this->_parse_headers($mime_headers) + $struct->headers;

			// get real headers for message of type 'message/rfc822'
			if ($struct->mimetype == 'message/rfc822') {
			if (empty($raw_headers)) {
			$raw_headers = $this->conn->fetchMIMEHeaders(
			$this->mailbox, $this->_msg_id, (array)$struct->mime_id, false);
			}
			$struct->real_headers = $this->_parse_headers($raw_headers);

			// get real content-type of message/rfc822
			if (preg_match('/^([a-z0-9_\/-]+)/i', $struct->real_headers['content-type'], $matches)) {
			$struct->real_mimetype = strtolower($matches[1]);
			}
			}
			}

			if ($struct->ctype_primary=='message') {
			if (is_array($part[8]) && $di != 8 && empty($struct->parts))
			$struct->parts[] = $this->_structure_part($part[8], ++$count, $struct->mime_id);
			}

			// normalize filename property
			$this->_set_part_filename($struct, $mime_headers);

			return $struct;
			}


			/**
			* Set attachment filename from message part structure
			*
			* @access private
			* @param object rcube_message_part Part object
			* @param string Part's raw headers
			*/
			private function _set_part_filename(&$part, $headers=null)
			{
			if (!empty($part->d_parameters['filename']))
			$filename_mime = $part->d_parameters['filename'];
			else if (!empty($part->d_parameters['filename*']))
			$filename_encoded = $part->d_parameters['filename*'];
			else if (!empty($part->ctype_parameters['name*']))
			$filename_encoded = $part->ctype_parameters['name*'];
			// RFC2231 value continuations
			// TODO: this should be rewrited to support RFC2231 4.1 combinations
			else if (!empty($part->d_parameters['filename*0'])) {
			$i = 0;
			while (isset($part->d_parameters['filename*'.$i])) {
			$filename_mime .= $part->d_parameters['filename*'.$i];
			$i++;
			}
			// some servers (eg. dovecot-1.x) have no support for parameter value continuations
			// we must fetch and parse headers "manually"
			if ($i<2) {
			if (!$headers) {
			$headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $part->mime_id);
			}
			$filename_mime = '';
			$i = 0;
			while (preg_match('/filename\'.$i.'\s=\s"([^"\n;]+)[";]*/', $headers, $matches)) {
			$filename_mime .= $matches[1];
			$i++;
			}
			}
			}
			else if (!empty($part->d_parameters['filename0'])) {
			$i = 0;
			while (isset($part->d_parameters['filename'.$i.''])) {
			$filename_encoded .= $part->d_parameters['filename'.$i.''];
			$i++;
			}
			if ($i<2) {
			if (!$headers) {
			$headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $part->mime_id);
			}
			$filename_encoded = '';
			$i = 0; $matches = array();
			while (preg_match('/filename\'.$i.'\\s=\s"([^"\n;]+)[";]/', $headers, $matches)) {
			$filename_encoded .= $matches[1];
			$i++;
			}
			}
			}
			else if (!empty($part->ctype_parameters['name*0'])) {
			$i = 0;
			while (isset($part->ctype_parameters['name*'.$i])) {
			$filename_mime .= $part->ctype_parameters['name*'.$i];
			$i++;
			}
			if ($i<2) {
			if (!$headers) {
			$headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $part->mime_id);
			}
			$filename_mime = '';
			$i = 0; $matches = array();
			while (preg_match('/\s+name\'.$i.'\s=\s"([^"\n;]+)[";]*/', $headers, $matches)) {
			$filename_mime .= $matches[1];
			$i++;
			}
			}
			}
			else if (!empty($part->ctype_parameters['name0'])) {
			$i = 0;
			while (isset($part->ctype_parameters['name'.$i.''])) {
			$filename_encoded .= $part->ctype_parameters['name'.$i.''];
			$i++;
			}
			if ($i<2) {
			if (!$headers) {
			$headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $part->mime_id);
			}
			$filename_encoded = '';
			$i = 0; $matches = array();
			while (preg_match('/\s+name\'.$i.'\\s=\s"([^"\n;]+)[";]/', $headers, $matches)) {
			$filename_encoded .= $matches[1];
			$i++;
			}
			}
			}
			// read 'name' after rfc2231 parameters as it may contains truncated filename (from Thunderbird)
			else if (!empty($part->ctype_parameters['name']))
			$filename_mime = $part->ctype_parameters['name'];
			// Content-Disposition
			else if (!empty($part->headers['content-description']))
			$filename_mime = $part->headers['content-description'];
			else
			return;

			// decode filename
			if (!empty($filename_mime)) {
			$part->filename = rcube_imap::decode_mime_string($filename_mime,
			$part->charset ? $part->charset : ($this->struct_charset ? $this->struct_charset :
			rc_detect_encoding($filename_mime, $this->default_charset)));
			}
			else if (!empty($filename_encoded)) {
			// decode filename according to RFC 2231, Section 4
			if (preg_match("/^([^'])'[^']'(.*)$/", $filename_encoded, $fmatches)) {
			$filename_charset = $fmatches[1];
			$filename_encoded = $fmatches[2];
			}
			$part->filename = rcube_charset_convert(urldecode($filename_encoded), $filename_charset);
			}
			}


			/**
			* Get charset name from message structure (first part)
			*
			* @access private
			* @param array Message structure
			* @return string Charset name
			*/
			function _structure_charset($structure)
			{
			while (is_array($structure)) {
			if (is_array($structure[2]) && $structure[2][0] == 'charset')
			return $structure[2][1];
			$structure = $structure[0];
			}
			}


			/**
			* Fetch message body of a specific message from the server
			*
			* @param int Message UID
			* @param string Part number
			* @param object rcube_message_part Part object created by get_structure()
			* @param mixed True to print part, ressource to write part contents in
			* @param resource File pointer to save the message part
			* @return string Message/part body if not printed
			*/
			function &get_message_part($uid, $part=1, $o_part=NULL, $print=NULL, $fp=NULL)
			{
			// get part encoding if not provided
			if (!is_object($o_part)) {
			$structure_str = $this->conn->fetchStructureString($this->mailbox, $uid, true);
			$structure = new rcube_mime_struct();
			// error or message not found
			if (!$structure->loadStructure($structure_str)) {
			return false;
			}

			$o_part = new rcube_message_part;
			$o_part->ctype_primary = strtolower($structure->getPartType($part));
			$o_part->encoding = strtolower($structure->getPartEncoding($part));
			$o_part->charset = $structure->getPartCharset($part);
			}

			// TODO: Add caching for message parts

			if (!$part) $part = 'TEXT';

			$body = $this->conn->handlePartBody($this->mailbox, $uid, true, $part,
			$o_part->encoding, $print, $fp);

			if ($fp \|\| $print)
			return true;

			// convert charset (if text or message part)
			if ($o_part->ctype_primary=='text' \|\| $o_part->ctype_primary=='message') {
			// assume default if no charset specified
			if (empty($o_part->charset) \|\| strtolower($o_part->charset) == 'us-ascii')
			$o_part->charset = $this->default_charset;

			$body = rcube_charset_convert($body, $o_part->charset);
			}

			return $body;
			}


			/**
			* Fetch message body of a specific message from the server
			*
			* @param int Message UID
			* @return string Message/part body
			* @see rcube_imap::get_message_part()
			*/
			function &get_body($uid, $part=1)
			{
			$headers = $this->get_headers($uid);
			return rcube_charset_convert($this->get_message_part($uid, $part, NULL),
			$headers->charset ? $headers->charset : $this->default_charset);
			}


			/**
			* Returns the whole message source as string
			*
			* @param int Message UID
			* @return string Message source string
			*/
			function &get_raw_body($uid)
			{
			return $this->conn->handlePartBody($this->mailbox, $uid, true);
			}


			/**
			* Returns the message headers as string
			*
			* @param int Message UID
			* @return string Message headers string
			*/
			function &get_raw_headers($uid)
			{
			return $this->conn->fetchPartHeader($this->mailbox, $uid, true);
			}


			/**
			* Sends the whole message source to stdout
			*
			* @param int Message UID
			*/
			function print_raw_body($uid)
			{
			$this->conn->handlePartBody($this->mailbox, $uid, true, NULL, NULL, true);
			}


			/**
			* Set message flag to one or several messages
			*
			* @param mixed Message UIDs as array or comma-separated string, or '*'
			* @param string Flag to set: SEEN, UNDELETED, DELETED, RECENT, ANSWERED, DRAFT, MDNSENT
			* @param string Folder name
			* @param boolean True to skip message cache clean up
			* @return int Number of flagged messages, -1 on failure
			*/
			function set_flag($uids, $flag, $mbox_name=NULL, $skip_cache=false)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;

			$flag = strtoupper($flag);
			list($uids, $all_mode) = $this->_parse_uids($uids, $mailbox);

			if (strpos($flag, 'UN') === 0)
			$result = $this->conn->unflag($mailbox, $uids, substr($flag, 2));
			else
			$result = $this->conn->flag($mailbox, $uids, $flag);

			if ($result >= 0) {
			// reload message headers if cached
			if ($this->caching_enabled && !$skip_cache) {
			$cache_key = $mailbox.'.msg';
			if ($all_mode)
			$this->clear_message_cache($cache_key);
			else
			$this->remove_message_cache($cache_key, explode(',', $uids));
			}
			// update counters
			if ($flag=='SEEN')
			$this->_set_messagecount($mailbox, 'UNSEEN', $result*(-1));
			else if ($flag=='UNSEEN')
			$this->_set_messagecount($mailbox, 'UNSEEN', $result);
			else if ($flag=='DELETED')
			$this->_set_messagecount($mailbox, 'ALL', $result*(-1));
			}

			return $result;
			}


			/**
			* Remove message flag for one or several messages
			*
			* @param mixed Message UIDs as array or comma-separated string, or '*'
			* @param string Flag to unset: SEEN, DELETED, RECENT, ANSWERED, DRAFT, MDNSENT
			* @param string Folder name
			* @return int Number of flagged messages, -1 on failure
			* @see set_flag
			*/
			function unset_flag($uids, $flag, $mbox_name=NULL)
			{
			return $this->set_flag($uids, 'UN'.$flag, $mbox_name);
			}


			/**
			* Append a mail message (source) to a specific mailbox
			*
			* @param string Target mailbox
			* @param string The message source string or filename
			* @param string Headers string if $message contains only the body
			* @param boolean True if $message is a filename
			*
			* @return boolean True on success, False on error
			*/
			function save_message($mbox_name, &$message, $headers='', $is_file=false)
			{
			$mailbox = $this->mod_mailbox($mbox_name);

			// make sure mailbox exists
			if ($this->mailbox_exists($mbox_name, true)) {
			if ($is_file) {
			$separator = rcmail::get_instance()->config->header_delimiter();
			$saved = $this->conn->appendFromFile($mailbox, $message,
			$headers, $separator.$separator);
			}
			else
			$saved = $this->conn->append($mailbox, $message);
			}

			if ($saved) {
			// increase messagecount of the target mailbox
			$this->_set_messagecount($mailbox, 'ALL', 1);
			}

			return $saved;
			}


			/**
			* Move a message from one mailbox to another
			*
			* @param mixed Message UIDs as array or comma-separated string, or '*'
			* @param string Target mailbox
			* @param string Source mailbox
			* @return boolean True on success, False on error
			*/
			function move_message($uids, $to_mbox, $from_mbox='')
			{
			$fbox = $from_mbox;
			$tbox = $to_mbox;
			$to_mbox = $this->mod_mailbox($to_mbox);
			$from_mbox = $from_mbox ? $this->mod_mailbox($from_mbox) : $this->mailbox;

			list($uids, $all_mode) = $this->_parse_uids($uids, $from_mbox);

			// exit if no message uids are specified
			if (empty($uids))
			return false;

			// make sure mailbox exists
			if ($to_mbox != 'INBOX' && !$this->mailbox_exists($tbox, true)) {
			if (in_array($tbox, $this->default_folders))
			$this->create_mailbox($tbox, true);
			else
			return false;
			}

			// flag messages as read before moving them
			$config = rcmail::get_instance()->config;
			if ($config->get('read_when_deleted') && $tbox == $config->get('trash_mbox')) {
			// don't flush cache (4th argument)
			$this->set_flag($uids, 'SEEN', $fbox, true);
			}

			// move messages
			$move = $this->conn->move($uids, $from_mbox, $to_mbox);
			$moved = !($move === false \|\| $move < 0);

			// send expunge command in order to have the moved message
			// really deleted from the source mailbox
			if ($moved) {
			$this->_expunge($from_mbox, false, $uids);
			$this->_clear_messagecount($from_mbox);
			$this->_clear_messagecount($to_mbox);
			}
			// moving failed
			else if ($config->get('delete_always', false) && $tbox == $config->get('trash_mbox')) {
			$moved = $this->delete_message($uids, $fbox);
			}

			if ($moved) {
			// unset threads internal cache
			unset($this->icache['threads']);

			// remove message ids from search set
			if ($this->search_set && $from_mbox == $this->mailbox) {
			// threads are too complicated to just remove messages from set
			if ($this->search_threads \|\| $all_mode)
			$this->refresh_search();
			else {
			$uids = explode(',', $uids);
			foreach ($uids as $uid)
			$a_mids[] = $this->_uid2id($uid, $from_mbox);
			$this->search_set = array_diff($this->search_set, $a_mids);
			}
			}

			// update cached message headers
			$cache_key = $from_mbox.'.msg';
			if ($all_mode \|\| ($start_index = $this->get_message_cache_index_min($cache_key, $uids))) {
			// clear cache from the lowest index on
			$this->clear_message_cache($cache_key, $all_mode ? 1 : $start_index);
			}
			}

			return $moved;
			}


			/**
			* Copy a message from one mailbox to another
			*
			* @param mixed Message UIDs as array or comma-separated string, or '*'
			* @param string Target mailbox
			* @param string Source mailbox
			* @return boolean True on success, False on error
			*/
			function copy_message($uids, $to_mbox, $from_mbox='')
			{
			$fbox = $from_mbox;
			$tbox = $to_mbox;
			$to_mbox = $this->mod_mailbox($to_mbox);
			$from_mbox = $from_mbox ? $this->mod_mailbox($from_mbox) : $this->mailbox;

			list($uids, $all_mode) = $this->_parse_uids($uids, $from_mbox);

			// exit if no message uids are specified
			if (empty($uids))
			return false;

			// make sure mailbox exists
			if ($to_mbox != 'INBOX' && !$this->mailbox_exists($tbox, true)) {
			if (in_array($tbox, $this->default_folders))
			$this->create_mailbox($tbox, true);
			else
			return false;
			}

			// copy messages
			$copy = $this->conn->copy($uids, $from_mbox, $to_mbox);
			$copied = !($copy === false \|\| $copy < 0);

			if ($copied) {
			$this->_clear_messagecount($to_mbox);
			}

			return $copied;
			}


			/**
			* Mark messages as deleted and expunge mailbox
			*
			* @param mixed Message UIDs as array or comma-separated string, or '*'
			* @param string Source mailbox
			* @return boolean True on success, False on error
			*/
			function delete_message($uids, $mbox_name='')
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;

			list($uids, $all_mode) = $this->_parse_uids($uids, $mailbox);

			// exit if no message uids are specified
			if (empty($uids))
			return false;

			$deleted = $this->conn->delete($mailbox, $uids);

			if ($deleted) {
			// send expunge command in order to have the deleted message
			// really deleted from the mailbox
			$this->_expunge($mailbox, false, $uids);
			$this->_clear_messagecount($mailbox);
			unset($this->uid_id_map[$mailbox]);

			// unset threads internal cache
			unset($this->icache['threads']);

			// remove message ids from search set
			if ($this->search_set && $mailbox == $this->mailbox) {
			// threads are too complicated to just remove messages from set
			if ($this->search_threads \|\| $all_mode)
			$this->refresh_search();
			else {
			$uids = explode(',', $uids);
			foreach ($uids as $uid)
			$a_mids[] = $this->_uid2id($uid, $mailbox);
			$this->search_set = array_diff($this->search_set, $a_mids);
			}
			}

			// remove deleted messages from cache
			$cache_key = $mailbox.'.msg';
			if ($all_mode \|\| ($start_index = $this->get_message_cache_index_min($cache_key, $uids))) {
			// clear cache from the lowest index on
			$this->clear_message_cache($cache_key, $all_mode ? 1 : $start_index);
			}
			}

			return $deleted;
			}


			/**
			* Clear all messages in a specific mailbox
			*
			* @param string Mailbox name
			* @return int Above 0 on success
			*/
			function clear_mailbox($mbox_name=NULL)
			{
			$mailbox = !empty($mbox_name) ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			$msg_count = $this->_messagecount($mailbox, 'ALL');

			if (!$msg_count) {
			return 0;
			}

			$cleared = $this->conn->clearFolder($mailbox);

			// make sure the message count cache is cleared as well
			if ($cleared) {
			$this->clear_message_cache($mailbox.'.msg');
			$a_mailbox_cache = $this->get_cache('messagecount');
			unset($a_mailbox_cache[$mailbox]);
			$this->update_cache('messagecount', $a_mailbox_cache);
			}

			return $cleared;
			}


			/**
			* Send IMAP expunge command and clear cache
			*
			* @param string Mailbox name
			* @param boolean False if cache should not be cleared
			* @return boolean True on success
			*/
			function expunge($mbox_name='', $clear_cache=true)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_expunge($mailbox, $clear_cache);
			}


			/**
			* Send IMAP expunge command and clear cache
			*
			* @param string Mailbox name
			* @param boolean False if cache should not be cleared
			* @param mixed Message UIDs as array or comma-separated string, or '*'
			* @return boolean True on success
			* @access private
			* @see rcube_imap::expunge()
			*/
			private function _expunge($mailbox, $clear_cache=true, $uids=NULL)
			{
			if ($uids && $this->get_capability('UIDPLUS'))
			$a_uids = is_array($uids) ? join(',', $uids) : $uids;
			else
			$a_uids = NULL;

			$result = $this->conn->expunge($mailbox, $a_uids);

			if ($result>=0 && $clear_cache) {
			$this->clear_message_cache($mailbox.'.msg');
			$this->_clear_messagecount($mailbox);
			}

			return $result;
			}


			/**
			* Parse message UIDs input
			*
			* @param mixed UIDs array or comma-separated list or '' or '1:'
			* @param string Mailbox name
			* @return array Two elements array with UIDs converted to list and ALL flag
			* @access private
			*/
			private function _parse_uids($uids, $mailbox)
			{
			if ($uids === '' \|\| $uids === '1:') {
			if (empty($this->search_set)) {
			$uids = '1:*';
			$all = true;
			}
			// get UIDs from current search set
			// @TODO: skip fetchUIDs() and work with IDs instead of UIDs (?)
			else {
			if ($this->search_threads)
			$uids = $this->conn->fetchUIDs($mailbox, array_keys($this->search_set['depth']));
			else
			$uids = $this->conn->fetchUIDs($mailbox, $this->search_set);

			// save ID-to-UID mapping in local cache
			if (is_array($uids))
			foreach ($uids as $id => $uid)
			$this->uid_id_map[$mailbox][$uid] = $id;

			$uids = join(',', $uids);
			}
			}
			else {
			if (is_array($uids))
			$uids = join(',', $uids);

			if (preg_match('/[^0-9,]/', $uids))
			$uids = '';
			}

			return array($uids, (bool) $all);
			}


			/**
			* Translate UID to message ID
			*
			* @param int Message UID
			* @param string Mailbox name
			* @return int Message ID
			*/
			function get_id($uid, $mbox_name=NULL)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_uid2id($uid, $mailbox);
			}


			/**
			* Translate message number to UID
			*
			* @param int Message ID
			* @param string Mailbox name
			* @return int Message UID
			*/
			function get_uid($id,$mbox_name=NULL)
			{
			$mailbox = $mbox_name ? $this->mod_mailbox($mbox_name) : $this->mailbox;
			return $this->_id2uid($id, $mailbox);
			}



			/* --------------------------------
			* folder managment
			* --------------------------------*/

			/**
			* Public method for listing subscribed folders
			*
			* Converts mailbox name with root dir first
			*
			* @param string Optional root folder
			* @param string Optional filter for mailbox listing
			* @return array List of mailboxes/folders
			* @access public
			*/
			function list_mailboxes($root='', $filter='*')
			{
			$a_out = array();
			$a_mboxes = $this->_list_mailboxes($root, $filter);

			foreach ($a_mboxes as $idx => $mbox_row) {
			if ($name = $this->mod_mailbox($mbox_row, 'out'))
			$a_out[] = $name;
			unset($a_mboxes[$idx]);
			}

			// INBOX should always be available
			if (!in_array('INBOX', $a_out))
			array_unshift($a_out, 'INBOX');

			// sort mailboxes
			$a_out = $this->_sort_mailbox_list($a_out);

			return $a_out;
			}


			/**
			* Private method for mailbox listing
			*
			* @return array List of mailboxes/folders
			* @see rcube_imap::list_mailboxes()
			* @access private
			*/
			private function _list_mailboxes($root='', $filter='*')
			{
			// get cached folder list
			$a_mboxes = $this->get_cache('mailboxes');
			if (is_array($a_mboxes))
			return $a_mboxes;

			$a_defaults = $a_out = array();

			// Give plugins a chance to provide a list of mailboxes
			$data = rcmail::get_instance()->plugins->exec_hook('list_mailboxes',
			array('root' => $root, 'filter' => $filter, 'mode' => 'LSUB'));

			if (isset($data['folders'])) {
			$a_folders = $data['folders'];
			}
			else {
			// retrieve list of folders from IMAP server
			$a_folders = $this->conn->listSubscribed($this->mod_mailbox($root), $filter);
			}

			if (!is_array($a_folders) \|\| !sizeof($a_folders))
			$a_folders = array();

			// write mailboxlist to cache
			$this->update_cache('mailboxes', $a_folders);

			return $a_folders;
			}


			/**
			* Get a list of all folders available on the IMAP server
			*
			* @param string IMAP root dir
			* @param string Optional filter for mailbox listing
			* @return array Indexed array with folder names
			*/
			function list_unsubscribed($root='', $filter='*')
			{
			// Give plugins a chance to provide a list of mailboxes
			$data = rcmail::get_instance()->plugins->exec_hook('list_mailboxes',
			array('root' => $root, 'filter' => $filter, 'mode' => 'LIST'));

			if (isset($data['folders'])) {
			$a_mboxes = $data['folders'];
			}
			else {
			// retrieve list of folders from IMAP server
			$a_mboxes = $this->conn->listMailboxes($this->mod_mailbox($root), $filter);
			}

			if (empty($result[$key]['name']))
			$result[$key]['name'] = $result[$key]['address'];
			elseif (empty($result[$key]['address']))
			$result[$key]['address'] = $result[$key]['name'];
			}

			return $result;
			$a_folders = array();
			if (!is_array($a_mboxes))
			$a_mboxes = array();

			// modify names with root dir
			foreach ($a_mboxes as $idx => $mbox_name) {
			if ($name = $this->mod_mailbox($mbox_name, 'out'))
			$a_folders[] = $name;
			unset($a_mboxes[$idx]);
			}

			// INBOX should always be available
			if (!in_array('INBOX', $a_folders))
			array_unshift($a_folders, 'INBOX');

			// filter folders and sort them
			$a_folders = $this->_sort_mailbox_list($a_folders);
			return $a_folders;
			}


			/**
			* Get mailbox quota information
			* added by Nuny
			*
			* @return mixed Quota info or False if not supported
			*/
			function get_quota()
			{
			if ($this->get_capability('QUOTA'))
			return $this->conn->getQuota();

			return false;
			}


			/**
			* Subscribe to a specific mailbox(es)
			*
			* @param array Mailbox name(s)
			* @return boolean True on success
			*/
			function subscribe($a_mboxes)
			{
			if (!is_array($a_mboxes))
			$a_mboxes = array($a_mboxes);

			// let this common function do the main work
			return $this->_change_subscription($a_mboxes, 'subscribe');
			}


			/**
			* Unsubscribe mailboxes
			*
			* @param array Mailbox name(s)
			* @return boolean True on success
			*/
			function unsubscribe($a_mboxes)
			{
			if (!is_array($a_mboxes))
			$a_mboxes = array($a_mboxes);

			// let this common function do the main work
			return $this->_change_subscription($a_mboxes, 'unsubscribe');
			}


			/**
			* Create a new mailbox on the server and register it in local cache
			*
			* @param string New mailbox name (as utf-7 string)
			* @param boolean True if the new mailbox should be subscribed
			* @param string Name of the created mailbox, false on error
			*/
			function create_mailbox($name, $subscribe=false)
			{
			$result = false;

			// reduce mailbox name to 100 chars
			$name = substr($name, 0, 100);
			$abs_name = $this->mod_mailbox($name);
			$result = $this->conn->createFolder($abs_name);

			// try to subscribe it
			if ($result && $subscribe)
			$this->subscribe($name);

			return $result ? $name : false;
			}


			/**
			* Set a new name to an existing mailbox
			*
			* @param string Mailbox to rename (as utf-7 string)
			* @param string New mailbox name (as utf-7 string)
			* @return string Name of the renames mailbox, False on error
			*/
			function rename_mailbox($mbox_name, $new_name)
			{
			$result = false;

			// encode mailbox name and reduce it to 100 chars
			$name = substr($new_name, 0, 100);

			// make absolute path
			$mailbox = $this->mod_mailbox($mbox_name);
			$abs_name = $this->mod_mailbox($name);

			// check if mailbox is subscribed
			$a_subscribed = $this->_list_mailboxes();
			$subscribed = in_array($mailbox, $a_subscribed);

			// unsubscribe folder
			if ($subscribed)
			$this->conn->unsubscribe($mailbox);

			if (strlen($abs_name))
			$result = $this->conn->renameFolder($mailbox, $abs_name);

			if ($result) {
			$delm = $this->get_hierarchy_delimiter();

			// check if mailbox children are subscribed
			foreach ($a_subscribed as $c_subscribed)
			if (preg_match('/^'.preg_quote($mailbox.$delm, '/').'/', $c_subscribed)) {
			$this->conn->unsubscribe($c_subscribed);
			$this->conn->subscribe(preg_replace('/^'.preg_quote($mailbox, '/').'/',
			$abs_name, $c_subscribed));
			}

			// clear cache
			$this->clear_message_cache($mailbox.'.msg');
			$this->clear_cache('mailboxes');
			}

			// try to subscribe it
			if ($result && $subscribed)
			$this->conn->subscribe($abs_name);

			return $result ? $name : false;
			}


			/**
			* Remove mailboxes from server
			*
			* @param string Mailbox name(s) string/array
			* @return boolean True on success
			*/
			function delete_mailbox($mbox_name)
			{
			$deleted = false;

			if (is_array($mbox_name))
			$a_mboxes = $mbox_name;
			else if (is_string($mbox_name) && strlen($mbox_name))
			$a_mboxes = explode(',', $mbox_name);

			if (is_array($a_mboxes)) {
			foreach ($a_mboxes as $mbox_name) {
			$mailbox = $this->mod_mailbox($mbox_name);
			$sub_mboxes = $this->conn->listMailboxes($this->mod_mailbox(''),
			$mbox_name . $this->delimiter . '*');

			// unsubscribe mailbox before deleting
			$this->conn->unsubscribe($mailbox);

			// send delete command to server
			$result = $this->conn->deleteFolder($mailbox);
			if ($result) {
			$deleted = true;
			$this->clear_message_cache($mailbox.'.msg');
			}

			foreach ($sub_mboxes as $c_mbox) {
			if ($c_mbox != 'INBOX') {
			$this->conn->unsubscribe($c_mbox);
			$result = $this->conn->deleteFolder($c_mbox);
			if ($result) {
			$deleted = true;
			$this->clear_message_cache($c_mbox.'.msg');
			}
			}
			}
			}
			}

			// clear mailboxlist cache
			if ($deleted)
			$this->clear_cache('mailboxes');

			return $deleted;
			}


			/**
			* Create all folders specified as default
			*/
			function create_default_folders()
			{
			// create default folders if they do not exist
			foreach ($this->default_folders as $folder) {
			if (!$this->mailbox_exists($folder))
			$this->create_mailbox($folder, true);
			else if (!$this->mailbox_exists($folder, true))
			$this->subscribe($folder);
			}
			}


			/**
			* Checks if folder exists and is subscribed
			*
			* @param string Folder name
			* @param boolean Enable subscription checking
			* @return boolean TRUE or FALSE
			*/
			function mailbox_exists($mbox_name, $subscription=false)
			{
			if ($mbox_name) {
			if ($mbox_name == 'INBOX')
			return true;

			$key = $subscription ? 'subscribed' : 'existing';
			if (is_array($this->icache[$key]) && in_array($mbox_name, $this->icache[$key]))
			return true;

			if ($subscription) {
			$a_folders = $this->conn->listSubscribed($this->mod_mailbox(''), $mbox_name);
			}
			else {
			$a_folders = $this->conn->listMailboxes($this->mod_mailbox(''), $mbox_name);
			}

			if (is_array($a_folders) && in_array($this->mod_mailbox($mbox_name), $a_folders)) {
			$this->icache[$key][] = $mbox_name;
			return true;
			}
			}

			return false;
			}


			/**
			* Modify folder name for input/output according to root dir and namespace
			*
			* @param string Folder name
			* @param string Mode
			* @return string Folder name
			*/
			function mod_mailbox($mbox_name, $mode='in')
			{
			if ($mbox_name == 'INBOX')
			return $mbox_name;

			if (!empty($this->root_dir)) {
			if ($mode=='in')
			$mbox_name = $this->root_dir.$this->delimiter.$mbox_name;
			else if (!empty($mbox_name)) // $mode=='out'
			$mbox_name = substr($mbox_name, strlen($this->root_dir)+1);
			}

			return $mbox_name;
			}


			/* --------------------------------
			* internal caching methods
			* --------------------------------*/

			/**
			* @access public
			*/
			function set_caching($set)
			{
			if ($set && is_object($this->db))
			$this->caching_enabled = true;
			else
			$this->caching_enabled = false;
			}

			/**
			* @access public
			*/
			function get_cache($key)
			{
			// read cache (if it was not read before)
			if (!count($this->cache) && $this->caching_enabled) {
			return $this->_read_cache_record($key);
			}

			return $this->cache[$key];
			}

			/**
			* @access private
			*/
			private function update_cache($key, $data)
			{
			$this->cache[$key] = $data;
			$this->cache_changed = true;
			$this->cache_changes[$key] = true;
			}

			/**
			* @access private
			*/
			private function write_cache()
			{
			if ($this->caching_enabled && $this->cache_changed) {
			foreach ($this->cache as $key => $data) {
			if ($this->cache_changes[$key])
			$this->_write_cache_record($key, serialize($data));
			}
			}
			}

			/**
			* @access public
			*/
			function clear_cache($key=NULL)
			{
			if (!$this->caching_enabled)
			return;

			if ($key===NULL) {
			foreach ($this->cache as $key => $data)
			$this->_clear_cache_record($key);

			$this->cache = array();
			$this->cache_changed = false;
			$this->cache_changes = array();
			}
			else {
			$this->_clear_cache_record($key);
			$this->cache_changes[$key] = false;
			unset($this->cache[$key]);
			}
			}

			/**
			* @access private
			*/
			private function _read_cache_record($key)
			{
			if ($this->db) {
			// get cached data from DB
			$sql_result = $this->db->query(
			"SELECT cache_id, data, cache_key ".
			"FROM ".get_table_name('cache').
			" WHERE user_id=? ".
			"AND cache_key LIKE 'IMAP.%'",
			$_SESSION['user_id']);

			while ($sql_arr = $this->db->fetch_assoc($sql_result)) {
			$sql_key = preg_replace('/^IMAP\./', '', $sql_arr['cache_key']);
			$this->cache_keys[$sql_key] = $sql_arr['cache_id'];
			if (!isset($this->cache[$sql_key]))
			$this->cache[$sql_key] = $sql_arr['data'] ? unserialize($sql_arr['data']) : false;
			}
			}

			return $this->cache[$key];
			}

			/**
			* @access private
			*/
			private function _write_cache_record($key, $data)
			{
			if (!$this->db)
			return false;

			// update existing cache record
			if ($this->cache_keys[$key]) {
			$this->db->query(
			"UPDATE ".get_table_name('cache').
			" SET created=". $this->db->now().", data=? ".
			"WHERE user_id=? ".
			"AND cache_key=?",
			$data,
			$_SESSION['user_id'],
			'IMAP.'.$key);
			}
			// add new cache record
			else {
			$this->db->query(
			"INSERT INTO ".get_table_name('cache').
			" (created, user_id, cache_key, data) ".
			"VALUES (".$this->db->now().", ?, ?, ?)",
			$_SESSION['user_id'],
			'IMAP.'.$key,
			$data);

			// get cache entry ID for this key
			$sql_result = $this->db->query(
			"SELECT cache_id ".
			"FROM ".get_table_name('cache').
			" WHERE user_id=? ".
			"AND cache_key=?",
			$_SESSION['user_id'],
			'IMAP.'.$key);

			if ($sql_arr = $this->db->fetch_assoc($sql_result))
			$this->cache_keys[$key] = $sql_arr['cache_id'];
			}
			}

			/**
			* @access private
			*/
			private function _clear_cache_record($key)
			{
			$this->db->query(
			"DELETE FROM ".get_table_name('cache').
			" WHERE user_id=? ".
			"AND cache_key=?",
			$_SESSION['user_id'],
			'IMAP.'.$key);

			unset($this->cache_keys[$key]);
			}



			/* --------------------------------
			* message caching methods
			* --------------------------------*/

			/**
			* Checks if the cache is up-to-date
			*
			* @param string Mailbox name
			* @param string Internal cache key
			* @return int Cache status: -3 = off, -2 = incomplete, -1 = dirty, 1 = OK
			*/
			private function check_cache_status($mailbox, $cache_key)
			{
			if (!$this->caching_enabled)
			return -3;

			$cache_index = $this->get_message_cache_index($cache_key);
			$msg_count = $this->_messagecount($mailbox);
			$cache_count = count($cache_index);

			// empty mailbox
			if (!$msg_count)
			return $cache_count ? -2 : 1;

			// @TODO: We've got one big performance problem in cache status checking method
			// E.g. mailbox contains 1000 messages, in cache table we've got first 100
			// of them. Now if we want to display only that 100 (which we've got)
			// check_cache_status returns 'incomplete' and messages are fetched
			// from IMAP instead of DB.

			if ($cache_count==$msg_count) {
			if ($this->skip_deleted) {
			$h_index = $this->conn->fetchHeaderIndex($mailbox, "1:*", 'UID', $this->skip_deleted);

			if (empty($h_index))
			return -2;

			if (sizeof($h_index) == $cache_count) {
			$cache_index = array_flip($cache_index);
			foreach ($h_index as $idx => $uid)
			unset($cache_index[$uid]);

			if (empty($cache_index))
			return 1;
			}
			return -2;
			} else {
			// get UID of message with highest index
			$uid = $this->conn->ID2UID($mailbox, $msg_count);
			$cache_uid = array_pop($cache_index);

			// uids of highest message matches -> cache seems OK
			if ($cache_uid == $uid)
			return 1;
			}
			// cache is dirty
			return -1;
			}
			// if cache count differs less than 10% report as dirty
			else if (abs($msg_count - $cache_count) < $msg_count/10)
			return -1;
			else
			return -2;
			}

			/**
			* @access private
			*/
			private function get_message_cache($key, $from, $to, $sort_field, $sort_order)
			{
			$cache_key = "$key:$from:$to:$sort_field:$sort_order";

			// use idx sort as default sorting
			if (!$sort_field \|\| !in_array($sort_field, $this->db_header_fields)) {
			$sort_field = 'idx';
			}

			if ($this->caching_enabled && !isset($this->cache[$cache_key])) {
			$this->cache[$cache_key] = array();
			$sql_result = $this->db->limitquery(
			"SELECT idx, uid, headers".
			" FROM ".get_table_name('messages').
			" WHERE user_id=?".
			" AND cache_key=?".
			" ORDER BY ".$this->db->quoteIdentifier($sort_field)." ".strtoupper($sort_order),
			$from,
			$to - $from,
			$_SESSION['user_id'],
			$key);

			while ($sql_arr = $this->db->fetch_assoc($sql_result)) {
			$uid = $sql_arr['uid'];
			$this->cache[$cache_key][$uid] = $this->db->decode(unserialize($sql_arr['headers']));

			// featch headers if unserialize failed
			if (empty($this->cache[$cache_key][$uid]))
			$this->cache[$cache_key][$uid] = $this->conn->fetchHeader(
			preg_replace('/.msg$/', '', $key), $uid, true, $this->fetch_add_headers);
			}
			}

			return $this->cache[$cache_key];
			}

			/**
			* @access private
			*/
			private function &get_cached_message($key, $uid)
			{
			$internal_key = 'message';

			if ($this->caching_enabled && !isset($this->icache[$internal_key][$uid])) {
			$sql_result = $this->db->query(
			"SELECT idx, headers, structure".
			" FROM ".get_table_name('messages').
			" WHERE user_id=?".
			" AND cache_key=?".
			" AND uid=?",
			$_SESSION['user_id'],
			$key,
			$uid);

			if ($sql_arr = $this->db->fetch_assoc($sql_result)) {
			$this->uid_id_map[preg_replace('/\.msg$/', '', $key)][$uid] = $sql_arr['idx'];
			$this->icache[$internal_key][$uid] = $this->db->decode(unserialize($sql_arr['headers']));
			if (is_object($this->icache[$internal_key][$uid]) && !empty($sql_arr['structure']))
			$this->icache[$internal_key][$uid]->structure = $this->db->decode(unserialize($sql_arr['structure']));
			}
			}

			return $this->icache[$internal_key][$uid];
			}

			/**
			* @access private
			*/
			private function get_message_cache_index($key, $force=false, $sort_field='idx', $sort_order='ASC')
			{
			static $sa_message_index = array();

			// empty key -> empty array
			if (!$this->caching_enabled \|\| empty($key))
			return array();

			if (!empty($sa_message_index[$key]) && !$force)
			return $sa_message_index[$key];

			// use idx sort as default
			if (!$sort_field \|\| !in_array($sort_field, $this->db_header_fields))
			$sort_field = 'idx';

			$sa_message_index[$key] = array();
			$sql_result = $this->db->query(
			"SELECT idx, uid".
			" FROM ".get_table_name('messages').
			" WHERE user_id=?".
			" AND cache_key=?".
			" ORDER BY ".$this->db->quote_identifier($sort_field)." ".$sort_order,
			$_SESSION['user_id'],
			$key);

			while ($sql_arr = $this->db->fetch_assoc($sql_result))
			$sa_message_index[$key][$sql_arr['idx']] = $sql_arr['uid'];

			return $sa_message_index[$key];
			}

			/**
			* @access private
			*/
			private function add_message_cache($key, $index, $headers, $struct=null, $force=false)
			{
			if (empty($key) \|\| !is_object($headers) \|\| empty($headers->uid))
			return;

			// add to internal (fast) cache
			$this->icache['message'][$headers->uid] = clone $headers;
			$this->icache['message'][$headers->uid]->structure = $struct;

			// no further caching
			if (!$this->caching_enabled)
			return;

			// check for an existing record (probably headers are cached but structure not)
			if (!$force) {
			$sql_result = $this->db->query(
			"SELECT message_id".
			" FROM ".get_table_name('messages').
			" WHERE user_id=?".
			" AND cache_key=?".
			" AND uid=?",
			$_SESSION['user_id'],
			$key,
			$headers->uid);

			if ($sql_arr = $this->db->fetch_assoc($sql_result))
			$message_id = $sql_arr['message_id'];
			}

			// update cache record
			if ($message_id) {
			$this->db->query(
			"UPDATE ".get_table_name('messages').
			" SET idx=?, headers=?, structure=?".
			" WHERE message_id=?",
			$index,
			serialize($this->db->encode(clone $headers)),
			is_object($struct) ? serialize($this->db->encode(clone $struct)) : NULL,
			$message_id
			);
			}
			else { // insert new record
			$this->db->query(
			"INSERT INTO ".get_table_name('messages').
			" (user_id, del, cache_key, created, idx, uid, subject, ".
			$this->db->quoteIdentifier('from').", ".
			$this->db->quoteIdentifier('to').", ".
			"cc, date, size, headers, structure)".
			" VALUES (?, 0, ?, ".$this->db->now().", ?, ?, ?, ?, ?, ?, ".
			$this->db->fromunixtime($headers->timestamp).", ?, ?, ?)",
			$_SESSION['user_id'],
			$key,
			$index,
			$headers->uid,
			(string)mb_substr($this->db->encode($this->decode_header($headers->subject, true)), 0, 128),
			(string)mb_substr($this->db->encode($this->decode_header($headers->from, true)), 0, 128),
			(string)mb_substr($this->db->encode($this->decode_header($headers->to, true)), 0, 128),
			(string)mb_substr($this->db->encode($this->decode_header($headers->cc, true)), 0, 128),
			(int)$headers->size,
			serialize($this->db->encode(clone $headers)),
			is_object($struct) ? serialize($this->db->encode(clone $struct)) : NULL
			);
			}
			}

			/**
			* @access private
			*/
			private function remove_message_cache($key, $ids, $idx=false)
			{
			if (!$this->caching_enabled)
			return;

			$this->db->query(
			"DELETE FROM ".get_table_name('messages').
			" WHERE user_id=?".
			" AND cache_key=?".
			" AND ".($idx ? "idx" : "uid")." IN (".$this->db->array2list($ids, 'integer').")",
			$_SESSION['user_id'],
			$key);
			}

			/**
			* @access private
			*/
			private function clear_message_cache($key, $start_index=1)
			{
			if (!$this->caching_enabled)
			return;

			$this->db->query(
			"DELETE FROM ".get_table_name('messages').
			" WHERE user_id=?".
			" AND cache_key=?".
			" AND idx>=?",
			$_SESSION['user_id'], $key, $start_index);
			}

			/**
			* @access private
			*/
			private function get_message_cache_index_min($key, $uids=NULL)
			{
			if (!$this->caching_enabled)
			return;

			if (!empty($uids) && !is_array($uids)) {
			if ($uids == '' \|\| $uids == '1:')
			$uids = NULL;
			else
			$uids = explode(',', $uids);
			}

			$sql_result = $this->db->query(
			"SELECT MIN(idx) AS minidx".
			" FROM ".get_table_name('messages').
			" WHERE user_id=?".
			" AND cache_key=?"
			.(!empty($uids) ? " AND uid IN (".$this->db->array2list($uids, 'integer').")" : ''),
			$_SESSION['user_id'],
			$key);

			if ($sql_arr = $this->db->fetch_assoc($sql_result))
			return $sql_arr['minidx'];
			else
			return 0;
			}


			/* --------------------------------
			* encoding/decoding methods
			* --------------------------------*/

			/**
			* Split an address list into a structured array list
			*
			* @param string Input string
			* @param int List only this number of addresses
			* @param boolean Decode address strings
			* @return array Indexed list of addresses
			*/
			function decode_address_list($input, $max=null, $decode=true)
			{
			$a = $this->_parse_address_list($input, $decode);
			$out = array();
			// Special chars as defined by RFC 822 need to in quoted string (or escaped).
			$special_chars = '[\<\>\\\.\[\]@,;:"]';

			if (!is_array($a))
			return $out;

			$c = count($a);
			$j = 0;

			foreach ($a as $val) {
			$j++;
			$address = trim($val['address']);
			$name = trim($val['name']);

			if (preg_match('/^[\'"]/', $name) && preg_match('/[\'"]$/', $name))
			$name = preg_replace(array('/^[\'"]/', '/[\'"]$/'), '', $name);

			if ($name && $address && $name != $address)
			$string = sprintf('%s <%s>', preg_match("/$special_chars/", $name) ? '"'.addcslashes($name, '"').'"' : $name, $address);
			else if ($address)
			$string = $address;
			else if ($name)
			$string = $name;

			$out[$j] = array('name' => $name,
			'mailto' => $address,
			'string' => $string
			);

			if ($max && $j==$max)
			break;
			}

			return $out;
			}


			/**
			* Decode a Microsoft Outlook TNEF part (winmail.dat)
			*
			* @param object rcube_message_part Message part to decode
			* @param string UID of the message
			* @return array List of rcube_message_parts extracted from windmail.dat
			*/
			function tnef_decode(&$part, $uid)
			{
			if (!isset($part->body))
			$part->body = $this->get_message_part($uid, $part->mime_id, $part);

			require_once('lib/tnef_decoder.inc');

			$pid = 0;
			$tnef_parts = array();
			$tnef_arr = tnef_decode($part->body);

			foreach ($tnef_arr as $winatt) {
			$tpart = new rcube_message_part;
			$tpart->filename = trim($winatt['name']);
			$tpart->encoding = 'stream';
			$tpart->ctype_primary = trim(strtolower($winatt['type0']));
			$tpart->ctype_secondary = trim(strtolower($winatt['type1']));
			$tpart->mimetype = $tpart->ctype_primary . '/' . $tpart->ctype_secondary;
			$tpart->mime_id = "winmail." . $part->mime_id . ".$pid";
			$tpart->size = $winatt['size'];
			$tpart->body = $winatt['stream'];

			$tnef_parts[] = $tpart;
			$pid++;
			}

			return $tnef_parts;
			}


			/**
			* Decode a message header value
			*
			* @param string Header value
			* @param boolean Remove quotes if necessary
			* @return string Decoded string
			*/
			function decode_header($input, $remove_quotes=false)
			{
			$str = rcube_imap::decode_mime_string((string)$input, $this->default_charset);
			if ($str{0}=='"' && $remove_quotes)
			$str = str_replace('"', '', $str);

			return $str;
			}


			/**
			* Decode a mime-encoded string to internal charset
			*
			* @param string $input Header value
			* @param string $fallback Fallback charset if none specified
			*
			* @return string Decoded string
			* @static
			*/
			public static function decode_mime_string($input, $fallback=null)
			{
			// Initialize variable
			$out = '';

			// Iterate instead of recursing, this way if there are too many values we don't have stack overflows
			// rfc: all line breaks or other characters not found
			// in the Base64 Alphabet must be ignored by decoding software
			// delete all blanks between MIME-lines, differently we can
			// receive unnecessary blanks and broken utf-8 symbols
			$input = preg_replace("/\?=\s+=\?/", '?==?', $input);

			// Check if there is stuff to decode
			if (strpos($input, '=?') !== false) {
			// Loop through the string to decode all occurences of =? ?= into the variable $out
			while(($pos = strpos($input, '=?')) !== false) {
			// Append everything that is before the text to be decoded
			$out .= substr($input, 0, $pos);

			// Get the location of the text to decode
			$end_cs_pos = strpos($input, "?", $pos+2);
			$end_en_pos = strpos($input, "?", $end_cs_pos+1);
			$end_pos = strpos($input, "?=", $end_en_pos+1);

			// Extract the encoded string
			$encstr = substr($input, $pos+2, ($end_pos-$pos-2));
			// Extract the remaining string
			$input = substr($input, $end_pos+2);

			// Decode the string fragement
			$out .= rcube_imap::_decode_mime_string_part($encstr);
			}

			// Deocde the rest (if any)
			if (strlen($input) != 0)
			$out .= rcube_imap::decode_mime_string($input, $fallback);

			// return the results
			return $out;
			}

			// no encoding information, use fallback
			return rcube_charset_convert($input,
			!empty($fallback) ? $fallback : rcmail::get_instance()->config->get('default_charset', 'ISO-8859-1'));
			}


			/**
			* Decode a part of a mime-encoded string
			*
			* @access private
			*/
			private function _decode_mime_string_part($str)
			{
			$a = explode('?', $str);
			$count = count($a);

			// should be in format "charset?encoding?base64_string"
			if ($count >= 3) {
			for ($i=2; $i<$count; $i++)
			$rest .= $a[$i];

			if (($a[1]=='B') \|\| ($a[1]=='b'))
			$rest = base64_decode($rest);
			else if (($a[1]=='Q') \|\| ($a[1]=='q')) {
			$rest = str_replace('_', ' ', $rest);
			$rest = quoted_printable_decode($rest);
			}

			return rcube_charset_convert($rest, $a[0]);
			}

			// we dont' know what to do with this
			return $str;
			}


			/**
			* Decode a mime part
			*
			* @param string Input string
			* @param string Part encoding
			* @return string Decoded string
			*/
			function mime_decode($input, $encoding='7bit')
			{
			switch (strtolower($encoding)) {
			case 'quoted-printable':
			return quoted_printable_decode($input);
			case 'base64':
			return base64_decode($input);
			case 'x-uuencode':
			case 'x-uue':
			case 'uue':
			case 'uuencode':
			return convert_uudecode($input);
			case '7bit':
			default:
			return $input;
			}
			}


			/**
			* Convert body charset to RCMAIL_CHARSET according to the ctype_parameters
			*
			* @param string Part body to decode
			* @param string Charset to convert from
			* @return string Content converted to internal charset
			*/
			function charset_decode($body, $ctype_param)
			{
			if (is_array($ctype_param) && !empty($ctype_param['charset']))
			return rcube_charset_convert($body, $ctype_param['charset']);

			// defaults to what is specified in the class header
			return rcube_charset_convert($body, $this->default_charset);
			}


			/* --------------------------------
			* private methods
			* --------------------------------*/

			/**
			* Validate the given input and save to local properties
			* @access private
			*/
			private function _set_sort_order($sort_field, $sort_order)
			{
			if ($sort_field != null)
			$this->sort_field = asciiwords($sort_field);
			if ($sort_order != null)
			$this->sort_order = strtoupper($sort_order) == 'DESC' ? 'DESC' : 'ASC';
			}

			/**
			* Sort mailboxes first by default folders and then in alphabethical order
			* @access private
			*/
			private function _sort_mailbox_list($a_folders)
			{
			$a_out = $a_defaults = $folders = array();

			$delimiter = $this->get_hierarchy_delimiter();

			// find default folders and skip folders starting with '.'
			foreach ($a_folders as $i => $folder) {
			if ($folder[0] == '.')
			continue;

			if (($p = array_search($folder, $this->default_folders)) !== false && !$a_defaults[$p])
			$a_defaults[$p] = $folder;
			else
			$folders[$folder] = rcube_charset_convert($folder, 'UTF7-IMAP');
			}

			// sort folders and place defaults on the top
			asort($folders, SORT_LOCALE_STRING);
			ksort($a_defaults);
			$folders = array_merge($a_defaults, array_keys($folders));

			// finally we must rebuild the list to move
			// subfolders of default folders to their place...
			// ...also do this for the rest of folders because
			// asort() is not properly sorting case sensitive names
			while (list($key, $folder) = each($folders)) {
			// set the type of folder name variable (#1485527)
			$a_out[] = (string) $folder;
			unset($folders[$key]);
			$this->_rsort($folder, $delimiter, $folders, $a_out);
			}

			return $a_out;
			}


			/**
			* @access private
			*/
			private function _rsort($folder, $delimiter, &$list, &$out)
			{
			while (list($key, $name) = each($list)) {
			if (strpos($name, $folder.$delimiter) === 0) {
			// set the type of folder name variable (#1485527)
			$out[] = (string) $name;
			unset($list[$key]);
			$this->_rsort($name, $delimiter, $list, $out);
			}
			}
			reset($list);
			}


			/**
			* @access private
			*/
			private function _uid2id($uid, $mbox_name=NULL)
			{
			if (!$mbox_name)
			$mbox_name = $this->mailbox;

			if (!isset($this->uid_id_map[$mbox_name][$uid]))
			$this->uid_id_map[$mbox_name][$uid] = $this->conn->UID2ID($mbox_name, $uid);

			return $this->uid_id_map[$mbox_name][$uid];
			}

			/**
			* @access private
			*/
			private function _id2uid($id, $mbox_name=NULL)
			{
			if (!$mbox_name)
			$mbox_name = $this->mailbox;

			if ($uid = array_search($id, (array)$this->uid_id_map[$mbox_name]))
			return $uid;

			$uid = $this->conn->ID2UID($mbox_name, $id);
			$this->uid_id_map[$mbox_name][$uid] = $id;

			return $uid;
			}


			/**
			* Subscribe/unsubscribe a list of mailboxes and update local cache
			* @access private
			*/
			private function _change_subscription($a_mboxes, $mode)
			{
			$updated = false;

			if (is_array($a_mboxes))
			foreach ($a_mboxes as $i => $mbox_name) {
			$mailbox = $this->mod_mailbox($mbox_name);
			$a_mboxes[$i] = $mailbox;

			if ($mode=='subscribe')
			$updated = $this->conn->subscribe($mailbox);
			else if ($mode=='unsubscribe')
			$updated = $this->conn->unsubscribe($mailbox);
			}

			// get cached mailbox list
			if ($updated) {
			$a_mailbox_cache = $this->get_cache('mailboxes');
			if (!is_array($a_mailbox_cache))
			return $updated;

			// modify cached list
			if ($mode=='subscribe')
			$a_mailbox_cache = array_merge($a_mailbox_cache, $a_mboxes);
			else if ($mode=='unsubscribe')
			$a_mailbox_cache = array_diff($a_mailbox_cache, $a_mboxes);

			// write mailboxlist to cache
			$this->update_cache('mailboxes', $this->_sort_mailbox_list($a_mailbox_cache));
			}

			return $updated;
			}


			/**
			* Increde/decrese messagecount for a specific mailbox
			* @access private
			*/
			private function _set_messagecount($mbox_name, $mode, $increment)
			{
			$a_mailbox_cache = false;
			$mailbox = $mbox_name ? $mbox_name : $this->mailbox;
			$mode = strtoupper($mode);

			$a_mailbox_cache = $this->get_cache('messagecount');

			if (!is_array($a_mailbox_cache[$mailbox]) \|\| !isset($a_mailbox_cache[$mailbox][$mode]) \|\| !is_numeric($increment))
			return false;

			// add incremental value to messagecount
			$a_mailbox_cache[$mailbox][$mode] += $increment;

			// there's something wrong, delete from cache
			if ($a_mailbox_cache[$mailbox][$mode] < 0)
			unset($a_mailbox_cache[$mailbox][$mode]);

			// write back to cache
			$this->update_cache('messagecount', $a_mailbox_cache);

			return true;
			}


			/**
			* Remove messagecount of a specific mailbox from cache
			* @access private
			*/
			private function _clear_messagecount($mbox_name='')
			{
			$a_mailbox_cache = false;
			$mailbox = $mbox_name ? $mbox_name : $this->mailbox;

			$a_mailbox_cache = $this->get_cache('messagecount');

			if (is_array($a_mailbox_cache[$mailbox])) {
			unset($a_mailbox_cache[$mailbox]);
			$this->update_cache('messagecount', $a_mailbox_cache);
			}
			}


			/**
			* Split RFC822 header string into an associative array
			* @access private
			*/
			private function _parse_headers($headers)
			{
			$a_headers = array();
			$headers = preg_replace('/\r?\n(\t\| )+/', ' ', $headers);
			$lines = explode("\n", $headers);
			$c = count($lines);

			for ($i=0; $i<$c; $i++) {
			if ($p = strpos($lines[$i], ': ')) {
			$field = strtolower(substr($lines[$i], 0, $p));
			$value = trim(substr($lines[$i], $p+1));
			if (!empty($value))
			$a_headers[$field] = $value;
			}
			}

			return $a_headers;
			}


			/**
			* @access private
			*/
			private function _parse_address_list($str, $decode=true)
			{
			// remove any newlines and carriage returns before
			$a = rcube_explode_quoted_string('[,;]', preg_replace( "/[\r\n]/", " ", $str));
			$result = array();

			foreach ($a as $key => $val) {
			$val = preg_replace("/([\"\w])</", "$1 <", $val);
			$sub_a = rcube_explode_quoted_string(' ', $decode ? $this->decode_header($val) : $val);
			$result[$key]['name'] = '';

			foreach ($sub_a as $k => $v) {
			// use angle brackets in regexp to not handle names with @ sign
			if (preg_match('/^<\S+@\S+>$/', $v))
			$result[$key]['address'] = trim($v, '<>');
			else
			$result[$key]['name'] .= (empty($result[$key]['name'])?'':' ').str_replace("\"",'',stripslashes($v));
			}

			if (empty($result[$key]['name']))
			$result[$key]['name'] = $result[$key]['address'];
			elseif (empty($result[$key]['address']))
			$result[$key]['address'] = $result[$key]['name'];
			}

			return $result;
			}

			} // end class rcube_imap
			@@ -3172,80 +3822,80 @@
			*/
			class rcube_message_part
			{
			var $mime_id = '';
			var $ctype_primary = 'text';
			var $ctype_secondary = 'plain';
			var $mimetype = 'text/plain';
			var $disposition = '';
			var $filename = '';
			var $encoding = '8bit';
			var $charset = '';
			var $size = 0;
			var $headers = array();
			var $d_parameters = array();
			var $ctype_parameters = array();
			var $mime_id = '';
			var $ctype_primary = 'text';
			var $ctype_secondary = 'plain';
			var $mimetype = 'text/plain';
			var $disposition = '';
			var $filename = '';
			var $encoding = '8bit';
			var $charset = '';
			var $size = 0;
			var $headers = array();
			var $d_parameters = array();
			var $ctype_parameters = array();

			function __clone()
			{
			if (isset($this->parts))
			foreach ($this->parts as $idx => $part)
			if (is_object($part))
			$this->parts[$idx] = clone $part;
			}
			function __clone()
			{
			if (isset($this->parts))
			foreach ($this->parts as $idx => $part)
			if (is_object($part))
			$this->parts[$idx] = clone $part;
			}
			}


			/**
			* Class for sorting an array of iilBasicHeader objects in a predetermined order.
			* Class for sorting an array of rcube_mail_header objects in a predetermined order.
			*
			* @package Mail
			* @author Eric Stadtherr
			*/
			class rcube_header_sorter
			{
			var $sequence_numbers = array();

			/**
			* Set the predetermined sort order.
			*
			* @param array Numerically indexed array of IMAP message sequence numbers
			*/
			function set_sequence_numbers($seqnums)
			{
			$this->sequence_numbers = array_flip($seqnums);
			}

			/**
			* Sort the array of header objects
			*
			* @param array Array of iilBasicHeader objects indexed by UID
			*/
			function sort_headers(&$headers)
			{
			/*
			* uksort would work if the keys were the sequence number, but unfortunately
			* the keys are the UIDs. We'll use uasort instead and dereference the value
			* to get the sequence number (in the "id" field).
			*
			* uksort($headers, array($this, "compare_seqnums"));
			*/
			uasort($headers, array($this, "compare_seqnums"));
			}

			/**
			* Sort method called by uasort()
			*/
			function compare_seqnums($a, $b)
			{
			// First get the sequence number from the header object (the 'id' field).
			$seqa = $a->id;
			$seqb = $b->id;

			// then find each sequence number in my ordered list
			$posa = isset($this->sequence_numbers[$seqa]) ? intval($this->sequence_numbers[$seqa]) : -1;
			$posb = isset($this->sequence_numbers[$seqb]) ? intval($this->sequence_numbers[$seqb]) : -1;

			// return the relative position as the comparison value
			return $posa - $posb;
			}
			var $sequence_numbers = array();

			/**
			* Set the predetermined sort order.
			*
			* @param array Numerically indexed array of IMAP message sequence numbers
			*/
			function set_sequence_numbers($seqnums)
			{
			$this->sequence_numbers = array_flip($seqnums);
			}

			/**
			* Sort the array of header objects
			*
			* @param array Array of rcube_mail_header objects indexed by UID
			*/
			function sort_headers(&$headers)
			{
			/*
			* uksort would work if the keys were the sequence number, but unfortunately
			* the keys are the UIDs. We'll use uasort instead and dereference the value
			* to get the sequence number (in the "id" field).
			*
			* uksort($headers, array($this, "compare_seqnums"));
			*/
			uasort($headers, array($this, "compare_seqnums"));
			}

			/**
			* Sort method called by uasort()
			*/
			function compare_seqnums($a, $b)
			{
			// First get the sequence number from the header object (the 'id' field).
			$seqa = $a->id;
			$seqb = $b->id;

			// then find each sequence number in my ordered list
			$posa = isset($this->sequence_numbers[$seqa]) ? intval($this->sequence_numbers[$seqa]) : -1;
			$posb = isset($this->sequence_numbers[$seqb]) ? intval($this->sequence_numbers[$seqb]) : -1;

			// return the relative position as the comparison value
			return $posa - $posb;
			}
			}