githubFork/roundcubemail.git

			@@ -5,7 +5,8 @@
			\| program/include/rcube_imap.php \|
			\| \|
			\| This file is part of the Roundcube Webmail client \|
			\| Copyright (C) 2005-2010, The Roundcube Dev Team \|
			\| Copyright (C) 2005-2011, The Roundcube Dev Team \|
			\| Copyright (C) 2011, Kolab Systems AG \|
			\| Licensed under the GNU GPL \|
			\| \|
			\| PURPOSE: \|
			@@ -31,7 +32,6 @@
			*/
			class rcube_imap
			{
			public $debug_level = 1;
			public $skip_deleted = false;
			public $page_size = 10;
			public $list_page = 1;
			@@ -47,11 +47,11 @@
			public $conn;

			/**
			* Instance of rcube_mdb2
			* Instance of rcube_imap_cache
			*
			* @var rcube_mdb2
			* @var rcube_imap_cache
			*/
			private $db;
			private $mcache;

			/**
			* Instance of rcube_cache
			@@ -59,6 +59,14 @@
			* @var rcube_cache
			*/
			private $cache;

			/**
			* Internal (in-memory) cache
			*
			* @var array
			*/
			private $icache = array();

			private $mailbox = 'INBOX';
			private $delimiter = NULL;
			private $namespace = NULL;
			@@ -67,8 +75,6 @@
			private $default_charset = 'ISO-8859-1';
			private $struct_charset = NULL;
			private $default_folders = array('INBOX');
			private $messages_caching = false;
			private $icache = array();
			private $uid_id_map = array();
			private $msg_headers = array();
			public $search_set = NULL;
			@@ -77,10 +83,10 @@
			private $search_sort_field = '';
			private $search_threads = false;
			private $search_sorted = 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;
			private $caching = false;
			private $messages_caching = false;

			/**
			* All (additional) headers used (in any way) by Roundcube
			@@ -96,7 +102,6 @@
			'MESSAGE-ID',
			'CONTENT-TRANSFER-ENCODING',
			'REFERENCES',
			'X-PRIORITY',
			'X-DRAFT-INFO',
			'MAIL-FOLLOWUP-TO',
			'MAIL-REPLY-TO',
			@@ -170,12 +175,13 @@
			$attempt = 0;
			do {
			$data = rcmail::get_instance()->plugins->exec_hook('imap_connect',
			array('host' => $host, 'user' => $user, 'attempt' => ++$attempt));
			array_merge($this->options, array('host' => $host, 'user' => $user,
			'attempt' => ++$attempt)));

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

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

			$this->host = $data['host'];
			@@ -214,6 +220,8 @@
			function close()
			{
			$this->conn->closeConnection();
			if ($this->mcache)
			$this->mcache->close();
			}


			@@ -305,6 +313,19 @@
			function set_options($opt)
			{
			$this->options = array_merge($this->options, (array)$opt);
			}


			/**
			* Activate/deactivate debug mode
			*
			* @param boolean $dbg True if IMAP conversation should be logged
			* @access public
			*/
			function set_debug($dbg = true)
			{
			$this->options['debug'] = $dbg;
			$this->conn->setDebug($dbg, array($this, 'debug_handler'));
			}


			@@ -418,7 +439,7 @@
			function set_search_set($str=null, $msgs=null, $charset=null, $sort_field=null, $threads=false, $sorted=false)
			{
			if (is_array($str) && $msgs == null)
			list($str, $msgs, $charset, $sort_field, $threads) = $str;
			list($str, $msgs, $charset, $sort_field, $threads, $sorted) = $str;
			if ($msgs === false)
			$msgs = array();
			else if ($msgs != null && !is_array($msgs))
			@@ -457,7 +478,7 @@
			*/
			function get_mailbox_name()
			{
			return $this->conn->connected() ? $this->mailbox : '';
			return $this->mailbox;
			}


			@@ -689,7 +710,7 @@

			if ($status) {
			$this->set_folder_stats($mailbox, 'cnt', $res['msgcount']);
			$this->set_folder_stats($mailbox, 'maxuid', $res['maxuid'] ? $this->_id2uid($res['maxuid'], $mailbox) : 0);
			$this->set_folder_stats($mailbox, 'maxuid', $res['maxuid'] ? $this->id2uid($res['maxuid'], $mailbox) : 0);
			}
			}
			// RECENT count is fetched a bit different
			@@ -722,9 +743,9 @@
			$count = is_array($index) ? $index['COUNT'] : 0;

			if ($mode == 'ALL') {
			if ($need_uid && $this->messages_caching) {
			// Save messages index for check_cache_status()
			$this->icache['all_undeleted_idx'] = $index['ALL'];
			if ($this->messages_caching) {
			// Save additional info required by cache status check
			$this->icache['undeleted_idx'] = array($mailbox, $index['ALL'], $index['COUNT']);
			}
			if ($status) {
			$this->set_folder_stats($mailbox, 'cnt', $count);
			@@ -739,7 +760,7 @@
			$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);
			$this->set_folder_stats($mailbox, 'maxuid', $count ? $this->id2uid($count, $mailbox) : 0);
			}
			}
			}
			@@ -774,7 +795,7 @@
			'maxuid' => $dcount ? max(array_keys($this->icache['threads']['depth'])) : 0,
			);
			}
			else if (is_array($result = $this->_fetch_threads($mailbox))) {
			else if (is_array($result = $this->fetch_threads($mailbox))) {
			$dcount = count($result[1]);
			$result = array(
			'count' => count($result[0]),
			@@ -805,7 +826,7 @@
			$mailbox = $this->mailbox;
			}

			return $this->_list_headers($mailbox, $page, $sort_field, $sort_order, false, $slice);
			return $this->_list_headers($mailbox, $page, $sort_field, $sort_order, $slice);
			}


			@@ -817,11 +838,11 @@
			* @param string $sort_field Header field to sort by
			* @param string $sort_order Sort order [ASC\|DESC]
			* @param int $slice Number of slice items to extract from result array
			*
			* @return array Indexed array with message header objects
			* @access private
			* @see rcube_imap::list_headers
			*/
			private function _list_headers($mailbox='', $page=NULL, $sort_field=NULL, $sort_order=NULL, $recursive=false, $slice=0)
			private function _list_headers($mailbox='', $page=NULL, $sort_field=NULL, $sort_order=NULL, $slice=0)
			{
			if (!strlen($mailbox))
			return array();
			@@ -831,41 +852,39 @@
			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);
			return $this->_list_thread_headers($mailbox, $page, $sort_field, $sort_order, $slice);

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

			$page = $page ? $page : $this->list_page;
			$cache_key = $mailbox.'.msg';
			$page = $page ? $page : $this->list_page;

			if ($this->messages_caching) {
			// cache is OK, we can get messages from local cache
			// (assume cache is in sync when in recursive mode)
			if ($recursive \|\| $this->check_cache_status($mailbox, $cache_key)>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 $result;
			}
			// cache is incomplete, sync it (all messages in the folder)
			else if (!$recursive) {
			$this->sync_header_index($mailbox);
			return $this->_list_headers($mailbox, $page, $this->sort_field, $this->sort_order, true, $slice);
			}
			// Use messages cache
			if ($mcache = $this->get_mcache_engine()) {
			$msg_index = $mcache->get_index($mailbox, $this->sort_field, $this->sort_order);

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

			$from = ($page-1) * $this->page_size;
			$to = $from + $this->page_size;
			$msg_index = array_values($msg_index); // UIDs
			$is_uid = true;
			$sorted = true;

			if ($from \|\| $to)
			$msg_index = array_slice($msg_index, $from, $to - $from);

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

			$a_msg_headers = $mcache->get_messages($mailbox, $msg_index);
			}

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

			// use message index sort as default sorting (for better performance)
			if (!$this->sort_field) {
			else if (!$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);
			}
			@@ -882,30 +901,32 @@

			// fetch reqested headers from server
			if ($msg_index)
			$this->_fetch_headers($mailbox, join(",", $msg_index), $a_msg_headers, $cache_key);
			$a_msg_headers = $this->fetch_headers($mailbox, $msg_index);
			}
			// use SORT command
			else if ($this->get_capability('SORT') &&
			// Courier-IMAP provides SORT capability but allows to disable it by admin (#1486959)
			($msg_index = $this->conn->sort($mailbox, $this->sort_field, $this->skip_deleted ? 'UNDELETED' : '')) !== false
			($msg_index = $this->conn->sort($mailbox, $this->sort_field,
			$this->skip_deleted ? 'UNDELETED' : '', true)) !== false
			) {
			if (!empty($msg_index)) {
			list($begin, $end) = $this->_get_message_range(count($msg_index), $page);
			$max = max($msg_index);
			$msg_index = array_slice($msg_index, $begin, $end-$begin);
			$is_uid = true;

			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);
			$a_msg_headers = $this->fetch_headers($mailbox, $msg_index, true);
			}
			}
			// fetch specified header for all messages and sort
			else if ($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);
			else if ($msg_index = $this->conn->fetchHeaderIndex($mailbox, "1:*",
			$this->sort_field, $this->skip_deleted)
			) {
			asort($msg_index); // ASC
			$msg_index = array_keys($msg_index);
			list($begin, $end) = $this->_get_message_range(count($msg_index), $page);
			$msg_index = array_slice($msg_index, $begin, $end-$begin);

			@@ -913,15 +934,8 @@
			$msg_index = array_slice($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);
			$a_msg_headers = $this->fetch_headers($mailbox, $msg_index);
			}

			// 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))
			@@ -929,10 +943,10 @@

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

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

			return array_values($a_msg_headers);
			@@ -946,27 +960,28 @@
			* @param int $page Current page to list
			* @param string $sort_field Header field to sort by
			* @param string $sort_order Sort order [ASC\|DESC]
			* @param boolean $recursive True if called recursively
			* @param int $slice Number of slice items to extract from result array
			*
			* @return array Indexed array with message header objects
			* @access private
			* @see rcube_imap::list_headers
			*/
			private function _list_thread_headers($mailbox, $page=NULL, $sort_field=NULL, $sort_order=NULL, $recursive=false, $slice=0)
			private function _list_thread_headers($mailbox, $page=NULL, $sort_field=NULL, $sort_order=NULL, $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);
			$page = $page ? $page : $this->list_page;
			$mcache = $this->get_mcache_engine();

			// get all threads (default sort order)
			list ($thread_tree, $msg_depth, $has_children) = $this->_fetch_threads($mailbox);
			// get all threads (not sorted)
			if ($mcache)
			list ($thread_tree, $msg_depth, $has_children) = $mcache->get_thread($mailbox);
			else
			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);
			$msg_index = $this->sort_threads($mailbox, $thread_tree);

			return $this->_fetch_thread_headers($mailbox,
			$thread_tree, $msg_depth, $has_children, $msg_index, $page, $slice);
			@@ -974,14 +989,20 @@


			/**
			* Private method for fetching threads data
			* Method for fetching threads data
			*
			* @param string $mailbox Mailbox/folder name
			* @param string $mailbox Folder name
			* @param bool $force Use IMAP server, no cache
			*
			* @return array Array with thread data
			* @access private
			*/
			private function _fetch_threads($mailbox)
			function fetch_threads($mailbox, $force = false)
			{
			if (!$force && ($mcache = $this->get_mcache_engine())) {
			// don't store in self's internal cache, cache has it's own internal cache
			return $mcache->get_thread($mailbox);
			}

			if (empty($this->icache['threads'])) {
			// get all threads
			$result = $this->conn->thread($mailbox, $this->threading,
			@@ -1012,12 +1033,12 @@
			* @param array $msg_index Messages index
			* @param int $page List page number
			* @param int $slice Number of threads to slice
			*
			* @return array Messages headers
			* @access private
			*/
			private function _fetch_thread_headers($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);
			@@ -1038,7 +1059,7 @@
			}

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

			// return empty array if no messages found
			if (!is_array($a_msg_headers) \|\| empty($a_msg_headers))
			@@ -1046,7 +1067,7 @@

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

			// Set depth, has_children and unread_children fields in headers
			@@ -1077,7 +1098,7 @@

			if (!empty($parents)) {
			$headers[$idx]->parent_uid = end($parents);
			if (!$header->seen)
			if (empty($header->flags['SEEN']))
			$headers[$parents[0]]->unread_children++;
			}
			array_push($parents, $header->uid);
			@@ -1135,11 +1156,11 @@
			$msgs = array_slice($msgs, -$slice, $slice);

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

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

			return array_values($a_msg_headers);
			@@ -1165,10 +1186,10 @@
			$msgs = array_slice($msgs, -$slice, $slice);

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

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

			return array_values($a_msg_headers);
			@@ -1184,21 +1205,22 @@
			if ($slice)
			$msgs = array_slice($msgs, -$slice, $slice);
			// ...and fetch headers
			$this->_fetch_headers($mailbox, join(',', $msgs), $a_msg_headers, NULL);
			$a_msg_headers = $this->fetch_headers($mailbox, $msgs);


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

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

			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);
			$a_msg_headers = $this->fetch_headers($mailbox, $msgs);

			// return empty array if no messages found
			if (!is_array($a_msg_headers) \|\| empty($a_msg_headers))
			@@ -1256,7 +1278,7 @@

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

			$msg_index = $this->_sort_threads($mailbox, $thread_tree, array_keys($msg_depth));
			$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);
			@@ -1297,64 +1319,37 @@


			/**
			* Fetches message headers (used for loop)
			* Fetches messages headers
			*
			* @param string $mailbox Mailbox name
			* @param string $msgs Message index to fetch
			* @param array $a_msg_headers Reference to message headers array
			* @param string $cache_key Cache index key
			* @return int Messages count
			* @param string $mailbox Mailbox name
			* @param array $msgs Messages sequence numbers
			* @param bool $is_uid Enable if $msgs numbers are UIDs
			* @param bool $force Disables cache use
			*
			* @return array Messages headers indexed by UID
			* @access private
			*/
			private function _fetch_headers($mailbox, $msgs, &$a_msg_headers, $cache_key)
			function fetch_headers($mailbox, $msgs, $is_uid = false, $force = false)
			{
			if (empty($msgs))
			return array();

			if (!$force && ($mcache = $this->get_mcache_engine())) {
			return $mcache->get_messages($mailbox, $msgs, $is_uid);
			}

			// fetch reqested headers from server
			$a_header_index = $this->conn->fetchHeaders(
			$mailbox, $msgs, false, false, $this->get_fetch_headers());
			$index = $this->conn->fetchHeaders(
			$mailbox, $msgs, $is_uid, false, $this->get_fetch_headers());

			if (empty($a_header_index))
			return 0;
			if (empty($index))
			return array();

			foreach ($a_header_index as $i => $headers) {
			foreach ($index as $headers) {
			$a_msg_headers[$headers->uid] = $headers;
			}

			// Update cache
			if ($this->messages_caching && $cache_key) {
			// cache is incomplete?
			$cache_index = $this->get_message_cache_index($cache_key);

			foreach ($a_header_index as $headers) {
			// message in cache
			if ($cache_index[$headers->id] == $headers->uid) {
			unset($cache_index[$headers->id]);
			continue;
			}
			// wrong UID at this position
			if ($cache_index[$headers->id]) {
			$for_remove[] = $cache_index[$headers->id];
			unset($cache_index[$headers->id]);
			}
			// message UID in cache but at wrong position
			if (is_int($key = array_search($headers->uid, $cache_index))) {
			$for_remove[] = $cache_index[$key];
			unset($cache_index[$key]);
			}

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

			if ($for_remove)
			$this->remove_message_cache($cache_key, $for_remove);

			// add messages to cache
			foreach ((array)$for_create as $uid) {
			$headers = $a_msg_headers[$uid];
			$this->add_message_cache($cache_key, $headers->id, $headers, NULL, true);
			}
			}

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


			@@ -1378,6 +1373,11 @@
			$this->_messagecount($mailbox, 'ALL', true);

			$result = 0;

			if (empty($old)) {
			return $result;
			}

			$new = $this->get_folder_stats($mailbox);

			// got new messages
			@@ -1471,7 +1471,7 @@
			}
			else {
			$a_index = $this->conn->fetchHeaderIndex($mailbox,
			join(',', $this->search_set), $this->sort_field, $this->skip_deleted);
			join(',', $this->search_set), $this->sort_field, $this->skip_deleted);

			if (is_array($a_index)) {
			if ($this->sort_order=="ASC")
			@@ -1492,50 +1492,65 @@
			return $this->icache[$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,
			$this->sort_field, $this->sort_order);
			return array_keys($a_index);
			if ($mcache = $this->get_mcache_engine()) {
			$a_index = $mcache->get_index($mailbox, $this->sort_field, $this->sort_order);
			$this->icache[$key] = array_keys($a_index);
			}
			// fetch from IMAP server
			else {
			$this->icache[$key] = $this->message_index_direct(
			$mailbox, $this->sort_field, $this->sort_order);
			}

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


			/**
			* Return sorted array of message IDs (not UIDs) directly from IMAP server.
			* Doesn't use cache and ignores current search settings.
			*
			* @param string $mailbox Mailbox to get index from
			* @param string $sort_field Sort column
			* @param string $sort_order Sort order [ASC, DESC]
			*
			* @return array Indexed array with message IDs
			*/
			function message_index_direct($mailbox, $sort_field = null, $sort_order = null)
			{
			// use message index sort as default sorting
			if (!$this->sort_field) {
			if (!$sort_field) {
			if ($this->skip_deleted) {
			$a_index = $this->_search_index($mailbox, 'ALL');
			} else if ($max = $this->_messagecount($mailbox)) {
			$a_index = $this->conn->search($mailbox, 'ALL UNDELETED');
			// I didn't found that SEARCH should return sorted IDs
			if (is_array($a_index))
			sort($a_index);
			} else if ($max = $this->_messagecount($mailbox, 'ALL', true, false)) {
			$a_index = range(1, $max);
			}

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

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

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

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

			return $this->icache[$key] !== false ? $this->icache[$key] : array();
			return $a_index !== false ? $a_index : array();
			}


			@@ -1567,19 +1582,9 @@
			// have stored it in RAM
			if (isset($this->icache[$key]))
			return $this->icache[$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, $this->sort_field, $this->sort_order);
			return array_keys($a_index);
			}
			*/
			// get all threads (default sort order)
			list ($thread_tree) = $this->_fetch_threads($mailbox);
			list ($thread_tree) = $this->fetch_threads($mailbox);

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

			@@ -1591,7 +1596,7 @@
			* Return array of threaded messages (all, not only roots)
			*
			* @param string $mailbox Mailbox to get index from
			* @param array $thread_tree Threaded messages array (see _fetch_threads())
			* @param array $thread_tree Threaded messages array (see fetch_threads())
			* @param array $ids Message IDs if we know what we need (e.g. search result)
			* for better performance
			* @return array Indexed array with message IDs
			@@ -1603,7 +1608,7 @@
			if (empty($thread_tree))
			return array();

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

			if ($this->sort_order == 'DESC')
			$msg_index = array_reverse($msg_index);
			@@ -1619,99 +1624,6 @@
			}

			return $all_ids;
			}


			/**
			* @param string $mailbox Mailbox name
			* @access private
			*/
			private function sync_header_index($mailbox)
			{
			$cache_key = $mailbox.'.msg';
			$cache_index = $this->get_message_cache_index($cache_key);
			$chunk_size = 1000;

			// cache is empty, get all messages
			if (is_array($cache_index) && empty($cache_index)) {
			$max = $this->_messagecount($mailbox);
			// syncing a big folder maybe slow
			@set_time_limit(0);
			$start = 1;
			$end = min($chunk_size, $max);
			while (true) {
			// do this in loop to save memory (1000 msgs ~= 10 MB)
			if ($headers = $this->conn->fetchHeaders($mailbox,
			"$start:$end", false, false, $this->get_fetch_headers())
			) {
			foreach ($headers as $header) {
			$this->add_message_cache($cache_key, $header->id, $header, NULL, true);
			}
			}
			if ($end - $start < $chunk_size - 1)
			break;

			$end = min($end+$chunk_size, $max);
			$start += $chunk_size;
			}
			return;
			}

			// fetch complete message index
			if (isset($this->icache['folder_index']))
			$a_message_index = &$this->icache['folder_index'];
			else
			$a_message_index = $this->conn->fetchHeaderIndex($mailbox, "1:*", 'UID', $this->skip_deleted);

			if ($a_message_index === false \|\| $cache_index === null)
			return;

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

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

			// message in cache but at wrong position
			if (is_int($key = array_search($uid, $cache_index))) {
			$for_remove[] = $uid;
			unset($cache_index[$key]);
			}

			$for_update[] = $id;
			}

			// remove 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)) {
			// syncing a big folder maybe slow
			@set_time_limit(0);
			// To save memory do this in chunks
			$for_update = array_chunk($for_update, $chunk_size);
			foreach ($for_update as $uids) {
			if ($headers = $this->conn->fetchHeaders($mailbox,
			$uids, false, false, $this->get_fetch_headers())
			) {
			foreach ($headers as $header) {
			$this->add_message_cache($cache_key, $header->id, $header, NULL, true);
			}
			}
			}
			}
			}


			@@ -1750,8 +1662,8 @@
			* @param string $criteria Search criteria
			* @param string $charset Charset
			* @param string $sort_field Sorting field
			*
			* @return array search results as list of message ids
			* @access private
			* @see rcube_imap::search()
			*/
			private function _search_index($mailbox, $criteria='ALL', $charset=NULL, $sort_field=NULL)
			@@ -1773,9 +1685,9 @@
			if ($a_messages !== false) {
			list ($thread_tree, $msg_depth, $has_children) = $a_messages;
			$a_messages = array(
			'tree' => $thread_tree,
			'depth' => $msg_depth,
			'children' => $has_children
			'tree' => $thread_tree,
			'depth'=> $msg_depth,
			'children' => $has_children
			);
			}

			@@ -1787,7 +1699,7 @@
			$a_messages = $this->conn->sort($mailbox, $sort_field, $criteria, false, $charset);

			// Error, try with US-ASCII (RFC5256: SORT/THREAD must support US-ASCII and UTF-8,
			// but I've seen that Courier doesn't support UTF-8)
			// but I've seen Courier with disabled UTF-8 support)
			if ($a_messages === false && $charset && $charset != 'US-ASCII')
			$a_messages = $this->conn->sort($mailbox, $sort_field,
			$this->convert_criteria($criteria, $charset), false, 'US-ASCII');
			@@ -1799,7 +1711,7 @@
			}

			if ($orig_criteria == 'ALL') {
			$max = $this->_messagecount($mailbox);
			$max = $this->_messagecount($mailbox, 'ALL', true, false);
			$a_messages = $max ? range(1, $max) : array();
			}
			else {
			@@ -1829,8 +1741,8 @@
			* @param string $mailbox Mailbox name to search in
			* @param string $str Search string
			* @param boolean $ret_uid True if UIDs should be returned
			*
			* @return array Search results as list of message IDs or UIDs
			* @access public
			*/
			function search_once($mailbox='', $str=NULL, $ret_uid=false)
			{
			@@ -1884,43 +1796,53 @@
			* @param string $mailbox Mailbox name
			* @param array $thread_tree Unsorted thread tree (rcube_imap_generic::thread() result)
			* @param array $ids Message IDs if we know what we need (e.g. search result)
			*
			* @return array Sorted roots IDs
			* @access private
			*/
			private function _sort_threads($mailbox, $thread_tree, $ids=NULL)
			function sort_threads($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
			// 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' && $this->threading != 'REFS')
			}
			// here we'll implement REFS sorting
			else {
			if ($mcache = $this->get_mcache_engine()) {
			$a_index = $mcache->get_index($mailbox, $this->sort_field, 'ASC');
			if (is_array($a_index)) {
			$a_index = array_keys($a_index);
			// now we must remove IDs that doesn't exist in $ids
			if (!empty($ids))
			$a_index = array_intersect($a_index, $ids);
			}
			}
			// use SORT command
			if ($this->get_capability('SORT') &&
			else if ($this->get_capability('SORT') &&
			($a_index = $this->conn->sort($mailbox, $this->sort_field,
			!empty($ids) ? $ids : ($this->skip_deleted ? 'UNDELETED' : ''))) !== false
			!empty($ids) ? $ids : ($this->skip_deleted ? 'UNDELETED' : ''))) !== false
			) {
			// return unsorted tree if we've got no index data
			if (!$a_index)
			return array_keys((array)$thread_tree);
			// do nothing
			}
			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);
			$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 unsorted tree if we've got no index data
			if (!empty($a_index)) {
			asort($a_index); // ASC
			$a_index = array_values($a_index);
			}
			}

			return $this->_sort_thread_refs($thread_tree, $a_index);
			if (empty($a_index))
			return array_keys((array)$thread_tree);

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

			@@ -1928,10 +1850,10 @@
			/**
			* THREAD=REFS sorting implementation
			*
			* @param array $tree Thread tree array (message identifiers as keys)
			* @param array $index Array of sorted message identifiers
			* @param array $tree Thread tree array (message identifiers as keys)
			* @param array $index Array of sorted message identifiers
			*
			* @return array Array of sorted roots messages
			* @access private
			*/
			private function _sort_thread_refs($tree, $index)
			{
			@@ -1980,7 +1902,7 @@
			{
			if (!empty($this->search_string))
			$this->search_set = $this->search('', $this->search_string, $this->search_charset,
			$this->search_sort_field, $this->search_threads, $this->search_sorted);
			$this->search_sort_field, $this->search_threads, $this->search_sorted);

			return $this->get_search_set();
			}
			@@ -2008,32 +1930,25 @@
			/**
			* Return message headers object of a specific message
			*
			* @param int $id Message ID
			* @param int $id Message sequence ID or UID
			* @param string $mailbox Mailbox to read from
			* @param boolean $is_uid True if $id is the message UID
			* @param boolean $bodystr True if we need also BODYSTRUCTURE in headers
			* @return object Message headers representation
			* @param bool $force True to skip cache
			*
			* @return rcube_mail_header Message headers
			*/
			function get_headers($id, $mailbox=null, $is_uid=true, $bodystr=false)
			function get_headers($uid, $mailbox = null, $force = false)
			{
			if (!strlen($mailbox)) {
			$mailbox = $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->get_fetch_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, $headers, NULL, false, true);
			if (!$force && $uid && ($mcache = $this->get_mcache_engine())) {
			$headers = $mcache->get_message($mailbox, $uid);
			}
			else {
			$headers = $this->conn->fetchHeader(
			$mailbox, $uid, true, true, $this->get_fetch_headers());
			}

			return $headers;
			@@ -2041,33 +1956,47 @@


			/**
			* Fetch body structure from the IMAP server and build
			* Fetch message headers and body structure from the IMAP server and build
			* an object structure similar to the one generated by PEAR::Mail_mimeDecode
			*
			* @param int $uid Message UID to fetch
			* @param string $structure_str Message BODYSTRUCTURE string (optional)
			* @return object rcube_message_part Message part tree or False on failure
			* @param int $uid Message UID to fetch
			* @param string $mailbox Mailbox to read from
			*
			* @return object rcube_mail_header Message data
			*/
			function &get_structure($uid, $structure_str='')
			function get_message($uid, $mailbox = null)
			{
			$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 $headers->structure;
			if (!strlen($mailbox)) {
			$mailbox = $this->mailbox;
			}

			if (!$structure_str) {
			$structure_str = $this->conn->fetchStructureString($this->mailbox, $uid, true);
			// Check internal cache
			if (!empty($this->icache['message'])) {
			if (($headers = $this->icache['message']) && $headers->uid == $uid) {
			return $headers;
			}
			}
			$structure = rcube_mime_struct::parseStructure($structure_str);
			$struct = false;

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

			// message doesn't exist?
			if (empty($headers))
			return null;

			// structure might be cached
			if (!empty($headers->structure))
			return $headers;

			$this->_msg_uid = $uid;

			if (empty($headers->bodystructure)) {
			$headers->bodystructure = $this->conn->getStructure($mailbox, $uid, true);
			}

			$structure = $headers->bodystructure;

			if (empty($structure))
			return $headers;

			// set message charset from message headers
			if ($headers->charset)
			@@ -2090,26 +2019,21 @@
			$structure[1] = $m[2];
			}
			else
			return false;
			return $headers;
			}

			$struct = &$this->_structure_part($structure, 0, '', $headers);
			$struct->headers = get_object_vars($headers);

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

			// write structure to cache
			if ($this->messages_caching)
			$this->add_message_cache($cache_key, $this->_msg_id, $headers, $struct,
			$this->icache['message.id'][$uid], true);
			}
			$headers->structure = $struct;

			return $struct;
			return $this->icache['message'] = $headers;
			}


			@@ -2174,7 +2098,7 @@
			// headers for parts on all levels
			if ($mime_part_headers) {
			$mime_part_headers = $this->conn->fetchMIMEHeaders($this->mailbox,
			$this->_msg_id, $mime_part_headers);
			$this->_msg_uid, $mime_part_headers);
			}

			$struct->parts = array();
			@@ -2276,7 +2200,7 @@
			if ($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);
			$this->mailbox, $this->_msg_uid, true, $struct->mime_id);
			}

			if (is_string($mime_headers))
			@@ -2339,7 +2263,7 @@
			if ($i<2) {
			if (!$headers) {
			$headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $part->mime_id);
			$this->mailbox, $this->_msg_uid, true, $part->mime_id);
			}
			$filename_mime = '';
			$i = 0;
			@@ -2358,7 +2282,7 @@
			if ($i<2) {
			if (!$headers) {
			$headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $part->mime_id);
			$this->mailbox, $this->_msg_uid, true, $part->mime_id);
			}
			$filename_encoded = '';
			$i = 0; $matches = array();
			@@ -2377,7 +2301,7 @@
			if ($i<2) {
			if (!$headers) {
			$headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $part->mime_id);
			$this->mailbox, $this->_msg_uid, true, $part->mime_id);
			}
			$filename_mime = '';
			$i = 0; $matches = array();
			@@ -2396,7 +2320,7 @@
			if ($i<2) {
			if (!$headers) {
			$headers = $this->conn->fetchPartHeader(
			$this->mailbox, $this->_msg_id, false, $part->mime_id);
			$this->mailbox, $this->_msg_uid, true, $part->mime_id);
			}
			$filename_encoded = '';
			$i = 0; $matches = array();
			@@ -2417,9 +2341,14 @@

			// 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, $this->default_charset)));
			if (!empty($part->charset))
			$charset = $part->charset;
			else if (!empty($this->struct_charset))
			$charset = $this->struct_charset;
			else
			$charset = rc_detect_encoding($filename_mime, $this->default_charset);

			$part->filename = rcube_imap::decode_mime_string($filename_mime, $charset);
			}
			else if (!empty($filename_encoded)) {
			// decode filename according to RFC 2231, Section 4
			@@ -2427,6 +2356,7 @@
			$filename_charset = $fmatches[1];
			$filename_encoded = $fmatches[2];
			}

			$part->filename = rcube_charset_convert(urldecode($filename_encoded), $filename_charset);
			}
			}
			@@ -2463,42 +2393,42 @@
			*/
			function &get_message_part($uid, $part=1, $o_part=NULL, $print=NULL, $fp=NULL, $skip_charset_conv=false)
			{
			// get part encoding if not provided
			// get part data if not provided
			if (!is_object($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;
			}
			$structure = $this->conn->getStructure($this->mailbox, $uid, true);
			$part_data = rcube_imap_generic::getStructurePartData($structure, $part);

			$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);
			$o_part->ctype_primary = $part_data['type'];
			$o_part->encoding = $part_data['encoding'];
			$o_part->charset = $part_data['charset'];
			$o_part->size = $part_data['size'];
			}

			// TODO: Add caching for message parts

			if (!$part) {
			$part = 'TEXT';
			if ($o_part && $o_part->size) {
			$body = $this->conn->handlePartBody($this->mailbox, $uid, true,
			$part ? $part : 'TEXT', $o_part->encoding, $print, $fp);
			}

			$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 ($body && !$skip_charset_conv &&
			preg_match('/^(text\|message)$/', $o_part->ctype_primary)
			) {
			if (!$o_part->charset \|\| strtoupper($o_part->charset) == 'US-ASCII') {
			$o_part->charset = $this->default_charset;
			if ($body && preg_match('/^(text\|message)$/', $o_part->ctype_primary)) {
			// Remove NULL characters (#1486189)
			$body = str_replace("\x00", '', $body);

			if (!$skip_charset_conv) {
			if (!$o_part->charset \|\| strtoupper($o_part->charset) == 'US-ASCII') {
			// try to extract charset information from HTML meta tag (#1488125)
			if ($o_part->ctype_secondary == 'html' && preg_match('/<meta[^>]+charset=([a-z0-9-_]+)/i', $body, $m))
			$o_part->charset = strtoupper($m[1]);
			else
			$o_part->charset = $this->default_charset;
			}
			$body = rcube_charset_convert($body, $o_part->charset);
			}
			$body = rcube_charset_convert($body, $o_part->charset);
			}

			return $body;
			@@ -2584,12 +2514,12 @@

			if ($result) {
			// reload message headers if cached
			if ($this->messages_caching && !$skip_cache) {
			$cache_key = $mailbox.'.msg';
			if ($all_mode)
			$this->clear_message_cache($cache_key);
			else
			$this->remove_message_cache($cache_key, explode(',', $uids));
			// @TODO: update flags instead removing from cache
			if (!$skip_cache && ($mcache = $this->get_mcache_engine())) {
			$status = strpos($flag, 'UN') !== 0;
			$mflag = preg_replace('/^UN/', '', $flag);
			$mcache->change_flag($mailbox, $all_mode ? null : explode(',', $uids),
			$mflag, $status);
			}

			// clear cached counters
			@@ -2630,7 +2560,7 @@
			* @param string $headers Headers string if $message contains only the body
			* @param boolean $is_file True if $message is a filename
			*
			* @return boolean True on success, False on error
			* @return int\|bool Appended message UID or True on success, False on error
			*/
			function save_message($mailbox, &$message, $headers='', $is_file=false)
			{
			@@ -2681,10 +2611,14 @@

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

			$config = rcmail::get_instance()->config;
			@@ -2721,19 +2655,18 @@
			if ($this->search_threads \|\| $all_mode)
			$this->refresh_search();
			else {
			$uids = explode(',', $uids);
			foreach ($uids as $uid)
			$a_mids[] = $this->_uid2id($uid, $from_mbox);
			$a_uids = explode(',', $uids);
			foreach ($a_uids as $uid)
			$a_mids[] = $this->uid2id($uid, $from_mbox);
			$this->search_set = array_diff($this->search_set, $a_mids);
			}
			unset($a_mids);
			unset($a_uids);
			}

			// 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);
			}
			// remove cached messages
			// @TODO: do cache update instead of clearing it
			$this->clear_message_cache($from_mbox, $all_mode ? null : explode(',', $uids));
			}

			return $moved;
			@@ -2763,10 +2696,14 @@

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

			// copy messages
			@@ -2818,19 +2755,17 @@
			if ($this->search_threads \|\| $all_mode)
			$this->refresh_search();
			else {
			$uids = explode(',', $uids);
			foreach ($uids as $uid)
			$a_mids[] = $this->_uid2id($uid, $mailbox);
			$a_uids = explode(',', $uids);
			foreach ($a_uids as $uid)
			$a_mids[] = $this->uid2id($uid, $mailbox);
			$this->search_set = array_diff($this->search_set, $a_mids);
			unset($a_uids);
			unset($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);
			}
			// remove cached messages
			$this->clear_message_cache($mailbox, $all_mode ? null : explode(',', $uids));
			}

			return $deleted;
			@@ -2855,9 +2790,9 @@
			$cleared = $this->conn->clearFolder($mailbox);
			}

			// make sure the message count cache is cleared as well
			// make sure the cache is cleared as well
			if ($cleared) {
			$this->clear_message_cache($mailbox.'.msg');
			$this->clear_message_cache($mailbox);
			$a_mailbox_cache = $this->get_cache('messagecount');
			unset($a_mailbox_cache[$mailbox]);
			$this->update_cache('messagecount', $a_mailbox_cache);
			@@ -2898,9 +2833,9 @@
			private function _expunge($mailbox, $clear_cache=true, $uids=NULL)
			{
			if ($uids && $this->get_capability('UIDPLUS'))
			$a_uids = is_array($uids) ? join(',', $uids) : $uids;
			list($uids, $all_mode) = $this->_parse_uids($uids, $mailbox);
			else
			$a_uids = NULL;
			$uids = null;

			// force mailbox selection and check if mailbox is writeable
			// to prevent a situation when CLOSE is executed on closed
			@@ -2915,13 +2850,13 @@
			}

			// CLOSE(+SELECT) should be faster than EXPUNGE
			if (empty($a_uids) \|\| $a_uids == '1:*')
			if (empty($uids) \|\| $all_mode)
			$result = $this->conn->close();
			else
			$result = $this->conn->expunge($mailbox, $a_uids);
			$result = $this->conn->expunge($mailbox, $uids);

			if ($result && $clear_cache) {
			$this->clear_message_cache($mailbox.'.msg');
			$this->clear_message_cache($mailbox, $all_mode ? null : explode(',', $uids));
			$this->_clear_messagecount($mailbox);
			}

			@@ -2986,7 +2921,7 @@
			$mailbox = $this->mailbox;
			}

			return $this->_uid2id($uid, $mailbox);
			return $this->uid2id($uid, $mailbox);
			}


			@@ -3004,7 +2939,7 @@
			$mailbox = $this->mailbox;
			}

			return $this->_id2uid($id, $mailbox);
			return $this->id2uid($id, $mailbox);
			}


			@@ -3016,47 +2951,22 @@
			/**
			* Public method for listing subscribed folders
			*
			* @param string $root Optional root folder
			* @param string $name Optional name pattern
			* @param string $filter Optional filter
			* @param string $root Optional root folder
			* @param string $name Optional name pattern
			* @param string $filter Optional filter
			* @param string $rights Optional ACL requirements
			* @param bool $skip_sort Enable to return unsorted list (for better performance)
			*
			* @return array List of mailboxes/folders
			* @return array List of folders
			* @access public
			*/
			function list_mailboxes($root='', $name='*', $filter=null)
			{
			$a_mboxes = $this->_list_mailboxes($root, $name, $filter);

			// INBOX should always be available
			if ((!$filter \|\| $filter == 'mail') && !in_array('INBOX', $a_mboxes)) {
			array_unshift($a_mboxes, 'INBOX');
			}

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

			return $a_mboxes;
			}


			/**
			* Private method for mailbox listing
			*
			* @param string $root Optional root folder
			* @param string $name Optional name pattern
			* @param mixed $filter Optional filter
			*
			* @return array List of mailboxes/folders
			* @see rcube_imap::list_mailboxes()
			* @access private
			*/
			private function _list_mailboxes($root='', $name='*', $filter=null)
			function list_mailboxes($root='', $name='*', $filter=null, $rights=null, $skip_sort=false)
			{
			$cache_key = $root.':'.$name;
			if (!empty($filter)) {
			$cache_key .= ':'.(is_string($filter) ? $filter : serialize($filter));
			}

			$cache_key .= ':'.$rights;
			$cache_key = 'mailboxes.'.md5($cache_key);

			// get cached folder list
			@@ -3065,6 +2975,48 @@
			return $a_mboxes;
			}

			$a_mboxes = $this->_list_mailboxes($root, $name, $filter, $rights);

			if (!is_array($a_mboxes)) {
			return array();
			}

			// filter folders list according to rights requirements
			if ($rights && $this->get_capability('ACL')) {
			$a_mboxes = $this->filter_rights($a_mboxes, $rights);
			}

			// INBOX should always be available
			if ((!$filter \|\| $filter == 'mail') && !in_array('INBOX', $a_mboxes)) {
			array_unshift($a_mboxes, 'INBOX');
			}

			// sort mailboxes (always sort for cache)
			if (!$skip_sort \|\| $this->cache) {
			$a_mboxes = $this->_sort_mailbox_list($a_mboxes);
			}

			// write mailboxlist to cache
			$this->update_cache($cache_key, $a_mboxes);

			return $a_mboxes;
			}


			/**
			* Private method for mailbox listing (LSUB)
			*
			* @param string $root Optional root folder
			* @param string $name Optional name pattern
			* @param mixed $filter Optional filter
			* @param string $rights Optional ACL requirements
			*
			* @return array List of subscribed folders
			* @see rcube_imap::list_mailboxes()
			* @access private
			*/
			private function _list_mailboxes($root='', $name='*', $filter=null, $rights=null)
			{
			$a_defaults = $a_out = array();

			// Give plugins a chance to provide a list of mailboxes
			@@ -3073,6 +3025,9 @@

			if (isset($data['folders'])) {
			$a_folders = $data['folders'];
			}
			else if (!$this->conn->connected()) {
			return null;
			}
			else {
			// Server supports LIST-EXTENDED, we can use selection options
			@@ -3083,29 +3038,42 @@
			$a_folders = $this->conn->listMailboxes($root, $name,
			NULL, array('SUBSCRIBED'));

			// remove non-existent folders
			if (is_array($a_folders)) {
			// unsubscribe non-existent folders, remove from the list
			if (is_array($a_folders) && $name == '*') {
			foreach ($a_folders as $idx => $folder) {
			if ($this->conn->data['LIST'] && ($opts = $this->conn->data['LIST'][$folder])
			&& in_array('\\NonExistent', $opts)
			) {
			$this->conn->unsubscribe($folder);
			unset($a_folders[$idx]);
			}
			}
			}
			}
			}
			// retrieve list of folders from IMAP server using LSUB
			else {
			$a_folders = $this->conn->listSubscribed($root, $name);

			// unsubscribe non-existent folders, remove from the list
			if (is_array($a_folders) && $name == '*') {
			foreach ($a_folders as $idx => $folder) {
			if ($this->conn->data['LIST'] && ($opts = $this->conn->data['LIST'][$folder])
			&& in_array('\\Noselect', $opts)
			) {
			// Some servers returns \Noselect for existing folders
			if (!$this->mailbox_exists($folder)) {
			$this->conn->unsubscribe($folder);
			unset($a_folders[$idx]);
			}
			}
			}
			}
			}
			}

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

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

			return $a_folders;
			}
			@@ -3114,15 +3082,29 @@
			/**
			* Get a list of all folders available on the IMAP server
			*
			* @param string $root IMAP root dir
			* @param string $name Optional name pattern
			* @param mixed $filter Optional filter
			* @param string $root IMAP root dir
			* @param string $name Optional name pattern
			* @param mixed $filter Optional filter
			* @param string $rights Optional ACL requirements
			* @param bool $skip_sort Enable to return unsorted list (for better performance)
			*
			* @return array Indexed array with folder names
			*/
			function list_unsubscribed($root='', $name='*', $filter=null)
			function list_unsubscribed($root='', $name='*', $filter=null, $rights=null, $skip_sort=false)
			{
			// @TODO: caching
			$cache_key = $root.':'.$name;
			if (!empty($filter)) {
			$cache_key .= ':'.(is_string($filter) ? $filter : serialize($filter));
			}
			$cache_key .= ':'.$rights;
			$cache_key = 'mailboxes.list.'.md5($cache_key);

			// get cached folder list
			$a_mboxes = $this->get_cache($cache_key);
			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('mailboxes_list',
			array('root' => $root, 'name' => $name, 'filter' => $filter, 'mode' => 'LIST'));
			@@ -3132,7 +3114,7 @@
			}
			else {
			// retrieve list of folders from IMAP server
			$a_mboxes = $this->conn->listMailboxes($root, $name);
			$a_mboxes = $this->_list_unsubscribed($root, $name);
			}

			if (!is_array($a_mboxes)) {
			@@ -3144,10 +3126,105 @@
			array_unshift($a_mboxes, 'INBOX');
			}

			// cache folder attributes
			if ($root == '' && $name == '*' && empty($filter)) {
			$this->update_cache('mailboxes.attributes', $this->conn->data['LIST']);
			}

			// filter folders list according to rights requirements
			if ($rights && $this->get_capability('ACL')) {
			$a_folders = $this->filter_rights($a_folders, $rights);
			}

			// filter folders and sort them
			$a_mboxes = $this->_sort_mailbox_list($a_mboxes);
			if (!$skip_sort) {
			$a_mboxes = $this->_sort_mailbox_list($a_mboxes);
			}

			// write mailboxlist to cache
			$this->update_cache($cache_key, $a_mboxes);

			return $a_mboxes;
			}


			/**
			* Private method for mailbox listing (LIST)
			*
			* @param string $root Optional root folder
			* @param string $name Optional name pattern
			*
			* @return array List of folders
			* @see rcube_imap::list_unsubscribed()
			*/
			private function _list_unsubscribed($root='', $name='*')
			{
			$result = $this->conn->listMailboxes($root, $name);

			if (!is_array($result)) {
			return array();
			}

			// #1486796: some server configurations doesn't
			// return folders in all namespaces, we'll try to detect that situation
			// and ask for these namespaces separately
			if ($root == '' && $name == '*') {
			$delim = $this->get_hierarchy_delimiter();
			$namespace = $this->get_namespace();
			$search = array();

			// build list of namespace prefixes
			foreach ((array)$namespace as $ns) {
			if (is_array($ns)) {
			foreach ($ns as $ns_data) {
			if (strlen($ns_data[0])) {
			$search[] = $ns_data[0];
			}
			}
			}
			}

			if (!empty($search)) {
			// go through all folders detecting namespace usage
			foreach ($result as $folder) {
			foreach ($search as $idx => $prefix) {
			if (strpos($folder, $prefix) === 0) {
			unset($search[$idx]);
			}
			}
			if (empty($search)) {
			break;
			}
			}

			// get folders in hidden namespaces and add to the result
			foreach ($search as $prefix) {
			$list = $this->conn->listMailboxes($prefix, $name);

			if (!empty($list)) {
			$result = array_merge($result, $list);
			}
			}
			}
			}

			return $result;
			}


			/**
			* Filter the given list of folders according to access rights
			*/
			private function filter_rights($a_folders, $rights)
			{
			$regex = '/('.$rights.')/';
			foreach ($a_folders as $idx => $folder) {
			$myrights = join('', (array)$this->my_rights($folder));
			if ($myrights !== null && !preg_match($regex, $myrights))
			unset($a_folders[$idx]);
			}

			return $a_folders;
			}


			@@ -3283,11 +3360,14 @@
			$this->conn->unsubscribe($c_subscribed);
			$this->conn->subscribe(preg_replace('/^'.preg_quote($mailbox, '/').'/',
			$new_name, $c_subscribed));

			// clear cache
			$this->clear_message_cache($c_subscribed);
			}
			}

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

			@@ -3323,13 +3403,13 @@
			if (preg_match('/^'.preg_quote($mailbox.$delm, '/').'/', $c_mbox)) {
			$this->conn->unsubscribe($c_mbox);
			if ($this->conn->deleteFolder($c_mbox)) {
			$this->clear_message_cache($c_mbox.'.msg');
			$this->clear_message_cache($c_mbox);
			}
			}
			}

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

			@@ -3404,8 +3484,8 @@
			foreach ($this->namespace as $type => $namespace) {
			if (is_array($namespace)) {
			foreach ($namespace as $ns) {
			if (strlen($ns[0])) {
			if ((strlen($ns[0])>1 && $mailbox == substr($ns[0], 0, -1))
			if ($len = strlen($ns[0])) {
			if (($len > 1 && $mailbox == substr($ns[0], 0, -1))
			\|\| strpos($mailbox, $ns[0]) === 0
			) {
			return $type;
			@@ -3459,32 +3539,63 @@


			/**
			* Gets folder options from LIST response, e.g. \Noselect, \Noinferiors
			* Gets folder attributes from LIST response, e.g. \Noselect, \Noinferiors
			*
			* @param string $mailbox Folder name
			* @param bool $force Set to True if options should be refreshed
			* Options are available after LIST command only
			* @param bool $force Set to True if attributes should be refreshed
			*
			* @return array Options list
			*/
			function mailbox_options($mailbox, $force=false)
			function mailbox_attributes($mailbox, $force=false)
			{
			if ($mailbox == 'INBOX') {
			return array();
			// get attributes directly from LIST command
			if (!empty($this->conn->data['LIST']) && is_array($this->conn->data['LIST'][$mailbox])) {
			$opts = $this->conn->data['LIST'][$mailbox];
			}
			// get cached folder attributes
			else if (!$force) {
			$opts = $this->get_cache('mailboxes.attributes');
			$opts = $opts[$mailbox];
			}

			if (!is_array($this->conn->data['LIST']) \|\| !is_array($this->conn->data['LIST'][$mailbox])) {
			if ($force) {
			$this->conn->listMailboxes('', $mailbox);
			}
			else {
			return array();
			}
			if (!is_array($opts)) {
			$this->conn->listMailboxes('', $mailbox);
			$opts = $this->conn->data['LIST'][$mailbox];
			}

			$opts = $this->conn->data['LIST'][$mailbox];

			return is_array($opts) ? $opts : array();
			}


			/**
			* Gets connection (and current mailbox) data: UIDVALIDITY, EXISTS, RECENT,
			* PERMANENTFLAGS, UIDNEXT, UNSEEN
			*
			* @param string $mailbox Folder name
			*
			* @return array Data
			*/
			function mailbox_data($mailbox)
			{
			if (!strlen($mailbox))
			$mailbox = $this->mailbox !== null ? $this->mailbox : 'INBOX';

			if ($this->conn->selected != $mailbox) {
			if ($this->conn->select($mailbox))
			$this->mailbox = $mailbox;
			else
			return null;
			}

			$data = $this->conn->data;

			// add (E)SEARCH result for ALL UNDELETED query
			if (!empty($this->icache['undeleted_idx']) && $this->icache['undeleted_idx'][0] == $mailbox) {
			$data['ALL_UNDELETED'] = $this->icache['undeleted_idx'][1];
			$data['COUNT_UNDELETED'] = $this->icache['undeleted_idx'][2];
			}

			return $data;
			}


			@@ -3497,6 +3608,10 @@
			*/
			function mailbox_info($mailbox)
			{
			if ($this->icache['options'] && $this->icache['options']['name'] == $mailbox) {
			return $this->icache['options'];
			}

			$acl = $this->get_capability('ACL');
			$namespace = $this->get_namespace();
			$options = array();
			@@ -3529,16 +3644,17 @@
			}
			}

			$options['name'] = $mailbox;
			$options['options'] = $this->mailbox_options($mailbox, true);
			$options['namespace'] = $this->mailbox_namespace($mailbox);
			$options['rights'] = $acl && !$options['is_root'] ? (array)$this->my_rights($mailbox) : array();
			$options['special'] = in_array($mailbox, $this->default_folders);
			$options['name'] = $mailbox;
			$options['attributes'] = $this->mailbox_attributes($mailbox, true);
			$options['namespace'] = $this->mailbox_namespace($mailbox);
			$options['rights'] = $acl && !$options['is_root'] ? (array)$this->my_rights($mailbox) : array();
			$options['special'] = in_array($mailbox, $this->default_folders);

			if (is_array($options['options'])) {
			foreach ($options['options'] as $opt) {
			$opt = strtolower($opt);
			if ($opt == '\noselect' \|\| $opt == '\nonexistent') {
			// Set 'noselect' and 'norename' flags
			if (is_array($options['attributes'])) {
			foreach ($options['attributes'] as $attrib) {
			$attrib = strtolower($attrib);
			if ($attrib == '\noselect' \|\| $attrib == '\nonexistent') {
			$options['noselect'] = true;
			}
			}
			@@ -3548,14 +3664,32 @@
			}

			if (!empty($options['rights'])) {
			$options['norename'] = !in_array('x', $options['rights']) &&
			(!in_array('c', $options['rights']) \|\| !in_array('d', $options['rights']));
			$options['norename'] = !in_array('x', $options['rights']) && !in_array('d', $options['rights']);

			if (!$options['noselect']) {
			$options['noselect'] = !in_array('r', $options['rights']);
			}
			}
			else {
			$options['norename'] = $options['is_root'] \|\| $options['namespace'] != 'personal';
			}

			$this->icache['options'] = $options;

			return $options;
			}


			/**
			* Synchronizes messages cache.
			*
			* @param string $mailbox Folder name
			*/
			public function mailbox_sync($mailbox)
			{
			if ($mcache = $this->get_mcache_engine()) {
			$mcache->synchronize($mailbox);
			}
			}


			@@ -3771,7 +3905,7 @@
			// @TODO: Honor MAXSIZE and DEPTH options
			foreach ($queries as $attrib => $entry)
			if ($result = $this->conn->getAnnotation($mailbox, $entry, $attrib))
			$res = array_merge($res, $result);
			$res = array_merge_recursive($res, $result);

			return $res;
			}
			@@ -3809,18 +3943,18 @@
			/**
			* Enable or disable indexes caching
			*
			* @param boolean $type Cache type (@see rcmail::get_cache)
			* @param string $type Cache type (@see rcmail::get_cache)
			* @access public
			*/
			function set_caching($type)
			{
			if ($type) {
			$this->caching = true;
			$this->caching = $type;
			}
			else {
			if ($this->cache)
			$this->cache->close();
			$this->cache = null;
			$this->cache = null;
			$this->caching = false;
			}
			}
			@@ -3832,7 +3966,7 @@
			{
			if ($this->caching && !$this->cache) {
			$rcmail = rcmail::get_instance();
			$this->cache = $rcmail->get_cache('IMAP', $type);
			$this->cache = $rcmail->get_cache('IMAP', $this->caching);
			}

			return $this->cache;
			@@ -3890,418 +4024,49 @@
			* Enable or disable messages caching
			*
			* @param boolean $set Flag
			* @access public
			*/
			function set_messages_caching($set)
			{
			$rcmail = rcmail::get_instance();

			if ($set && ($dbh = $rcmail->get_dbh())) {
			$this->db = $dbh;
			if ($set) {
			$this->messages_caching = true;
			}
			else {
			if ($this->mcache)
			$this->mcache->close();
			$this->mcache = null;
			$this->messages_caching = false;
			}
			}

			/**
			* Checks if the cache is up-to-date
			* Getter for messages cache object
			*/
			private function get_mcache_engine()
			{
			if ($this->messages_caching && !$this->mcache) {
			$rcmail = rcmail::get_instance();
			if ($dbh = $rcmail->get_dbh()) {
			$this->mcache = new rcube_imap_cache(
			$dbh, $this, $rcmail->user->ID, $this->skip_deleted);
			}
			}

			return $this->mcache;
			}

			/**
			* Clears the messages cache.
			*
			* @param string $mailbox Mailbox name
			* @param string $cache_key Internal cache key
			* @return int Cache status: -3 = off, -2 = incomplete, -1 = dirty, 1 = OK
			* @param string $mailbox Folder name
			* @param array $uids Optional message UIDs to remove from cache
			*/
			private function check_cache_status($mailbox, $cache_key)
			function clear_message_cache($mailbox = null, $uids = null)
			{
			if (!$this->messages_caching)
			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 $cache_count ? -2 : 1;
			if ($mcache = $this->get_mcache_engine()) {
			$mcache->clear($mailbox, $uids);
			}

			if ($cache_count == $msg_count) {
			if ($this->skip_deleted) {
			if (!empty($this->icache['all_undeleted_idx'])) {
			$uids = rcube_imap_generic::uncompressMessageSet($this->icache['all_undeleted_idx']);
			$uids = array_flip($uids);
			foreach ($cache_index as $uid) {
			unset($uids[$uid]);
			}
			}
			else {
			// get all undeleted messages excluding cached UIDs
			$uids = $this->search_once($mailbox, 'ALL UNDELETED NOT UID '.
			rcube_imap_generic::compressMessageSet($cache_index));
			}
			if (empty($uids)) {
			return 1;
			}
			} else {
			// get UID of the message with highest index
			$uid = $this->_id2uid($msg_count, $mailbox);
			$cache_uid = array_pop($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
			return (abs($msg_count - $cache_count) < $msg_count/10) ? -1 : -2;
			}


			/**
			* @param string $key Cache key
			* @param string $from
			* @param string $to
			* @param string $sort_field
			* @param string $sort_order
			* @access private
			*/
			private function get_message_cache($key, $from, $to, $sort_field, $sort_order)
			{
			if (!$this->messages_caching)
			return NULL;

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

			$result = 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)) {
			$uid = intval($sql_arr['uid']);
			$result[$uid] = $this->db->decode(unserialize($sql_arr['headers']));

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

			return $result;
			}


			/**
			* @param string $key Cache key
			* @param int $uid Message UID
			* @return mixed
			* @access private
			*/
			private function &get_cached_message($key, $uid)
			{
			$internal_key = 'message';

			if ($this->messages_caching && !isset($this->icache[$internal_key][$uid])) {
			$sql_result = $this->db->query(
			"SELECT idx, headers, structure, message_id".
			" 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)) {
			$this->icache['message.id'][$uid] = intval($sql_arr['message_id']);
			$this->uid_id_map[preg_replace('/\.msg$/', '', $key)][$uid] = intval($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];
			}


			/**
			* @param string $key Cache key
			* @param string $sort_field Sorting column
			* @param string $sort_order Sorting order
			* @return array Messages index
			* @access private
			*/
			private function get_message_cache_index($key, $sort_field='idx', $sort_order='ASC')
			{
			if (!$this->messages_caching \|\| empty($key))
			return NULL;

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

			if (array_key_exists('index', $this->icache)
			&& $this->icache['index']['key'] == $key
			&& $this->icache['index']['sort_field'] == $sort_field
			) {
			if ($this->icache['index']['sort_order'] == $sort_order)
			return $this->icache['index']['result'];
			else
			return array_reverse($this->icache['index']['result'], true);
			}

			$this->icache['index'] = array(
			'result' => array(),
			'key' => $key,
			'sort_field' => $sort_field,
			'sort_order' => $sort_order,
			);

			$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))
			$this->icache['index']['result'][$sql_arr['idx']] = intval($sql_arr['uid']);

			return $this->icache['index']['result'];
			}


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

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

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

			// known message id
			if (is_int($force) && $force > 0) {
			$message_id = $force;
			}
			// check for an existing record (probably headers are cached but structure not)
			else if (!$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
			);
			}

			unset($this->icache['index']);
			}


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

			unset($this->icache['index']);
			}


			/**
			* @param string $key Cache key
			* @param int $start_index Start index
			* @access private
			*/
			private function clear_message_cache($key, $start_index=1)
			{
			if (!$this->messages_caching)
			return;

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

			unset($this->icache['index']);
			}


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


			/**
			* @param string $key Cache key
			* @param int $id Message (sequence) ID
			* @return int Message UID
			* @access private
			*/
			private function get_cache_id2uid($key, $id)
			{
			if (!$this->messages_caching)
			return null;

			if (array_key_exists('index', $this->icache)
			&& $this->icache['index']['key'] == $key
			) {
			return $this->icache['index']['result'][$id];
			}

			$sql_result = $this->db->query(
			"SELECT uid".
			" FROM ".get_table_name('messages').
			" WHERE user_id=?".
			" AND cache_key=?".
			" AND idx=?",
			$_SESSION['user_id'], $key, $id);

			if ($sql_arr = $this->db->fetch_assoc($sql_result))
			return intval($sql_arr['uid']);

			return null;
			}


			/**
			* @param string $key Cache key
			* @param int $uid Message UID
			* @return int Message (sequence) ID
			* @access private
			*/
			private function get_cache_uid2id($key, $uid)
			{
			if (!$this->messages_caching)
			return null;

			if (array_key_exists('index', $this->icache)
			&& $this->icache['index']['key'] == $key
			) {
			return array_search($uid, $this->icache['index']['result']);
			}

			$sql_result = $this->db->query(
			"SELECT idx".
			" 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))
			return intval($sql_arr['idx']);

			return null;
			}


			/* --------------------------------
			@@ -4599,36 +4364,46 @@


			/**
			* @param int $uid Message UID
			* @param string $mailbox Mailbox name
			* Finds message sequence ID for specified UID
			*
			* @param int $uid Message UID
			* @param string $mailbox Mailbox name
			* @param bool $force True to skip cache
			*
			* @return int Message (sequence) ID
			* @access private
			*/
			private function _uid2id($uid, $mailbox=NULL)
			function uid2id($uid, $mailbox = null, $force = false)
			{
			if (!strlen($mailbox)) {
			$mailbox = $this->mailbox;
			}

			if (!isset($this->uid_id_map[$mailbox][$uid])) {
			if (!($id = $this->get_cache_uid2id($mailbox.'.msg', $uid)))
			$id = $this->conn->UID2ID($mailbox, $uid);

			$this->uid_id_map[$mailbox][$uid] = $id;
			if (!empty($this->uid_id_map[$mailbox][$uid])) {
			return $this->uid_id_map[$mailbox][$uid];
			}

			return $this->uid_id_map[$mailbox][$uid];
			if (!$force && ($mcache = $this->get_mcache_engine()))
			$id = $mcache->uid2id($mailbox, $uid);

			if (empty($id))
			$id = $this->conn->UID2ID($mailbox, $uid);

			$this->uid_id_map[$mailbox][$uid] = $id;

			return $id;
			}


			/**
			* @param int $id Message (sequence) ID
			* @param string $mailbox Mailbox name
			* Find UID of the specified message sequence ID
			*
			* @param int $id Message (sequence) ID
			* @param string $mailbox Mailbox name
			* @param bool $force True to skip cache
			*
			* @return int Message UID
			* @access private
			*/
			private function _id2uid($id, $mailbox=null)
			function id2uid($id, $mailbox = null, $force = false)
			{
			if (!strlen($mailbox)) {
			$mailbox = $this->mailbox;
			@@ -4638,9 +4413,11 @@
			return $uid;
			}

			if (!($uid = $this->get_cache_id2uid($mailbox.'.msg', $id))) {
			if (!$force && ($mcache = $this->get_mcache_engine()))
			$uid = $mcache->id2uid($mailbox, $id);

			if (empty($uid))
			$uid = $this->conn->ID2UID($mailbox, $id);
			}

			$this->uid_id_map[$mailbox][$uid] = $id;

			@@ -4757,16 +4534,19 @@
			$str = self::explode_header_string(',;', $str, true);
			$result = array();

			// simplified regexp, supporting quoted local part
			$email_rx = '(\S+\|("\s(?:[^"\f\n\r\t\v\b\s]+\s)+"))@\S+';

			foreach ($str as $key => $val) {
			$name = '';
			$address = '';
			$val = trim($val);

			if (preg_match('/(.*)<(\S+@\S+)>$/', $val, $m)) {
			if (preg_match('/(.*)<('.$email_rx.')>$/', $val, $m)) {
			$address = $m[2];
			$name = trim($m[1]);
			}
			else if (preg_match('/^(\S+@\S+)$/', $val, $m)) {
			else if (preg_match('/^('.$email_rx.')$/', $val, $m)) {
			$address = $m[1];
			$name = '';
			}
			@@ -4776,7 +4556,7 @@

			// dequote and/or decode name
			if ($name) {
			if ($name[0] == '"') {
			if ($name[0] == '"' && $name[strlen($name)-1] == '"') {
			$name = substr($name, 1, -1);
			$name = stripslashes($name);
			}
			@@ -4923,16 +4703,24 @@
			*/
			class rcube_header_sorter
			{
			var $sequence_numbers = array();
			private $seqs = array();
			private $uids = array();


			/**
			* Set the predetermined sort order.
			*
			* @param array $seqnums Numerically indexed array of IMAP message sequence numbers
			* @param array $index Numerically indexed array of IMAP ID or UIDs
			* @param bool $is_uid Set to true if $index contains UIDs
			*/
			function set_sequence_numbers($seqnums)
			function set_index($index, $is_uid = false)
			{
			$this->sequence_numbers = array_flip($seqnums);
			$index = array_flip($index);

			if ($is_uid)
			$this->uids = $index;
			else
			$this->seqs = $index;
			}

			/**
			@@ -4942,14 +4730,10 @@
			*/
			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($this, "compare_seqnums"));
			if (!empty($this->uids))
			uksort($headers, array($this, "compare_uids"));
			else
			uasort($headers, array($this, "compare_seqnums"));
			}

			/**
			@@ -4965,8 +4749,24 @@
			$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;
			$posa = isset($this->seqs[$seqa]) ? intval($this->seqs[$seqa]) : -1;
			$posb = isset($this->seqs[$seqb]) ? intval($this->seqs[$seqb]) : -1;

			// return the relative position as the comparison value
			return $posa - $posb;
			}

			/**
			* Sort method called by uksort()
			*
			* @param int $a Array key (UID)
			* @param int $b Array key (UID)
			*/
			function compare_uids($a, $b)
			{
			// then find each sequence number in my ordered list
			$posa = isset($this->uids[$a]) ? intval($this->uids[$a]) : -1;
			$posb = isset($this->uids[$b]) ? intval($this->uids[$b]) : -1;

			// return the relative position as the comparison value
			return $posa - $posb;