diff --git a/plugins/libkolab/lib/kolab_dav_client.php b/plugins/libkolab/lib/kolab_dav_client.php
index 726cdc7f..60c3a49e 100644
--- a/plugins/libkolab/lib/kolab_dav_client.php
+++ b/plugins/libkolab/lib/kolab_dav_client.php
@@ -1,1266 +1,1255 @@
 <?php
 
 /**
  * A *DAV client.
  *
  * @author Aleksander Machniak <machniak@apheleia-it.ch>
  *
  * Copyright (C) 2022, Apheleia IT AG <contact@apheleia-it.ch>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 class kolab_dav_client
 {
     public const ACL_PRINCIPAL_SELF = 'self';
     public const ACL_PRINCIPAL_ALL = 'all';
     public const ACL_PRINCIPAL_AUTH = 'authenticated';
     public const ACL_PRINCIPAL_UNAUTH = 'unauthenticated';
 
     public const INVITE_ACCEPTED = 'accepted';
     public const INVITE_DECLINED = 'declined';
 
     public const NOTIFICATION_SHARE_INVITE = 'share-invite-notification';
     public const NOTIFICATION_SHARE_REPLY = 'share-reply-notification';
 
     public const SHARING_READ = 'read';
     public const SHARING_READ_WRITE = 'read-write';
     public const SHARING_NO_ACCESS = 'no-access';
     public const SHARING_OWNER = 'shared-owner';
     public const SHARING_NOT_SHARED = 'not-shared';
 
     public $url;
 
     protected $user;
     protected $password;
     protected $rc;
     protected $responseHeaders = [];
 
     /**
      * Object constructor
      */
     public function __construct($url)
     {
         $this->rc = rcube::get_instance();
 
         $parsedUrl = parse_url($url);
 
         if (!empty($parsedUrl['user']) && !empty($parsedUrl['pass'])) {
             $this->user     = rawurldecode($parsedUrl['user']);
             $this->password = rawurldecode($parsedUrl['pass']);
 
             $url = str_replace(rawurlencode($this->user) . ':' . rawurlencode($this->password) . '@', '', $url);
         } else {
             $this->user     = $this->rc->get_user_name();
             $this->password = $this->rc->get_user_password();
         }
 
         $this->url = $url;
     }
 
     /**
      * Execute HTTP request to a DAV server
      */
     protected function request($path, $method, $body = '', $headers = [])
     {
         $rcube = rcube::get_instance();
         $debug = (bool) $rcube->config->get('dav_debug');
 
         $request_config = [
             'store_body'       => true,
             'follow_redirects' => true,
         ];
 
         $this->responseHeaders = [];
 
         if ($path && ($rootPath = parse_url($this->url, PHP_URL_PATH)) && strpos($path, $rootPath) === 0) {
             $path = substr($path, strlen($rootPath));
         }
 
         try {
             $request = $this->initRequest($this->url . $path, $method, $request_config);
 
             $request->setAuth($this->user, $this->password);
 
             if ($body) {
                 $request->setBody($body);
                 $request->setHeader(['Content-Type' => 'application/xml; charset=utf-8']);
             }
 
             if (!empty($headers)) {
                 $request->setHeader($headers);
             }
 
             if ($debug) {
                 rcube::write_log('dav', "C: {$method}: " . (string) $request->getUrl()
                      . "\n" . $this->debugBody($body, $request->getHeaders()));
             }
 
             $response = $request->send();
 
             $body = $response->getBody();
             $code = $response->getStatus();
 
             if ($debug) {
                 rcube::write_log('dav', "S: [{$code}]\n" . $this->debugBody($body, $response->getHeader()));
             }
 
             if ($code >= 300) {
                 throw new Exception("DAV Error ($code):\n{$body}");
             }
 
             $this->responseHeaders = $response->getHeader();
 
             return $this->parseXML($body);
         } catch (Exception $e) {
             rcube::raise_error($e, true, false);
             return false;
         }
     }
 
     /**
      * Discover (common) DAV home collections.
      *
      * @return array|false Homes locations or False on error
      */
     public function discover()
     {
         if ($cache = $this->get_cache()) {
             $cache_key = "discover." . md5($this->url);
 
             if ($homes = $cache->get($cache_key)) {
                 return $homes;
             }
         }
 
         $path = parse_url($this->url, PHP_URL_PATH);
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . '<d:propfind xmlns:d="DAV:">'
                 . '<d:prop>'
                     . '<d:current-user-principal />'
                 . '</d:prop>'
             . '</d:propfind>';
 
         // Note: Cyrus CardDAV service requires Depth:1 (CalDAV works without it)
         $response = $this->request('/', 'PROPFIND', $body, ['Depth' => 1, 'Prefer' => 'return-minimal']);
 
         if (empty($response)) {
             return false;
         }
 
         $elements = $response->getElementsByTagName('response');
         $principal_href = '';
 
         foreach ($elements as $element) {
             foreach ($element->getElementsByTagName('current-user-principal') as $prop) {
                 $principal_href = $prop->nodeValue;
                 break;
             }
         }
 
         if ($path && strpos($principal_href, $path) === 0) {
             $principal_href = substr($principal_href, strlen($path));
         }
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . '<d:propfind xmlns:d="DAV:" xmlns:cal="urn:ietf:params:xml:ns:caldav" xmlns:card="urn:ietf:params:xml:ns:carddav">'
                 . '<d:prop>'
                     . '<cal:calendar-home-set/>'
                     . '<card:addressbook-home-set/>'
                     . '<d:notification-URL/>'
                 . '</d:prop>'
             . '</d:propfind>';
 
         $response = $this->request($principal_href, 'PROPFIND', $body);
 
         if (empty($response)) {
             return false;
         }
 
         $elements = $response->getElementsByTagName('response');
         $homes = [];
 
         if ($element = $response->getElementsByTagName('response')->item(0)) {
             if ($prop = $element->getElementsByTagName('prop')->item(0)) {
                 foreach ($prop->childNodes as $home) {
                     if ($home->firstChild && $home->firstChild->localName == 'href') {
                         $href = $home->firstChild->nodeValue;
 
                         if ($path && strpos($href, $path) === 0) {
                             $href = substr($href, strlen($path));
                         }
 
                         $homes[$home->localName] = $href;
                     }
                 }
             }
         }
 
         if ($cache) {
             $cache->set($cache_key, $homes);
         }
 
         return $homes;
     }
 
     /**
      * Get user home folder of specified type
      *
      * @param string $type Home type or component name
      *
      * @return string|null Folder location href
      */
     public function getHome($type)
     {
         $options = [
             'VEVENT' => 'calendar-home-set',
             'VTODO' => 'calendar-home-set',
             'VCARD' => 'addressbook-home-set',
             'NOTIFICATION' => 'notification-URL',
         ];
 
         $homes = $this->discover();
 
         if (is_array($homes) && isset($options[$type])) {
             return $homes[$options[$type]] ?? null;
         }
 
         return null;
     }
 
     /**
      * Get list of folders of specified type.
      *
      * @param string $component Component to filter by (VEVENT, VTODO, VCARD)
      *
      * @return false|array List of folders' metadata or False on error
      */
     public function listFolders($component = 'VEVENT')
     {
         $root_href = $this->getHome($component);
 
         if ($root_href === null) {
             return false;
         }
 
         $ns    = 'xmlns:d="DAV:" xmlns:cs="http://calendarserver.org/ns/"';
         $props = '';
 
         if ($component != 'VCARD') {
             $ns .= ' xmlns:c="urn:ietf:params:xml:ns:caldav" xmlns:a="http://apple.com/ns/ical/" xmlns:k="Kolab:"';
             $props = '<c:supported-calendar-component-set />'
                 . '<a:calendar-color />'
                 . '<k:alarms />';
         }
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . '<d:propfind ' . $ns . '>'
                 . '<d:prop>'
                     . '<d:resourcetype />'
                     . '<d:displayname />'
                     . '<d:share-access/>'   // draft-pot-webdav-resource-sharing-04
                     . '<d:owner/>'          // RFC 3744 (ACL)
                     . '<cs:getctag />'
                     . $props
                 . '</d:prop>'
             . '</d:propfind>';
 
         // Note: Cyrus CardDAV service requires Depth:1 (CalDAV works without it)
         $response = $this->request($root_href, 'PROPFIND', $body, ['Depth' => 1, 'Prefer' => 'return-minimal']);
 
         if (empty($response)) {
             return false;
         }
 
         $folders = [];
         foreach ($response->getElementsByTagName('response') as $element) {
             $folder = $this->getFolderPropertiesFromResponse($element);
 
             // Filter out the folders of other type
             if ($component == 'VCARD') {
                 if (in_array('addressbook', $folder['resource_type'])) {
                     $folders[] = $folder;
                 }
             } elseif (in_array('calendar', $folder['resource_type']) && in_array($component, (array) $folder['types'])) {
                 $folders[] = $folder;
             }
         }
 
         return $folders;
     }
 
     /**
      * Create a DAV object in a folder
      *
      * @param string $location  Object location
      * @param string $content   Object content
      * @param string $component Content type (VEVENT, VTODO, VCARD)
      *
      * @return false|string|null ETag string (or NULL) on success, False on error
      */
     public function create($location, $content, $component = 'VEVENT')
     {
         $ctype = [
             'VEVENT' => 'text/calendar',
             'VTODO' => 'text/calendar',
             'VCARD' => 'text/vcard',
         ];
 
         $headers = ['Content-Type' => $ctype[$component] . '; charset=utf-8'];
 
         $response = $this->request($location, 'PUT', $content, $headers);
 
         return $this->getETagFromResponse($response);
     }
 
     /**
      * Update a DAV object in a folder
      *
      * @param string $location  Object location
      * @param string $content   Object content
      * @param string $component Content type (VEVENT, VTODO, VCARD)
      *
      * @return false|string|null ETag string (or NULL) on success, False on error
      */
     public function update($location, $content, $component = 'VEVENT')
     {
         return $this->create($location, $content, $component);
     }
 
     /**
      * Delete a DAV object from a folder
      *
      * @param string $location Object location
      *
      * @return bool True on success, False on error
      */
     public function delete($location)
     {
         $response = $this->request($location, 'DELETE');
 
         return $response !== false;
     }
 
     /**
      * Move a DAV object
      *
      * @param string $source Source object location
      * @param string $target Target object content
      *
      * @return false|string|null ETag string (or NULL) on success, False on error
      */
     public function move($source, $target)
     {
         $headers = ['Destination' => $target];
 
         $response = $this->request($source, 'MOVE', '', $headers);
 
         return $this->getETagFromResponse($response);
     }
 
     /**
      * Get folder properties.
      *
      * @param string $location Object location
      *
      * @return false|array Folder metadata or False on error
      */
     public function folderInfo($location)
     {
         $ns = implode(' ', [
             'xmlns:d="DAV:"',
             'xmlns:cs="http://calendarserver.org/ns/"',
             'xmlns:c="urn:ietf:params:xml:ns:caldav"',
             'xmlns:a="http://apple.com/ns/ical/"',
             'xmlns:k="Kolab:"',
         ]);
 
         // Note: <allprop> does not include some of the properties we're interested in
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . '<d:propfind ' . $ns . '>'
                 . '<d:prop>'
                     . '<a:calendar-color/>'
                     . '<c:supported-calendar-component-set/>'
                     . '<cs:getctag/>'
                     . '<d:acl/>'
                     . '<d:current-user-privilege-set/>'
                     . '<d:resourcetype/>'
                     . '<d:displayname/>'
                     . '<d:share-access/>'   // draft-pot-webdav-resource-sharing-04
                     . '<d:owner/>'          // RFC 3744 (ACL)
                     . '<d:invite/>'
                     . '<k:alarms/>'
                 . '</d:prop>'
             . '</d:propfind>';
 
         // Note: Cyrus CardDAV service requires Depth:1 (CalDAV works without it)
         $response = $this->request($location, 'PROPFIND', $body, ['Depth' => 0, 'Prefer' => 'return-minimal']);
 
         if (!empty($response)
             && ($element = $response->getElementsByTagName('response')->item(0))
             && ($folder = $this->getFolderPropertiesFromResponse($element))
         ) {
             return $folder;
         }
 
         return false;
     }
 
     /**
      * Create a DAV folder
      *
      * @param string $location   Object location (relative to the user home)
      * @param string $component  Content type (VEVENT, VTODO, VCARD)
      * @param array  $properties Object content
      *
      * @return bool True on success, False on error
      */
     public function folderCreate($location, $component, $properties = [])
     {
-        $ns    = 'xmlns:d="DAV:"';
-        $props = '';
+        [$props, $ns] = $this->folderPropertiesToXml($properties, 'xmlns:d="DAV:"');
 
         if ($component == 'VCARD') {
             $ns .= ' xmlns:c="urn:ietf:params:xml:ns:carddav"';
-            $props = '<d:resourcetype><d:collection/><c:addressbook/></d:resourcetype>';
+            $props .= '<d:resourcetype><d:collection/><c:addressbook/></d:resourcetype>';
         } else {
             $ns .= ' xmlns:c="urn:ietf:params:xml:ns:caldav"';
-            $props = '<d:resourcetype><d:collection/><c:calendar/></d:resourcetype>';
+            $props .= '<d:resourcetype><d:collection/><c:calendar/></d:resourcetype>'
+                // Note: Some clients, but also Cyrus by default allows everything in calendar folders,
+                // i.e. VEVENT, VTODO, VJOURNAL, VFREEBUSY, VAVAILABILITY, but we prefer a single-type folders,
+                // to keep tasks and event separated
+                . '<c:supported-calendar-component-set><c:comp name="' . $component . '"/></c:supported-calendar-component-set>';
         }
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . '<d:mkcol ' . $ns . '>'
                 . '<d:set>'
                     . '<d:prop>' . $props . '</d:prop>'
                 . '</d:set>'
             . '</d:mkcol>';
 
         // Create the collection
         $response = $this->request($location, 'MKCOL', $body);
 
-        if (empty($response)) {
-            return false;
-        }
-
-        // Update collection properties
-        return $this->folderUpdate($location, $component, $properties);
+        return $response !== false;
     }
 
     /**
      * Delete a DAV folder
      *
      * @param string $location Folder location
      *
      * @return bool True on success, False on error
      */
     public function folderDelete($location)
     {
         $response = $this->request($location, 'DELETE');
 
         return $response !== false;
     }
 
     /**
      * Update a DAV folder
      *
      * @param string $location   Object location
      * @param string $component  Content type (VEVENT, VTODO, VCARD)
      * @param array  $properties Object content
      *
      * @return bool True on success, False on error
      */
     public function folderUpdate($location, $component, $properties = [])
     {
-        $ns    = 'xmlns:d="DAV:"';
-        $props = '';
+        // Note: Changing resourcetype property is forbidden (at least by Cyrus)
 
-        if ($component == 'VCARD') {
-            $ns .= ' xmlns:c="urn:ietf:params:xml:ns:carddav"';
-            // Resourcetype property is protected
-            // $props = '<d:resourcetype><d:collection/><c:addressbook/></d:resourcetype>';
-        } else {
-            $ns .= ' xmlns:c="urn:ietf:params:xml:ns:caldav"';
-            // Resourcetype property is protected
-            // $props = '<d:resourcetype><d:collection/><c:calendar/></d:resourcetype>';
-            /*
-                // Note: These are set by Cyrus automatically for calendars
-                . '<c:supported-calendar-component-set>'
-                    . '<c:comp name="VEVENT"/>'
-                    . '<c:comp name="VTODO"/>'
-                    . '<c:comp name="VJOURNAL"/>'
-                    . '<c:comp name="VFREEBUSY"/>'
-                    . '<c:comp name="VAVAILABILITY"/>'
-                . '</c:supported-calendar-component-set>';
-            */
+        [$props, $ns] = $this->folderPropertiesToXml($properties, 'xmlns:d="DAV:"');
+
+        if (empty($props)) {
+            return true;
         }
 
+        $body = '<?xml version="1.0" encoding="utf-8"?>'
+            . '<d:propertyupdate ' . $ns . '>'
+                . '<d:set>'
+                    . '<d:prop>' . $props . '</d:prop>'
+                . '</d:set>'
+            . '</d:propertyupdate>';
+
+        $response = $this->request($location, 'PROPPATCH', $body);
+
+        // TODO: Should we make sure "200 OK" status is set for all requested properties?
+
+        return $response !== false;
+    }
+
+    /**
+     * Parse folder properties input into XML string to use in a request
+     */
+    protected function folderPropertiesToXml($properties, $ns = '')
+    {
+        $props = '';
+
         foreach ($properties as $name => $value) {
             if ($name == 'name') {
                 $props .= '<d:displayname>' . htmlspecialchars($value, ENT_XML1, 'UTF-8') . '</d:displayname>';
             } elseif ($name == 'color' && strlen($value)) {
                 if ($value[0] != '#') {
                     $value = '#' . $value;
                 }
 
                 $ns .= ' xmlns:a="http://apple.com/ns/ical/"';
                 $props .= '<a:calendar-color>' . htmlspecialchars($value, ENT_XML1, 'UTF-8') . '</a:calendar-color>';
             } elseif ($name == 'alarms') {
                 if (!strpos($ns, 'Kolab:')) {
                     $ns .= ' xmlns:k="Kolab:"';
                 }
 
                 $props .= "<k:{$name}>" . ($value ? 'true' : 'false') . "</k:{$name}>";
             }
         }
 
-        if (empty($props)) {
-            return true;
-        }
-
-        $body = '<?xml version="1.0" encoding="utf-8"?>'
-            . '<d:propertyupdate ' . $ns . '>'
-                . '<d:set>'
-                    . '<d:prop>' . $props . '</d:prop>'
-                . '</d:set>'
-            . '</d:propertyupdate>';
-
-        $response = $this->request($location, 'PROPPATCH', $body);
-
-        // TODO: Should we make sure "200 OK" status is set for all requested properties?
-
-        return $response !== false;
+        return [$props, $ns];
     }
 
     /**
      * Fetch DAV notifications
      *
      * @param ?array $types Notification types to return
      *
      * @return false|array Notification objects on success, False on error
      */
     public function listNotifications($types = [])
     {
         $root_href = $this->getHome('NOTIFICATION');
 
         if ($root_href === null) {
             return false;
         }
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . ' <d:propfind xmlns:d="DAV:">'
                 . '<d:prop>'
                     . '<d:notificationtype/>'
                 . '</d:prop>'
             . '</d:propfind>';
 
         $response = $this->request($root_href, 'PROPFIND', $body, ['Depth' => 1, 'Prefer' => 'return-minimal']);
 
         if (empty($response)) {
             return false;
         }
 
         $objects = [];
 
         foreach ($response->getElementsByTagName('response') as $element) {
             $type = $element->getElementsByTagName('notificationtype')->item(0);
 
             if ($type && $type->firstChild) {
                 $type = $type->firstChild->localName;
 
                 if (empty($types) || in_array($type, $types)) {
                     $href = $element->getElementsByTagName('href')->item(0);
                     if ($notification = $this->getNotification($href->nodeValue)) {
                         $objects[] = $notification;
                     }
                 }
             }
         }
 
         return $objects;
     }
 
     /**
      * Get a single DAV notification
      *
      * @param string $location Notification href
      *
      * @return false|array Notification data on success, False on error
      */
     public function getNotification($location)
     {
         $response = $this->request($location, 'GET', '', ['Content-Type' => 'application/davnotification+xml']);
 
         if (empty($response)) {
             return false;
         }
 
         // Note: Cyrus implements draft-pot-webdav-resource-sharing v02, not the most recent one(s),
         // and even v02 support is broken in some places
 
         if ($access = $response->getElementsByTagName('access')->item(0)) {
             $access = $access->firstChild;
             $access = $access->localName; // 'read' or 'read-write'
         }
 
         foreach (['invite-noresponse', 'invite-accepted', 'invite-declined', 'invite-invalid', 'invite-deleted'] as $name) {
             if ($node = $response->getElementsByTagName($name)->item(0)) {
                 $result['status'] = str_replace('invite-', '', $node->localName);
             }
         }
 
         if ($organizer = $response->getElementsByTagName('organizer')->item(0)) {
             if ($href = $organizer->getElementsByTagName('href')->item(0)) {
                 $organizer = $href->nodeValue;
             }
             // There should be also 'displayname', but Cyrus uses 'common-name',
             // we'll ignore it for now anyway.
         } elseif ($organizer = $response->getElementsByTagName('principal')->item(0)) {
             if ($href = $organizer->getElementsByTagName('href')->item(0)) {
                 $organizer = $href->nodeValue;
             }
             // There should be also 'displayname', but Cyrus uses 'common-name',
             // we'll ignore it for now anyway.
         }
 
         $components = [];
         if ($set_element = $response->getElementsByTagName('supported-calendar-component-set')->item(0)) {
             foreach ($set_element->getElementsByTagName('comp') as $comp_element) {
                 $components[] = $comp_element->attributes->getNamedItem('name')->nodeValue;
             }
         }
 
         $result = [
             'href' => $location,
             'access' => $access,
             'types' => $components,
             'organizer' => $organizer,
         ];
 
         // Cyrus uses 'summary', but it's 'comment' in more recent standard
         foreach (['dtstamp', 'summary', 'comment'] as $name) {
             if ($node = $response->getElementsByTagName($name)->item(0)) {
                 $result[$name] = $node->nodeValue;
             }
         }
 
         // Note: In more recent standard there are 'displayname' and 'resourcetype' props
 
         // Note: 'hosturl' exists in v2, but starting from v3 'sharer-resource-uri' is used
         if ($hosturl = $response->getElementsByTagName('hosturl')->item(0)) {
             if ($href = $hosturl->getElementsByTagName('href')->item(0)) {
                 $result['resource-uri'] = $href->nodeValue;
             }
         } elseif ($hosturl = $response->getElementsByTagName('sharer-resource-uri')->item(0)) {
             if ($href = $hosturl->getElementsByTagName('href')->item(0)) {
                 $result['resource-uri'] = $href->nodeValue;
             }
         }
 
         return $result;
     }
 
     /**
      * Fetch DAV objects metadata (ETag, href) a folder
      *
      * @param string $location  Folder location
      * @param string $component Object type (VEVENT, VTODO, VCARD)
      *
      * @return false|array Objects metadata on success, False on error
      */
     public function getIndex($location, $component = 'VEVENT')
     {
         $queries = [
             'VEVENT' => 'calendar-query',
             'VTODO' => 'calendar-query',
             'VCARD' => 'addressbook-query',
         ];
 
         $ns = [
             'VEVENT' => 'caldav',
             'VTODO' => 'caldav',
             'VCARD' => 'carddav',
         ];
 
         $filter = '';
         if ($component != 'VCARD') {
             $filter = '<c:comp-filter name="VCALENDAR">'
                     . '<c:comp-filter name="' . $component . '" />'
                 . '</c:comp-filter>';
         }
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . ' <c:' . $queries[$component] . ' xmlns:d="DAV:" xmlns:c="urn:ietf:params:xml:ns:' . $ns[$component] . '">'
                 . '<d:prop>'
                     . '<d:getetag />'
                 . '</d:prop>'
                 . ($filter ? "<c:filter>$filter</c:filter>" : '')
             . '</c:' . $queries[$component] . '>';
 
         $response = $this->request($location, 'REPORT', $body, ['Depth' => 1, 'Prefer' => 'return-minimal']);
 
         if (empty($response)) {
             return false;
         }
 
         $objects = [];
 
         foreach ($response->getElementsByTagName('response') as $element) {
             $objects[] = $this->getObjectPropertiesFromResponse($element);
         }
 
         return $objects;
     }
 
     /**
      * Fetch DAV objects data from a folder
      *
      * @param string $location  Folder location
      * @param string $component Object type (VEVENT, VTODO, VCARD)
      * @param array  $hrefs     List of objects' locations to fetch (empty for all objects)
      *
      * @return false|array Objects metadata on success, False on error
      */
     public function getData($location, $component = 'VEVENT', $hrefs = [])
     {
         if (empty($hrefs)) {
             return [];
         }
 
         $body = '';
         foreach ($hrefs as $href) {
             $body .= '<d:href>' . $href . '</d:href>';
         }
 
         $queries = [
             'VEVENT' => 'calendar-multiget',
             'VTODO' => 'calendar-multiget',
             'VCARD' => 'addressbook-multiget',
         ];
 
         $ns = [
             'VEVENT' => 'caldav',
             'VTODO' => 'caldav',
             'VCARD' => 'carddav',
         ];
 
         $types = [
             'VEVENT' => 'calendar-data',
             'VTODO' => 'calendar-data',
             'VCARD' => 'address-data',
         ];
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . ' <c:' . $queries[$component] . ' xmlns:d="DAV:" xmlns:c="urn:ietf:params:xml:ns:' . $ns[$component] . '">'
                 . '<d:prop>'
                     . '<d:getetag />'
                     . '<c:' . $types[$component] . ' />'
                 . '</d:prop>'
                 . $body
             . '</c:' . $queries[$component] . '>';
 
         $response = $this->request($location, 'REPORT', $body, ['Depth' => 1, 'Prefer' => 'return-minimal']);
 
         if (empty($response)) {
             return false;
         }
 
         $objects = [];
 
         foreach ($response->getElementsByTagName('response') as $element) {
             $objects[] = $this->getObjectPropertiesFromResponse($element);
         }
 
         return $objects;
     }
 
     /**
      * Accept/Deny a share invitation (draft-pot-webdav-resource-sharing)
      *
      * @param string $location Notification location
      * @param string $action   Reply action ('accepted' or 'declined')
      * @param array  $props    Additional reply properties (slug, comment)
      *
      * @return bool True on success, False on error
      */
     public function inviteReply($location, $action = self::INVITE_ACCEPTED, $props = [])
     {
         $reply = '<d:invite-' . $action . '/>';
 
         // Note: <create-in> and <slug> are ignored by Cyrus
 
         if (!empty($props['comment'])) {
             $reply .= '<d:comment>' . htmlspecialchars($props['comment'], ENT_XML1, 'UTF-8') . '</d:comment>';
         }
 
         $headers = ['Content-Type' => 'application/davsharing+xml; charset=utf-8'];
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . '<d:invite-reply xmlns:d="DAV:">' . $reply . '</d:invite-reply>';
 
         $response = $this->request($location, 'POST', $body, $headers);
 
         return $response !== false;
     }
 
     /**
      * Set ACL on a DAV folder
      *
      * @param string $location Object location (relative to the user home)
      * @param array  $acl      ACL definition
      *
      * @return bool True on success, False on error
      */
     public function setACL($location, $acl)
     {
         $ns_privileges = [
             // CalDAV
             'read-free-busy' => 'c:read-free-busy',
             // Cyrus
             'admin' => 'cy:admin',
             'add-resource' => 'cy:add-resource',
             'remove-resource' => 'cy:remove-resource',
             'make-collection' => 'cy:make-collection',
             'remove-collection' => 'cy:remove-collection',
         ];
 
         foreach ($acl as $idx => $privileges) {
             if (preg_match('/^[a-z]+$/', $idx)) {
                 $principal = '<d:' . $idx . '/>';
             } else {
                 $principal = '<d:href>' . htmlspecialchars($idx, ENT_XML1, 'UTF-8') . '</d:href>';
             }
 
             $grant = [];
             $deny = [];
 
             foreach ($privileges['grant'] ?? [] as $i => $p) {
                 $p = '<' . ($ns_privileges[$p] ?? "d:{$p}") . '/>';
                 $grant[$i] = '<d:privilege>' . $p . '</d:privilege>';
             }
             foreach ($privileges['deny'] ?? [] as $i => $p) {
                 $p = '<' . ($ns_privileges[$p] ?? "d:{$p}") . '/>';
                 $deny[$i] = '<d:privilege>' . $p . '</d:privilege>';
             }
 
             $acl[$idx] = '<d:ace>'
                 . '<d:principal>' . $principal . '</d:principal>'
                 . (count($grant) > 0 ? '<d:grant>' . implode('', $grant) . '</d:grant>' : '')
                 . (count($deny) > 0 ? '<d:deny>' . implode('', $deny) . '</d:deny>' : '')
                 . '</d:ace>';
         }
 
         $acl = implode('', $acl);
         $ns = 'xmlns:d="DAV:"';
 
         if (strpos($acl, '<c:')) {
             $ns .= ' xmlns:c="urn:ietf:params:xml:ns:caldav"';
         }
         if (strpos($acl, '<cy:')) {
             $ns .= ' xmlns:cy="http://cyrusimap.org/ns/"';
         }
 
         $body = '<?xml version="1.0" encoding="utf-8"?><d:acl ' . $ns . '>' . $acl . '</d:acl>';
 
         $response = $this->request($location, 'ACL', $body);
 
         return $response !== false;
     }
 
     /**
      * Share a reasource (draft-pot-webdav-resource-sharing)
      *
      * @param string $location Resource location
      * @param array  $sharees  Sharees list
      *
      * @return bool True on success, False on error
      */
     public function shareResource($location, $sharees = [])
     {
         $props = '';
 
         foreach ($sharees as $href => $sharee) {
             $props .= '<d:sharee>'
                 . '<d:href>' . htmlspecialchars($href, ENT_XML1, 'UTF-8') . '</d:href>'
                 . '<d:share-access><d:' . ($sharee['access'] ?? self::SHARING_NO_ACCESS) . '/></d:share-access>'
                 . '<d:' . ($sharee['status'] ?? 'noresponse') . '/>';
 
             if (isset($sharee['comment']) && strlen($sharee['comment'])) {
                 $props .= '<d:comment>' . htmlspecialchars($sharee['comment'], ENT_XML1, 'UTF-8') . '</d:comment>';
             }
 
             if (isset($sharee['displayname']) && strlen($sharee['displayname'])) {
                 $props .= '<d:prop><d:displayname>'
                     . htmlspecialchars($sharee['comment'], ENT_XML1, 'UTF-8')
                     . '</d:displayname></d:prop>';
             }
 
             $props .= '</d:sharee>';
         }
 
         $headers = ['Content-Type' => 'application/davsharing+xml; charset=utf-8'];
 
         $body = '<?xml version="1.0" encoding="utf-8"?>'
             . '<d:share-resource xmlns:d="DAV:">' . $props . '</d:share-resource>';
 
         $response = $this->request($location, 'POST', $body, $headers);
 
         return $response !== false;
     }
 
     /**
      * Parse XML content
      */
     protected function parseXML($xml)
     {
         $doc = new DOMDocument('1.0', 'UTF-8');
 
         if (stripos($xml, '<?xml') === 0) {
             if (!$doc->loadXML($xml)) {
                 throw new Exception("Failed to parse XML");
             }
 
             $doc->formatOutput = true;
         }
 
         return $doc;
     }
 
     /**
      * Parse request/response body for debug purposes
      */
     protected function debugBody($body, $headers)
     {
         $head = '';
         foreach ($headers as $header_name => $header_value) {
             $head .= "{$header_name}: {$header_value}\n";
         }
 
         if (stripos($body, '<?xml') === 0) {
             $doc = new DOMDocument('1.0', 'UTF-8');
 
             $doc->formatOutput = true;
             $doc->preserveWhiteSpace = false;
 
             if (!$doc->loadXML($body)) {
                 throw new Exception("Failed to parse XML");
             }
 
             $body = $doc->saveXML();
         }
 
         return $head . "\n" . rtrim($body);
     }
 
     /**
      * Extract folder properties from a server 'response' element
      */
     protected function getFolderPropertiesFromResponse(DOMElement $element)
     {
         if ($href = $element->getElementsByTagName('href')->item(0)) {
             $href = $href->nodeValue;
             /*
                         $path = parse_url($this->url, PHP_URL_PATH);
                         if ($path && strpos($href, $path) === 0) {
                             $href = substr($href, strlen($path));
                         }
             */
         }
 
         if ($color = $element->getElementsByTagName('calendar-color')->item(0)) {
             if (preg_match('/^#[0-9a-fA-F]{6,8}$/', $color->nodeValue)) {
                 $color = substr($color->nodeValue, 1);
             } else {
                 $color = null;
             }
         }
 
         if ($name = $element->getElementsByTagName('displayname')->item(0)) {
             $name = $name->nodeValue;
         }
 
         if ($ctag = $element->getElementsByTagName('getctag')->item(0)) {
             $ctag = $ctag->nodeValue;
         }
 
         $components = [];
         if ($set_element = $element->getElementsByTagName('supported-calendar-component-set')->item(0)) {
             foreach ($set_element->getElementsByTagName('comp') as $comp_element) {
                 $components[] = $comp_element->attributes->getNamedItem('name')->nodeValue;
             }
         }
 
         $types = [];
         if ($type_element = $element->getElementsByTagName('resourcetype')->item(0)) {
             foreach ($type_element->childNodes as $node) {
                 $types[] = $node->localName;
             }
         }
 
         $result = [
             'href' => $href,
             'name' => $name,
             'ctag' => $ctag,
             'color' => $color,
             'types' => $components,
             'resource_type' => $types,
         ];
 
         // Note: We're supporting only a subset of RFC 3744, it is:
         //     - grant, deny
         //     - principal (all, self, authenticated, href)
         if ($acl_element = $element->getElementsByTagName('acl')->item(0)) {
             $acl = [];
             $special = [
                 self::ACL_PRINCIPAL_SELF,
                 self::ACL_PRINCIPAL_ALL,
                 self::ACL_PRINCIPAL_AUTH,
                 self::ACL_PRINCIPAL_UNAUTH,
             ];
 
             foreach ($acl_element->getElementsByTagName('ace') as $ace) {
                 $principal = $ace->getElementsByTagName('principal')->item(0);
                 $grant = [];
                 $deny = [];
 
                 if ($principal->firstChild && $principal->firstChild->localName == 'href') {
                     $principal = $principal->firstChild->nodeValue;
                 } elseif ($principal->firstChild && in_array($principal->firstChild->localName, $special)) {
                     $principal = $principal->firstChild->localName;
                 } else {
                     continue;
                 }
 
                 if ($grant_element = $ace->getElementsByTagName('grant')->item(0)) {
                     foreach ($grant_element->childNodes as $privilege) {
                         if (strpos($privilege->nodeName, ':privilege') !== false && $privilege->firstChild) {
                             $grant[] = preg_replace('/^[^:]+:/', '', $privilege->firstChild->nodeName);
                         }
                     }
                 }
 
                 if ($deny_element = $ace->getElementsByTagName('deny')->item(0)) {
                     foreach ($deny_element->childNodes as $privilege) {
                         if (strpos($privilege->nodeName, ':privilege') !== false && $privilege->firstChild) {
                             $deny[] = preg_replace('/^[^:]+:/', '', $privilege->firstChild->nodeName);
                         }
                     }
                 }
 
                 if (count($grant) > 0 || count($deny) > 0) {
                     $acl[$principal] = [
                         'grant' => $grant,
                         'deny' => $deny,
                     ];
                 }
             }
 
             $result['acl'] = $acl;
         }
 
         if ($set_element = $element->getElementsByTagName('current-user-privilege-set')->item(0)) {
             $rights = [];
 
             foreach ($set_element->childNodes as $privilege) {
                 if (strpos($privilege->nodeName, ':privilege') !== false && $privilege->firstChild) {
                     $rights[] = preg_replace('/^[^:]+:/', '', $privilege->firstChild->nodeName);
                 }
             }
 
             $result['myrights'] = $rights;
         }
 
         if ($owner = $element->getElementsByTagName('owner')->item(0)) {
             if ($owner->firstChild) {
                 $result['owner'] = $owner->firstChild->nodeValue;
             }
         }
 
         // 'share-access' from draft-pot-webdav-resource-sharing
         if ($share = $element->getElementsByTagName('share-access')->item(0)) {
             if ($share->firstChild) {
                 $result['share-access'] = $share->firstChild->localName;
             }
         }
 
         // 'invite' from draft-pot-webdav-resource-sharing
         if ($invite_element = $element->getElementsByTagName('invite')->item(0)) {
             $invites = [];
             foreach ($invite_element->childNodes as $sharee) {
                 /** @var DOMElement $sharee */
                 $href = $sharee->getElementsByTagName('href')->item(0)->nodeValue;
                 $status = 'noresponse';
 
                 if ($comment = $sharee->getElementsByTagName('comment')->item(0)) {
                     $comment = $comment->nodeValue;
                 }
 
                 if ($displayname = $sharee->getElementsByTagName('displayname')->item(0)) {
                     $displayname = $displayname->nodeValue;
                 }
 
                 if ($access = $sharee->getElementsByTagName('share-access')->item(0)) {
                     $access = $access->firstChild->localName;
                 } else {
                     $access = self::SHARING_NOT_SHARED;
                 }
 
                 foreach (['invite-noresponse', 'invite-accepted', 'invite-declined', 'invite-invalid', 'invite-deleted'] as $name) {
                     if ($node = $sharee->getElementsByTagName($name)->item(0)) {
                         $status = str_replace('invite-', '', $node->localName);
                     }
                 }
 
                 $invites[$href] = [
                     'access' => $access,
                     'status' => $status,
                     'comment' => $comment,
                     'displayname' => $displayname,
                 ];
             }
 
             $result['invite'] = $invites;
         }
 
         foreach (['alarms'] as $tag) {
             if ($el = $element->getElementsByTagName($tag)->item(0)) {
                 if (strlen($el->nodeValue) > 0) {
                     $result[$tag] = strtolower($el->nodeValue) === 'true';
                 }
             }
         }
 
         return $result;
     }
 
     /**
      * Extract object properties from a server 'response' element
      */
     protected function getObjectPropertiesFromResponse(DOMElement $element)
     {
         $uid = null;
         if ($href = $element->getElementsByTagName('href')->item(0)) {
             $href = $href->nodeValue;
             /*
                         $path = parse_url($this->url, PHP_URL_PATH);
                         if ($path && strpos($href, $path) === 0) {
                             $href = substr($href, strlen($path));
                         }
             */
             // Extract UID from the URL
             $href_parts = explode('/', $href);
             $uid = preg_replace('/\.[a-z]+$/', '', $href_parts[count($href_parts) - 1]);
         }
 
         if ($data = $element->getElementsByTagName('calendar-data')->item(0)) {
             $data = $data->nodeValue;
         } elseif ($data = $element->getElementsByTagName('address-data')->item(0)) {
             $data = $data->nodeValue;
         }
 
         if ($etag = $element->getElementsByTagName('getetag')->item(0)) {
             $etag = $etag->nodeValue;
             if (preg_match('|^".*"$|', $etag)) {
                 $etag = substr($etag, 1, -1);
             }
         }
 
         return [
             'href' => $href,
             'data' => $data,
             'etag' => $etag,
             'uid' => $uid,
         ];
     }
 
     /**
      * Get ETag from a response
      */
     protected function getETagFromResponse($response)
     {
         if ($response !== false) {
             // Note: ETag is not always returned, e.g. https://github.com/cyrusimap/cyrus-imapd/issues/2456
             $etag = $this->responseHeaders['etag'] ?? null;
 
             if (is_string($etag) && preg_match('|^".*"$|', $etag)) {
                 $etag = substr($etag, 1, -1);
             }
 
             return $etag;
         }
 
         return false;
     }
 
     /**
      * Initialize HTTP request object
      */
     protected function initRequest($url = '', $method = 'GET', $config = [])
     {
         $rcube       = rcube::get_instance();
         $http_config = (array) $rcube->config->get('kolab_http_request');
 
         // deprecated configuration options
         if (empty($http_config)) {
             foreach (['ssl_verify_peer', 'ssl_verify_host'] as $option) {
                 $value = $rcube->config->get('kolab_' . $option, true);
                 if (is_bool($value)) {
                     $http_config[$option] = $value;
                 }
             }
         }
 
         if (!empty($config)) {
             $http_config = array_merge($http_config, $config);
         }
 
         // load HTTP_Request2 (support both composer-installed and system-installed package)
         if (!class_exists('HTTP_Request2')) {
             require_once 'HTTP/Request2.php';
         }
 
         try {
             $request = new HTTP_Request2();
             $request->setConfig($http_config);
 
             // proxy User-Agent string
             if (isset($_SERVER['HTTP_USER_AGENT'])) {
                 $request->setHeader('user-agent', $_SERVER['HTTP_USER_AGENT']);
             }
 
             // cleanup
             $request->setBody('');
             $request->setUrl($url);
             $request->setMethod($method);
 
             return $request;
         } catch (Exception $e) {
             rcube::raise_error($e, true, true);
         }
     }
 
     /**
      * Return caching object if enabled
      */
     protected function get_cache()
     {
         $rcube = rcube::get_instance();
         if ($cache_type = $rcube->config->get('dav_cache', 'db')) {
             $cache_ttl  = $rcube->config->get('dav_cache_ttl', '10m');
             $cache_name = 'DAV';
 
             return $rcube->get_cache($cache_name, $cache_type, $cache_ttl);
         }
     }
 }