Fix various calendar recurrence issues

plugins/calendar/calendar.php

@@ -2457,11 +2457,10 @@ $("#rcmfd_new_category").keypress(function(event) {
      */
     private function notify_attendees($event, $old, $action = 'edit', $comment = null, $rsvp = null)
     {
-        $is_cancelled = false;
+        $is_cancelled = $action == 'remove'
-        if ($action == 'remove' || ($event['status'] == 'CANCELLED' && ($old['status'] ?? '') != $event['status'])) {
+            || (!empty($event['status']) && $event['status'] == 'CANCELLED' && ($old['status'] ?? '') != $event['status']);
-            $event['cancelled'] = true;
+
-            $is_cancelled = true;
+        $event['cancelled'] = $is_cancelled;
-        }
 
         if ($rsvp === null) {
             $rsvp = !$old || ($event['sequence'] ?? 0) > ($old['sequence'] ?? 0);

plugins/calendar/drivers/caldav/caldav_calendar.php

@@ -298,7 +298,7 @@ class caldav_calendar extends kolab_storage_dav_folder
                 // find and merge exception for the first instance
                 if ($virtual && !empty($event['recurrence']) && !empty($event['recurrence']['EXCEPTIONS'])) {
                     foreach ($event['recurrence']['EXCEPTIONS'] as $exception) {
-                        if ($event['_instance'] == $exception['_instance']) {
+                        if (libcalendaring::is_recurrence_exception($event, $exception)) {
                             unset($exception['calendar'], $exception['className'], $exception['_folder_id']);
                             // clone date objects from main event before adjusting them with exception data
                             if (is_object($event['start'])) {
@@ -307,6 +307,7 @@ class caldav_calendar extends kolab_storage_dav_folder
                             if (is_object($event['end'])) {
                                 $event['end'] = clone $record['end'];
                             }
+
                             kolab_driver::merge_exception_data($event, $exception);
                         }
                     }
@@ -365,9 +366,6 @@ class caldav_calendar extends kolab_storage_dav_folder
         // $config = kolab_storage_config::get_instance();
         // $config->apply_links($events);
 
-        // Avoid session race conditions that will loose temporary subscriptions
-        // $this->cal->rc->session->nowrite = true;
-
         return $events;
     }
 
@@ -649,7 +647,7 @@ class caldav_calendar extends kolab_storage_dav_folder
             return $events;
         }
 
-        // use libkolab to compute recurring events
+        // use libcalendaring to compute recurring events
         $recurrence = libcalendaring::get_recurrence($event);
 
         $i = 0;

plugins/calendar/drivers/kolab/kolab_driver.php

@@ -829,7 +829,7 @@ class kolab_driver extends calendar_driver
     {
         $ret      = true;
         $success  = false;
-        $savemode = isset($event['_savemode']) ? $event['_savemode'] : null;
+        $savemode = $event['_savemode'] ?? null;
 
         if (!$force) {
             unset($event['attendees']);
@@ -864,7 +864,7 @@ class kolab_driver extends calendar_driver
             // removing an exception instance
             if ((!empty($event['recurrence_id']) || !empty($event['isexception'])) && !empty($master['exceptions'])) {
                 foreach ($master['exceptions'] as $i => $exception) {
-                    if ($exception['_instance'] == $event['_instance']) {
+                    if (libcalendaring::is_recurrence_exception($event, $exception)) {
                         unset($master['exceptions'][$i]);
                         // set event date back to the actual occurrence
                         if (!empty($exception['recurrence_date'])) {
@@ -1071,6 +1071,7 @@ class kolab_driver extends calendar_driver
             }
 
             // Stick to the master timezone for all occurrences (Bifrost#T104637)
+            if (empty($master['allday']) || !empty($event['allday'])) {
                 $master_tz = $master['start']->getTimezone();
                 $event_tz  = $event['start']->getTimezone();
 
@@ -1079,6 +1080,7 @@ class kolab_driver extends calendar_driver
                     $event['end']->setTimezone($master_tz);
                 }
             }
+        }
 
         // check if update affects scheduling and update attendee status accordingly
         $reschedule = $this->check_scheduling($event, $old, true);
@@ -1138,7 +1140,8 @@ class kolab_driver extends calendar_driver
             if ($reschedule) {
                 unset($event['recurrence']['EXCEPTIONS'], $event['exceptions'], $master['recurrence']['EXDATE']);
             }
-            else if (isset($event['recurrence']['EXCEPTIONS']) && is_array($event['recurrence']['EXCEPTIONS'])) {
+            else {
+                if (isset($event['recurrence']['EXCEPTIONS']) && is_array($event['recurrence']['EXCEPTIONS'])) {
                     // only keep relevant exceptions
                     $event['recurrence']['EXCEPTIONS'] = array_filter(
                         $event['recurrence']['EXCEPTIONS'],
@@ -1146,6 +1149,11 @@ class kolab_driver extends calendar_driver
                             return $exception['start'] > $event['start'];
                         }
                     );
+
+                    // set link to top-level exceptions
+                    $event['exceptions'] = &$event['recurrence']['EXCEPTIONS'];
+                }
+
                 if (isset($event['recurrence']['EXDATE']) && is_array($event['recurrence']['EXDATE'])) {
                     $event['recurrence']['EXDATE'] = array_filter(
                         $event['recurrence']['EXDATE'],
@@ -1154,8 +1162,6 @@ class kolab_driver extends calendar_driver
                         }
                     );
                 }
-                // set link to top-level exceptions
-                $event['exceptions'] = &$event['recurrence']['EXCEPTIONS'];
             }
 
             // compute remaining occurrences
@@ -1223,7 +1229,7 @@ class kolab_driver extends calendar_driver
                 $event['sequence'] = max($old['sequence'] ?? 0, $master['sequence'] ?? 0) + 1;
             }
             else if (!isset($event['sequence'])) {
-                $event['sequence'] = !empty($old['sequence']) ? $old['sequence'] : $master['sequence'];
+                $event['sequence'] = !empty($old['sequence']) ? $old['sequence'] : $master['sequence'] ?? 1;
             }
 
             // save properties to a recurrence exception instance
@@ -1306,7 +1312,7 @@ class kolab_driver extends calendar_driver
             }
 
             // TODO: forward changes to exceptions (which do not yet have differing values stored)
-            if (!empty($event['recurrence']) && !empty($event['recurrence']['EXCEPTIONS']) && !$with_exceptions) {
+            if (!empty($event['recurrence']) && !empty($event['recurrence']['EXCEPTIONS']) && empty($with_exceptions)) {
                 // determine added and removed attendees
                 $old_attendees = $current_attendees = $added_attendees = [];
 
@@ -1464,7 +1470,7 @@ class kolab_driver extends calendar_driver
 
         foreach ($master['recurrence']['EXCEPTIONS'] as $i => $exception) {
             // update a specific instance
-            if ($exception['_instance'] == $old['_instance']) {
+            if (libcalendaring::is_recurrence_exception($old, $exception)) {
                 $existing = $i;
 
                 // check savemode against existing exception mode.
@@ -1472,7 +1478,7 @@ class kolab_driver extends calendar_driver
                 $thisandfuture = !empty($exception['thisandfuture']);
                 if ($thisandfuture === ($savemode == 'future')) {
                     $event['_instance']       = $old['_instance'];
-                    $event['thisandfuture']   = $old['thisandfuture'];
+                    $event['thisandfuture']   = !empty($old['thisandfuture']);
                     $event['recurrence_date'] = $old['recurrence_date'];
                     $master['recurrence']['EXCEPTIONS'][$i] = $event;
                     $saved = true;
@@ -1480,7 +1486,11 @@ class kolab_driver extends calendar_driver
             }
 
             // merge the new event properties onto future exceptions
-            if ($savemode == 'future' && $exception['_instance'] >= $old['_instance']) {
+            if ($savemode == 'future') {
+                $exception_instance = libcalendaring::recurrence_instance_identifier($exception, true);
+                $old_instance = libcalendaring::recurrence_instance_identifier($old, true);
+
+                if ($exception_instance >= $old_instance) {
                     unset($event['thisandfuture']);
                     self::merge_exception_data($master['recurrence']['EXCEPTIONS'][$i], $event, ['attendees']);
 
@@ -1489,6 +1499,7 @@ class kolab_driver extends calendar_driver
                     }
                 }
             }
+        }
 /*
         // we could not update the existing exception due to savemode mismatch...
         if (!$saved && isset($existing) && !empty($master['recurrence']['EXCEPTIONS'][$existing]['thisandfuture'])) {
@@ -1525,7 +1536,7 @@ class kolab_driver extends calendar_driver
     public static function add_exception(&$master, $event, $old = null)
     {
         if ($old) {
-            $event['_instance'] = $old['_instance'];
+            $event['_instance'] = $old['_instance'] ?? null;
             if (empty($event['recurrence_date'])) {
                 $event['recurrence_date'] = !empty($old['recurrence_date']) ? $old['recurrence_date'] : $old['start'];
             }
@@ -1534,10 +1545,6 @@ class kolab_driver extends calendar_driver
             $event['recurrence_date'] = $event['start'];
         }
 
-        if (empty($event['_instance']) && $event['recurrence_date'] instanceof DateTimeInterface) {
-            $event['_instance'] = libcalendaring::recurrence_instance_identifier($event, !empty($master['allday']));
-        }
-
         if (!isset($master['exceptions'])) {
             if (isset($master['recurrence']['EXCEPTIONS'])) {
                 $master['exceptions'] = &$master['recurrence']['EXCEPTIONS'];
@@ -1549,7 +1556,7 @@ class kolab_driver extends calendar_driver
 
         $existing = false;
         foreach ($master['exceptions'] as $i => $exception) {
-            if ($exception['_instance'] == $event['_instance']) {
+            if (libcalendaring::is_recurrence_exception($event, $exception)) {
                 $master['exceptions'][$i] = $event;
                 $existing = true;
             }
@@ -2139,7 +2146,7 @@ class kolab_driver extends calendar_driver
             return $record;
         }
 
-        $record['id'] = $record['uid'];
+        $record['id'] = $record['uid'] ?? null;
 
         if (!empty($record['_instance'])) {
             $record['id'] .= '-' . $record['_instance'];

plugins/libcalendaring/lib/libcalendaring_recurrence.php

@@ -33,6 +33,7 @@ class libcalendaring_recurrence
     protected $dateonly = false;
     protected $event;
     protected $duration;
+    protected $isStart = true;
 
     /**
      * Default constructor
@@ -109,7 +110,23 @@ class libcalendaring_recurrence
      */
     public function next_instance()
     {
-        if ($next_start = $this->next_start()) {
+        // Here's the workaround for an issue for an event with its start date excluded
+        // E.g. A daily event starting on 10th which is one of EXDATE dates
+        // should return 11th as next_instance() when called for the first time.
+        // Looks like Sabre is setting internal "current date" to 11th on such an object
+        // initialization, therefore calling next() would move it to 12th.
+        if ($this->isStart && ($next_start = $this->engine->getDtStart())
+            && $next_start->format('Ymd') != $this->start->format('Ymd')
+        ) {
+            $next_start = $this->toDateTime($next_start);
+        }
+        else {
+            $next_start = $this->next_start();
+        }
+
+        $this->isStart = false;
+
+        if ($next_start) {
             $next = $this->event;
             $next['start'] = $next_start;
 
@@ -119,7 +136,7 @@ class libcalendaring_recurrence
             }
 
             $next['recurrence_date'] = clone $next_start;
-            $next['_instance'] = libcalendaring::recurrence_instance_identifier($next, !empty($this->event['allday']));
+            $next['_instance'] = libcalendaring::recurrence_instance_identifier($next);
 
             unset($next['_formatobj']);
 

plugins/libcalendaring/libcalendaring.php

@@ -1348,6 +1348,27 @@ class libcalendaring extends rcube_plugin
         }
     }
 
+    /**
+     * Check if a specified event is "identical" to the specified recurrence exception
+     *
+     * @param array Hash array with occurrence properties
+     * @param array Hash array with exception properties
+     *
+     * @return bool
+     */
+    public static function is_recurrence_exception($event, $exception)
+    {
+        $instance_date = !empty($event['recurrence_date']) ? $event['recurrence_date'] : $event['start'];
+        $exception_date = !empty($exception['recurrence_date']) ? $exception['recurrence_date'] : $exception['start'];
+
+        if ($instance_date instanceof DateTimeInterface && $exception_date instanceof DateTimeInterface) {
+            // Timezone???
+            return $instance_date->format('Ymd') === $exception_date->format('Ymd');
+        }
+
+        return false;
+    }
+
 
     /*********  Attendee handling functions  *********/
 

plugins/libcalendaring/tests/RecurrenceTest.php

@@ -158,13 +158,11 @@ class RecurrenceTest extends PHPUnit\Framework\TestCase
                 '2017-09-08 11:00:00',
                 '2017-09-08 11:00:00',
             ),
-/*
             array(
                 array('FREQ' => 'MONTHLY', 'INTERVAL' => '1', 'BYMONTHDAY' => '8,9'),
                 '2017-08-31 11:00:00',
                 '2017-09-08 11:00:00',
             ),
-*/
             array(
                 array('FREQ' => 'MONTHLY', 'INTERVAL' => '1', 'BYMONTHDAY' => '8,9'),
                 '2017-09-08 11:00:00',
@@ -185,13 +183,11 @@ class RecurrenceTest extends PHPUnit\Framework\TestCase
                 '2017-09-08 11:00:00',
                 '2017-09-08 11:00:00',
             ),
-/*
             array(
                 array('FREQ' => 'MONTHLY', 'INTERVAL' => '2', 'BYMONTHDAY' => '8'),
                 '2017-08-31 11:00:00',
                 '2017-09-08 11:00:00', // ??????
             ),
-*/
             // yearly
             array(
                 array('FREQ' => 'YEARLY', 'INTERVAL' => '1'),
@@ -204,6 +200,7 @@ class RecurrenceTest extends PHPUnit\Framework\TestCase
                 '2017-08-16 12:00:00',
             ),
 /*
+            // Not supported by Sabre (requires BYMONTH too)
             array(
                 array('FREQ' => 'YEARLY', 'INTERVAL' => '1', 'BYDAY' => '-1MO'),
                 '2017-08-16 11:00:00',
@@ -215,7 +212,6 @@ class RecurrenceTest extends PHPUnit\Framework\TestCase
                 '2017-08-16 11:00:00',
                 '2017-08-28 11:00:00',
             ),
-/*
             array(
                 array('FREQ' => 'YEARLY', 'INTERVAL' => '1', 'BYMONTH' => '1', 'BYDAY' => '1MO'),
                 '2017-08-16 11:00:00',
@@ -226,7 +222,6 @@ class RecurrenceTest extends PHPUnit\Framework\TestCase
                 '2017-08-16 11:00:00',
                 '2017-09-04 11:00:00',
             ),
-*/
             array(
                 array('FREQ' => 'YEARLY', 'INTERVAL' => '2'),
                 '2017-08-16 11:00:00',
@@ -238,6 +233,7 @@ class RecurrenceTest extends PHPUnit\Framework\TestCase
                 '2017-08-16 11:00:00',
             ),
 /*
+            // Not supported by Sabre (requires BYMONTH too)
             array(
                 array('FREQ' => 'YEARLY', 'INTERVAL' => '2', 'BYDAY' => '-1MO'),
                 '2017-08-16 11:00:00',
@@ -334,4 +330,104 @@ class RecurrenceTest extends PHPUnit\Framework\TestCase
         $this->assertEquals($start->getTimezone()->getName(), $next['start']->getTimezone()->getName(), 'Same timezone');
         $this->assertTrue($next['start']->_dateonly, '_dateonly flag');
     }
+
+    /**
+     * Test for libcalendaring_recurrence::next_instance()
+     */
+    function test_next_instance_exdate()
+    {
+        date_default_timezone_set('America/New_York');
+
+        $start = new libcalendaring_datetime('2023-01-18 10:00:00', new DateTimeZone('Europe/Berlin'));
+        $end = new libcalendaring_datetime('2023-01-18 10:30:00', new DateTimeZone('Europe/Berlin'));
+        $event = [
+            'start' => $start,
+            'end' => $end,
+            'recurrence' => [
+                'FREQ' => 'DAILY',
+                'INTERVAL' => '1',
+                'EXDATE' => [
+                    // Exclude the start date
+                    new libcalendaring_datetime('2023-01-18 10:00:00', new DateTimeZone('Europe/Berlin')),
+                ],
+            ],
+        ];
+
+        $recurrence = new libcalendaring_recurrence($this->plugin, $event);
+
+        $next = $recurrence->next_instance();
+
+        $this->assertEquals('2023-01-19 10:00:00', $next['start']->format('Y-m-d H:i:s'));
+        $this->assertEquals('Europe/Berlin', $next['start']->getTimezone()->getName());
+        $this->assertFalse($next['start']->_dateonly);
+
+        $next = $recurrence->next_instance();
+
+        $this->assertEquals('2023-01-20 10:00:00', $next['start']->format('Y-m-d H:i:s'));
+        $this->assertEquals('Europe/Berlin', $next['start']->getTimezone()->getName());
+        $this->assertFalse($next['start']->_dateonly);
+    }
+
+    /**
+     * Test for libcalendaring_recurrence::next_instance()
+     */
+    function test_next_instance_dst()
+    {
+        date_default_timezone_set('America/New_York');
+
+        $start = new libcalendaring_datetime('2021-03-10 10:00:00', new DateTimeZone('Europe/Berlin'));
+        $end = new libcalendaring_datetime('2021-03-10 10:30:00', new DateTimeZone('Europe/Berlin'));
+        $event = [
+            'start' => $start,
+            'end' => $end,
+            'recurrence' => [
+                'FREQ' => 'MONTHLY',
+                'INTERVAL' => '1',
+            ],
+        ];
+
+        $recurrence = new libcalendaring_recurrence($this->plugin, $event);
+
+        $next = $recurrence->next_instance();
+
+        $this->assertEquals('2021-04-10 10:00:00', $next['start']->format('Y-m-d H:i:s'));
+        $this->assertEquals('Europe/Berlin', $next['start']->getTimezone()->getName());
+
+        $next = $recurrence->next_instance();
+
+        $this->assertEquals('2021-05-10 10:00:00', $next['start']->format('Y-m-d H:i:s'));
+        $this->assertEquals('Europe/Berlin', $next['start']->getTimezone()->getName());
+
+        $start = new libcalendaring_datetime('2021-10-10 10:00:00', new DateTimeZone('Europe/Berlin'));
+        $end = new libcalendaring_datetime('2021-10-10 10:30:00', new DateTimeZone('Europe/Berlin'));
+        $event = [
+            'start' => $start,
+            'end' => $end,
+            'recurrence' => [
+                'FREQ' => 'MONTHLY',
+                'INTERVAL' => '1',
+            ],
+        ];
+
+        $recurrence = new libcalendaring_recurrence($this->plugin, $event);
+
+        $next = $recurrence->next_instance();
+
+        $this->assertEquals('2021-11-10 10:00:00', $next['start']->format('Y-m-d H:i:s'));
+        $this->assertEquals('Europe/Berlin', $next['start']->getTimezone()->getName());
+
+        $next = $recurrence->next_instance();
+
+        $this->assertEquals('2021-12-10 10:00:00', $next['start']->format('Y-m-d H:i:s'));
+        $this->assertEquals('Europe/Berlin', $next['start']->getTimezone()->getName());
+
+        $next = $recurrence->next_instance();
+        $next = $recurrence->next_instance();
+        $next = $recurrence->next_instance();
+        $next = $recurrence->next_instance();
+
+        $this->assertEquals('2022-04-10 10:00:00', $next['start']->format('Y-m-d H:i:s'));
+        $this->assertEquals('Europe/Berlin', $next['start']->getTimezone()->getName());
+
+    }
 }