1 files changed, 20 insertions, 12 deletions

diff --git a/vendor/sabre/vobject/lib/ITip/Broker.php b/vendor/sabre/vobject/lib/ITip/Broker.php
index 80d9a5b31..9d68fc4c6 100644
--- a/vendor/sabre/vobject/lib/ITip/Broker.php
+++ b/vendor/sabre/vobject/lib/ITip/Broker.php
@@ -108,7 +108,7 @@ class Broker
      *
      * @return VCalendar|null
      */
-    public function processMessage(Message $itipMessage, VCalendar $existingObject = null)
+    public function processMessage(Message $itipMessage, ?VCalendar $existingObject = null)
     {
         // We only support events at the moment.
         if ('VEVENT' !== $itipMessage->component) {
@@ -266,7 +266,7 @@ class Broker
      *
      * @return VCalendar|null
      */
-    protected function processMessageRequest(Message $itipMessage, VCalendar $existingObject = null)
+    protected function processMessageRequest(Message $itipMessage, ?VCalendar $existingObject = null)
     {
         if (!$existingObject) {
             // This is a new invite, and we're just going to copy over
@@ -301,7 +301,7 @@ class Broker
      *
      * @return VCalendar|null
      */
-    protected function processMessageCancel(Message $itipMessage, VCalendar $existingObject = null)
+    protected function processMessageCancel(Message $itipMessage, ?VCalendar $existingObject = null)
     {
         if (!$existingObject) {
             // The event didn't exist in the first place, so we're just
@@ -326,7 +326,7 @@ class Broker
      *
      * @return VCalendar|null
      */
-    protected function processMessageReply(Message $itipMessage, VCalendar $existingObject = null)
+    protected function processMessageReply(Message $itipMessage, ?VCalendar $existingObject = null)
     {
         // A reply can only be processed based on an existing object.
         // If the object is not available, the reply is ignored.
@@ -338,7 +338,10 @@ class Broker
 
         // Finding all the instances the attendee replied to.
         foreach ($itipMessage->message->VEVENT as $vevent) {
-            $recurId = isset($vevent->{'RECURRENCE-ID'}) ? $vevent->{'RECURRENCE-ID'}->getValue() : 'master';
+            // Use the Unix timestamp returned by getTimestamp as a unique identifier for the recurrence.
+            // The Unix timestamp will be the same for an event, even if the reply from the attendee
+            // used a different format/timezone to express the event date-time.
+            $recurId = isset($vevent->{'RECURRENCE-ID'}) ? $vevent->{'RECURRENCE-ID'}->getDateTime()->getTimestamp() : 'master';
             $attendee = $vevent->ATTENDEE;
             $instances[$recurId] = $attendee['PARTSTAT']->getValue();
             if (isset($vevent->{'REQUEST-STATUS'})) {
@@ -351,7 +354,8 @@ class Broker
         // all the instances where we have a reply for.
         $masterObject = null;
         foreach ($existingObject->VEVENT as $vevent) {
-            $recurId = isset($vevent->{'RECURRENCE-ID'}) ? $vevent->{'RECURRENCE-ID'}->getValue() : 'master';
+            // Use the Unix timestamp returned by getTimestamp as a unique identifier for the recurrence.
+            $recurId = isset($vevent->{'RECURRENCE-ID'}) ? $vevent->{'RECURRENCE-ID'}->getDateTime()->getTimestamp() : 'master';
             if ('master' === $recurId) {
                 $masterObject = $vevent;
             }
@@ -398,7 +402,10 @@ class Broker
                 $newObject = $recurrenceIterator->getEventObject();
                 $recurrenceIterator->next();
 
-                if (isset($newObject->{'RECURRENCE-ID'}) && $newObject->{'RECURRENCE-ID'}->getValue() === $recurId) {
+                // Compare the Unix timestamp returned by getTimestamp with the previously calculated timestamp.
+                // If they are the same, then this is a matching recurrence, even though its date-time may have
+                // been expressed in a different format/timezone.
+                if (isset($newObject->{'RECURRENCE-ID'}) && $newObject->{'RECURRENCE-ID'}->getDateTime()->getTimestamp() === $recurId) {
                     $found = true;
                 }
                 --$iterations;
@@ -503,10 +510,11 @@ class Broker
                 $icalMsg->add(clone $timezone);
             }
 
-            if (!$attendee['newInstances']) {
-                // If there are no instances the attendee is a part of, it
-                // means the attendee was removed and we need to send him a
-                // CANCEL.
+            if (!$attendee['newInstances'] || 'CANCELLED' === $eventInfo['status']) {
+                // If there are no instances the attendee is a part of, it means
+                // the attendee was removed and we need to send them a CANCEL message.
+                // Also If the meeting STATUS property was changed to CANCELLED
+                // we need to send the attendee a CANCEL message.
                 $message->method = 'CANCEL';
 
                 $icalMsg->METHOD = $message->method;
@@ -800,7 +808,7 @@ class Broker
      *
      * @return array
      */
-    protected function parseEventInfo(VCalendar $calendar = null)
+    protected function parseEventInfo(?VCalendar $calendar = null)
     {
         $uid = null;
         $organizer = null;