Process event attendee reply status

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -158,8 +158,9 @@ import javax.mail.internet.ParseException;
 import biweekly.Biweekly;
 import biweekly.ICalendar;
 import biweekly.component.VEvent;
+import biweekly.parameter.ParticipationStatus;
+import biweekly.property.Attendee;
 import biweekly.property.Method;
-import biweekly.property.Status;
 import ezvcard.VCard;
 import ezvcard.VCardVersion;
 import ezvcard.io.text.VCardWriter;
@@ -4453,12 +4454,27 @@ public class MessageHelper {
                 else if (method == null || method.isRequest() || method.isReply()) {
                     int status = CalendarContract.Events.STATUS_TENTATIVE;
                     if (method != null && method.isReply()) {
-                        Status istatus = event.getStatus();
-                        if (istatus != null)
-                            if (Status.ACCEPTED.equals(istatus.getValue()))
+                        List<Attendee> attendees = event.getAttendees();
+                        if (attendees != null && message.to != null)
+                            for (Attendee attendee : attendees) {
+                                String email = attendee.getEmail();
+                                for (Address to : message.to) {
+                                    String recipient = ((InternetAddress) to).getAddress();
+                                    if (!TextUtils.isEmpty(email) && email.equalsIgnoreCase(recipient)) {
+                                        ParticipationStatus pstatus = attendee.getParticipationStatus();
+                                        if (ParticipationStatus.ACCEPTED.equals(pstatus))
                                             status = CalendarContract.Events.STATUS_CONFIRMED;
-                            else if (Status.CANCELLED.equals(istatus.getValue()))
+                                        else if (ParticipationStatus.DECLINED.equals(pstatus))
                                             status = CalendarContract.Events.STATUS_CANCELED;
+                                        break;
+                                    }
+                                }
+                            }
+                    }
+
+                    if (status == CalendarContract.Events.STATUS_CANCELED) {
+                        CalendarHelper.delete(context, event, message);
+                        return;
                     }
 
                     if (status == CalendarContract.Events.STATUS_TENTATIVE && !ical_tentative) {