iTIP: Include event details in REPLY messages (fixes #2102)

crates/groupware/src/scheduling/attendee.rs

@@ -318,6 +318,23 @@ pub(crate) fn attendee_decline<'x>(
         cancel_comp.add_uid(itip.uid);
         cancel_comp.add_dtstamp(dt_stamp.clone());
         cancel_comp.add_sequence(comp.sequence.unwrap_or_default());
+        cancel_comp.entries.extend(
+            component
+                .entries
+                .iter()
+                .filter(|e| {
+                    matches!(
+                        e.name,
+                        ICalendarProperty::Dtstart
+                            | ICalendarProperty::Dtend
+                            | ICalendarProperty::Duration
+                            | ICalendarProperty::Due
+                            | ICalendarProperty::Description
+                            | ICalendarProperty::Summary
+                    )
+                })
+                .cloned(),
+        );
 
         if let InstanceId::Recurrence(recurrence_id) = instance_id {
             cancel_comp

crates/groupware/src/scheduling/event_cancel.rs

@@ -148,6 +148,7 @@ pub(crate) fn build_cancel_component(
                 | ICalendarProperty::Summary
                 | ICalendarProperty::Dtstart
                 | ICalendarProperty::Dtend
+                | ICalendarProperty::Duration
                 | ICalendarProperty::Due
                 | ICalendarProperty::RecurrenceId
                 | ICalendarProperty::Created

crates/groupware/src/scheduling/itip.rs

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
  */
 
+use crate::scheduling::{ArchivedItipSummary, ItipMessage, ItipMessages};
 use calcard::{
     common::PartialDateTime,
     icalendar::{
@@ -18,8 +19,6 @@ use store::{
 };
 use trc::AddContext;
 
-use crate::scheduling::{ArchivedItipSummary, ItipMessage, ItipMessages};
-
 pub(crate) fn itip_build_envelope(method: ICalendarMethod) -> ICalendarComponent {
     ICalendarComponent {
         component_type: ICalendarComponentType::VCalendar,