From 3840ffc5fe51acf75e84f28273a8c764b49bb7bd Mon Sep 17 00:00:00 2001
From: Aleksander Machniak <machniak@kolabsys.com>
Date: Thu, 30 Mar 2017 10:25:12 +0200
Subject: [PATCH] Allow accept/decline/delegate (again) on event update request
 (Bifrost#T27859)

When handling an iTip request for an updated event where
start or end date has been changed, user will be able to change
his participant status.

In such cases we display RSVP buttons instead of "Update in my calendar"
button and highlight the event date.

So, e.g. if you accepted the event and then its time has been
changed by the organizer, you will be able to decline it or vice-versa.
---
 plugins/calendar/skins/larry/calendar.css     |  5 +++
 .../lib/libcalendaring_itip.php               | 31 +++++++++++++------
 plugins/libcalendaring/libcalendaring.js      |  6 +++-
 3 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/plugins/calendar/skins/larry/calendar.css b/plugins/calendar/skins/larry/calendar.css
index 4a035cb0..c8f36b14 100644
--- a/plugins/calendar/skins/larry/calendar.css
+++ b/plugins/calendar/skins/larry/calendar.css
@@ -2222,6 +2222,11 @@ div.calendar-invitebox td em {
 	font-weight: bold;
 }
 
+div.calendar-invitebox td.date.modified {
+	font-weight: bold;
+	color: red;
+}
+
 #event-rsvp .rsvp-buttons,
 div.calendar-invitebox .itip-buttons div {
 	margin-top: 0.5em;
diff --git a/plugins/libcalendaring/lib/libcalendaring_itip.php b/plugins/libcalendaring/lib/libcalendaring_itip.php
index c6eef240..c7986175 100644
--- a/plugins/libcalendaring/lib/libcalendaring_itip.php
+++ b/plugins/libcalendaring/lib/libcalendaring_itip.php
@@ -359,8 +359,8 @@ class libcalendaring_itip
     {
       $action = $event['rsvp'] ? 'rsvp' : '';
       $status = $event['fallback'];
-      $latest = false;
-      $html = '';
+      $latest = $resheduled = false;
+      $html   = '';
 
       if (is_numeric($event['changed']))
         $event['changed'] = new DateTime('@'.$event['changed']);
@@ -384,6 +384,13 @@ class libcalendaring_itip
               break;
             }
           }
+
+          // Detect re-sheduling
+          if (!$latest) {
+            // FIXME: This is probably to simplistic, or maybe we should just check
+            //        attendee's RSVP flag in the new event?
+            $resheduled = $existing['start'] != $event['start'] || $existing['end'] > $event['end'];
+          }
         }
         else {
           $rsvp = $event['rsvp'] && $this->rc->config->get('calendar_allow_itip_uninvited', true);
@@ -406,6 +413,9 @@ class libcalendaring_itip
           else if (!$existing && !$rsvp) {
             $action = 'import';
           }
+          else if ($resheduled) {
+            $action = 'rsvp';
+          }
           else if ($status_lc != 'needs-action') {
             $action = !$latest ? 'update' : '';
           }
@@ -453,14 +463,15 @@ class libcalendaring_itip
       }
 
       return array(
-          'uid' => $event['uid'],
-          'id' => asciiwords($event['uid'], true),
-          'existing' => $existing ? true : false,
-          'saved' => $existing ? true : false,
-          'latest' => $latest,
-          'status' => $status,
-          'action' => $action,
-          'html' => $html,
+          'uid'        => $event['uid'],
+          'id'         => asciiwords($event['uid'], true),
+          'existing'   => $existing ? true : false,
+          'saved'      => $existing ? true : false,
+          'latest'     => $latest,
+          'status'     => $status,
+          'action'     => $action,
+          'resheduled' => $resheduled,
+          'html'       => $html,
       );
     }
 
diff --git a/plugins/libcalendaring/libcalendaring.js b/plugins/libcalendaring/libcalendaring.js
index 985271e1..c15fa048 100644
--- a/plugins/libcalendaring/libcalendaring.js
+++ b/plugins/libcalendaring/libcalendaring.js
@@ -1287,10 +1287,14 @@ rcube_libcalendaring.update_itip_object_status = function(p)
     $('#rsvp-'+p.id+' input.button').prop('disabled', false)
       .filter('.'+String(p.status||'unknown').toLowerCase()).prop('disabled', p.latest);
   }
- 
+
   // show rsvp/import buttons (with calendar selector)
   $('#'+p.action+'-'+p.id).show().find('input.button').last().after(p.select);
 
+  // highlight date if date change detected
+  if (p.resheduled)
+    $('.calendar-eventdetails td.date').addClass('modified');
+
   // show itip box appendix after replacing the given placeholders
   if (p.append && p.append.selector) {
     var elem = $(p.append.selector);