Fix support for recurrent tasks (cont'd)

Fixes #3864

SoObjects/Appointments/SOGoAppointmentFolder.m

@@ -1007,13 +1007,13 @@ firstInstanceCalendarDateRange: (NGCalendarDateRange *) fir
     {
       master = [[[component parent] events] objectAtIndex: 0];
       masterEndDate = [master endDate];
-      endDate = [component endDate];
+      endDate = [(iCalEvent*) component endDate];
     }
   else
     {
       master = [[[component parent] todos] objectAtIndex: 0];
       masterEndDate = [master due];
-      endDate = [component due];
+      endDate = [(iCalToDo*) component due];
     }
 
   delta = [masterEndDate timeIntervalSinceDate: [master startDate]];
@@ -1027,7 +1027,7 @@ firstInstanceCalendarDateRange: (NGCalendarDateRange *) fir
       if (recordIndex > -1)
 	{
           if ([dateRange containsDate: [component startDate]] ||
-	      [dateRange containsDate: endDate])
+	      (endDate && [dateRange containsDate: endDate]))
 	    {
               // We must pass nil to :container here in order to avoid re-entrancy issues.
               newRecord = [self _fixupRecord: [component quickRecordFromContent: nil  container: nil]];

SoObjects/Appointments/iCalToDo+SOGo.m

@@ -1,6 +1,6 @@
 /* iCalToDot+SOGo.m - this file is part of SOGo
  *
- * Copyright (C) 2008-2014 Inverse inc.
+ * Copyright (C) 2008-2016 Inverse inc.
  *
  * This file is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -32,6 +32,7 @@
 
 #import <SoObjects/SOGo/WOContext+SOGo.h>
 
+#import <SOGo/CardElement+SOGo.h>
 #import <SOGo/NSCalendarDate+SOGo.h>
 #import <SOGo/SOGoUser.h>
 #import <SOGo/SOGoUserDefaults.h>
@@ -367,7 +368,11 @@
 
 - (NSTimeInterval) occurenceInterval
 {
-  return [[self due] timeIntervalSinceDate: [self startDate]];
+  if ([self due])
+    return [[self due] timeIntervalSinceDate: [self startDate]];
+  else
+    // When no due date is defined, base recurrence calculation on a 60-minute duration
+    return 3600;
 }
 
 @end