Index: calendar/ChangeLog
===================================================================
--- calendar/ChangeLog	(revision 10220)
+++ calendar/ChangeLog	(working copy)
@@ -1,3 +1,10 @@
+2009-04-16  Milan Crha  <mcrha@redhat.com>
+
+	** Fix for bug #579176
+
+	* file/e-cal-backend-file.c: (e_cal_backend_file_get_object):
+	Detached instances don't have a master object.
+
 2009-04-13  Matthew Barnes  <mbarnes@redhat.com>
 
 	* libedata-cal/e-cal-backend-sync.c:
Index: calendar/backends/file/e-cal-backend-file.c
===================================================================
--- calendar/backends/file/e-cal-backend-file.c	(revision 10220)
+++ calendar/backends/file/e-cal-backend-file.c	(working copy)
@@ -1250,9 +1250,12 @@ e_cal_backend_file_get_object (ECalBacke
 
 			/* if we have detached recurrences, return a VCALENDAR */
 			icalcomp = e_cal_util_new_top_level ();
-			icalcomponent_add_component (
-				icalcomp,
-				icalcomponent_new_clone (e_cal_component_get_icalcomponent (obj_data->full_object)));
+
+			/* detached recurrences don't have full_object (always?) */
+			if (obj_data->full_object)
+				icalcomponent_add_component (
+					icalcomp,
+					icalcomponent_new_clone (e_cal_component_get_icalcomponent (obj_data->full_object)));
 
 			/* add all detached recurrences */
 			g_hash_table_foreach (obj_data->recurrences, (GHFunc) add_detached_recur_to_vcalendar, icalcomp);
