Bug 383462 - fallback to DUE if no DTSTART is present

calendar/base/src/calTodo.js

@@ -21,6 +21,7 @@
  *
  * Contributor(s):
  *   Vladimir Vukicevic <vladimir.vukicevic@oracle.com>
+ *   Daniel Boelzle <daniel.boelzle@sun.com>
  *
  * Alternatively, the contents of this file may be used under the terms of
  * either the GNU General Public License Version 2 or later (the "GPL"), or
@@ -168,7 +169,9 @@ calTodo.prototype = {
     },
 
     get recurrenceStartDate() {
-        return this.entryDate;
+        // DTSTART is optional for VTODOs, so it's unclear if RRULE is allowed then,
+        // so fallback to DUE if no DTSTART is present:
+        return this.entryDate || this.dueDate;
     },
 
     icsEventPropMap: [