[california] Don't crash when updating recurring event: Bug #737235

[Jim Nelson <jnelson src gnome org>]

commit 353e96d6201b4eb08ad0dd9b76a35a07f52d6c9b
Author: Jim Nelson <jim yorba org>
Date:   Wed Sep 24 13:45:18 2014 -0700

    Don't crash when updating recurring event: Bug #737235
    
    Property notification can cause make_rrule() from being called before
    widgets are properly configured to reflect RRULE.

 src/host/host-create-update-recurring.vala |   21 +++++++++++++++++++--
 1 files changed, 19 insertions(+), 2 deletions(-)
---
diff --git a/src/host/host-create-update-recurring.vala b/src/host/host-create-update-recurring.vala
index ad49c4a..86ab149 100644
--- a/src/host/host-create-update-recurring.vala
+++ b/src/host/host-create-update-recurring.vala
@@ -410,7 +410,7 @@ public class CreateUpdateRecurring : Gtk.Grid, Toolkit.Card {
     
     [GtkCallback]
     private void on_update_explanation() {
-        update_explanation(make_recurring_checkbutton.active ? make_rrule() : null, start_date);
+        update_explanation(can_make_rrule() ? make_rrule() : null, start_date);
     }
     
     [GtkCallback]
@@ -491,6 +491,23 @@ public class CreateUpdateRecurring : Gtk.Grid, Toolkit.Card {
         jump_to_card_by_name(CreateUpdateEvent.ID, event);
     }
     
+    private bool can_make_rrule() {
+        if (!make_recurring_checkbutton.active)
+            return false;
+        
+        switch (repeats_combobox.active) {
+            case Repeats.DAILY:
+            case Repeats.WEEKLY:
+            case Repeats.DAY_OF_THE_WEEK:
+            case Repeats.DAY_OF_THE_MONTH:
+            case Repeats.YEARLY:
+                return true;
+            
+            default:
+                return false;
+        }
+    }
+    
     private Component.RecurrenceRule make_rrule() {
         iCal.icalrecurrencetype_frequency freq;
         switch (repeats_combobox.active) {
@@ -593,7 +610,7 @@ public class CreateUpdateRecurring : Gtk.Grid, Toolkit.Card {
         master.exdates = null;
         master.rdates = null;
         
-        if (!make_recurring_checkbutton.active)
+        if (!can_make_rrule())
             master.make_recurring(null);
         else
             master.make_recurring(make_rrule());