[evolution] I#1853 - Tasks: Cannot remove recurrence and Start date at the same time

[Milan Crha <mcrha src gnome org>]

commit 6268ff9717b907b86ac3cb74618ab2e1495c17cf
Author: Milan Crha <mcrha redhat com>
Date:   Fri Apr 1 12:28:17 2022 +0200

    I#1853 - Tasks: Cannot remove recurrence and Start date at the same time
    
    Closes https://gitlab.gnome.org/GNOME/evolution/-/issues/1853

 src/calendar/gui/e-comp-editor-task.c | 37 +++++++++++++++++------------------
 1 file changed, 18 insertions(+), 19 deletions(-)
---
diff --git a/src/calendar/gui/e-comp-editor-task.c b/src/calendar/gui/e-comp-editor-task.c
index 3fde93a7ac..26ac39e9fa 100644
--- a/src/calendar/gui/e-comp-editor-task.c
+++ b/src/calendar/gui/e-comp-editor-task.c
@@ -621,25 +621,6 @@ ece_task_fill_component (ECompEditor *comp_editor,
                return FALSE;
        }
 
-       if (e_cal_util_component_has_recurrences (component)) {
-               ICalTime *dtstart;
-
-               dtstart = e_comp_editor_property_part_datetime_get_value 
(E_COMP_EDITOR_PROPERTY_PART_DATETIME (task_editor->priv->dtstart));
-
-               if (!dtstart || i_cal_time_is_null_time (dtstart) || !i_cal_time_is_valid_time (dtstart)) {
-                       e_comp_editor_set_validation_error (comp_editor,
-                               task_editor->priv->page_general,
-                               e_comp_editor_property_part_get_edit_widget (task_editor->priv->dtstart),
-                               _("Start date is required for recurring tasks"));
-
-                       g_clear_object (&dtstart);
-
-                       return FALSE;
-               }
-
-               g_clear_object (&dtstart);
-       }
-
        if (!e_comp_editor_property_part_datetime_check_validity (
                E_COMP_EDITOR_PROPERTY_PART_DATETIME (task_editor->priv->due_date), NULL, NULL)) {
 
@@ -715,6 +696,24 @@ ece_task_fill_component (ECompEditor *comp_editor,
 
        if (e_cal_util_component_has_recurrences (component)) {
                ECalClient *cal_client;
+               ICalTime *dtstart;
+
+               /* Check this only after the recurrence page updates the component,
+                  like when the component is not recurring anymore. */
+               dtstart = e_comp_editor_property_part_datetime_get_value 
(E_COMP_EDITOR_PROPERTY_PART_DATETIME (task_editor->priv->dtstart));
+
+               if (!dtstart || i_cal_time_is_null_time (dtstart) || !i_cal_time_is_valid_time (dtstart)) {
+                       e_comp_editor_set_validation_error (comp_editor,
+                               task_editor->priv->page_general,
+                               e_comp_editor_property_part_get_edit_widget (task_editor->priv->dtstart),
+                               _("Start date is required for recurring tasks"));
+
+                       g_clear_object (&dtstart);
+
+                       return FALSE;
+               }
+
+               g_clear_object (&dtstart);
 
                cal_client = e_comp_editor_get_source_client (comp_editor);
                if (!cal_client)