[evolution] Bug 618125 - Due date time zone not set when using "Click to add task"

[Milan Crha <mcrha src gnome org>]

commit a00f6b1db15b755237963edb7381c9fff040dfb5
Author: Milan Crha <mcrha redhat com>
Date:   Fri Sep 1 10:03:43 2017 +0200

    Bug 618125 - Due date time zone not set when using "Click to add task"

 src/calendar/gui/e-cal-model.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)
---
diff --git a/src/calendar/gui/e-cal-model.c b/src/calendar/gui/e-cal-model.c
index fa41077..6c1e872 100644
--- a/src/calendar/gui/e-cal-model.c
+++ b/src/calendar/gui/e-cal-model.c
@@ -2626,6 +2626,7 @@ e_cal_model_update_comp_time (ECalModel *model,
        ECellDateEditValue *dv = (ECellDateEditValue *) time_value;
        icalproperty *prop;
        icalparameter *param;
+       icaltimezone *model_zone;
        struct icaltimetype tt;
 
        g_return_if_fail (model != NULL);
@@ -2650,8 +2651,9 @@ e_cal_model_update_comp_time (ECalModel *model,
                return;
        }
 
+       model_zone = e_cal_model_get_timezone (model);
        tt = dv->tt;
-       datetime_to_zone (comp_data->client, &tt, e_cal_model_get_timezone (model), param ? 
icalparameter_get_tzid (param) : NULL);
+       datetime_to_zone (comp_data->client, &tt, model_zone, param ? icalparameter_get_tzid (param) : NULL);
 
        if (prop) {
                set_func (prop, tt);
@@ -2664,11 +2666,16 @@ e_cal_model_update_comp_time (ECalModel *model,
                const gchar *tzid = icalparameter_get_tzid (param);
 
                /* If the TZID is set to "UTC", we don't want to save the TZID. */
-               if (tzid && strcmp (tzid, "UTC")) {
-                       icalparameter_set_tzid (param, (gchar *) tzid);
-               } else {
+               if (!tzid || !*tzid || !strcmp (tzid, "UTC")) {
                        icalproperty_remove_parameter_by_kind (prop, ICAL_TZID_PARAMETER);
                }
+       } else if (model_zone) {
+               const gchar *tzid = icaltimezone_get_tzid (model_zone);
+
+               if (tzid && *tzid) {
+                       param = icalparameter_new_tzid (tzid);
+                       icalproperty_add_parameter (prop, param);
+               }
        }
 }