[gnome-calendar] year-view: fix dnd

[Ernestas Kulik <ernestask src gnome org>]

commit 04617fc06b09ee62b19805f26ac0f4feb673893e
Author: Ernestas Kulik <ernestask src gnome org>
Date:   Sat Aug 6 16:40:43 2016 +0300

    year-view: fix dnd
    
    Currently, the end date is set by calling gcal_event_set_date_end() with
    new_start instead of new_end, which is incorrect.
    
    With the former issue fixed, the difference evaluates to one less than
    required when dragging to a later date. This can be fixed by calculating
    the drop date by adding to the start date and adding the difference.
    
    This commit fixes both issues.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=769470

 src/gcal-year-view.c |   29 +++++++++++------------------
 1 files changed, 11 insertions(+), 18 deletions(-)
---
diff --git a/src/gcal-year-view.c b/src/gcal-year-view.c
index 990af1d..0f512c2 100644
--- a/src/gcal-year-view.c
+++ b/src/gcal-year-view.c
@@ -1337,7 +1337,7 @@ navigator_drag_drop_cb (GcalYearView   *self,
                         guint           time,
                         GtkWidget      *navigator)
 {
-  gint day, month, diff;
+  gint day, month;
   gboolean is_title;
 
   if (calculate_day_month_for_coord (self, x, y, &day, &month, &is_title))
@@ -1354,25 +1354,18 @@ navigator_drag_drop_cb (GcalYearView   *self,
           start_dt = gcal_event_get_date_start (event);
           end_dt = gcal_event_get_date_end (event);
 
-          /*
-           * The difference is calculated in number of days. Here we have to
-           * use the start_dt's hour/minute/second since otherwise we may not
-           * calculate the difference correctly.
-           */
-          drop_date = g_date_time_new_local (self->date->year,
-                                             month + 1,
-                                             day,
-                                             g_date_time_get_hour (start_dt),
-                                             g_date_time_get_minute (start_dt),
-                                             g_date_time_get_second (start_dt));
-
-          diff = g_date_time_difference (drop_date, start_dt) / G_TIME_SPAN_DAY;
+          drop_date = g_date_time_add_full (start_dt,
+                                            self->date->year - g_date_time_get_year (start_dt),
+                                            (month + 1) - g_date_time_get_month (start_dt),
+                                            day - g_date_time_get_day_of_month (start_dt),
+                                            0, 0, 0);
 
-          if (diff != 0)
+          if (!g_date_time_equal (start_dt, drop_date))
             {
+              GTimeSpan diff = g_date_time_difference (drop_date, start_dt);
               GDateTime *new_start;
 
-              new_start = g_date_time_add_days (start_dt, diff);
+              new_start = g_date_time_add (start_dt, diff);
               gcal_event_set_date_start (event, new_start);
 
               /* The event may have a NULL end date, so we have to check it here */
@@ -1380,8 +1373,8 @@ navigator_drag_drop_cb (GcalYearView   *self,
                 {
                   GDateTime *new_end;
 
-                  new_end = g_date_time_add_days (end_dt, diff);
-                  gcal_event_set_date_end (event, new_start);
+                  new_end = g_date_time_add (end_dt, diff);
+                  gcal_event_set_date_end (event, new_end);
 
                   g_clear_pointer (&new_end, g_date_time_unref);
                 }