[gnome-calendar] week-grid: make sure events span at least 1 minute

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit cdc5bde96a56bf338216158dc1e9ebb34f8f054d
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Thu Jan 26 19:14:42 2017 -0200

    week-grid: make sure events span at least 1 minute
    
    When adding an event with the same start and end dates and
    times, the event effectively spans 0 minutes, leading a division
    by zero and causing varius UI glitches.
    
    Fix that by making sure events span at least 1 minute.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=777414

 src/views/gcal-week-grid.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/src/views/gcal-week-grid.c b/src/views/gcal-week-grid.c
index 15b5892..54fb6af 100644
--- a/src/views/gcal-week-grid.c
+++ b/src/views/gcal-week-grid.c
@@ -166,6 +166,14 @@ get_event_range (GcalWeekGrid *self,
       diff = g_date_time_difference (event_end, week_start);
       *end = CLAMP (diff / G_TIME_SPAN_MINUTE, 0, MAX_MINUTES);
 
+      /*
+       * XXX: it may happen that the event has the same start and end
+       * dates. For this case, just enforce that the event is at least
+       * 1 minute long.
+       */
+      if (start && *start == *end)
+        *end = *end + 1;
+
       g_clear_pointer (&event_end, g_date_time_unref);
     }