From 0811242180be940df8351c52ac11e30eebd0283a Mon Sep 17 00:00:00 2001
From: Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
Date: Tue, 7 Dec 2021 12:25:37 -0300
Subject: [PATCH] event: Query client timezone on failure

If we can't find an appropriate timezone, query the ECalClient
for it and give it an extra chance of finding the right timezone.

Thanks to Milan Crha for proposing this fix.

Related: https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/444
---
 src/core/gcal-event.c | 40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/src/core/gcal-event.c b/src/core/gcal-event.c
index e752abfe..717b4e23 100644
--- a/src/core/gcal-event.c
+++ b/src/core/gcal-event.c
@@ -148,11 +148,12 @@ clear_range (GcalEvent *self)
 }
 
 static GTimeZone*
-get_timezone_from_ical (ECalComponentDateTime *comp)
+get_timezone_from_ical (GcalEvent             *self,
+                        ECalComponentDateTime *comp)
 {
+  g_autoptr (GTimeZone) tz = NULL;
   ICalTimezone *zone;
   ICalTime *itt;
-  GTimeZone *tz;
 
   itt = e_cal_component_datetime_get_value (comp);
   zone = i_cal_time_get_timezone (itt);
@@ -168,16 +169,29 @@ get_timezone_from_ical (ECalComponentDateTime *comp)
     }
   else if (e_cal_component_datetime_get_tzid (comp))
     {
-      const gchar *real_tzid;
+      const gchar *original_tzid, *tzid;
 
-      real_tzid = e_cal_component_datetime_get_tzid (comp);
+      tzid = e_cal_component_datetime_get_tzid (comp);
+      original_tzid = tzid;
 
-      if (g_str_has_prefix (real_tzid, LIBICAL_TZID_PREFIX))
-        real_tzid += strlen (LIBICAL_TZID_PREFIX);
+      if (g_str_has_prefix (tzid, LIBICAL_TZID_PREFIX))
+        tzid += strlen (LIBICAL_TZID_PREFIX);
 
-      tz = g_time_zone_new_identifier (real_tzid);
+      tz = g_time_zone_new_identifier (tzid);
+
+      if (!tz && self->calendar)
+        {
+          ICalTimezone *tzone = NULL;
+          ECalClient *client;
+
+          client = gcal_calendar_get_client (self->calendar);
+
+          if (client && e_cal_client_get_timezone_sync (client, original_tzid, &tzone, NULL, NULL))
+            zone = tzone;
+        }
     }
-  else if (zone)
+
+  if (!tz && zone)
     {
       g_autofree gchar *tzid = NULL;
       gint offset;
@@ -186,10 +200,6 @@ get_timezone_from_ical (ECalComponentDateTime *comp)
       tzid = format_utc_offset (offset);
       tz = g_time_zone_new_identifier (tzid);
     }
-  else
-    {
-      tz = g_time_zone_new_utc ();
-    }
 
   /*
    * If tz is NULL, the timezone identifier is invalid. Fallback to UTC
@@ -200,7 +210,7 @@ get_timezone_from_ical (ECalComponentDateTime *comp)
 
   GCAL_TRACE_MSG ("%s (%p)", g_time_zone_get_identifier (tz), tz);
 
-  return tz;
+  return g_steal_pointer (&tz);
 }
 
 static ECalComponentDateTime*
@@ -340,7 +350,7 @@ gcal_event_set_component_internal (GcalEvent     *self,
   GCAL_TRACE_MSG ("Retrieving start timezone");
 
   date = i_cal_time_normalize (e_cal_component_datetime_get_value (start));
-  zone_start = get_timezone_from_ical (start);
+  zone_start = get_timezone_from_ical (self, start);
   date_start = g_date_time_new (zone_start,
                                 i_cal_time_get_year (date),
                                 i_cal_time_get_month (date),
@@ -366,7 +376,7 @@ gcal_event_set_component_internal (GcalEvent     *self,
       GCAL_TRACE_MSG ("Retrieving end timezone");
 
       date = i_cal_time_normalize (e_cal_component_datetime_get_value (end));
-      zone_end = get_timezone_from_ical (end);
+      zone_end = get_timezone_from_ical (self, end);
       date_end = g_date_time_new (zone_end,
                                   i_cal_time_get_year (date),
                                   i_cal_time_get_month (date),