[gnome-calendar/mcatanzaro/#485] date-time-utils: fall back to UTC when timezone is unrecognized

[Michael Catanzaro <mcatanzaro src gnome org>]

commit d3b14a2ea9decbf2fcd97e3d4b799829a3171bc2
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Tue Feb 18 15:46:24 2020 +0000

    date-time-utils: fall back to UTC when timezone is unrecognized
    
    For whatever reason, libical doesn't support the Etc/UTC timezone.
    Currently we crash gnome-calendar whenever libical doesn't support the
    current timezone (as returned by GTimeZone). Let's fall back to UTC
    instead.
    
    Fixes #485

 src/utils/gcal-date-time-utils.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/utils/gcal-date-time-utils.c b/src/utils/gcal-date-time-utils.c
index 48da114c..7555ec6c 100644
--- a/src/utils/gcal-date-time-utils.c
+++ b/src/utils/gcal-date-time-utils.c
@@ -249,7 +249,9 @@ gcal_timezone_to_icaltimezone (GTimeZone *tz)
   tzid = g_time_zone_get_identifier (tz);
   ical_tz = i_cal_timezone_get_builtin_timezone (tzid);
 
-  g_assert (ical_tz != NULL);
+  if (ical_tz == NULL)
+    ical_tz = i_cal_timezone_get_utc_timezone ();
+
   return ical_tz;
 }