[evolution-data-server] Prefer built-in timezone component in e_cal_util_copy_timezone()

[Milan Crha <mcrha src gnome org>]

commit d73d74bc4ce58d71f7bb4fa494ad695931638f6e
Author: Milan Crha <mcrha redhat com>
Date:   Wed Jun 26 18:35:55 2019 +0200

    Prefer built-in timezone component in e_cal_util_copy_timezone()
    
    This way also latitude and longitude properties are provided. It also
    makes the copied timezone more accurate to the built-in.

 src/calendar/libecal/e-cal-util.c | 9 +++++++++
 1 file changed, 9 insertions(+)
---
diff --git a/src/calendar/libecal/e-cal-util.c b/src/calendar/libecal/e-cal-util.c
index ce0f60164..2a91f7e46 100644
--- a/src/calendar/libecal/e-cal-util.c
+++ b/src/calendar/libecal/e-cal-util.c
@@ -120,6 +120,15 @@ e_cal_util_copy_timezone (const ICalTimezone *zone)
        if (!zone_copy)
                return NULL;
 
+       /* If the original component is one of the built-in, then libcal
+          loads it during the i_cal_timezone_get_component() call and
+          assigns a component to it. */
+       comp = i_cal_timezone_get_component (zone_copy);
+       if (comp) {
+               g_object_unref (comp);
+               return zone_copy;
+       }
+
        comp = i_cal_timezone_get_component (zone);
        if (comp) {
                ICalComponent *comp_copy;