[evolution-mapi] Include timezone components in meeting invitation mails/components

[Milan Crha <mcrha src gnome org>]

commit 96fd08743cee5da62d66830f4fd59e66dc639ec1
Author: Milan Crha <mcrha redhat com>
Date:   Wed Aug 31 16:03:39 2016 +0200

    Include timezone components in meeting invitation mails/components
    
    Without the timezone component the time cannot be properly
    computed, it can be only guessed. This makes it sure that
    the correct timezone is used.

 src/libexchangemapi/e-mapi-mail-utils.c |   51 +++++++++++++++++++++++++++++-
 1 files changed, 49 insertions(+), 2 deletions(-)
---
diff --git a/src/libexchangemapi/e-mapi-mail-utils.c b/src/libexchangemapi/e-mapi-mail-utils.c
index f71aef1..835c687 100644
--- a/src/libexchangemapi/e-mapi-mail-utils.c
+++ b/src/libexchangemapi/e-mapi-mail-utils.c
@@ -281,6 +281,40 @@ is_apple_attach (EMapiAttachment *attach, guint32 *data_len, guint32 *resource_l
        return is_apple;
 }
 
+typedef struct {
+       GHashTable *tzids;
+       icalcomponent *icalcomp;
+} ForeachTZIDData;
+
+static void
+add_timezones_cb (icalparameter *param,
+                 gpointer data)
+{
+       ForeachTZIDData *tz_data = data;
+       const gchar *tzid;
+       icaltimezone *zone = NULL;
+       icalcomponent *vtimezone_comp;
+
+       /* Get the TZID string from the parameter. */
+       tzid = icalparameter_get_tzid (param);
+       if (!tzid || g_hash_table_lookup (tz_data->tzids, tzid))
+               return;
+
+       /* Look for the timezone */
+       zone = icaltimezone_get_builtin_timezone_from_tzid (tzid);
+       if (!zone)
+               return;
+
+       /* Convert it to a string and add it to the hash. */
+       vtimezone_comp = icaltimezone_get_component (zone);
+       if (!vtimezone_comp)
+               return;
+
+       icalcomponent_add_component (tz_data->icalcomp, icalcomponent_new_clone (vtimezone_comp));
+
+       g_hash_table_insert (tz_data->tzids, (gchar *) tzid, (gchar *) tzid);
+}
+
 static gchar *
 build_ical_string (EMapiConnection *conn,
                   EMapiObject *object,
@@ -334,12 +368,25 @@ build_ical_string (EMapiConnection *conn,
                return NULL;
 
        if (ical_method != ICAL_METHOD_NONE || detached_components) {
+               ForeachTZIDData tz_data;
+               icalcomponent *clone;
+
+               clone = icalcomponent_new_clone (e_cal_component_get_icalcomponent (comp));
+
                icalcomp = e_cal_util_new_top_level ();
                if (ical_method != ICAL_METHOD_NONE)
                        icalcomponent_set_method (icalcomp, ical_method);
 
-               icalcomponent_add_component (icalcomp,
-                       icalcomponent_new_clone (e_cal_component_get_icalcomponent (comp)));
+               tz_data.tzids = g_hash_table_new (g_str_hash, g_str_equal);
+               tz_data.icalcomp = icalcomp;
+
+               /* Add timezones first */
+               icalcomponent_foreach_tzid (clone, add_timezones_cb, &tz_data);
+
+               g_hash_table_destroy (tz_data.tzids);
+
+               /* Then the components */
+               icalcomponent_add_component (icalcomp, clone);
                for (iter = detached_components; iter; iter = g_slist_next (iter)) {
                        icalcomponent_add_component (icalcomp,
                                icalcomponent_new_clone (e_cal_component_get_icalcomponent (iter->data)));