Take the timezone link from /etc/localtime

src/slack-timedate.cpp

@@ -31,6 +31,7 @@ static void slack_method_call (GDBusConnection *connection, const gchar *sender,
 	gchar *timezone, *response;
 	gboolean user_interaction, relative, is_localtime, use_ntp;
 	gint64 usec_utc;
+    auto timedate1 = reinterpret_cast<dlackware::timedate::timedate1 *>(user_data);
 
 	// Set time zone
     if (g_strcmp0(method_name, "SetTimezone") == 0)
@@ -88,7 +89,7 @@ static void slack_method_call (GDBusConnection *connection, const gchar *sender,
         try
         {
             auto return_tuple = Glib::Variant<std::vector<Glib::ustring>>::create_tuple({
-                    dlackware::timedate::list_timezones()
+                    timedate1->list_timezones()
             });
             g_dbus_method_invocation_return_value(invocation, return_tuple.gobj());
         }
@@ -101,8 +102,10 @@ static void slack_method_call (GDBusConnection *connection, const gchar *sender,
 }
 
 static GVariant *slack_get_property (GDBusConnection *connection, const gchar *sender, const gchar *object_path, const gchar *interface_name, const gchar *prop_name, GError **slack_err, gpointer user_data) {
+    auto timedate1 = reinterpret_cast<dlackware::timedate::timedate1 *>(user_data);
+
 	if (g_strcmp0 ("Timezone", prop_name) == 0) {
-		return g_variant_new_string (slack_get_timezone ());
+		return Glib::Variant<Glib::ustring>::create(timedate1->timezone()).gobj_copy();
 	} if (g_strcmp0 ("LocalRTC", prop_name) == 0) {
 		return g_variant_new_boolean (slack_get_is_localtime ());
 	} if (g_strcmp0 ("NTP", prop_name) == 0) {
@@ -131,7 +134,7 @@ static void on_timedate_acquired (GDBusConnection *connection, const gchar *name
 			BUS_PATH,
 			introspection_data->interfaces[0],
 			&interface_vtable,
-			NULL,
+			user_data,
 			NULL,
 			&slack_err);
 
@@ -155,14 +158,15 @@ gboolean timeout_callback (Glib::RefPtr<Glib::MainLoop> loop2quit) {
 
 int main(int argc, char **argv)
 {
+    auto timedate1 = new dlackware::timedate::timedate1();
 	guint owner_id = g_bus_own_name (G_BUS_TYPE_SYSTEM,
 			BUS_NAME,
 			static_cast<GBusNameOwnerFlags>(G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT | G_BUS_NAME_OWNER_FLAGS_REPLACE),
 			on_timedate_acquired,
 			NULL,
 			on_timedate_lost,
-			NULL,
-			NULL);
+			timedate1,
+			[](void *memory) { delete reinterpret_cast<dlackware::timedate::timedate1 *>(memory); });
     Glib::RefPtr<Glib::MainLoop> loop = Glib::MainLoop::create(false);
 
     Glib::signal_timeout().connect_seconds(sigc::bind(&timeout_callback, loop), DEFAULT_EXIT_SEC);
@@ -175,7 +179,7 @@ int main(int argc, char **argv)
 
 namespace dlackware::timedate
 {
-    void list_timezones(const std::string& prefix, std::vector<Glib::ustring>& accumulator)
+    void timedate1::list_timezones(const std::string& prefix, std::vector<Glib::ustring>& accumulator)
     {
         constexpr Glib::FileTest is_directory = Glib::FILE_TEST_IS_DIR;
         constexpr Glib::FileTest is_regular = Glib::FILE_TEST_IS_REGULAR;
@@ -198,25 +202,25 @@ namespace dlackware::timedate
         }
     }
 
-    Glib::Variant<std::vector<Glib::ustring>> list_timezones()
+    Glib::Variant<std::vector<Glib::ustring>> timedate1::list_timezones()
     {
         std::vector<Glib::ustring> result;
 
         list_timezones("", result);
         return Glib::Variant<std::vector<Glib::ustring>>::create(result);
     }
-}
 
-gchar *slack_get_timezone () {
-	gchar *zone_copied_from, *zone;
+    Glib::ustring timedate1::timezone()
+    {
+        std::unique_ptr<gchar[], decltype(&g_free)> zone_copied_from(
+                g_file_read_link("/etc/localtime", NULL), &g_free);
 
-	zone_copied_from = g_file_read_link ("/etc/localtime-copied-from", NULL);
-	if (zone_copied_from == NULL) return NULL;
-
-	zone = g_strdup (zone_copied_from + strlen ("/usr/share/zoneinfo/") * sizeof (gchar));
-	g_free (zone_copied_from);
-
-	return zone;
+        if (zone_copied_from == nullptr)
+        {
+            return nullptr;
+        }
+        return Glib::ustring{ zone_copied_from.get() + strlen(zoneinfo_database) + 1 };
+    }
 }
 
 gboolean slack_set_timezone (gchar *zone) {

src/slack-timedate.h

@@ -63,12 +63,18 @@ namespace dlackware::timedate
 {
     constexpr const char *zoneinfo_database = "/usr/share/zoneinfo";
 
+    class timedate1
+    {
         void list_timezones(const std::string& prefix, std::vector<Glib::ustring>& accumulator);
-    Glib::Variant<std::vector<Glib::ustring>> list_timezones();
-}
 
-// Returns the system time zone
-gchar *slack_get_timezone ();
+    public:
+        // Returns the timezones available on the system.
+        Glib::Variant<std::vector<Glib::ustring>> list_timezones();
+
+        // Returns the system time zone.
+        Glib::ustring timezone();
+    };
+}
 
 // Sets the system time zone to the one passed by the argument
 // Returns true on success, false otherwise