[gnome-settings-daemon/gnome-3-18] media-keys: Fix shutdown dialog delay when using kbd shortcut

[Bastien Nocera <hadess src gnome org>]

commit ccd363432aed51ddd622268501c3636595ef18bf
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Nov 17 14:03:37 2016 +0100

    media-keys: Fix shutdown dialog delay when using kbd shortcut
    
    After pressing the Ctrl+Alt+Del shortcut, the shutdown dialog doesn't
    appear on screen for a couple of seconds.
    
    The media-keys daemon calls the 'Shutdown' method synchronously. After that
    gnome-session calls the daemon with 'QueryEndSession'. The daemon cannot
    reply as it's blocked waiting for the reply to the Shutdown method.
    
    Sending the message asynchronously fixes that delay.
    
    Based on report by Xiaoguang Wang <xwang suse com>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=774452

 plugins/media-keys/gsd-media-keys-manager.c |   46 ++++++++++++++++++---------
 1 files changed, 31 insertions(+), 15 deletions(-)
---
diff --git a/plugins/media-keys/gsd-media-keys-manager.c b/plugins/media-keys/gsd-media-keys-manager.c
index ae34db9..4341a2a 100644
--- a/plugins/media-keys/gsd-media-keys-manager.c
+++ b/plugins/media-keys/gsd-media-keys-manager.c
@@ -781,26 +781,42 @@ do_media_action (GsdMediaKeysManager *manager,
 }
 
 static void
+gnome_session_shutdown_cb (GObject *source_object,
+                           GAsyncResult *res,
+                           gpointer user_data)
+{
+        GVariant *result;
+        GError *error = NULL;
+
+        result = g_dbus_proxy_call_finish (G_DBUS_PROXY (source_object),
+                                           res,
+                                           &error);
+        if (result == NULL) {
+                if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+                        g_warning ("Failed to call Shutdown on session manager: %s",
+                                   error->message);
+                g_error_free (error);
+        } else {
+                g_variant_unref (result);
+        }
+}
+
+static void
 gnome_session_shutdown (GsdMediaKeysManager *manager)
 {
-       GError *error = NULL;
-       GVariant *variant;
         GDBusProxy *proxy;
 
         proxy = G_DBUS_PROXY (gnome_settings_bus_get_session_proxy ());
-       variant = g_dbus_proxy_call_sync (proxy,
-                                         "Shutdown",
-                                         NULL,
-                                         G_DBUS_CALL_FLAGS_NONE,
-                                         -1,
-                                         NULL,
-                                         &error);
-       if (variant == NULL) {
-               g_warning ("Failed to call Shutdown on session manager: %s", error->message);
-               g_error_free (error);
-               return;
-       }
-       g_variant_unref (variant);
+
+        g_dbus_proxy_call (proxy,
+                           "Shutdown",
+                           NULL,
+                           G_DBUS_CALL_FLAGS_NONE,
+                           -1,
+                           manager->priv->bus_cancellable,
+                           gnome_session_shutdown_cb,
+                           NULL);
+
         g_object_unref (proxy);
 }