GtkApplication: avoid using stale timestamps

Avoid using a stale timestamp (from the last user interaction with the
application) when a message arrives from D-Bus requesting that a new
window be created.

In this case the most-correct thing that we can do is to use no
timestamp at all.

We modify gdk_x11_display_set_startup_notification_id() to allow a NULL
value to mean "reset everything" and then call this function
unconditionally on receipt of D-Bus activation requests.  The result
will be that a missing desktop-startup-id in the platform-data struct
will reset the timestamp.

Under their default configuration metacity and mutter will both map
windows presented with no timestamp in the foreground.  This could
result in false-positive, but there is very little we can do about that
without the original timestamp from the user event.

https://bugzilla.gnome.org/show_bug.cgi?id=752000

1 files changed, 5 insertions, 8 deletions

diff --git a/gtk/gtkapplication-x11.c b/gtk/gtkapplication-x11.c
index 4ee5b8fec0..8c52be8490 100644
--- a/gtk/gtkapplication-x11.c
+++ b/gtk/gtkapplication-x11.c
@@ -82,14 +82,11 @@ static void
 gtk_application_impl_x11_before_emit (GtkApplicationImpl *impl,
                                       GVariant           *platform_data)
 {
-  const char *startup_notification_id;
-
-  if (g_variant_lookup (platform_data, "desktop-startup-id",
-                        "&s", &startup_notification_id))
-    {
-      gdk_x11_display_set_startup_notification_id (gdk_display_get_default (),
-                                                   startup_notification_id);
-    }
+  const char *startup_notification_id = NULL;
+
+  g_variant_lookup (platform_data, "desktop-startup-id", "&s", &startup_notification_id);
+
+  gdk_x11_display_set_startup_notification_id (gdk_display_get_default (), startup_notification_id);
 }
 
 static void