[gtk+] Avoid a critical

[Matthias Clasen <matthiasc src gnome org>]

commit e26fddc544c76bcc175a8b553525dcfb0daa8f67
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Nov 27 18:22:52 2014 -0500

    Avoid a critical
    
    gtk_window_get_focus can return NULL, deal with it.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=740812

 gtk/gtkpopover.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkpopover.c b/gtk/gtkpopover.c
index 38214c9..83a8111 100644
--- a/gtk/gtkpopover.c
+++ b/gtk/gtkpopover.c
@@ -311,7 +311,7 @@ window_focus_in (GtkWidget  *widget,
 
       focus = gtk_window_get_focus (GTK_WINDOW (widget));
 
-      if (!gtk_widget_is_ancestor (focus, GTK_WIDGET (popover)))
+      if (focus == NULL || !gtk_widget_is_ancestor (focus, GTK_WIDGET (popover)))
         gtk_widget_grab_focus (GTK_WIDGET (popover));
 
       if (priv->grab_notify_blocked)