[gtk+] popover: Ensure there is a child before focusing it

[Carlos Garnacho <carlosg src gnome org>]

commit 99791007a77abef9375c171c62592e4b3b397d24
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sat Dec 13 17:05:56 2014 +0100

    popover: Ensure there is a child before focusing it
    
    Fixes a warning in empty popovers being shown.

 gtk/gtkpopover.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkpopover.c b/gtk/gtkpopover.c
index ef2badc..a3a1902 100644
--- a/gtk/gtkpopover.c
+++ b/gtk/gtkpopover.c
@@ -1254,9 +1254,13 @@ gtk_popover_key_press (GtkWidget   *widget,
 static void
 gtk_popover_grab_focus (GtkWidget *widget)
 {
+  GtkWidget *child;
+
   /* Focus the first natural child */
-  gtk_widget_child_focus (gtk_bin_get_child (GTK_BIN (widget)),
-                          GTK_DIR_TAB_FORWARD);
+  child = gtk_bin_get_child (GTK_BIN (widget));
+
+  if (child)
+    gtk_widget_child_focus (child, GTK_DIR_TAB_FORWARD);
 }
 
 static gboolean