[gtk+/gtk-3-8] gtkdialog - more informative warning when ordering unexisting response_id (cherry picked from commit

[Jehan Pagès <jehanp src gnome org>]

commit 81f06e17494755d0f85b15856fb895702d448bbf
Author: Jehan <jehan girinstud io>
Date:   Wed Jul 17 19:05:21 2013 +0900

    gtkdialog - more informative warning when ordering unexisting response_id
    (cherry picked from commit 0e4d9b7793c16fd98b396ffe6b8db48b8e09f1d2)

 gtk/gtkdialog.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkdialog.c b/gtk/gtkdialog.c
index b88ca5f..70e2fe1 100644
--- a/gtk/gtkdialog.c
+++ b/gtk/gtkdialog.c
@@ -1254,7 +1254,11 @@ gtk_dialog_set_alternative_button_order_valist (GtkDialog *dialog,
     {
       /* reorder child with response_id to position */
       child = dialog_find_button (dialog, response_id);
-      gtk_box_reorder_child (GTK_BOX (priv->action_area), child, position);
+      if (child != NULL)
+        gtk_box_reorder_child (GTK_BOX (priv->action_area), child, position);
+      else
+        g_warning ("%s : no child button with response id %d.", G_STRFUNC,
+                   response_id);
 
       response_id = va_arg (args, gint);
       position++;
@@ -1365,7 +1369,11 @@ gtk_dialog_set_alternative_button_order_from_array (GtkDialog *dialog,
   {
       /* reorder child with response_id to position */
       child = dialog_find_button (dialog, new_order[position]);
-      gtk_box_reorder_child (GTK_BOX (priv->action_area), child, position);
+      if (child != NULL)
+        gtk_box_reorder_child (GTK_BOX (priv->action_area), child, position);
+      else
+        g_warning ("%s : no child button with response id %d.", G_STRFUNC,
+                   new_order[position]);
     }
 }