[glade] Fix bug 664912 "GtkGrid assumes 3x3 (edit)"

[Juan Pablo Ugarte <jpu src gnome org>]

commit 94b2137d8b0e1851626e1390f683a77cbb02d18e
Author: Juan Pablo Ugarte <juanpablougarte gmail com>
Date:   Wed Feb 15 19:09:31 2012 -0300

    Fix bug 664912 "GtkGrid assumes 3x3 (edit)"

 plugins/gtk+/glade-gtk-grid.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/plugins/gtk+/glade-gtk-grid.c b/plugins/gtk+/glade-gtk-grid.c
index e42f5f0..87e38cc 100644
--- a/plugins/gtk+/glade-gtk-grid.c
+++ b/plugins/gtk+/glade-gtk-grid.c
@@ -433,6 +433,8 @@ glade_gtk_grid_parse_finished (GladeProject *project, GObject *container)
     {
       GtkWidget *widget = list->data;
 
+      if (GLADE_IS_PLACEHOLDER (widget)) continue;
+
       glade_gtk_grid_get_child_attachments (GTK_WIDGET (container), widget, &attach);
 
       n_row = attach.top_attach + attach.height;