[gtk+/gtk-3-16] notebook: Protect against invalid allocations

[Matthias Clasen <matthiasc src gnome org>]

commit 79ab6c8963d8b18624604623d3cd764a07d5ff29
Author: Benjamin Otte <otte redhat com>
Date:   Tue Mar 17 16:45:05 2015 +0100

    notebook: Protect against invalid allocations
    
    A widget can be mapped but not have a size allocated yet. In that case
    avoid computing a broken rectangle.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=746301

 gtk/gtknotebook.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtknotebook.c b/gtk/gtknotebook.c
index 65cc32e..ef27191 100644
--- a/gtk/gtknotebook.c
+++ b/gtk/gtknotebook.c
@@ -4822,6 +4822,8 @@ gtk_notebook_redraw_tabs (GtkNotebook *notebook)
   redraw_rect.y = border;
 
   gtk_widget_get_allocation (widget, &allocation);
+  if (allocation.width <= 1)
+    return;
 
   get_padding_and_border (notebook, &padding);