[gtk+] overlay: do not to set uninitialized values in the main allocation

[Cosimo Cecchi <cosimoc src gnome org>]

commit 170e8712e9bfe792da29d6a3d1fb7a71fbe17336
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Wed Feb 29 12:21:59 2012 -0500

    overlay: do not to set uninitialized values in the main allocation
    
    gtk_widget_translate_coordinates() can fail in case the widget is not
    realized or there's no common ancestor. Don't use the x/y values
    returned by that method in that case, since their value is undefined.

 gtk/gtkoverlay.c |   14 ++++++++++++--
 1 files changed, 12 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkoverlay.c b/gtk/gtkoverlay.c
index 331d9ee..e273849 100644
--- a/gtk/gtkoverlay.c
+++ b/gtk/gtkoverlay.c
@@ -127,12 +127,22 @@ gtk_overlay_get_main_widget_allocation (GtkOverlay *overlay,
     {
       GtkWidget *grandchild;
       gint x, y;
+      gboolean res;
 
       grandchild = gtk_bin_get_child (GTK_BIN (main_widget));
       res = gtk_widget_translate_coordinates (grandchild, main_widget, 0, 0, &x, &y);
 
-      main_alloc.x = x;
-      main_alloc.y = y;
+      if (res)
+        {
+          main_alloc.x = x;
+          main_alloc.y = y;
+        }
+      else
+        {
+          main_alloc.x = 0;
+          main_alloc.y = 0;
+        }
+
       main_alloc.width = gtk_widget_get_allocated_width (grandchild);
       main_alloc.height = gtk_widget_get_allocated_height (grandchild);
     }