[gtk+] Fix set_focus_child handling during focus changes

[Alexander Larsson <alexl src gnome org>]

commit 10b5ec20f2d42949bbec2f3519dbf5dca380fe49
Author: Alexander Larsson <alexl redhat com>
Date:   Wed Dec 14 00:23:57 2011 +0100

    Fix set_focus_child handling during focus changes
    
    In many cases we used to set focus_child to NULL all the way up
    to the top and then to the right value, even if there was
    a common ancestor, meaning these see a temporary NULL value for
    focus_child. Only when the new focus widgets direct parent was
    in the previous ancestor list did we stop early.
    
    This fixes that by always stopping propagation when reaching
    the common ancestor.

 gtk/gtkwidget.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 8d772df..6b96be4 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -6468,10 +6468,15 @@ gtk_widget_real_grab_focus (GtkWidget *focus_widget)
 
 	  if (widget)
 	    {
-	      while (widget->priv->parent && widget->priv->parent != focus_widget->priv->parent)
+	      GtkWidget *common_ancestor = gtk_widget_common_ancestor (widget, focus_widget);
+
+	      if (widget != common_ancestor)
 		{
-		  widget = widget->priv->parent;
-		  gtk_container_set_focus_child (GTK_CONTAINER (widget), NULL);
+		  while (widget->priv->parent && widget->priv->parent != common_ancestor)
+		    {
+		      widget = widget->priv->parent;
+		      gtk_container_set_focus_child (GTK_CONTAINER (widget), NULL);
+		    }
 		}
 	    }
 	}