[gtk+] box: Document child node ordering

[Matthias Clasen <matthiasc src gnome org>]

commit 2677eee720f498a58540a694d6cb1498bebcfbeb
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jan 12 23:40:28 2016 -0500

    box: Document child node ordering

 gtk/gtkbox.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkbox.c b/gtk/gtkbox.c
index a99b4fd..a8a4dc6 100644
--- a/gtk/gtkbox.c
+++ b/gtk/gtkbox.c
@@ -74,7 +74,9 @@
  *
  * # CSS nodes
  *
- * GtkBox uses a single CSS node with name box.
+ * GtkBox uses a single CSS node with name box. The nodes of the children
+ * are always arranged from left to right. So box :first-child will always
+ * select the leftmost child, regardless of text direction.
  */
 
 #include "config.h"