[gtk+] docs: gtk_menu_attach_to_widget()

[Murray Cumming <murrayc src gnome org>]

commit 9ea08fae04590fd66d5e64a8dd43b301c961f9d7
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Jul 22 14:08:11 2013 +0200

    docs: gtk_menu_attach_to_widget()
    
    Add a few more clues about why this is useful,
    based on
    https://mail.gnome.org/archives/gtk-devel-list/2007-November/msg00176.html
    and the reference to it from gtk_menu_new_from_model().

 gtk/gtkmenu.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkmenu.c b/gtk/gtkmenu.c
index 5280975..d0c757f 100644
--- a/gtk/gtkmenu.c
+++ b/gtk/gtkmenu.c
@@ -1206,6 +1206,11 @@ attach_widget_screen_changed (GtkWidget *attach_widget,
  * Attaches the menu to the widget and provides a callback function
  * that will be invoked when the menu calls gtk_menu_detach() during
  * its destruction.
+ *
+ * If the menu is attached to the widget then it will be destroyed
+ * when the widget is destroyed, as if it was a child widget.
+ * An attached menu will also move between screens correctly if the
+ * widgets moves between screens.
  */
 void
 gtk_menu_attach_to_widget (GtkMenu           *menu,