[gtk+] Prevent box gadget content from being drawn twice

[Emmanuele Bassi <ebassi src gnome org>]

commit f68eaae581b3ae80828692537f29fc2caac32c6c
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Aug 6 19:33:47 2016 -0400

    Prevent box gadget content from being drawn twice
    
    Now that we split out box gadget children into separate
    render nodes, we must not draw them onto the box gadgets
    node anymore.

 gtk/gtkboxgadget.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkboxgadget.c b/gtk/gtkboxgadget.c
index 3cc94da..10bc0df 100644
--- a/gtk/gtkboxgadget.c
+++ b/gtk/gtkboxgadget.c
@@ -518,6 +518,12 @@ gtk_box_gadget_draw (GtkCssGadget *gadget,
   return FALSE;
 }
 
+static gboolean
+gtk_box_gadget_has_content (GtkCssGadget *gadget)
+{
+  return FALSE;
+}
+
 static void
 gtk_box_gadget_finalize (GObject *object)
 {
@@ -539,6 +545,7 @@ gtk_box_gadget_class_init (GtkBoxGadgetClass *klass)
   gadget_class->get_preferred_size = gtk_box_gadget_get_preferred_size;
   gadget_class->allocate = gtk_box_gadget_allocate;
   gadget_class->draw = gtk_box_gadget_draw;
+  gadget_class->has_content = gtk_box_gadget_has_content;
 }
 
 static void