[gtk+] level bar: Don't leave css nodes behind

[Matthias Clasen <matthiasc src gnome org>]

commit 37007c47a55cae23c120040fb6a2f9199481b14d
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Mar 1 15:35:32 2016 -0500

    level bar: Don't leave css nodes behind
    
    We create and destroy gadgets inside the levelbar hierarchy here,
    and if we don't explicitly remove their CSS nodes from the parent,
    they stick around.

 gtk/gtklevelbar.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtklevelbar.c b/gtk/gtklevelbar.c
index 99317dc..d293661 100644
--- a/gtk/gtklevelbar.c
+++ b/gtk/gtklevelbar.c
@@ -586,7 +586,10 @@ update_block_nodes (GtkLevelBar *self)
   else if (n_blocks < priv->n_blocks)
     {
       for (i = n_blocks; i < priv->n_blocks; i++)
-        g_clear_object (&priv->block_gadget[i]);
+        {
+          gtk_css_node_set_parent (gtk_css_gadget_get_node (priv->block_gadget[i]), NULL);
+          g_clear_object (&priv->block_gadget[i]);
+        }
       priv->block_gadget = g_renew (GtkCssGadget*, priv->block_gadget, n_blocks);
       priv->n_blocks = n_blocks;
     }