[libdazzle] tree-node: set tree and parent for dummy nodes

[Christian Hergert <chergert src gnome org>]

commit a1e354dc81a09955d49621422e07d80d271f3118
Author: Christian Hergert <chergert redhat com>
Date:   Mon Dec 4 17:50:29 2017 -0800

    tree-node: set tree and parent for dummy nodes
    
    This can be useful if builders need to access the node for some
    reason (such as during DnD operations).

 src/tree/dzl-tree-node.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/tree/dzl-tree-node.c b/src/tree/dzl-tree-node.c
index a531672..92d6ef9 100644
--- a/src/tree/dzl-tree-node.c
+++ b/src/tree/dzl-tree-node.c
@@ -1079,6 +1079,8 @@ _dzl_tree_node_add_dummy_child (DzlTreeNode *self)
   model = _dzl_tree_get_store (self->tree);
   dzl_tree_node_get_iter (self, &parent);
   dummy = g_object_ref_sink (dzl_tree_node_new ());
+  _dzl_tree_node_set_tree (dummy, self->tree);
+  _dzl_tree_node_set_parent (dummy, self);
   gtk_tree_store_insert_with_values (model, &iter, &parent, -1,
                                      0, dummy,
                                      -1);