[gnome-builder] tree: return NULL path for root node

[Christian Hergert <chergert src gnome org>]

commit 278452cc9a037ef32382e692ec8583f63ac5d9ca
Author: Christian Hergert <christian hergert me>
Date:   Sun Jun 14 20:10:32 2015 -0700

    tree: return NULL path for root node

 src/tree/gb-tree-node.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/tree/gb-tree-node.c b/src/tree/gb-tree-node.c
index 6bd202f..411afcf 100644
--- a/src/tree/gb-tree-node.c
+++ b/src/tree/gb-tree-node.c
@@ -199,6 +199,9 @@ gb_tree_node_get_path (GbTreeNode *node)
 
   g_return_val_if_fail (GB_IS_TREE_NODE (node), NULL);
 
+  if ((node->parent == NULL) || (node->tree == NULL))
+    return NULL;
+
   do
     list = g_list_prepend (list, node);
   while ((node = node->parent));