[libdazzle] tree: check return values before removal

[Christian Hergert <chergert src gnome org>]

commit 8c1e00c19e1d8590e27a8e607f40f81009a1f7ad
Author: Christian Hergert <chergert redhat com>
Date:   Tue Nov 28 23:11:25 2017 -0800

    tree: check return values before removal

 src/tree/dzl-tree.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/src/tree/dzl-tree.c b/src/tree/dzl-tree.c
index 858792a..711bf5e 100644
--- a/src/tree/dzl-tree.c
+++ b/src/tree/dzl-tree.c
@@ -1516,13 +1516,13 @@ _dzl_tree_invalidate (DzlTree     *self,
 
   if (path != NULL)
     {
-      gtk_tree_model_get_iter (model, &iter, path);
 
-      if (gtk_tree_model_iter_children (model, &child, &iter))
+      if (gtk_tree_model_get_iter (model, &iter, path))
         {
-          while (gtk_tree_store_remove (priv->store, &child))
+          if (gtk_tree_model_iter_children (model, &child, &iter))
             {
-              /* Do nothing */
+              while (gtk_tree_store_remove (priv->store, &child))
+                { /* Do nothing */ }
             }
         }