rbtree: Add assertions to clarify usage

diff --git a/gtk/gtkrbtree.c b/gtk/gtkrbtree.c
index 53faea2bea1ea6a6ebd9b95acaffcf0bc390bb69..279df205df4a483dc80c6e8bd84e737b2a365482 100644 (file)
--- a/gtk/gtkrbtree.c
+++ b/gtk/gtkrbtree.c
@@ -472,6 +472,7 @@ _gtk_rbtree_insert_after (GtkRBTree *tree,
     }
   else
     {
+      g_assert (tree->root == tree->nil);
       tree->root = node;
       tmp_node = tree->parent_node;
       tmp_tree = tree->parent_tree;
@@ -558,6 +559,7 @@ _gtk_rbtree_insert_before (GtkRBTree *tree,
     }
   else
     {
+      g_assert (tree->root == tree->nil);
       tree->root = node;
       tmp_node = tree->parent_node;
       tmp_tree = tree->parent_tree;