aatree: add 'const' to aatree_is_nil_node()

diff --git a/usual/aatree.h b/usual/aatree.h
index 821a1ea6d06036a9679bd58951e718609cbc8baa..aff1a9dc664758d999df609cc6928a28d97c87b4 100644 (file)
--- a/usual/aatree.h
+++ b/usual/aatree.h
@@ -63,7 +63,7 @@ void aatree_walk(struct AATree *tree, enum AATreeWalkType wtype, aatree_walker_f
 void aatree_destroy(struct AATree *tree);
 
 /* aatree does not use NULL pointers */
-static inline int aatree_is_nil_node(struct AANode *node)
+static inline int aatree_is_nil_node(const struct AANode *node)
 {
        return (node->left == node);
 }