Add reset key function for maps

Allows changing the pointer to key when they are equivalent (by cmp
function), to avoid memory leaks that could happen if we assumed either
pointer was to be freed or overwritten.

1 files changed, 23 insertions, 0 deletions

diff --git a/collections/map/map.c b/collections/map/map.c
index 83a446d..7de58e4 100644
--- a/collections/map/map.c
+++ b/collections/map/map.c
@@ -82,6 +82,29 @@ void *key, *val;
 	return 0;
 }
 
+void* map_reset_key(root, key)
+map *root;
+void *key;
+{
+	void *tmp;
+	int cmp;
+
+	if (!root || !key)
+		return NULL;
+
+	cmp = root->cmp(root->key, key);
+
+	if (cmp < 0)
+		return map_reset_key(root->left, key);
+
+	if (cmp > 0)
+		return map_reset_key(root->right, key);
+
+	tmp = root->key;
+	root->key = key;
+	return tmp;
+}
+
 void map_clear(root)
 map *root;
 {