liblist-c

commit 2f54fc46a72f532feb3f98a4cc2cae88bbd0169f
parent f4883a69092d5a6f7ce0a66bfdcd89b6e91fd84c
Author: Louis Burda <quent.burda@gmail.com>
Date:   Fri, 25 Feb 2022 01:31:00 +0100

Ensure list_at only returns links that may be UPCAST

Diffstat:
M
src/list.c
 | 
8
++++++--

1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/src/list.c b/src/list.c
@@ -143,12 +143,16 @@ list_index(struct list *list, struct link *target)
 struct link *
 list_at(struct list *list, int n)
 {
+	struct link * link;
+
 	ASSERT(list != NULL);
 
 	if (n >= 0)
-		return link_iter_fwd(list->head.next, n);
+		link = link_iter_fwd(list->head.next, n);
 	else
-		return link_iter_bwd(&list->tail, -n);
+		link = link_iter_bwd(&list->tail, -n);
+
+	return LIST_INNER(link) ? link : NULL;
 }
 
 struct link *