From 23dd9eaa94e97450582059763fcb479e1e8fe818 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Sat, 2 Jul 2016 08:02:51 -0400 Subject: [PATCH] list: fix list_replace() for empty lists Before, it would happily copy list_head next/prev (ie. pointer to the *from* list_head), leaving things in a confused state and causing much mayhem. Signed-off-by: Rob Clark Reviewed-by: Jason Ekstrand --- src/util/list.h | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/src/util/list.h b/src/util/list.h index f0dec5da608..e8a99ac8e00 100644 --- a/src/util/list.h +++ b/src/util/list.h @@ -71,12 +71,18 @@ static inline void list_addtail(struct list_head *item, struct list_head *list) list->prev = item; } +static inline bool list_empty(struct list_head *list); + static inline void list_replace(struct list_head *from, struct list_head *to) { - to->prev = from->prev; - to->next = from->next; - from->next->prev = to; - from->prev->next = to; + if (list_empty(from)) { + list_inithead(to); + } else { + to->prev = from->prev; + to->next = from->next; + from->next->prev = to; + from->prev->next = to; + } } static inline void list_del(struct list_head *item) -- 2.30.2