From eed36075645ecc3d3ef202c94badb66818114c2c Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 19 Sep 2008 12:41:12 +0000 Subject: [PATCH] Avoid undefined behavior for removing elements that were not in the tree. Originally committed as revision 15368 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavutil/tree.c | 10 ++++++---- libavutil/tree.h | 3 +-- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/libavutil/tree.c b/libavutil/tree.c index cb442ff4b0..64653aaccb 100644 --- a/libavutil/tree.c +++ b/libavutil/tree.c @@ -119,8 +119,11 @@ void *av_tree_insert(AVTreeNode **tp, void *key, int (*cmp)(void *key, const voi return ret; }else{ *tp= *next; *next= NULL; - (*tp)->elem= key; - return NULL; + if(*tp){ + (*tp)->elem= key; + return NULL; + }else + return key; } } @@ -188,8 +191,7 @@ int main(void){ av_tree_insert(&root, (void*)(j+1), cmp, &node); j= (random()%86294); - k= av_tree_find(root, (void*)(j+1), cmp, NULL); - if(k){ + { AVTreeNode *node2=NULL; av_log(NULL, AV_LOG_ERROR, "removing %4d\n", j); av_tree_insert(&root, (void*)(j+1), cmp, &node2); diff --git a/libavutil/tree.h b/libavutil/tree.h index c457234b09..ed6611c520 100644 --- a/libavutil/tree.h +++ b/libavutil/tree.h @@ -45,8 +45,7 @@ void *av_tree_find(const struct AVTreeNode *root, void *key, int (*cmp)(void *ke /** * Inserts or removes an element. - * If *next is NULL then the element supplied will be removed, if no such - * element exists behavior is undefined. + * If *next is NULL then the element supplied will be removed if it exists. * If *next is not NULL then the element supplied will be inserted, unless * it already exists in the tree. * @param rootp A pointer to a pointer to the root node of the tree. Note that