diff options
Diffstat (limited to 'main/musl/0016-fix-tdelete-to-properly-balance-the-tree.patch')
| -rw-r--r-- | main/musl/0016-fix-tdelete-to-properly-balance-the-tree.patch | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/main/musl/0016-fix-tdelete-to-properly-balance-the-tree.patch b/main/musl/0016-fix-tdelete-to-properly-balance-the-tree.patch new file mode 100644 index 0000000000..bb3c79cfbf --- /dev/null +++ b/main/musl/0016-fix-tdelete-to-properly-balance-the-tree.patch @@ -0,0 +1,53 @@ +From e4f9d811684011d8a67e363827de39d5f2d3ae5a Mon Sep 17 00:00:00 2001 +From: Szabolcs Nagy <nsz@port70.net> +Date: Sat, 5 Dec 2015 21:02:34 +0100 +Subject: [PATCH] fix tdelete to properly balance the tree + +the tsearch data structure is an avl tree, but it did not implement +the deletion operation correctly so the tree could become unbalanced. + +reported by Ed Schouten. +--- + src/search/tsearch_avl.c | 19 ++++++++++++++----- + 1 file changed, 14 insertions(+), 5 deletions(-) + +diff --git a/src/search/tsearch_avl.c b/src/search/tsearch_avl.c +index 8620092..0864460 100644 +--- a/src/search/tsearch_avl.c ++++ b/src/search/tsearch_avl.c +@@ -105,10 +105,13 @@ static struct node *insert(struct node **n, const void *k, + return r; + } + +-static struct node *movr(struct node *n, struct node *r) { +- if (!n) +- return r; +- n->right = movr(n->right, r); ++static struct node *remove_rightmost(struct node *n, struct node **rightmost) ++{ ++ if (!n->right) { ++ *rightmost = n; ++ return n->left; ++ } ++ n->right = remove_rightmost(n->right, rightmost); + return balance(n); + } + +@@ -122,7 +125,13 @@ static struct node *remove(struct node **n, const void *k, + c = cmp(k, (*n)->key); + if (c == 0) { + struct node *r = *n; +- *n = movr(r->left, r->right); ++ if (r->left) { ++ r->left = remove_rightmost(r->left, n); ++ (*n)->left = r->left; ++ (*n)->right = r->right; ++ *n = balance(*n); ++ } else ++ *n = r->right; + free(r); + return parent; + } +-- +2.7.0 + |