From: Renato Westphal <renato@opensourcerouting.org>
Date: Mon, 24 Jul 2017 21:41:30 +0000 (-0300)
Subject: lib: fix corrupted RB trees
X-Git-Tag: frr-4.0-dev~492^2
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=refs%2Fpull%2F848%2Fhead;p=mirror%2Ffrr.git

lib: fix corrupted RB trees

Commit 8f942af90 introduced a bug while silencing a clang warning. Silence
the warning in a different way to fix our red-black tree implementation.

Fixes #841.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
---

diff --git a/lib/openbsd-tree.c b/lib/openbsd-tree.c
index 7e753554c9..d171e14d25 100644
--- a/lib/openbsd-tree.c
+++ b/lib/openbsd-tree.c
@@ -222,12 +222,8 @@ rbe_remove_color(const struct rb_type *t, struct rbt_tree *rbt,
 {
 	struct rb_entry *tmp;
 
-	/* Silence clang possible NULL deference warning. */
-	if (parent == NULL)
-		return;
-
 	while ((rbe == NULL || RBE_COLOR(rbe) == RB_BLACK) &&
-	    rbe != RBH_ROOT(rbt)) {
+	    rbe != RBH_ROOT(rbt) && parent) {
 		if (RBE_LEFT(parent) == rbe) {
 			tmp = RBE_RIGHT(parent);
 			if (RBE_COLOR(tmp) == RB_RED) {