From 88475f2e2be3e59ac7800783af6dde85a4f19dd4 Mon Sep 17 00:00:00 2001
From: Max Kellermann <mk@cm4all.com>
Date: Wed, 10 Apr 2024 12:15:22 +0200
Subject: [PATCH] util/RedBlackTree: swap colors when swapping with successor

Swapping was incomplete without swapping the colors; this led to
assertion failures under certain conditions.
---
 src/util/RedBlackTree.hxx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/util/RedBlackTree.hxx b/src/util/RedBlackTree.hxx
index 07012cede..2cffb156f 100644
--- a/src/util/RedBlackTree.hxx
+++ b/src/util/RedBlackTree.hxx
@@ -275,6 +275,8 @@ public:
 			auto &p = *parent;
 			const auto direction_in_parent = p.GetChildDirection(*this);
 
+			std::swap(color, successor.color);
+
 			successor.SetChild(Direction::LEFT, GetLeft());
 			SetChild(Direction::LEFT, nullptr);
 			SetChild(Direction::RIGHT, successor.GetRight());