From 44f55e1866cdfc50d1a046040df8405d171af80d Mon Sep 17 00:00:00 2001
From: Max Kellermann <max.kellermann@gmail.com>
Date: Mon, 11 Sep 2023 21:14:39 +0200
Subject: [PATCH] util/IntrusiveList: add missing initializer to insert_after()

We must not call std::next() if the list head was not yet initialized.
This was missing in commit 70654259270fdaae2906fb9fe4f34c6e3a740c37
---
 src/util/IntrusiveList.hxx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/util/IntrusiveList.hxx b/src/util/IntrusiveList.hxx
index e5af95e16..a004759a0 100644
--- a/src/util/IntrusiveList.hxx
+++ b/src/util/IntrusiveList.hxx
@@ -538,6 +538,10 @@ public:
 	 * Like insert(), but insert after the given position.
 	 */
 	void insert_after(iterator p, reference t) noexcept {
+		if constexpr (options.zero_initialized)
+			if (head.next == nullptr)
+				head = {&head, &head};
+
 		insert(std::next(p), t);
 	}