From 4cc97e04e63884e8e37058153a76b8e8adb1dd76 Mon Sep 17 00:00:00 2001
From: Rubidium <rubidium@openttd.org>
Date: Wed, 17 Jan 2024 22:45:33 +0100
Subject: [PATCH] Fix #11801, 51f1e93: CalcClosestTownFromTile needs the
 kd-tree to be valid

---
 src/saveload/oldloader_sl.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/saveload/oldloader_sl.cpp b/src/saveload/oldloader_sl.cpp
index e784eb8ca9..06c0af9084 100644
--- a/src/saveload/oldloader_sl.cpp
+++ b/src/saveload/oldloader_sl.cpp
@@ -499,7 +499,12 @@ static Town *RemapTown(TileIndex fallback)
 {
 	/* In some cases depots, industries and stations could refer to a missing town. */
 	Town *t = Town::GetIfValid(RemapTownIndex(_old_town_index));
-	if (t == nullptr) t = CalcClosestTownFromTile(fallback);
+	if (t == nullptr) {
+		/* In case the town that was refered to does not exist, find the closest.
+		 * However, this needs the kd-tree to be present. */
+		RebuildTownKdtree();
+		t = CalcClosestTownFromTile(fallback);
+	}
 	return t;
 }