From ba47d1ca2b443d61babebcdad93666d15737e685 Mon Sep 17 00:00:00 2001
From: Peter Nelson <peter1138@openttd.org>
Date: Sat, 18 May 2024 12:33:50 +0100
Subject: [PATCH] Fix: Allow resolving house parent scope (town) of unbuilt
 houses. (#12695)

Return unavailable variable result, instead of nullptr dereference.
---
 src/newgrf_town.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/newgrf_town.cpp b/src/newgrf_town.cpp
index 2843869de4..fb4f2e1ae1 100644
--- a/src/newgrf_town.cpp
+++ b/src/newgrf_town.cpp
@@ -17,6 +17,11 @@
 
 /* virtual */ uint32_t TownScopeResolver::GetVariable(uint8_t variable, [[maybe_unused]] uint32_t parameter, bool *available) const
 {
+	if (this->t == nullptr) {
+		*available = false;
+		return UINT_MAX;
+	}
+
 	CargoID cid;
 	switch (variable) {
 		/* Larger towns */