From 6ccf020dc2e80f92fb4b4d99fe2c7e2fe7771c1f Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sat, 29 Jan 2022 13:22:03 +0000
Subject: [PATCH] Fix #9802: Assertion failure in BuildRailWaypointWindow
 constructor

---
 src/rail_gui.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/rail_gui.cpp b/src/rail_gui.cpp
index bab6b4c555..267caee17e 100644
--- a/src/rail_gui.cpp
+++ b/src/rail_gui.cpp
@@ -2011,6 +2011,7 @@ struct BuildRailWaypointWindow : PickerWindowBase {
 		this->FinishInitNested(TRANSPORT_RAIL);
 
 		matrix->SetCount(_waypoint_count);
+		if (_cur_waypoint_type >= _waypoint_count) _cur_waypoint_type = 0;
 		matrix->SetClicked(_cur_waypoint_type);
 	}