From 12380fc1bb952d5b8a368249082cd85291a78e82 Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sun, 5 Jan 2020 14:49:11 +0000
Subject: [PATCH] Fix: Assertion failure when post road-works cleanup removes
 all road pieces

---
 src/road_cmd.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/road_cmd.cpp b/src/road_cmd.cpp
index ace8edff7f..5a9efb8567 100644
--- a/src/road_cmd.cpp
+++ b/src/road_cmd.cpp
@@ -1955,6 +1955,12 @@ static void TileLoop_Road(TileIndex tile)
 
 			if (old_rb != new_rb) {
 				RemoveRoad(tile, DC_EXEC | DC_AUTO | DC_NO_WATER, (old_rb ^ new_rb), RTT_ROAD, true);
+
+				/* If new_rb is 0, there are now no road pieces left and the tile is no longer a road tile */
+				if (new_rb == 0) {
+					MarkTileDirtyByTile(tile);
+					return;
+				}
 			}
 		}