From 6be456052859844de5efe0e3890df93422e50676 Mon Sep 17 00:00:00 2001
From: yexo <yexo@openttd.org>
Date: Thu, 28 Jan 2010 19:27:10 +0000
Subject: [PATCH] (svn r18937) -Fix (r15190): TileAddWrap didn't return
 INVALID_TILE for void tiles at the north border

---
 src/map.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/map.cpp b/src/map.cpp
index 0d2b146cef..9c930d694f 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -115,9 +115,11 @@ TileIndex TileAddWrap(TileIndex tile, int addx, int addy)
 	uint x = TileX(tile) + addx;
 	uint y = TileY(tile) + addy;
 
+	/* Disallow void tiles at the north border. */
+	if (_settings_game.construction.freeform_edges && (x == 0 || y == 0)) return INVALID_TILE;
+
 	/* Are we about to wrap? */
-	if (x < MapMaxX() && y < MapMaxY())
-		return tile + TileDiffXY(addx, addy);
+	if (x < MapMaxX() && y < MapMaxY()) return tile + TileDiffXY(addx, addy);
 
 	return INVALID_TILE;
 }