From 8ffc288901163dd49e69938bb49930a5db6a2d34 Mon Sep 17 00:00:00 2001
From: frosch <frosch@openttd.org>
Date: Sun, 9 Jan 2011 13:53:05 +0000
Subject: (svn r21745) -Fix: [NewGRF] Canal variable 80 shall return consistent
 heights within a lock.

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

diff --git a/src/newgrf_canal.cpp b/src/newgrf_canal.cpp
index 2b17fcb5e..4d28d3cef 100644
--- a/src/newgrf_canal.cpp
+++ b/src/newgrf_canal.cpp
@@ -47,7 +47,12 @@ static uint32 CanalGetVariable(const ResolverObject *object, byte variable, byte
 
 	switch (variable) {
 		/* Height of tile */
-		case 0x80: return GetTileZ(tile) / TILE_HEIGHT;
+		case 0x80: {
+			uint z = GetTileZ(tile) / TILE_HEIGHT;
+			/* Return consistent height within locks */
+			if (IsTileType(tile, MP_WATER) && IsLock(tile) && GetSection(tile) == LOCK_UPPER) z--;
+			return z;
+		}
 
 		/* Terrain type */
 		case 0x81: return GetTerrainType(tile);
-- 
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