From 9823fac63b8dde1ca0d90e2ec9a639e14a363429 Mon Sep 17 00:00:00 2001
From: planetmaker <planetmaker@openttd.org>
Date: Sun, 20 Jan 2013 13:50:10 +0000
Subject: [PATCH] (svn r24924) -Fix (r24923): Make sure that autoslope on steep
 coast tiles cannot not leave invalid canals

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

diff --git a/src/water_cmd.cpp b/src/water_cmd.cpp
index ae5efada70..9d099f5dc3 100644
--- a/src/water_cmd.cpp
+++ b/src/water_cmd.cpp
@@ -175,8 +175,8 @@ void MakeWaterKeepingClass(TileIndex tile, Owner o)
 			wc = WATER_CLASS_INVALID;
 		}
 
-		/* There must not be water sloped invalidly, whatever class it may be */
-		if (GetInclinedSlopeDirection(slope) == INVALID_DIAGDIR) {
+		/* Only river water should be restored on appropriate slopes. Other water would be invalid on slopes */
+		if (wc != WATER_CLASS_RIVER || GetInclinedSlopeDirection(slope) == INVALID_DIAGDIR) {
 			wc = WATER_CLASS_INVALID;
 		}
 	}