(svn r20721) -Fix: objects that can be built on water shouldn't be drowned.

src/object_cmd.cpp

@@ -374,6 +374,9 @@ static CommandCost ClearTile_Object(TileIndex tile, DoCommandFlag flags)
 			/* Removing with the cheat costs more in TTDPatch / the specs. */
 			cost.MultiplyCost(25);
 		}
+	} else if ((spec->flags & (OBJECT_FLAG_BUILT_ON_WATER | OBJECT_FLAG_NOT_ON_LAND)) != 0) {
+		/* Water can't remove objects that are buildable on water. */
+		return CMD_ERROR;
 	}
 
 	switch (type) {