(svn r19404) -Codechange: CheckAllowRemoveTunnelBridge() returns a CommandCost.

src/tunnelbridge_cmd.cpp

@@ -586,10 +586,14 @@ CommandCost CmdBuildTunnel(TileIndex start_tile, DoCommandFlag flags, uint32 p1,
 }
 
 
-static inline bool CheckAllowRemoveTunnelBridge(TileIndex tile)
+/** Are we allowed to remove the tunnel or bridge at \a tile?
+ * @param tile End point of the tunnel or bridge.
+ * @return A succeeded command if the tunnel or bridge may be removed, a failed command otherwise.
+ */
+static inline CommandCost CheckAllowRemoveTunnelBridge(TileIndex tile)
 {
 	/* Floods can remove anything as well as the scenario editor */
-	if (_current_company == OWNER_WATER || _game_mode == GM_EDITOR) return true;
+	if (_current_company == OWNER_WATER || _game_mode == GM_EDITOR) return CommandCost();
 
 	switch (GetTunnelBridgeTransportType(tile)) {
 		case TRANSPORT_ROAD: {
@@ -602,17 +606,19 @@ static inline bool CheckAllowRemoveTunnelBridge(TileIndex tile)
 
 			/* We can remove unowned road and if the town allows it */
 			if (road_owner == OWNER_TOWN && !(_settings_game.construction.extra_dynamite || _cheats.magic_bulldozer.value)) {
-				return CheckTileOwnership(tile).Succeeded();
+				CommandCost ret = CheckTileOwnership(tile);
+				ret.SetGlobalErrorMessage();
+				return ret;
 			}
 			if (road_owner == OWNER_NONE || road_owner == OWNER_TOWN) road_owner = _current_company;
 			if (tram_owner == OWNER_NONE) tram_owner = _current_company;
 
-			return CheckOwnership(road_owner, tile) && CheckOwnership(tram_owner, tile);
+			return (CheckOwnership(road_owner, tile) && CheckOwnership(tram_owner, tile)) ? CommandCost() : CMD_ERROR;
 		}
 
 		case TRANSPORT_RAIL:
 		case TRANSPORT_WATER:
-			return CheckOwnership(GetTileOwner(tile));
+			return CheckOwnership(GetTileOwner(tile)) ? CommandCost() : CMD_ERROR;
 
 		default: NOT_REACHED();
 	}
@@ -623,11 +629,13 @@ static CommandCost DoClearTunnel(TileIndex tile, DoCommandFlag flags)
 	Town *t = NULL;
 	TileIndex endtile;
 
-	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
+	CommandCost ret = CheckAllowRemoveTunnelBridge(tile);
+	ret.SetGlobalErrorMessage();
+	if (ret.Failed()) return ret;
 
 	endtile = GetOtherTunnelEnd(tile);
 
-	CommandCost ret = TunnelBridgeIsFree(tile, endtile);
+	ret = TunnelBridgeIsFree(tile, endtile);
 	ret.SetGlobalErrorMessage();
 	if (ret.Failed()) return ret;
 
@@ -689,11 +697,13 @@ static CommandCost DoClearBridge(TileIndex tile, DoCommandFlag flags)
 	TileIndex endtile;
 	Town *t = NULL;
 
-	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
+	CommandCost ret = CheckAllowRemoveTunnelBridge(tile);
+	ret.SetGlobalErrorMessage();
+	if (ret.Failed()) return ret;
 
 	endtile = GetOtherBridgeEnd(tile);
 
-	CommandCost ret = TunnelBridgeIsFree(tile, endtile);
+	ret = TunnelBridgeIsFree(tile, endtile);
 	ret.SetGlobalErrorMessage();
 	if (ret.Failed()) return ret;