Codechange: Don't use a global for the 'not enough cash' message.

12 files changed, 63 insertions, 55 deletions

diff --git a/src/command.cpp b/src/command.cpp
index 08fe7b265..c02796fef 100644
--- a/src/command.cpp
+++ b/src/command.cpp
@@ -287,9 +287,6 @@ void CommandHelperBase::LogCommandExecution(Commands cmd, StringID err_message,
  */
 bool CommandHelperBase::InternalExecutePrepTest(CommandFlags cmd_flags, TileIndex tile, Backup<CompanyID> &cur_company)
 {
-	/* Reset the state. */
-	_additional_cash_required = 0;
-
 	/* Do not even think about executing out-of-bounds tile-commands */
 	if (tile != 0 && (tile >= MapSize() || (!IsValidTile(tile) && (cmd_flags & CMD_ALL_TILES) == 0))) return false;
 
@@ -356,11 +353,12 @@ std::tuple<bool, bool, bool> CommandHelperBase::InternalExecuteValidateTestAndPr
  * @param cmd_flags Command flags.
  * @param res_test Command result of test run.
  * @param tes_exec Command result of real run.
+ * @param extra_cash Additional cash required for successful command execution.
  * @param tile Tile of command execution.
  * @param[in,out] cur_company Backup of current company at start of command execution.
  * @return Final command result.
  */
-CommandCost CommandHelperBase::InternalExecuteProcessResult(Commands cmd, CommandFlags cmd_flags, const CommandCost &res_test, const CommandCost &res_exec, TileIndex tile, Backup<CompanyID> &cur_company)
+CommandCost CommandHelperBase::InternalExecuteProcessResult(Commands cmd, CommandFlags cmd_flags, const CommandCost &res_test, const CommandCost &res_exec, Money extra_cash, TileIndex tile, Backup<CompanyID> &cur_company)
 {
 	BasePersistentStorageArray::SwitchMode(PSM_LEAVE_COMMAND);
 
@@ -389,11 +387,11 @@ CommandCost CommandHelperBase::InternalExecuteProcessResult(Commands cmd, Comman
 
 	/* If we're needing more money and we haven't done
 	 * anything yet, ask for the money! */
-	if (_additional_cash_required != 0 && res_exec.GetCost() == 0) {
+	if (extra_cash != 0 && res_exec.GetCost() == 0) {
 		/* It could happen we removed rail, thus gained money, and deleted something else.
 		 * So make sure the signal buffer is empty even in this case */
 		UpdateSignalsInBuffer();
-		SetDParam(0, _additional_cash_required);
+		SetDParam(0, extra_cash);
 		return CommandCost(STR_ERROR_NOT_ENOUGH_CASH_REQUIRES_CURRENCY);
 	}
 
diff --git a/src/command_func.h b/src/command_func.h
index 117fed917..861dd480b 100644
--- a/src/command_func.h
+++ b/src/command_func.h
@@ -39,8 +39,6 @@ static const CommandCost CMD_ERROR = CommandCost(INVALID_STRING_ID);
 
 void NetworkSendCommand(Commands cmd, StringID err_message, CommandCallback *callback, CompanyID company, TileIndex location, const CommandDataBuffer &cmd_data);
 
-extern Money _additional_cash_required;
-
 bool IsValidCommand(Commands cmd);
 CommandFlags GetCommandFlags(Commands cmd);
 const char *GetCommandName(Commands cmd);
@@ -103,7 +101,7 @@ protected:
 	static void InternalPostResult(const CommandCost &res, TileIndex tile, bool estimate_only, bool only_sending, StringID err_message, bool my_cmd);
 	static bool InternalExecutePrepTest(CommandFlags cmd_flags, TileIndex tile, Backup<CompanyID> &cur_company);
 	static std::tuple<bool, bool, bool> InternalExecuteValidateTestAndPrepExec(CommandCost &res, CommandFlags cmd_flags, bool estimate_only, bool network_command, Backup<CompanyID> &cur_company);
-	static CommandCost InternalExecuteProcessResult(Commands cmd, CommandFlags cmd_flags, const CommandCost &res_test, const CommandCost &res_exec, TileIndex tile, Backup<CompanyID> &cur_company);
+	static CommandCost InternalExecuteProcessResult(Commands cmd, CommandFlags cmd_flags, const CommandCost &res_test, const CommandCost &res_exec, Money extra_cash, TileIndex tile, Backup<CompanyID> &cur_company);
 	static void LogCommandExecution(Commands cmd, StringID err_message, TileIndex tile, const CommandDataBuffer &args, bool failed);
 };
 
@@ -354,6 +352,16 @@ protected:
 		return (ClientIdIsSet(std::get<Tindices>(values)) && ...);
 	}
 
+	template<class Ttuple>
+	static inline Money ExtractAdditionalMoney(Ttuple &values)
+	{
+		if constexpr (std::is_same_v<std::tuple_element_t<1, Tret>, Money>) {
+			return std::get<1>(values);
+		} else {
+			return {};
+		}
+	}
+
 	static Tret Execute(StringID err_message, CommandCallback *callback, bool my_cmd, bool estimate_only, bool network_command, TileIndex tile, std::tuple<Targs...> args)
 	{
 		/* Prevent recursion; it gives a mess over the network */
@@ -403,10 +411,17 @@ protected:
 		/* Actually try and execute the command. */
 		Tret res2 = std::apply(CommandTraits<Tcmd>::proc, std::tuple_cat(std::make_tuple(flags | DC_EXEC), args));
 
+		/* Convention: If the second result element is of type Money,
+		 * this is the additional cash required for the command. */
+		Money additional_money{};
+		if constexpr (!std::is_same_v<Tret, CommandCost>) { // No short-circuiting for 'if constexpr'.
+			additional_money = ExtractAdditionalMoney(res2);
+		}
+
 		if constexpr (std::is_same_v<Tret, CommandCost>) {
-			return InternalExecuteProcessResult(Tcmd, cmd_flags, res, res2, tile, cur_company);
+			return InternalExecuteProcessResult(Tcmd, cmd_flags, res, res2, additional_money, tile, cur_company);
 		} else {
-			std::get<0>(res2) = InternalExecuteProcessResult(Tcmd, cmd_flags, ExtractCommandCost(res), ExtractCommandCost(res2), tile, cur_company);
+			std::get<0>(res2) = InternalExecuteProcessResult(Tcmd, cmd_flags, ExtractCommandCost(res), ExtractCommandCost(res2), additional_money, tile, cur_company);
 			return res2;
 		}
 	}
diff --git a/src/economy.cpp b/src/economy.cpp
index 7080aad8e..f2e70f34f 100644
--- a/src/economy.cpp
+++ b/src/economy.cpp
@@ -99,7 +99,6 @@ const ScoreInfo _score_info[] = {
 int64 _score_part[MAX_COMPANIES][SCORE_END];
 Economy _economy;
 Prices _price;
-Money _additional_cash_required;
 static PriceMultipliers _price_base_multiplier;
 
 /**
diff --git a/src/landscape.cpp b/src/landscape.cpp
index 43bc238ac..b921deef2 100644
--- a/src/landscape.cpp
+++ b/src/landscape.cpp
@@ -736,9 +736,9 @@ CommandCost CmdLandscapeClear(DoCommandFlag flags, TileIndex tile)
  * @param diagonal Whether to use the Orthogonal (false) or Diagonal (true) iterator.
  * @return the cost of this operation or an error
  */
-CommandCost CmdClearArea(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal)
+std::tuple<CommandCost, Money> CmdClearArea(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal)
 {
-	if (start_tile >= MapSize()) return CMD_ERROR;
+	if (start_tile >= MapSize()) return { CMD_ERROR, 0 };
 
 	Money money = GetAvailableMoneyForCommand();
 	CommandCost cost(EXPENSES_CONSTRUCTION);
@@ -764,9 +764,8 @@ CommandCost CmdClearArea(DoCommandFlag flags, TileIndex tile, TileIndex start_ti
 		if (flags & DC_EXEC) {
 			money -= ret.GetCost();
 			if (ret.GetCost() > 0 && money < 0) {
-				_additional_cash_required = ret.GetCost();
 				delete iter;
-				return cost;
+				return { cost, ret.GetCost() };
 			}
 			Command<CMD_LANDSCAPE_CLEAR>::Do(flags, t);
 
@@ -786,7 +785,7 @@ CommandCost CmdClearArea(DoCommandFlag flags, TileIndex tile, TileIndex start_ti
 	}
 
 	delete iter;
-	return had_success ? cost : last_error;
+	return { had_success ? cost : last_error, 0 };
 }
 
 
diff --git a/src/landscape_cmd.h b/src/landscape_cmd.h
index 5af278723..40c0d20e3 100644
--- a/src/landscape_cmd.h
+++ b/src/landscape_cmd.h
@@ -13,7 +13,7 @@
 #include "command_type.h"
 
 CommandCost CmdLandscapeClear(DoCommandFlag flags, TileIndex tile);
-CommandCost CmdClearArea(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal);
+std::tuple<CommandCost, Money> CmdClearArea(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal);
 
 DEF_CMD_TRAIT(CMD_LANDSCAPE_CLEAR, CmdLandscapeClear, CMD_DEITY,   CMDT_LANDSCAPE_CONSTRUCTION)
 DEF_CMD_TRAIT(CMD_CLEAR_AREA,      CmdClearArea,      CMD_NO_TEST, CMDT_LANDSCAPE_CONSTRUCTION) // destroying multi-tile houses makes town rating differ between test and execution
diff --git a/src/road_cmd.cpp b/src/road_cmd.cpp
index 8cf07e8d6..070148111 100644
--- a/src/road_cmd.cpp
+++ b/src/road_cmd.cpp
@@ -1070,16 +1070,16 @@ CommandCost CmdBuildLongRoad(DoCommandFlag flags, TileIndex start_tile, TileInde
  * @param end_half end tile starts in the 2nd half of tile (p2 & 2)
  * @return the cost of this operation or an error
  */
-CommandCost CmdRemoveLongRoad(DoCommandFlag flags, TileIndex start_tile, TileIndex end_tile, RoadType rt, Axis axis, bool start_half, bool end_half)
+std::tuple<CommandCost, Money> CmdRemoveLongRoad(DoCommandFlag flags, TileIndex start_tile, TileIndex end_tile, RoadType rt, Axis axis, bool start_half, bool end_half)
 {
 	CommandCost cost(EXPENSES_CONSTRUCTION);
 
-	if (end_tile >= MapSize()) return CMD_ERROR;
-	if (!ValParamRoadType(rt) || !IsEnumValid(axis)) return CMD_ERROR;
+	if (end_tile >= MapSize()) return { CMD_ERROR, 0 };
+	if (!ValParamRoadType(rt) || !IsEnumValid(axis)) return { CMD_ERROR, 0 };
 
 	/* Only drag in X or Y direction dictated by the direction variable */
-	if (axis == AXIS_X && TileY(start_tile) != TileY(end_tile)) return CMD_ERROR; // x-axis
-	if (axis == AXIS_Y && TileX(start_tile) != TileX(end_tile)) return CMD_ERROR; // y-axis
+	if (axis == AXIS_X && TileY(start_tile) != TileY(end_tile)) return { CMD_ERROR, 0 }; // x-axis
+	if (axis == AXIS_Y && TileX(start_tile) != TileX(end_tile)) return { CMD_ERROR, 0 }; // y-axis
 
 	/* Swap start and ending tile, also the half-tile drag vars. */
 	if (start_tile > end_tile || (start_tile == end_tile && start_half)) {
@@ -1107,8 +1107,7 @@ CommandCost CmdRemoveLongRoad(DoCommandFlag flags, TileIndex start_tile, TileInd
 				if (flags & DC_EXEC) {
 					money_spent += ret.GetCost();
 					if (money_spent > 0 && money_spent > money_available) {
-						_additional_cash_required = Command<CMD_REMOVE_LONG_ROAD>::Do(flags & ~DC_EXEC, start_tile, end_tile, rt, axis, start_half, end_half).GetCost();
-						return cost;
+						return { cost, std::get<0>(Command<CMD_REMOVE_LONG_ROAD>::Do(flags & ~DC_EXEC, start_tile, end_tile, rt, axis, start_half, end_half)).GetCost() };
 					}
 					RemoveRoad(tile, flags, bits, rtt, true, false);
 				}
@@ -1125,7 +1124,7 @@ CommandCost CmdRemoveLongRoad(DoCommandFlag flags, TileIndex start_tile, TileInd
 		tile += (axis == AXIS_Y) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
 	}
 
-	return had_success ? cost : last_error;
+	return { had_success ? cost : last_error, 0 };
 }
 
 /**
diff --git a/src/road_cmd.h b/src/road_cmd.h
index 35903dd7a..82f09d2fa 100644
--- a/src/road_cmd.h
+++ b/src/road_cmd.h
@@ -18,7 +18,7 @@ void DrawRoadDepotSprite(int x, int y, DiagDirection dir, RoadType rt);
 void UpdateNearestTownForRoadTiles(bool invalidate);
 
 CommandCost CmdBuildLongRoad(DoCommandFlag flags, TileIndex start_tile, TileIndex end_tile, RoadType rt, Axis axis, DisallowedRoadDirections drd, bool start_half, bool end_half, bool is_ai);
-CommandCost CmdRemoveLongRoad(DoCommandFlag flags, TileIndex start_tile, TileIndex end_tile, RoadType rt, Axis axis, bool start_half, bool end_half);
+std::tuple<CommandCost, Money> CmdRemoveLongRoad(DoCommandFlag flags, TileIndex start_tile, TileIndex end_tile, RoadType rt, Axis axis, bool start_half, bool end_half);
 CommandCost CmdBuildRoad(DoCommandFlag flags, TileIndex tile, RoadBits pieces, RoadType rt, DisallowedRoadDirections toggle_drd, TownID town_id);
 CommandCost CmdBuildRoadDepot(DoCommandFlag flags, TileIndex tile, RoadType rt, DiagDirection dir);
 CommandCost CmdConvertRoad(DoCommandFlag flags, TileIndex tile, TileIndex area_start, RoadType to_type);
diff --git a/src/terraform_cmd.cpp b/src/terraform_cmd.cpp
index e4f6b141a..e1f794412 100644
--- a/src/terraform_cmd.cpp
+++ b/src/terraform_cmd.cpp
@@ -341,9 +341,9 @@ CommandCost CmdTerraformLand(DoCommandFlag flags, TileIndex tile, Slope slope, b
  * @param LevelMode Mode of leveling \c LevelMode.
  * @return the cost of this operation or an error
  */
-CommandCost CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal, LevelMode lm)
+std::tuple<CommandCost, Money> CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal, LevelMode lm)
 {
-	if (start_tile >= MapSize()) return CMD_ERROR;
+	if (start_tile >= MapSize()) return { CMD_ERROR, 0 };
 
 	_terraform_err_tile = INVALID_TILE;
 
@@ -356,11 +356,11 @@ CommandCost CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_ti
 		case LM_LEVEL: break;
 		case LM_RAISE: h++; break;
 		case LM_LOWER: h--; break;
-		default: return CMD_ERROR;
+		default: return { CMD_ERROR, 0 };
 	}
 
 	/* Check range of destination height */
-	if (h > _settings_game.construction.map_height_limit) return_cmd_error((oldh == 0) ? STR_ERROR_ALREADY_AT_SEA_LEVEL : STR_ERROR_TOO_HIGH);
+	if (h > _settings_game.construction.map_height_limit) return { CommandCost(oldh == 0 ? STR_ERROR_ALREADY_AT_SEA_LEVEL : STR_ERROR_TOO_HIGH), 0 };
 
 	Money money = GetAvailableMoneyForCommand();
 	CommandCost cost(EXPENSES_CONSTRUCTION);
@@ -369,7 +369,7 @@ CommandCost CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_ti
 
 	const Company *c = Company::GetIfValid(_current_company);
 	int limit = (c == nullptr ? INT32_MAX : GB(c->terraform_limit, 16, 16));
-	if (limit == 0) return_cmd_error(STR_ERROR_TERRAFORM_LIMIT_REACHED);
+	if (limit == 0) return { CommandCost(STR_ERROR_TERRAFORM_LIMIT_REACHED), 0 };
 
 	TileIterator *iter = diagonal ? (TileIterator *)new DiagonalTileIterator(tile, start_tile) : new OrthogonalTileIterator(tile, start_tile);
 	for (; *iter != INVALID_TILE; ++(*iter)) {
@@ -388,9 +388,8 @@ CommandCost CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_ti
 			if (flags & DC_EXEC) {
 				money -= ret.GetCost();
 				if (money < 0) {
-					_additional_cash_required = ret.GetCost();
 					delete iter;
-					return cost;
+					return { cost, ret.GetCost() };
 				}
 				Command<CMD_TERRAFORM_LAND>::Do(flags, t, SLOPE_N, curh <= h);
 			} else {
@@ -414,5 +413,5 @@ CommandCost CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_ti
 	}
 
 	delete iter;
-	return had_success ? cost : last_error;
+	return { had_success ? cost : last_error, 0 };
 }
diff --git a/src/terraform_cmd.h b/src/terraform_cmd.h
index 4daeeac48..52d7a78fe 100644
--- a/src/terraform_cmd.h
+++ b/src/terraform_cmd.h
@@ -15,7 +15,7 @@
 #include "slope_type.h"
 
 CommandCost CmdTerraformLand(DoCommandFlag flags, TileIndex tile, Slope slope, bool dir_up);
-CommandCost CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal, LevelMode lm);
+std::tuple<CommandCost, Money> CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal, LevelMode lm);
 
 DEF_CMD_TRAIT(CMD_TERRAFORM_LAND, CmdTerraformLand, CMD_ALL_TILES | CMD_AUTO,               CMDT_LANDSCAPE_CONSTRUCTION)
 DEF_CMD_TRAIT(CMD_LEVEL_LAND,     CmdLevelLand,     CMD_ALL_TILES | CMD_AUTO | CMD_NO_TEST, CMDT_LANDSCAPE_CONSTRUCTION) // test run might clear tiles multiple times, in execution that only happens once
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 5afc1d2c9..87d42628a 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -1935,41 +1935,41 @@ static bool IsUniqueTownName(const std::string &name)
  * @param text Custom name for the town. If empty, the town name parts will be used.
  * @return the cost of this operation or an error
  */
-std::tuple<CommandCost, TownID> CmdFoundTown(DoCommandFlag flags, TileIndex tile, TownSize size, bool city, TownLayout layout, bool random_location, uint32 townnameparts, const std::string &text)
+std::tuple<CommandCost, Money, TownID> CmdFoundTown(DoCommandFlag flags, TileIndex tile, TownSize size, bool city, TownLayout layout, bool random_location, uint32 townnameparts, const std::string &text)
 {
 	TownNameParams par(_settings_game.game_creation.town_name);
 
-	if (size >= TSZ_END) return { CMD_ERROR, INVALID_TOWN };
-	if (layout >= NUM_TLS) return { CMD_ERROR, INVALID_TOWN };
+	if (size >= TSZ_END) return { CMD_ERROR, 0, INVALID_TOWN };
+	if (layout >= NUM_TLS) return { CMD_ERROR, 0, INVALID_TOWN };
 
 	/* Some things are allowed only in the scenario editor and for game scripts. */
 	if (_game_mode != GM_EDITOR && _current_company != OWNER_DEITY) {
-		if (_settings_game.economy.found_town == TF_FORBIDDEN) return { CMD_ERROR, INVALID_TOWN };
-		if (size == TSZ_LARGE) return { CMD_ERROR, INVALID_TOWN };
-		if (random_location) return { CMD_ERROR, INVALID_TOWN };
+		if (_settings_game.economy.found_town == TF_FORBIDDEN) return { CMD_ERROR, 0, INVALID_TOWN };
+		if (size == TSZ_LARGE) return { CMD_ERROR, 0, INVALID_TOWN };
+		if (random_location) return { CMD_ERROR, 0, INVALID_TOWN };
 		if (_settings_game.economy.found_town != TF_CUSTOM_LAYOUT && layout != _settings_game.economy.town_layout) {
-			return { CMD_ERROR, INVALID_TOWN };
+			return { CMD_ERROR, 0, INVALID_TOWN };
 		}
 	} else if (_current_company == OWNER_DEITY && random_location) {
 		/* Random parameter is not allowed for Game Scripts. */
-		return { CMD_ERROR, INVALID_TOWN };
+		return { CMD_ERROR, 0, INVALID_TOWN };
 	}
 
 	if (text.empty()) {
 		/* If supplied name is empty, townnameparts has to generate unique automatic name */
-		if (!VerifyTownName(townnameparts, &par)) return { CommandCost(STR_ERROR_NAME_MUST_BE_UNIQUE), INVALID_TOWN };
+		if (!VerifyTownName(townnameparts, &par)) return { CommandCost(STR_ERROR_NAME_MUST_BE_UNIQUE), 0, INVALID_TOWN };
 	} else {
 		/* If name is not empty, it has to be unique custom name */
-		if (Utf8StringLength(text) >= MAX_LENGTH_TOWN_NAME_CHARS) return { CMD_ERROR, INVALID_TOWN };
-		if (!IsUniqueTownName(text)) return { CommandCost(STR_ERROR_NAME_MUST_BE_UNIQUE), INVALID_TOWN };
+		if (Utf8StringLength(text) >= MAX_LENGTH_TOWN_NAME_CHARS) return { CMD_ERROR, 0, INVALID_TOWN };
+		if (!IsUniqueTownName(text)) return { CommandCost(STR_ERROR_NAME_MUST_BE_UNIQUE), 0, INVALID_TOWN };
 	}
 
 	/* Allocate town struct */
-	if (!Town::CanAllocateItem()) return { CommandCost(STR_ERROR_TOO_MANY_TOWNS), INVALID_TOWN };
+	if (!Town::CanAllocateItem()) return { CommandCost(STR_ERROR_TOO_MANY_TOWNS), 0, INVALID_TOWN };
 
 	if (!random_location) {
 		CommandCost ret = TownCanBePlacedHere(tile);
-		if (ret.Failed()) return { ret, INVALID_TOWN };
+		if (ret.Failed()) return { ret, 0, INVALID_TOWN };
 	}
 
 	static const byte price_mult[][TSZ_RANDOM + 1] = {{ 15, 25, 40, 25 }, { 20, 35, 55, 35 }};
@@ -1985,8 +1985,7 @@ std::tuple<CommandCost, TownID> CmdFoundTown(DoCommandFlag flags, TileIndex tile
 	TownID new_town = INVALID_TOWN;
 	if (flags & DC_EXEC) {
 		if (cost.GetCost() > GetAvailableMoneyForCommand()) {
-			_additional_cash_required = cost.GetCost();
-			return { CommandCost(EXPENSES_OTHER), INVALID_TOWN };
+			return { CommandCost(EXPENSES_OTHER), cost.GetCost(), INVALID_TOWN };
 		}
 
 		Backup<bool> old_generating_world(_generating_world, true, FILE_LINE);
@@ -2031,7 +2030,7 @@ std::tuple<CommandCost, TownID> CmdFoundTown(DoCommandFlag flags, TileIndex tile
 			Game::NewEvent(new ScriptEventTownFounded(t->index));
 		}
 	}
-	return { cost, new_town };
+	return { cost, 0, new_town };
 }
 
 /**
diff --git a/src/town_cmd.h b/src/town_cmd.h
index e98fa571e..74af1e10e 100644
--- a/src/town_cmd.h
+++ b/src/town_cmd.h
@@ -16,7 +16,7 @@
 
 enum TownEffect : byte;
 
-std::tuple<CommandCost, TownID> CmdFoundTown(DoCommandFlag flags, TileIndex tile, TownSize size, bool city, TownLayout layout, bool random_location, uint32 townnameparts, const std::string &text);
+std::tuple<CommandCost, Money, TownID> CmdFoundTown(DoCommandFlag flags, TileIndex tile, TownSize size, bool city, TownLayout layout, bool random_location, uint32 townnameparts, const std::string &text);
 CommandCost CmdRenameTown(DoCommandFlag flags, TownID town_id, const std::string &text);
 CommandCost CmdDoTownAction(DoCommandFlag flags, TownID town_id, uint8 action);
 CommandCost CmdTownGrowthRate(DoCommandFlag flags, TownID town_id, uint16 growth_rate);
@@ -37,6 +37,6 @@ DEF_CMD_TRAIT(CMD_EXPAND_TOWN,      CmdExpandTown,     CMD_DEITY,
 DEF_CMD_TRAIT(CMD_DELETE_TOWN,      CmdDeleteTown,     CMD_OFFLINE,              CMDT_LANDSCAPE_CONSTRUCTION)
 
 CommandCallback CcFoundTown;
-void CcFoundRandomTown(Commands cmd, const CommandCost &result, TownID town_id);
+void CcFoundRandomTown(Commands cmd, const CommandCost &result, Money, TownID town_id);
 
 #endif /* TOWN_CMD_H */
diff --git a/src/town_gui.cpp b/src/town_gui.cpp
index fbc6a842a..6206ffc89 100644
--- a/src/town_gui.cpp
+++ b/src/town_gui.cpp
@@ -1017,7 +1017,7 @@ void CcFoundTown(Commands cmd, const CommandCost &result, TileIndex tile)
 	if (!_settings_client.gui.persistent_buildingtools) ResetObjectToPlace();
 }
 
-void CcFoundRandomTown(Commands cmd, const CommandCost &result, TownID town_id)
+void CcFoundRandomTown(Commands cmd, const CommandCost &result, Money, TownID town_id)
 {
 	if (result.Succeeded()) ScrollMainWindowToTile(Town::Get(town_id)->xy);
 }