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-rw-r--r--src/ai/ai_instance.cpp6
-rw-r--r--src/command_func.h97
-rw-r--r--src/command_type.h13
-rw-r--r--src/game/game_instance.cpp6
-rw-r--r--src/network/network_command.cpp2
-rw-r--r--src/script/api/script_object.cpp10
-rw-r--r--src/script/api/script_object.hpp36
-rw-r--r--src/script/script_instance.cpp3
-rw-r--r--src/script/script_instance.hpp3
-rw-r--r--src/script/script_storage.hpp1
10 files changed, 136 insertions, 41 deletions
diff --git a/src/ai/ai_instance.cpp b/src/ai/ai_instance.cpp
index e137745f1..0e8355d73 100644
--- a/src/ai/ai_instance.cpp
+++ b/src/ai/ai_instance.cpp
@@ -18,6 +18,7 @@
#include "ai.hpp"
#include "../script/script_storage.hpp"
+#include "../script/script_cmd.h"
#include "ai_info.hpp"
#include "ai_instance.hpp"
@@ -96,8 +97,9 @@ ScriptInfo *AIInstance::FindLibrary(const char *library, int version)
* @param result The result of the command.
* @param tile The tile on which the command was executed.
* @param data Command data as given to Command<>::Post.
+ * @param result_data Additional returned data from the command.
*/
-void CcAI(Commands cmd, const CommandCost &result, TileIndex tile, const CommandDataBuffer &data)
+void CcAI(Commands cmd, const CommandCost &result, TileIndex tile, const CommandDataBuffer &data, CommandDataBuffer result_data)
{
/*
* The company might not exist anymore. Check for this.
@@ -108,7 +110,7 @@ void CcAI(Commands cmd, const CommandCost &result, TileIndex tile, const Command
const Company *c = Company::GetIfValid(_current_company);
if (c == nullptr || c->ai_instance == nullptr) return;
- if (c->ai_instance->DoCommandCallback(result, tile, data, cmd)) {
+ if (c->ai_instance->DoCommandCallback(result, tile, data, std::move(result_data), cmd)) {
c->ai_instance->Continue();
}
}
diff --git a/src/command_func.h b/src/command_func.h
index 9219fd2b5..117fed917 100644
--- a/src/command_func.h
+++ b/src/command_func.h
@@ -111,10 +111,30 @@ protected:
* Templated wrapper that exposes the command parameter arguments
* for the various Command::Do/Post calls.
* @tparam Tcmd The command-id to execute.
+ * @tparam Tret Return type of the command.
* @tparam Targs The command parameter types.
*/
-template <Commands Tcmd, typename... Targs>
-struct CommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Targs...), true> : protected CommandHelperBase {
+template <Commands Tcmd, typename Tret, typename... Targs>
+struct CommandHelper<Tcmd, Tret(*)(DoCommandFlag, Targs...), true> : protected CommandHelperBase {
+private:
+ /** Extract the \c CommandCost from a command proc result. */
+ static inline CommandCost &ExtractCommandCost(Tret &ret)
+ {
+ if constexpr (std::is_same_v<Tret, CommandCost>) {
+ return ret;
+ } else {
+ return std::get<0>(ret);
+ }
+ }
+
+ /** Make a command proc result from a \c CommandCost. */
+ static inline Tret MakeResult(const CommandCost &cost)
+ {
+ Tret ret{};
+ ExtractCommandCost(ret) = cost;
+ return ret;
+ }
+
public:
/**
* This function executes a given command with the parameters from the #CommandProc parameter list.
@@ -129,12 +149,12 @@ public:
* @see CommandProc
* @return the cost
*/
- static CommandCost Do(DoCommandFlag flags, Targs... args)
+ static Tret Do(DoCommandFlag flags, Targs... args)
{
if constexpr (std::is_same_v<TileIndex, std::tuple_element_t<0, std::tuple<Targs...>>>) {
/* Do not even think about executing out-of-bounds tile-commands. */
TileIndex tile = std::get<0>(std::make_tuple(args...));
- if (tile != 0 && (tile >= MapSize() || (!IsValidTile(tile) && (flags & DC_ALL_TILES) == 0))) return CMD_ERROR;
+ if (tile != 0 && (tile >= MapSize() || (!IsValidTile(tile) && (flags & DC_ALL_TILES) == 0))) return MakeResult(CMD_ERROR);
}
RecursiveCommandCounter counter{};
@@ -142,17 +162,17 @@ public:
/* Only execute the test call if it's toplevel, or we're not execing. */
if (counter.IsTopLevel() || !(flags & DC_EXEC)) {
InternalDoBefore(counter.IsTopLevel(), true);
- CommandCost res = CommandTraits<Tcmd>::proc(flags & ~DC_EXEC, args...);
- InternalDoAfter(res, flags, counter.IsTopLevel(), true); // Can modify res.
+ Tret res = CommandTraits<Tcmd>::proc(flags & ~DC_EXEC, args...);
+ InternalDoAfter(ExtractCommandCost(res), flags, counter.IsTopLevel(), true); // Can modify res.
- if (res.Failed() || !(flags & DC_EXEC)) return res;
+ if (ExtractCommandCost(res).Failed() || !(flags & DC_EXEC)) return res;
}
/* Execute the command here. All cost-relevant functions set the expenses type
* themselves to the cost object at some point. */
InternalDoBefore(counter.IsTopLevel(), false);
- CommandCost res = CommandTraits<Tcmd>::proc(flags, args...);
- InternalDoAfter(res, flags, counter.IsTopLevel(), false);
+ Tret res = CommandTraits<Tcmd>::proc(flags, args...);
+ InternalDoAfter(ExtractCommandCost(res), flags, counter.IsTopLevel(), false);
return res;
}
@@ -237,7 +257,7 @@ public:
* @return the command cost of this function.
*/
template <typename Tcallback>
- static CommandCost Unsafe(StringID err_message, Tcallback *callback, bool my_cmd, bool estimate_only, TileIndex location, std::tuple<Targs...> args)
+ static Tret Unsafe(StringID err_message, Tcallback *callback, bool my_cmd, bool estimate_only, TileIndex location, std::tuple<Targs...> args)
{
return Execute(err_message, reinterpret_cast<CommandCallback *>(callback), my_cmd, estimate_only, false, location, std::move(args));
}
@@ -259,6 +279,13 @@ protected:
((SetClientIdHelper(std::get<Tindices>(values))), ...);
}
+ /** Remove the first element of a tuple. */
+ template <template <typename...> typename Tt, typename T1, typename... Ts>
+ static inline Tt<Ts...> RemoveFirstTupleElement(const Tt<T1, Ts...> &tuple)
+ {
+ return std::apply([](auto &&, const auto&... args) { return std::tie(args...); }, tuple);
+ }
+
template <typename Tcallback>
static bool InternalPost(StringID err_message, Tcallback *callback, bool my_cmd, bool network_command, std::tuple<Targs...> args)
{
@@ -280,23 +307,33 @@ protected:
/* Only set client IDs when the command does not come from the network. */
if (!network_command && GetCommandFlags<Tcmd>() & CMD_CLIENT_ID) SetClientIds(args, std::index_sequence_for<Targs...>{});
- CommandCost res = Execute(err_message, reinterpret_cast<CommandCallback *>(callback), my_cmd, estimate_only, network_command, tile, args);
- InternalPostResult(res, tile, estimate_only, only_sending, err_message, my_cmd);
+ Tret res = Execute(err_message, reinterpret_cast<CommandCallback *>(callback), my_cmd, estimate_only, network_command, tile, args);
+ InternalPostResult(ExtractCommandCost(res), tile, estimate_only, only_sending, err_message, my_cmd);
if (!estimate_only && !only_sending && callback != nullptr) {
if constexpr (std::is_same_v<Tcallback, CommandCallback>) {
/* Callback that doesn't need any command arguments. */
- callback(Tcmd, res, tile);
+ callback(Tcmd, ExtractCommandCost(res), tile);
} else if constexpr (std::is_same_v<Tcallback, CommandCallbackData>) {
/* Generic callback that takes packed arguments as a buffer. */
- callback(Tcmd, res, tile, EndianBufferWriter<CommandDataBuffer>::FromValue(args));
+ if constexpr (std::is_same_v<Tret, CommandCost>) {
+ callback(Tcmd, ExtractCommandCost(res), tile, EndianBufferWriter<CommandDataBuffer>::FromValue(args), {});
+ } else {
+ callback(Tcmd, ExtractCommandCost(res), tile, EndianBufferWriter<CommandDataBuffer>::FromValue(args), EndianBufferWriter<CommandDataBuffer>::FromValue(RemoveFirstTupleElement(res)));
+ }
+ } else if constexpr (!std::is_same_v<Tret, CommandCost> && std::is_same_v<Tcallback *, typename CommandTraits<Tcmd>::RetCallbackProc>) {
+ std::apply(callback, std::tuple_cat(std::make_tuple(Tcmd), res));
} else {
/* Callback with arguments. We assume that the tile is only interesting if it actually is in the command arguments. */
- std::apply(callback, std::tuple_cat(std::make_tuple(Tcmd, res), args));
+ if constexpr (std::is_same_v<Tret, CommandCost>) {
+ std::apply(callback, std::tuple_cat(std::make_tuple(Tcmd, res), args));
+ } else {
+ std::apply(callback, std::tuple_cat(std::make_tuple(Tcmd), res, args));
+ }
}
}
- return res.Succeeded();
+ return ExtractCommandCost(res).Succeeded();
}
/** Helper to process a single ClientID argument. */
@@ -317,7 +354,7 @@ protected:
return (ClientIdIsSet(std::get<Tindices>(values)) && ...);
}
- static CommandCost Execute(StringID err_message, CommandCallback *callback, bool my_cmd, bool estimate_only, bool network_command, TileIndex tile, std::tuple<Targs...> args)
+ 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 */
RecursiveCommandCounter counter{};
@@ -334,14 +371,14 @@ protected:
Backup<CompanyID> cur_company(_current_company, FILE_LINE);
if (!InternalExecutePrepTest(cmd_flags, tile, cur_company)) {
cur_company.Trash();
- return CMD_ERROR;
+ return MakeResult(CMD_ERROR);
}
/* Test the command. */
DoCommandFlag flags = CommandFlagsToDCFlags(cmd_flags);
- CommandCost res = std::apply(CommandTraits<Tcmd>::proc, std::tuple_cat(std::make_tuple(flags), args));
+ Tret res = std::apply(CommandTraits<Tcmd>::proc, std::tuple_cat(std::make_tuple(flags), args));
- auto [exit_test, desync_log, send_net] = InternalExecuteValidateTestAndPrepExec(res, cmd_flags, estimate_only, network_command, cur_company);
+ auto [exit_test, desync_log, send_net] = InternalExecuteValidateTestAndPrepExec(ExtractCommandCost(res), cmd_flags, estimate_only, network_command, cur_company);
if (exit_test) {
if (desync_log) LogCommandExecution(Tcmd, err_message, tile, EndianBufferWriter<CommandDataBuffer>::FromValue(args), true);
cur_company.Restore();
@@ -358,15 +395,20 @@ protected:
* This way it's not handled by DoCommand and only the
* actual execution of the command causes messages. Also
* reset the storages as we've not executed the command. */
- return CommandCost();
+ return {};
}
if (desync_log) LogCommandExecution(Tcmd, err_message, tile, EndianBufferWriter<CommandDataBuffer>::FromValue(args), false);
/* Actually try and execute the command. */
- CommandCost res2 = std::apply(CommandTraits<Tcmd>::proc, std::tuple_cat(std::make_tuple(flags | DC_EXEC), args));
+ Tret res2 = std::apply(CommandTraits<Tcmd>::proc, std::tuple_cat(std::make_tuple(flags | DC_EXEC), args));
- return InternalExecuteProcessResult(Tcmd, cmd_flags, res, res2, tile, cur_company);
+ if constexpr (std::is_same_v<Tret, CommandCost>) {
+ return InternalExecuteProcessResult(Tcmd, cmd_flags, res, res2, tile, cur_company);
+ } else {
+ std::get<0>(res2) = InternalExecuteProcessResult(Tcmd, cmd_flags, ExtractCommandCost(res), ExtractCommandCost(res2), tile, cur_company);
+ return res2;
+ }
}
};
@@ -374,13 +416,14 @@ protected:
* Overload for #CommandHelper that exposes additional \c Post variants
* for commands that don't take a TileIndex themselves.
* @tparam Tcmd The command-id to execute.
+ * @tparam Tret Return type of the command.
* @tparam Targs The command parameter types.
*/
-template <Commands Tcmd, typename... Targs>
-struct CommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Targs...), false> : CommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Targs...), true>
+template <Commands Tcmd, typename Tret, typename... Targs>
+struct CommandHelper<Tcmd, Tret(*)(DoCommandFlag, Targs...), false> : CommandHelper<Tcmd, Tret(*)(DoCommandFlag, Targs...), true>
{
/* Import Post overloads from our base class. */
- using CommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Targs...), true>::Post;
+ using CommandHelper<Tcmd, Tret(*)(DoCommandFlag, Targs...), true>::Post;
/**
* Shortcut for Post when not using an error message.
@@ -416,7 +459,7 @@ struct CommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Targs...), false> : Com
template <typename Tcallback>
static inline bool Post(StringID err_message, Tcallback *callback, TileIndex location, Targs... args)
{
- return CommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Targs...), true>::InternalPost(err_message, callback, true, false, location, std::forward_as_tuple(args...));
+ return CommandHelper<Tcmd, Tret(*)(DoCommandFlag, Targs...), true>::InternalPost(err_message, callback, true, false, location, std::forward_as_tuple(args...));
}
};
diff --git a/src/command_type.h b/src/command_type.h
index f607969cc..e8db1ed7f 100644
--- a/src/command_type.h
+++ b/src/command_type.h
@@ -409,6 +409,14 @@ template <typename T> struct CommandFunctionTraitHelper;
template <typename... Targs>
struct CommandFunctionTraitHelper<CommandCost(*)(DoCommandFlag, Targs...)> {
using Args = std::tuple<std::decay_t<Targs>...>;
+ using CbArgs = Args;
+ using CbProcType = void(*)(Commands, const CommandCost &);
+};
+template <template <typename...> typename Tret, typename... Tretargs, typename... Targs>
+struct CommandFunctionTraitHelper<Tret<CommandCost, Tretargs...>(*)(DoCommandFlag, Targs...)> {
+ using Args = std::tuple<std::decay_t<Targs>...>;
+ using CbArgs = std::tuple<std::decay_t<Tretargs>..., std::decay_t<Targs>...>;
+ using CbProcType = void(*)(Commands, const CommandCost &, Tretargs...);
};
/** Defines the traits of a command. */
@@ -418,6 +426,8 @@ template <Commands Tcmd> struct CommandTraits;
template<> struct CommandTraits<cmd_> { \
using ProcType = decltype(&proc_); \
using Args = typename CommandFunctionTraitHelper<ProcType>::Args; \
+ using CbArgs = typename CommandFunctionTraitHelper<ProcType>::CbArgs; \
+ using RetCallbackProc = typename CommandFunctionTraitHelper<ProcType>::CbProcType; \
static constexpr Commands cmd = cmd_; \
static constexpr auto &proc = proc_; \
static constexpr CommandFlags flags = (CommandFlags)(flags_); \
@@ -453,8 +463,9 @@ typedef void CommandCallback(Commands cmd, const CommandCost &result, TileIndex
* @param result The result of the executed command
* @param tile The tile of the command action
* @param data Additional data of the command
+ * @param result_data Additional returned data from the command
* @see CommandProc
*/
-typedef void CommandCallbackData(Commands cmd, const CommandCost &result, TileIndex tile, const CommandDataBuffer &data);
+typedef void CommandCallbackData(Commands cmd, const CommandCost &result, TileIndex tile, const CommandDataBuffer &data, CommandDataBuffer result_data);
#endif /* COMMAND_TYPE_H */
diff --git a/src/game/game_instance.cpp b/src/game/game_instance.cpp
index fa44ee97c..09bba1334 100644
--- a/src/game/game_instance.cpp
+++ b/src/game/game_instance.cpp
@@ -13,6 +13,7 @@
#include "../script/squirrel_class.hpp"
#include "../script/script_storage.hpp"
+#include "../script/script_cmd.h"
#include "../ai/ai_gui.hpp"
#include "game_config.hpp"
#include "game_info.hpp"
@@ -85,10 +86,11 @@ void GameInstance::Died()
* @param result The result of the command.
* @param tile The tile on which the command was executed.
* @param data Command data as given to Command<>::Post.
+ * @param result_data Additional returned data from the command.
*/
-void CcGame(Commands cmd, const CommandCost &result, TileIndex tile, const CommandDataBuffer &data)
+void CcGame(Commands cmd, const CommandCost &result, TileIndex tile, const CommandDataBuffer &data, CommandDataBuffer result_data)
{
- if (Game::GetGameInstance()->DoCommandCallback(result, tile, data, cmd)) {
+ if (Game::GetGameInstance()->DoCommandCallback(result, tile, data, std::move(result_data), cmd)) {
Game::GetGameInstance()->Continue();
}
}
diff --git a/src/network/network_command.cpp b/src/network/network_command.cpp
index 7b3721457..26f551f84 100644
--- a/src/network/network_command.cpp
+++ b/src/network/network_command.cpp
@@ -527,7 +527,7 @@ void UnpackNetworkCommand(const CommandPacket* cp)
/* Check if the callback matches with the command arguments. If not, drop the callback. */
using Tcallback = std::tuple_element_t<Tcb, decltype(_callback_tuple)>;
- if constexpr (std::is_same_v<Tcallback, CommandCallback * const> || std::is_same_v<Tcallback, CommandCallbackData * const> || std::is_same_v<typename CommandTraits<Tcmd>::Args, typename CallbackArgsHelper<Tcallback>::Args>) {
+ if constexpr (std::is_same_v<Tcallback, CommandCallback * const> || std::is_same_v<Tcallback, CommandCallbackData * const> || std::is_same_v<typename CommandTraits<Tcmd>::CbArgs, typename CallbackArgsHelper<Tcallback>::Args>) {
Command<Tcmd>::PostFromNet(cp->err_msg, std::get<Tcb>(_callback_tuple), cp->my_cmd, cp->tile, args);
} else {
Command<Tcmd>::PostFromNet(cp->err_msg, (CommandCallback *)nullptr, cp->my_cmd, cp->tile, args);
diff --git a/src/script/api/script_object.cpp b/src/script/api/script_object.cpp
index ff109dbdf..dad79309a 100644
--- a/src/script/api/script_object.cpp
+++ b/src/script/api/script_object.cpp
@@ -173,6 +173,16 @@ ScriptObject::ActiveInstance::~ActiveInstance()
return GetStorage()->last_command_res;
}
+/* static */ void ScriptObject::SetLastCommandResData(CommandDataBuffer data)
+{
+ GetStorage()->last_cmd_ret = std::move(data);
+}
+
+/* static */ const CommandDataBuffer &ScriptObject::GetLastCommandResData()
+{
+ return GetStorage()->last_cmd_ret;
+}
+
/* static */ void ScriptObject::SetNewVehicleID(VehicleID vehicle_id)
{
GetStorage()->new_vehicle_id = vehicle_id;
diff --git a/src/script/api/script_object.hpp b/src/script/api/script_object.hpp
index 11d9542c8..f9a66f8a8 100644
--- a/src/script/api/script_object.hpp
+++ b/src/script/api/script_object.hpp
@@ -62,6 +62,12 @@ public:
static void SetLastCommandRes(bool res);
/**
+ * Store the extra data return by the last DoCommand.
+ * @param data Extra data return by the command.
+ */
+ static void SetLastCommandResData(CommandDataBuffer data);
+
+ /**
* Get the currently active instance.
* @return The instance.
*/
@@ -74,10 +80,11 @@ protected:
* Templated wrapper that exposes the command parameter arguments
* on the various DoCommand calls.
* @tparam Tcmd The command-id to execute.
+ * @tparam Tret Return type of the command.
* @tparam Targs The command parameter types.
*/
- template <Commands Tcmd, typename... Targs>
- struct ScriptDoCommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Targs...)> {
+ template <Commands Tcmd, typename Tret, typename... Targs>
+ struct ScriptDoCommandHelper<Tcmd, Tret(*)(DoCommandFlag, Targs...)> {
static bool Do(Script_SuspendCallbackProc *callback, Targs... args)
{
return Execute(callback, std::forward_as_tuple(args...));
@@ -181,6 +188,11 @@ protected:
static bool GetLastCommandRes();
/**
+ * Get the extra return data from the last DoCommand.
+ */
+ static const CommandDataBuffer &GetLastCommandResData();
+
+ /**
* Get the latest stored new_vehicle_id.
*/
static VehicleID GetNewVehicleID();
@@ -363,10 +375,17 @@ namespace ScriptObjectInternal {
{
((SetClientIdHelper(std::get<Tindices>(values))), ...);
}
+
+ /** Remove the first element of a tuple. */
+ template <template <typename...> typename Tt, typename T1, typename... Ts>
+ static inline Tt<Ts...> RemoveFirstTupleElement(const Tt<T1, Ts...> &tuple)
+ {
+ return std::apply([](auto &&, const auto&... args) { return std::tie(args...); }, tuple);
+ }
}
-template <Commands Tcmd, typename... Targs>
-bool ScriptObject::ScriptDoCommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Targs...)>::Execute(Script_SuspendCallbackProc *callback, std::tuple<Targs...> args)
+template <Commands Tcmd, typename Tret, typename... Targs>
+bool ScriptObject::ScriptDoCommandHelper<Tcmd, Tret(*)(DoCommandFlag, Targs...)>::Execute(Script_SuspendCallbackProc *callback, std::tuple<Targs...> args)
{
auto [err, estimate_only, networking] = ScriptObject::DoCommandPrep();
if (err) return false;
@@ -387,9 +406,14 @@ bool ScriptObject::ScriptDoCommandHelper<Tcmd, CommandCost(*)(DoCommandFlag, Tar
if (!estimate_only && networking) ScriptObject::SetLastCommand(tile, EndianBufferWriter<CommandDataBuffer>::FromValue(args), Tcmd);
/* Try to perform the command. */
- CommandCost res = ::Command<Tcmd>::Unsafe((StringID)0, networking ? ScriptObject::GetDoCommandCallback() : nullptr, false, estimate_only, tile, args);
+ Tret res = ::Command<Tcmd>::Unsafe((StringID)0, networking ? ScriptObject::GetDoCommandCallback() : nullptr, false, estimate_only, tile, args);
- return ScriptObject::DoCommandProcessResult(res, callback, estimate_only);
+ if constexpr (std::is_same_v<Tret, CommandCost>) {
+ return ScriptObject::DoCommandProcessResult(res, callback, estimate_only);
+ } else {
+ ScriptObject::SetLastCommandResData(EndianBufferWriter<CommandDataBuffer>::FromValue(ScriptObjectInternal::RemoveFirstTupleElement(res)));
+ return ScriptObject::DoCommandProcessResult(std::get<0>(res), callback, estimate_only);
+ }
}
#endif /* SCRIPT_OBJECT_HPP */
diff --git a/src/script/script_instance.cpp b/src/script/script_instance.cpp
index ecf846b9f..0dfdd4b2a 100644
--- a/src/script/script_instance.cpp
+++ b/src/script/script_instance.cpp
@@ -687,7 +687,7 @@ SQInteger ScriptInstance::GetOpsTillSuspend()
return this->engine->GetOpsTillSuspend();
}
-bool ScriptInstance::DoCommandCallback(const CommandCost &result, TileIndex tile, const CommandDataBuffer &data, Commands cmd)
+bool ScriptInstance::DoCommandCallback(const CommandCost &result, TileIndex tile, const CommandDataBuffer &data, CommandDataBuffer result_data, Commands cmd)
{
ScriptObject::ActiveInstance active(this);
@@ -697,6 +697,7 @@ bool ScriptInstance::DoCommandCallback(const CommandCost &result, TileIndex tile
}
ScriptObject::SetLastCommandRes(result.Succeeded());
+ ScriptObject::SetLastCommandResData(std::move(result_data));
if (result.Failed()) {
ScriptObject::SetLastError(ScriptError::StringToError(result.GetErrorMessage()));
diff --git a/src/script/script_instance.hpp b/src/script/script_instance.hpp
index 290568fdd..57f8dcc72 100644
--- a/src/script/script_instance.hpp
+++ b/src/script/script_instance.hpp
@@ -179,10 +179,11 @@ public:
* @param result The result of the command.
* @param tile The tile on which the command was executed.
* @param data Command data as given to DoCommandPInternal.
+ * @param result_data Extra data return from the command.
* @param cmd cmd as given to DoCommandPInternal.
* @return true if we handled result.
*/
- bool DoCommandCallback(const CommandCost &result, TileIndex tile, const CommandDataBuffer &data, Commands cmd);
+ bool DoCommandCallback(const CommandCost &result, TileIndex tile, const CommandDataBuffer &data, CommandDataBuffer result_data, Commands cmd);
/**
* Insert an event for this script.
diff --git a/src/script/script_storage.hpp b/src/script/script_storage.hpp
index 3735adc1d..b8d1038a0 100644
--- a/src/script/script_storage.hpp
+++ b/src/script/script_storage.hpp
@@ -47,6 +47,7 @@ private:
TileIndex last_tile; ///< The last tile passed to a command.
CommandDataBuffer last_data; ///< The last data passed to a command.
Commands last_cmd; ///< The last cmd passed to a command.
+ CommandDataBuffer last_cmd_ret; ///< The extra data returned by the last command.
VehicleID new_vehicle_id; ///< The ID of the new Vehicle.
SignID new_sign_id; ///< The ID of the new Sign.