Fix: The first tile in commands received from a client wasn't validated properly.

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)
 {
-	/* 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;
-
 	/* Always execute server and spectator commands as spectator */
 	bool exec_as_spectator = (cmd_flags & (CMD_SPECTATOR | CMD_SERVER)) != 0;
 

src/command_func.h

@@ -222,6 +222,12 @@ public:
 	template <typename Tcallback>
 	static bool PostFromNet(StringID err_message, Tcallback *callback, bool my_cmd, TileIndex location, std::tuple<Targs...> args)
 	{
+		if constexpr (std::is_same_v<TileIndex, std::tuple_element_t<0, decltype(args)>>) {
+			/* Do not even think about executing out-of-bounds tile-commands. */
+			TileIndex tile = std::get<0>(args);
+			if (tile != 0 && (tile >= MapSize() || (!IsValidTile(tile) && (GetCommandFlags<Tcmd>() & CMD_ALL_TILES) == 0))) return false;
+		}
+
 		return InternalPost(err_message, callback, my_cmd, true, location, std::move(args));
 	}
 
@@ -299,6 +305,9 @@ protected:
 	template <typename Tcallback>
 	static bool InternalPost(StringID err_message, Tcallback *callback, bool my_cmd, bool network_command, TileIndex tile, std::tuple<Targs...> args)
 	{
+		/* Do not even think about executing out-of-bounds tile-commands. */
+		if (tile != 0 && (tile >= MapSize() || (!IsValidTile(tile) && (GetCommandFlags<Tcmd>() & CMD_ALL_TILES) == 0))) return false;
+
 		auto [err, estimate_only, only_sending] = InternalPostBefore(Tcmd, GetCommandFlags<Tcmd>(), tile, err_message, network_command);
 		if (err) return false;