Add console command to merge two companies

src/company_cmd.cpp

@@ -931,6 +931,7 @@ void CompanyAdminRemove(CompanyID company_id, CompanyRemoveReason reason)
  * - bits 0..15: CompanyCtrlAction
  * - bits 16..23: CompanyID
  * - bits 24..31: CompanyRemoveReason (with CCA_DELETE)
+ * - bits 24..31: CompanyID to merge (with CCA_MERGE)
  * @param p2 ClientID
  * @param text unused
  * @return the cost of this operation or an error
@@ -1071,6 +1072,38 @@ CommandCost CmdCompanyCtrl(TileIndex tile, DoCommandFlag flags, uint32_t p1, uin
 			break;
 		}
 
+		case CCA_MERGE: {
+			Company *c = Company::GetIfValid(company_id);
+			if (c == nullptr) return CMD_ERROR;
+
+			CompanyID to_merge_id = (CompanyID)GB(p1, 24, 8);
+			if (to_merge_id == company_id) return CMD_ERROR;
+
+			Company *to_merge = Company::GetIfValid(to_merge_id);
+			if (to_merge == nullptr) return CMD_ERROR;
+
+			if (!(flags & DC_EXEC)) return CommandCost();
+
+			SubtractMoneyFromAnyCompany(c, CommandCost(EXPENSES_OTHER, to_merge->current_loan - to_merge->money));
+
+			DEBUG(desync, 1, "merge_companies: %s, company_id: %u, merged_company_id: %u", debug_date_dumper().HexDate(), company_id, to_merge_id);
+
+			CompanyNewsInformation *cni = new CompanyNewsInformation(to_merge, c);
+
+			SetDParam(0, STR_NEWS_COMPANY_MERGER_TITLE);
+			SetDParam(1, STR_NEWS_MERGER_TAKEOVER_TITLE);
+			SetDParamStr(2, cni->company_name);
+			SetDParamStr(3, cni->other_company_name);
+			AddCompanyNewsItem(STR_MESSAGE_NEWS_FORMAT, cni);
+			AI::BroadcastNewEvent(new ScriptEventCompanyMerger(to_merge_id, company_id));
+			Game::NewEvent(new ScriptEventCompanyMerger(to_merge_id, company_id));
+
+			ChangeOwnershipOfCompanyItems(to_merge_id, company_id);
+
+			PostAcquireCompany(to_merge);
+			break;
+		}
+
 		default: return CMD_ERROR;
 	}
 

src/company_type.h

@@ -71,6 +71,7 @@ enum CompanyCtrlAction {
 	CCA_NEW_AI, ///< Create a new AI company.
 	CCA_DELETE, ///< Delete a company.
 	CCA_SALE,   ///< Offer a company for sale.
+	CCA_MERGE,  ///< Merge companies.
 
 	CCA_END,    ///< Sentinel for end.
 };

src/console_cmds.cpp

@@ -1183,6 +1183,35 @@ DEF_CONSOLE_CMD(ConOfferCompanySale)
 	return true;
 }
 
+DEF_CONSOLE_CMD(ConMergeCompanies)
+{
+	if (argc != 3) {
+		IConsolePrint(CC_HELP, "Merge two companies together. Usage: 'merge_companies <main-company-id> <to-merge-company-id>'");
+		IConsolePrint(CC_HELP, "The first company ID <main-company-id> will be left with the combined assets of both companies.");
+		IConsolePrint(CC_HELP, "The second company ID <to-merge-company-id> will be removed, with all assets transfered to the first company ID.");
+		IConsolePrint(CC_HELP, "For company-id's, see the list of companies from the dropdown menu. Company 1 is 1, etc.");
+		return true;
+	}
+
+	CompanyID main_company = (CompanyID)(atoi(argv[1]) - 1);
+	CompanyID to_merge_company = (CompanyID)(atoi(argv[2]) - 1);
+
+	/* Check valid range */
+	if (!Company::IsValidID(main_company)) {
+		IConsolePrintF(CC_ERROR, "Main company does not exist. Company-id must be between 1 and %d.", MAX_COMPANIES);
+		return true;
+	}
+	if (!Company::IsValidID(to_merge_company)) {
+		IConsolePrintF(CC_ERROR, "Company to merge does not exist. Company-id must be between 1 and %d.", MAX_COMPANIES);
+		return true;
+	}
+
+	DoCommandP(0, CCA_MERGE | (main_company << 16) | (to_merge_company << 24), 0, CMD_COMPANY_CTRL);
+	IConsolePrint(CC_DEFAULT, "Companies merged.");
+
+	return true;
+}
+
 DEF_CONSOLE_CMD(ConNetworkClients)
 {
 	if (argc == 0) {
@@ -4139,6 +4168,7 @@ void IConsoleStdLibRegister()
 	IConsole::CmdRegister("reset_company",           ConResetCompany,     ConHookServerOnly);
 	IConsole::AliasRegister("clean_company",         "reset_company %A");
 	IConsole::CmdRegister("offer_company_sale",      ConOfferCompanySale, ConHookServerOrNoNetwork);
+	IConsole::CmdRegister("merge_companies",         ConMergeCompanies,   ConHookServerOrNoNetwork);
 	IConsole::CmdRegister("client_name",             ConClientNickChange, ConHookServerOnly);
 	IConsole::CmdRegister("kick",                    ConKick,             ConHookServerOnly);
 	IConsole::CmdRegister("ban",                     ConBan,              ConHookServerOnly);

src/economy.cpp

@@ -2490,11 +2490,16 @@ static void DoAcquireCompany(Company *c, bool hostile_takeover)
 
 	ChangeOwnershipOfCompanyItems(ci, _current_company);
 
+	PostAcquireCompany(c);
+}
+
+void PostAcquireCompany(Company *c)
+{
 	if (c->is_ai) AI::Stop(c->index);
 
 	c->bankrupt_asked = 0;
 
-	DeleteCompanyWindows(ci);
+	DeleteCompanyWindows(c->index);
 	InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
 	InvalidateWindowClassesData(WC_TRACE_RESTRICT_SLOTS, 0);
 	InvalidateWindowClassesData(WC_SHIPS_LIST, 0);

src/economy_func.h

@@ -60,4 +60,6 @@ int PercentageToScaleQuantityFactor(uint percentage);
 
 void UpdateCargoScalers();
 
+void PostAcquireCompany(Company *c);
+
 #endif /* ECONOMY_FUNC_H */

src/network/network.cpp

@@ -1285,7 +1285,8 @@ void NetworkGameLoop()
 			} else if (strncmp(p, "msg: ", 5) == 0 || strncmp(p, "client: ", 8) == 0 ||
 						strncmp(p, "load: ", 6) == 0 || strncmp(p, "save: ", 6) == 0 ||
 						strncmp(p, "new_company: ", 13) == 0 || strncmp(p, "new_company_ai: ", 16) == 0 ||
-						strncmp(p, "buy_company: ", 13) == 0 || strncmp(p, "delete_company: ", 16) == 0) {
+						strncmp(p, "buy_company: ", 13) == 0 || strncmp(p, "delete_company: ", 16) == 0 ||
+						strncmp(p, "merge_companies: ", 17) == 0) {
 				/* A message that is not very important to the log playback, but part of the log. */
 #ifndef DEBUG_FAILED_DUMP_COMMANDS
 			} else if (strncmp(p, "cmdf: ", 6) == 0) {