From e21c6cfb8a14a0aa258baa8c9c2e40a1229bc47c Mon Sep 17 00:00:00 2001
From: Tyler Trahan <tyler@tylertrahan.com>
Date: Sun, 1 Jan 2023 13:00:01 -0500
Subject: [PATCH] Codechange: Sync economy and calendar dates when loading old
 saves

---
 src/saveload/afterload.cpp | 8 ++++++++
 src/saveload/misc_sl.cpp   | 3 +++
 src/saveload/saveload.h    | 1 +
 3 files changed, 12 insertions(+)

diff --git a/src/saveload/afterload.cpp b/src/saveload/afterload.cpp
index e6fd1c7ba1..b44b0b92c9 100644
--- a/src/saveload/afterload.cpp
+++ b/src/saveload/afterload.cpp
@@ -60,6 +60,7 @@
 #include "../water.h"
 #include "../timer/timer.h"
 #include "../timer/timer_game_calendar.h"
+#include "../timer/timer_game_economy.h"
 #include "../timer/timer_game_tick.h"
 
 #include "saveload_internal.h"
@@ -734,6 +735,13 @@ bool AfterLoadGame()
 	 * must be done before loading sprites as some newgrfs check it */
 	TimerGameCalendar::SetDate(TimerGameCalendar::date, TimerGameCalendar::date_fract);
 
+	/* Update economy year. If we don't have a separate economy date saved, follow the calendar date. */
+	if (IsSavegameVersionBefore(SLV_ECONOMY_DATE)) {
+		TimerGameEconomy::SetDate(TimerGameCalendar::date.base(), TimerGameCalendar::date_fract);
+	} else {
+		TimerGameEconomy::SetDate(TimerGameEconomy::date, TimerGameEconomy::date_fract);
+	}
+
 	/*
 	 * Force the old behaviour for compatibility reasons with old savegames. As new
 	 * settings can only be loaded from new savegames loading old savegames with new
diff --git a/src/saveload/misc_sl.cpp b/src/saveload/misc_sl.cpp
index f50cab48b5..a28021f520 100644
--- a/src/saveload/misc_sl.cpp
+++ b/src/saveload/misc_sl.cpp
@@ -13,6 +13,7 @@
 #include "compat/misc_sl_compat.h"
 
 #include "../timer/timer_game_calendar.h"
+#include "../timer/timer_game_economy.h"
 #include "../zoom_func.h"
 #include "../window_gui.h"
 #include "../window_func.h"
@@ -85,6 +86,8 @@ static const SaveLoad _date_desc[] = {
 	    SLEG_VAR("date_fract",             TimerGameCalendar::date_fract,             SLE_UINT16),
 	SLEG_CONDVAR("tick_counter",           TimerGameTick::counter,           SLE_FILE_U16 | SLE_VAR_U64,  SL_MIN_VERSION, SLV_U64_TICK_COUNTER),
 	SLEG_CONDVAR("tick_counter",           TimerGameTick::counter,           SLE_UINT64,                  SLV_U64_TICK_COUNTER, SL_MAX_VERSION),
+	SLEG_CONDVAR("economy_date",           TimerGameEconomy::date,           SLE_INT32,                   SLV_ECONOMY_DATE, SL_MAX_VERSION),
+	SLEG_CONDVAR("economy_date_fract",     TimerGameEconomy::date_fract,     SLE_UINT16,                  SLV_ECONOMY_DATE, SL_MAX_VERSION),
 	SLEG_CONDVAR("age_cargo_skip_counter", _age_cargo_skip_counter, SLE_UINT8,                   SL_MIN_VERSION, SLV_162),
 	SLEG_CONDVAR("cur_tileloop_tile",      _cur_tileloop_tile,      SLE_FILE_U16 | SLE_VAR_U32,  SL_MIN_VERSION, SLV_6),
 	SLEG_CONDVAR("cur_tileloop_tile",      _cur_tileloop_tile,      SLE_UINT32,                  SLV_6, SL_MAX_VERSION),
diff --git a/src/saveload/saveload.h b/src/saveload/saveload.h
index 4c784ba70d..97625fb482 100644
--- a/src/saveload/saveload.h
+++ b/src/saveload/saveload.h
@@ -368,6 +368,7 @@ enum SaveLoadVersion : uint16_t {
 	SLV_WATER_REGIONS,                      ///< 324  PR#10543 Water Regions for ship pathfinder.
 
 	SLV_WATER_REGION_EVAL_SIMPLIFIED,       ///< 325  PR#11750 Simplified Water Region evaluation.
+	SLV_ECONOMY_DATE,                       ///< 326  PR#10700 Split calendar and economy timers and dates.
 
 	SL_MAX_VERSION,                         ///< Highest possible saveload version
 };