From e676dbf8399e5cbfb0c36fe304abc670cd003c82 Mon Sep 17 00:00:00 2001
From: kanjitalk755 <kanjitalk755@yahoo.co.jp>
Date: Tue, 5 Feb 2019 18:44:24 +0900
Subject: [PATCH] BII/SS pref item "yearofs"

---
 BasiliskII/src/macos_util.cpp   | 3 +++
 BasiliskII/src/prefs_items.cpp  | 1 +
 SheepShaver/src/macos_util.cpp  | 3 +++
 SheepShaver/src/prefs_items.cpp | 1 +
 4 files changed, 8 insertions(+)

diff --git a/BasiliskII/src/macos_util.cpp b/BasiliskII/src/macos_util.cpp
index 6de3877f..85115df7 100644
--- a/BasiliskII/src/macos_util.cpp
+++ b/BasiliskII/src/macos_util.cpp
@@ -26,6 +26,8 @@
 #include "disk.h"
 #include "cdrom.h"
 #include "macos_util.h"
+#include "prefs.h"
+#include <algorithm>
 
 #define DEBUG 0
 #include "debug.h"
@@ -134,6 +136,7 @@ uint32 TimeToMacTime(time_t t)
 	struct tm *local = localtime(&t);
 	const int TM_EPOCH_YEAR = 1900;
 	const int MAC_EPOCH_YEAR = 1904;
+	local->tm_year = std::max(MAC_EPOCH_YEAR - TM_EPOCH_YEAR, local->tm_year - PrefsFindInt32("yearofs"));
 	int a4 = ((local->tm_year + TM_EPOCH_YEAR) >> 2) - !(local->tm_year & 3);
 	int b4 = (MAC_EPOCH_YEAR >> 2) - !(MAC_EPOCH_YEAR & 3);
 	int a100 = a4 / 25 - (a4 % 25 < 0);
diff --git a/BasiliskII/src/prefs_items.cpp b/BasiliskII/src/prefs_items.cpp
index 0de2f6ee..79eb7230 100644
--- a/BasiliskII/src/prefs_items.cpp
+++ b/BasiliskII/src/prefs_items.cpp
@@ -75,6 +75,7 @@ prefs_desc common_prefs_items[] = {
 	{"hotkey",TYPE_INT32,false,"hotkey modifier"},
 	{"scale_nearest",TYPE_BOOLEAN,false,"nearest neighbor scaling"},
 	{"scale_integer",TYPE_BOOLEAN,false,"integer scaling"},
+	{"yearofs", TYPE_INT32, 0,			"year offset"},
 	{NULL, TYPE_END, false, NULL} // End of list
 };
 
diff --git a/SheepShaver/src/macos_util.cpp b/SheepShaver/src/macos_util.cpp
index 517ab703..9afc2842 100644
--- a/SheepShaver/src/macos_util.cpp
+++ b/SheepShaver/src/macos_util.cpp
@@ -28,6 +28,8 @@
 #include "emul_op.h"
 #include "macos_util.h"
 #include "thunks.h"
+#include "prefs.h"
+#include <algorithm>
 
 #define DEBUG 0
 #include "debug.h"
@@ -333,6 +335,7 @@ uint32 TimeToMacTime(time_t t)
 #endif
 	const int TM_EPOCH_YEAR = 1900;
 	const int MAC_EPOCH_YEAR = 1904;
+	local->tm_year = std::max(MAC_EPOCH_YEAR - TM_EPOCH_YEAR, local->tm_year - PrefsFindInt32("yearofs"));
 	int a4 = ((local->tm_year + TM_EPOCH_YEAR) >> 2) - !(local->tm_year & 3);
 	int b4 = (MAC_EPOCH_YEAR >> 2) - !(MAC_EPOCH_YEAR & 3);
 	int a100 = a4 / 25 - (a4 % 25 < 0);
diff --git a/SheepShaver/src/prefs_items.cpp b/SheepShaver/src/prefs_items.cpp
index 5a7f7761..072c6fd9 100644
--- a/SheepShaver/src/prefs_items.cpp
+++ b/SheepShaver/src/prefs_items.cpp
@@ -63,6 +63,7 @@ prefs_desc common_prefs_items[] = {
 	{"scale_nearest",TYPE_BOOLEAN,false,"nearest neighbor scaling"},
 	{"scale_integer",TYPE_BOOLEAN,false,"integer scaling"},
 	{"cpuclock", TYPE_INT32, 0,			"CPU clock [MHz] of system info"},
+	{"yearofs", TYPE_INT32, 0,			"year offset"},
 	{NULL, TYPE_END, false, NULL} // End of list
 };