From 86d01c33997a313cc37213ffe183ddf9c0b513aa Mon Sep 17 00:00:00 2001
From: "Admiral H. Curtiss" <pikachu025@gmail.com>
Date: Mon, 7 Nov 2022 05:33:47 +0100
Subject: [PATCH] Config: Add option to use JPN as the Japanese region
 directory in GetDirectoryForRegion().

See https://bugs.dolphin-emu.org/issues/13076 for motivation for this.
---
 Source/Core/Common/CommonPaths.h         |  2 ++
 Source/Core/Core/Config/MainSettings.cpp |  7 ++++---
 Source/Core/Core/Config/MainSettings.h   | 10 +++++++++-
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/Source/Core/Common/CommonPaths.h b/Source/Core/Common/CommonPaths.h
index cb8aacddf8..187231f743 100644
--- a/Source/Core/Common/CommonPaths.h
+++ b/Source/Core/Common/CommonPaths.h
@@ -28,9 +28,11 @@
 #endif
 
 // Dirs in both User and Sys
+// Legacy setups used /JAP/ while newer setups use /JPN/ by default.
 #define EUR_DIR "EUR"
 #define USA_DIR "USA"
 #define JAP_DIR "JAP"
+#define JPN_DIR "JPN"
 
 // Subdirs in the User dir returned by GetUserPath(D_USER_IDX)
 #define GC_USER_DIR "GC"
diff --git a/Source/Core/Core/Config/MainSettings.cpp b/Source/Core/Core/Config/MainSettings.cpp
index 091fd3504f..4a8ae957f0 100644
--- a/Source/Core/Core/Config/MainSettings.cpp
+++ b/Source/Core/Core/Config/MainSettings.cpp
@@ -561,7 +561,7 @@ DiscIO::Region ToGameCubeRegion(DiscIO::Region region)
   return DiscIO::Region::NTSC_J;
 }
 
-const char* GetDirectoryForRegion(DiscIO::Region region)
+const char* GetDirectoryForRegion(DiscIO::Region region, RegionDirectoryStyle style)
 {
   if (region == DiscIO::Region::Unknown)
     region = ToGameCubeRegion(Config::Get(Config::MAIN_FALLBACK_REGION));
@@ -569,7 +569,7 @@ const char* GetDirectoryForRegion(DiscIO::Region region)
   switch (region)
   {
   case DiscIO::Region::NTSC_J:
-    return JAP_DIR;
+    return style == RegionDirectoryStyle::Legacy ? JAP_DIR : JPN_DIR;
 
   case DiscIO::Region::NTSC_U:
     return USA_DIR;
@@ -578,8 +578,9 @@ const char* GetDirectoryForRegion(DiscIO::Region region)
     return EUR_DIR;
 
   case DiscIO::Region::NTSC_K:
+    // See ToGameCubeRegion
     ASSERT_MSG(BOOT, false, "NTSC-K is not a valid GameCube region");
-    return JAP_DIR;  // See ToGameCubeRegion
+    return style == RegionDirectoryStyle::Legacy ? JAP_DIR : JPN_DIR;
 
   default:
     ASSERT_MSG(BOOT, false, "Default case should not be reached");
diff --git a/Source/Core/Core/Config/MainSettings.h b/Source/Core/Core/Config/MainSettings.h
index f30ef02a38..0730681f2d 100644
--- a/Source/Core/Core/Config/MainSettings.h
+++ b/Source/Core/Core/Config/MainSettings.h
@@ -344,8 +344,16 @@ void SetUSBDeviceWhitelist(const std::set<std::pair<u16, u16>>& devices);
 
 // Replaces NTSC-K with some other region, and doesn't replace non-NTSC-K regions
 DiscIO::Region ToGameCubeRegion(DiscIO::Region region);
+
 // The region argument must be valid for GameCube (i.e. must not be NTSC-K)
-const char* GetDirectoryForRegion(DiscIO::Region region);
+enum class RegionDirectoryStyle
+{
+  Legacy,
+  Modern,
+};
+const char* GetDirectoryForRegion(DiscIO::Region region,
+                                  RegionDirectoryStyle style = RegionDirectoryStyle::Legacy);
+
 std::string GetBootROMPath(const std::string& region_directory);
 // Builds the memory card according to the configuration with the given region and size. If the
 // given region is std::nullopt, the region in the configured path is used if there is one, or the