From 9aedb90fc62533df5f42c1b6c5caa8e7bbd5523e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=AF=E3=82=84=E3=81=97=E3=81=86=E3=82=81?=
 <122680126+HayashiUme@users.noreply.github.com>
Date: Tue, 9 Jun 2026 23:07:44 +0800
Subject: [PATCH] Set the console codepage to ensure correct text display
 regardless of encoding (#1337)

---
 .../Console/Windows/ConsoleEncoding/ConsoleEncoding.cs    | 8 ++++----
 BepInEx.Core/Console/Windows/WindowsConsoleDriver.cs      | 5 +++--
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/BepInEx.Core/Console/Windows/ConsoleEncoding/ConsoleEncoding.cs b/BepInEx.Core/Console/Windows/ConsoleEncoding/ConsoleEncoding.cs
index b70f1e1..b9d7c1c 100644
--- a/BepInEx.Core/Console/Windows/ConsoleEncoding/ConsoleEncoding.cs
+++ b/BepInEx.Core/Console/Windows/ConsoleEncoding/ConsoleEncoding.cs
@@ -41,7 +41,7 @@ internal partial class ConsoleEncoding : Encoding
     public override int GetByteCount(char[] chars, int index, int count)
     {
         WriteCharBuffer(chars, index, count);
-        var result = WideCharToMultiByte(_codePage, 0, chars, count, _zeroByte, 0, IntPtr.Zero, IntPtr.Zero);
+        var result = WideCharToMultiByte(_codePage, 0, _charBuffer, count, _zeroByte, 0, IntPtr.Zero, IntPtr.Zero);
         return result;
     }
 
@@ -50,7 +50,7 @@ internal partial class ConsoleEncoding : Encoding
         var byteCount = GetByteCount(chars, charIndex, charCount);
         WriteCharBuffer(chars, charIndex, charCount);
         ExpandByteBuffer(byteCount);
-        _ = WideCharToMultiByte(_codePage, 0, chars, charCount, _byteBuffer, byteCount, IntPtr.Zero,
+        _ = WideCharToMultiByte(_codePage, 0, _charBuffer, charCount, _byteBuffer, byteCount, IntPtr.Zero,
                                 IntPtr.Zero);
         var readCount = Math.Min(bytes.Length, byteCount);
         ReadByteBuffer(bytes, byteIndex, readCount);
@@ -60,7 +60,7 @@ internal partial class ConsoleEncoding : Encoding
     public override int GetCharCount(byte[] bytes, int index, int count)
     {
         WriteByteBuffer(bytes, index, count);
-        var result = MultiByteToWideChar(_codePage, 0, bytes, count, _zeroChar, 0);
+        var result = MultiByteToWideChar(_codePage, 0, _byteBuffer, count, _zeroChar, 0);
         return result;
     }
 
@@ -69,7 +69,7 @@ internal partial class ConsoleEncoding : Encoding
         var charCount = GetCharCount(bytes, byteIndex, byteCount);
         WriteByteBuffer(bytes, byteIndex, byteCount);
         ExpandCharBuffer(charCount);
-        _ = MultiByteToWideChar(_codePage, 0, bytes, byteCount, _charBuffer, charCount);
+        _ = MultiByteToWideChar(_codePage, 0, _byteBuffer, byteCount, _charBuffer, charCount);
         var readCount = Math.Min(chars.Length, charCount);
         ReadCharBuffer(chars, charIndex, readCount);
         return readCount;
diff --git a/BepInEx.Core/Console/Windows/WindowsConsoleDriver.cs b/BepInEx.Core/Console/Windows/WindowsConsoleDriver.cs
index 1edb857..802cd52 100644
--- a/BepInEx.Core/Console/Windows/WindowsConsoleDriver.cs
+++ b/BepInEx.Core/Console/Windows/WindowsConsoleDriver.cs
@@ -92,8 +92,9 @@ internal class WindowsConsoleDriver : IConsoleDriver
         // Make sure of ConsoleEncoding helper class because on some Monos
         // Encoding.GetEncoding throws NotImplementedException on most codepages
         // NOTE: We don't set Console.OutputEncoding because it resets any existing Console.Out writers
-        if (!useManagedEncoder)
-            ConsoleEncoding.ConsoleCodePage = codepage;
+        // Always set the console output codepage so the Windows console interprets bytes correctly,
+        // regardless of whether we use a managed encoder or ConsoleEncoding to produce those bytes.
+        ConsoleEncoding.ConsoleCodePage = codepage;
 
         // If stdout exists, write to it, otherwise make it the same as console out
         // Not sure if this is needed? Does the original Console.Out still work?