From 37cd35aea8afa35476640e454eaf2c53150dc014 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Wed, 1 Dec 2021 15:05:16 +0900
Subject: [PATCH] [win32] Transcode input from console [Bug #18353]

On Windows, as the input from console is encoded in the active
code page, convert the input to the internal encoding.
---
 io.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/io.c b/io.c
index 366225089c..b2ca5a69e3 100644
--- a/io.c
+++ b/io.c
@@ -12224,6 +12224,18 @@ rb_stdio_set_default_encoding(void)
 {
     VALUE val = Qnil;
 
+#ifdef _WIN32
+    if (isatty(fileno(stdin))) {
+        rb_encoding *external = rb_locale_encoding();
+        rb_encoding *internal = rb_default_internal_encoding();
+        if (!internal) internal = rb_default_external_encoding();
+        io_encoding_set(RFILE(rb_stdin)->fptr,
+                        rb_enc_from_encoding(external),
+                        rb_enc_from_encoding(internal),
+                        Qnil);
+    }
+    else
+#endif
     rb_io_set_encoding(1, &val, rb_stdin);
     rb_io_set_encoding(1, &val, rb_stdout);
     rb_io_set_encoding(1, &val, rb_stderr);