From dc516ef8395d15da0ab225eb0dceb2e0581f51ca Mon Sep 17 00:00:00 2001
From: Steve Dower <steve.dower@python.org>
Date: Thu, 22 Apr 2021 00:18:20 +0100
Subject: [PATCH] bpo-26227: Fixes decoding of host names on Windows from ANSI
 instead of UTF-8 (GH-25510)

---
 .../next/Windows/2021-04-21-23-37-34.bpo-26227.QMY_eA.rst       | 2 ++
 Modules/socketmodule.c                                          | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Windows/2021-04-21-23-37-34.bpo-26227.QMY_eA.rst

diff --git a/Misc/NEWS.d/next/Windows/2021-04-21-23-37-34.bpo-26227.QMY_eA.rst b/Misc/NEWS.d/next/Windows/2021-04-21-23-37-34.bpo-26227.QMY_eA.rst
new file mode 100644
index 00000000000..d6826fb3970
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2021-04-21-23-37-34.bpo-26227.QMY_eA.rst
@@ -0,0 +1,2 @@
+Fixed decoding of host names in :func:`socket.gethostbyaddr` and
+:func:`socket.gethostbyname_ex`.
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 23aab59d974..79559c04d51 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -5508,7 +5508,7 @@ sock_decode_hostname(const char *name)
 #ifdef MS_WINDOWS
     /* Issue #26227: gethostbyaddr() returns a string encoded
      * to the ANSI code page */
-    return PyUnicode_DecodeFSDefault(name);
+    return PyUnicode_DecodeMBCS(name, strlen(name), "surrogatepass");
 #else
     /* Decode from UTF-8 */
     return PyUnicode_FromString(name);