From 0f800bf44a126cb5d9bf66dce68d8a6effe2cfd7 Mon Sep 17 00:00:00 2001
From: Ken Brown <kbrown@cornell.edu>
Date: Wed, 7 Oct 2020 07:07:18 -0400
Subject: [PATCH] Cygwin: AF_UNIX: accept4: copy trailing NUL byte

If the caller has requested the peer's address, include the trailing
NUL byte of the address if possible.
---
 winsup/cygwin/fhandler_socket_unix.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler_socket_unix.cc b/winsup/cygwin/fhandler_socket_unix.cc
index b44f36a0a..a1d7cb49a 100644
--- a/winsup/cygwin/fhandler_socket_unix.cc
+++ b/winsup/cygwin/fhandler_socket_unix.cc
@@ -1665,7 +1665,7 @@ fhandler_socket_unix::accept4 (struct sockaddr *peer, int *len, int flags)
 			      if (sun)
 				{
 				  memcpy (peer, &sun->un,
-					  MIN (*len, sun->un_len));
+					  MIN (*len, sun->un_len + 1));
 				  *len = sun->un_len;
 				}
 			      else if (len)