From ef269531a96b649ae27395f272cf95aa2c7062fa Mon Sep 17 00:00:00 2001
From: Ken Brown <kbrown@cornell.edu>
Date: Sat, 20 Apr 2019 11:49:35 -0400
Subject: [PATCH] Cygwin: FIFO: duplicate the i/o handle when opening a
 duplexer

Don't use the same i/o handle for the first client handler as is used
for the fhandler itself; this can lead to a later attempt to close the
same handle twice.  Instead use a duplicate.
---
 winsup/cygwin/fhandler_fifo.cc | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler_fifo.cc b/winsup/cygwin/fhandler_fifo.cc
index 409144fda..0a6dc0591 100644
--- a/winsup/cygwin/fhandler_fifo.cc
+++ b/winsup/cygwin/fhandler_fifo.cc
@@ -480,7 +480,14 @@ fhandler_fifo::open (int flags, mode_t)
 	  res = error_errno_set;
 	  goto out;
 	}
-      fh->set_handle (ph);
+      if (!DuplicateHandle (GetCurrentProcess (), ph, GetCurrentProcess (),
+			    &fh->get_handle (), 0, true, DUPLICATE_SAME_ACCESS))
+	{
+	  res = error_set_errno;
+	  fh->close ();
+	  delete fh;
+	  goto out;
+	}
       fh->set_flags (flags);
       if (!(connect_evt = create_event ()))
 	{
-- 
2.43.5