From dc7c128d74876bf0bcef61e34bd858a675b7a43c Mon Sep 17 00:00:00 2001
From: =?utf8?q?Kristj=C3=A1n=20Valur=20J=C3=B3nsson?=
 <kristjan@ccpgames.com>
Date: Tue, 24 Mar 2009 13:21:53 +0000
Subject: [PATCH] http://bugs.python.org/issue5544 Someone may have closed the
 file descriptor, with something like f = open('test.test', 'w')
 os.close(f.fileno()) f.close() Protect against this by checking fd on windows
 before closing.

---
 Modules/_fileio.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/Modules/_fileio.c b/Modules/_fileio.c
index 88ee54c5f8..00065611e3 100644
--- a/Modules/_fileio.c
+++ b/Modules/_fileio.c
@@ -77,11 +77,15 @@ internal_close(PyFileIOObject *self)
 	if (self->fd >= 0) {
 		int fd = self->fd;
 		self->fd = -1;
-		Py_BEGIN_ALLOW_THREADS
-		err = close(fd);
-		if (err < 0)
-			save_errno = errno;
-		Py_END_ALLOW_THREADS
+		/* fd is accessible and someone else may have closed it */
+		if (_PyVerify_fd(fd)) {
+			Py_BEGIN_ALLOW_THREADS
+			err = close(fd);
+			if (err < 0)
+				save_errno = errno;
+			Py_END_ALLOW_THREADS
+		} else
+		save_errno = errno;
 	}
 	if (err < 0) {
 		errno = save_errno;
-- 
2.40.0