Index: Modules/posixmodule.c
===================================================================
--- Modules/posixmodule.c	(revision 69275)
+++ Modules/posixmodule.c	(working copy)
@@ -343,6 +343,35 @@
 #endif
 #endif
 
+#ifdef _MSC_VER /* touch MSVCRT internal */
+typedef struct {
+        long osfhnd;
+        char osfile;
+        char pipech;
+#ifdef _MT
+        int lockinitflag;
+        CRITICAL_SECTION lock;
+#endif /* _MT */
+    }   ioinfo;
+extern __declspec(dllimport) ioinfo * __pioinfo[];
+#define IOINFO_ARRAYS 64
+#define IOINFO_L2E 5
+#define FOPEN 0x01
+static int
+check_fd(int fd)
+{
+	const int i1 = fd >> IOINFO_L2E;
+	const int i2 = fd & ((1 << IOINFO_L2E) - 1);
+
+	if (0 <= i1 && i1 < IOINFO_ARRAYS && __pioinfo[i1] && (__pioinfo[i1][i2].osfile & FOPEN))
+		return 1;
+	else {
+		errno = EBADF;
+		return 0;
+	}
+}
+#endif
+
 /* Return a dictionary corresponding to the POSIX environment table */
 #ifdef WITH_NEXT_FRAMEWORK
 /* On Darwin/MacOSX a shared library or framework has no access to
@@ -581,6 +610,10 @@
 	fd = PyObject_AsFileDescriptor(fdobj);
 	if (fd < 0)
 		return NULL;
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 	res = (*func)(fd);
 	Py_END_ALLOW_THREADS
@@ -6188,6 +6221,10 @@
 	int fd, res;
 	if (!PyArg_ParseTuple(args, "i:close", &fd))
 		return NULL;
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 	res = close(fd);
 	Py_END_ALLOW_THREADS
@@ -6210,6 +6247,9 @@
 		return NULL;
 	Py_BEGIN_ALLOW_THREADS
 	for (i = fd_from; i < fd_to; i++)
+#ifdef _MSC_VER
+		if (check_fd(i))
+#endif
 		close(i);
 	Py_END_ALLOW_THREADS
 	Py_RETURN_NONE;
@@ -6226,6 +6266,10 @@
 	int fd;
 	if (!PyArg_ParseTuple(args, "i:dup", &fd))
 		return NULL;
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 	fd = dup(fd);
 	Py_END_ALLOW_THREADS
@@ -6245,6 +6289,10 @@
 	int fd, fd2, res;
 	if (!PyArg_ParseTuple(args, "ii:dup2", &fd, &fd2))
 		return NULL;
+#ifdef _MSC_VER
+	if (!check_fd(fd) || !check_fd(fd2))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 	res = dup2(fd, fd2);
 	Py_END_ALLOW_THREADS
@@ -6289,6 +6337,10 @@
 	if (PyErr_Occurred())
 		return NULL;
 
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 #if defined(MS_WIN64) || defined(MS_WINDOWS)
 	res = _lseeki64(fd, pos, how);
@@ -6325,6 +6377,10 @@
 	buffer = PyString_FromStringAndSize((char *)NULL, size);
 	if (buffer == NULL)
 		return NULL;
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 	n = read(fd, PyString_AsString(buffer), size);
 	Py_END_ALLOW_THREADS
@@ -6351,6 +6407,10 @@
 
 	if (!PyArg_ParseTuple(args, "is*:write", &fd, &pbuf))
 		return NULL;
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 	size = write(fd, pbuf.buf, (size_t)pbuf.len);
 	Py_END_ALLOW_THREADS
@@ -6377,6 +6437,10 @@
         /* on OpenVMS we must ensure that all bytes are written to the file */
         fsync(fd);
 #endif
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 	res = FSTAT(fd, &st);
 	Py_END_ALLOW_THREADS
@@ -6419,6 +6483,10 @@
 		PyMem_FREE(mode);
 		return NULL;
 	}
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return posix_error();
+#endif
 	Py_BEGIN_ALLOW_THREADS
 #if !defined(MS_WINDOWS) && defined(HAVE_FCNTL_H)
 	if (mode[0] == 'a') {
@@ -6458,6 +6526,10 @@
 	int fd;
 	if (!PyArg_ParseTuple(args, "i:isatty", &fd))
 		return NULL;
+#ifdef _MSC_VER
+	if (!check_fd(fd))
+		return PyBool_FromLong(0);
+#endif
 	return PyBool_FromLong(isatty(fd));
 }