Index: Lib/test/test_fileio.py
===================================================================
--- Lib/test/test_fileio.py	(revision 85314)
+++ Lib/test/test_fileio.py	(working copy)
@@ -398,6 +398,22 @@
             self.assertRaises(ValueError, _FileIO, "/some/invalid/name", "rt")
             self.assertEqual(w.warnings, [])
 
+    def testUnclosedFDOnException(self):
+        class MyException(Exception): pass
+        class MyFileIO(_FileIO):
+            def __setattr__(self, name, value):
+                if name == "name":
+                    raise MyException("blocked setting name")
+                return super(MyFileIO, self).__setattr__(name, value)
+        fd = os.open(__file__, os.O_RDONLY)
+        try:
+            MyFileIO(fd)
+        except MyException:
+            pass
+        else:
+            self.skipTest("MyException was not raised")
+        # exception set is cleared here. MyFileIO's dealloc is called
+        self.assertIsNone(os.close(fd)) # should not raise IOError(EBADF)
 
 def test_main():
     # Historically, these tests have been sloppy about removing TESTFN.
Index: Modules/_io/fileio.c
===================================================================
--- Modules/_io/fileio.c	(revision 85314)
+++ Modules/_io/fileio.c	(working copy)
@@ -325,27 +325,25 @@
     if (fd >= 0) {
         if (check_fd(fd))
             goto error;
-        self->fd = fd;
-        self->closefd = closefd;
     }
     else {
-        self->closefd = 1;
         if (!closefd) {
             PyErr_SetString(PyExc_ValueError,
                 "Cannot use closefd=False with file name");
             goto error;
         }
+        closefd = 1;
 
         Py_BEGIN_ALLOW_THREADS
         errno = 0;
 #ifdef MS_WINDOWS
         if (widename != NULL)
-            self->fd = _wopen(widename, flags, 0666);
+            fd = _wopen(widename, flags, 0666);
         else
 #endif
-            self->fd = open(name, flags, 0666);
+            fd = open(name, flags, 0666);
         Py_END_ALLOW_THREADS
-        if (self->fd < 0) {
+        if (fd < 0) {
 #ifdef MS_WINDOWS
             if (widename != NULL)
                 PyErr_SetFromErrnoWithUnicodeFilename(PyExc_IOError, widename);
@@ -365,12 +363,14 @@
         /* For consistent behaviour, we explicitly seek to the
            end of file (otherwise, it might be done only on the
            first write()). */
-        PyObject *pos = portable_lseek(self->fd, NULL, 2);
+        PyObject *pos = portable_lseek(fd, NULL, 2);
         if (pos == NULL)
             goto error;
         Py_DECREF(pos);
     }
 
+    self->fd = fd;
+    self->closefd = closefd;
     goto done;
 
  error: