diff --git a/Doc/howto/unicode.rst b/Doc/howto/unicode.rst
index 21ae111..561ce29 100644
--- a/Doc/howto/unicode.rst
+++ b/Doc/howto/unicode.rst
@@ -410,9 +410,9 @@
     
 The syntax is inspired by Emacs's notation for specifying variables local to a
 file.  Emacs supports many different variables, but Python only supports
-'coding'.  The ``-*-`` symbols indicate that the comment is special; within
-them, you must supply the name ``coding`` and the name of your chosen encoding,
-separated by ``':'``.
+'coding'.  The ``-*-`` symbols indicate to Emacs that the comment is special;
+they have no significance to Python but are a convention.  Python looks for
+``coding: name`` or ``coding=name`` in the comment.
 
 If you don't include such a comment, the default encoding used will be ASCII.
 Versions of Python before 2.4 were Euro-centric and assumed Latin-1 as a default
diff --git a/Doc/library/bdb.rst b/Doc/library/bdb.rst
index 82a1c21..3041b7b 100644
--- a/Doc/library/bdb.rst
+++ b/Doc/library/bdb.rst
@@ -107,8 +107,9 @@
 
       The *arg* parameter depends on the previous event.
 
-      For more information on trace functions, see :ref:`debugger-hooks`.  For
-      more information on code and frame objects, refer to :ref:`types`.
+      See the documentation for :func:`sys.settrace` for more information on the
+      trace function.  For more information on code and frame objects, refer to
+      :ref:`types`.
 
    .. method:: dispatch_line(frame)
 
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 258b54f..40ec9e8 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -60,7 +60,7 @@
                            :class:`Iterable`,     and ``__len__``         ``index``, and ``count``
                            :class:`Container`     
                                                   
-:class:`MutableSequnce`    :class:`Sequence`      ``__getitem__``         Inherited Sequence methods and
+:class:`MutableSequence`   :class:`Sequence`      ``__getitem__``         Inherited Sequence methods and
                                                   ``__delitem__``,        ``append``, ``reverse``, ``extend``, ``pop``,
                                                   ``insert``,             ``remove``, and ``__iadd__``
                                                   and ``__len__``
@@ -487,16 +487,16 @@
 self-documenting code.  They can be used wherever regular tuples are used, and
 they add the ability to access fields by name instead of position index.
 
-.. function:: namedtuple(typename, fieldnames, [verbose])
+.. function:: namedtuple(typename, field_names, [verbose])
 
    Returns a new tuple subclass named *typename*.  The new subclass is used to
    create tuple-like objects that have fields accessible by attribute lookup as
    well as being indexable and iterable.  Instances of the subclass also have a
-   helpful docstring (with typename and fieldnames) and a helpful :meth:`__repr__`
+   helpful docstring (with typename and field_names) and a helpful :meth:`__repr__`
    method which lists the tuple contents in a ``name=value`` format.
 
-   The *fieldnames* are a single string with each fieldname separated by whitespace
-   and/or commas, for example ``'x y'`` or ``'x, y'``.  Alternatively, *fieldnames*
+   The *field_names* are a single string with each fieldname separated by whitespace
+   and/or commas, for example ``'x y'`` or ``'x, y'``.  Alternatively, *field_names*
    can be a sequence of strings such as ``['x', 'y']``.
 
    Any valid Python identifier may be used for a fieldname except for names
diff --git a/Doc/library/ctypes.rst b/Doc/library/ctypes.rst
index 8e920f8..0e37332 100644
--- a/Doc/library/ctypes.rst
+++ b/Doc/library/ctypes.rst
@@ -1370,7 +1370,7 @@
 
 All these classes can be instantiated by calling them with at least one
 argument, the pathname of the shared library.  If you have an existing handle to
-an already loaded shard library, it can be passed as the ``handle`` named
+an already loaded shared library, it can be passed as the ``handle`` named
 parameter, otherwise the underlying platforms ``dlopen`` or :meth:`LoadLibrary`
 function is used to load the library into the process, and to get a handle to
 it.
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index 18df0e0..25d5f16 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -214,8 +214,10 @@
 
    .. method:: close()
 
-      Flush and close this stream.  This method has no effect if the file is
-      already closed.
+      Flush and close this stream. This method has no effect if the file is
+      already closed. Once the file is closed, any operation on the file 
+      (e.g. reading or writing) will raise an :exc:`IOError`. The internal
+      file descriptor isn't closed if *closefd* was False.
 
    .. attribute:: closed
 
diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
index 7a13183..e1992cc 100644
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -919,7 +919,7 @@
 
    Note that *lock* is a keyword only argument.
 
-   Note that an array of :data:`ctypes.c_char` has *value* and *rawvalue*
+   Note that an array of :data:`ctypes.c_char` has *value* and *raw*
    attributes which allow one to use it to store and retrieve strings.
 
 
@@ -968,7 +968,7 @@
    :func:`Value` instead to make sure that access is automatically synchronized
    using a lock.
 
-   Note that an array of :data:`ctypes.c_char` has ``value`` and ``rawvalue``
+   Note that an array of :data:`ctypes.c_char` has ``value`` and ``raw``
    attributes which allow one to use it to store and retrieve strings -- see
    documentation for :mod:`ctypes`.
 
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 14784fa..1cb450b 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -933,10 +933,10 @@
 
 .. function:: listdir(path)
 
-   Return a list containing the names of the entries in the directory. The list is
-   in arbitrary order.  It does not include the special entries ``'.'`` and
-   ``'..'`` even if they are present in the directory. Availability:
-   Unix, Windows.
+   Return a list containing the names of the entries in the directory given by
+   *path*.  The list is in arbitrary order.  It does not include the special
+   entries ``'.'`` and ``'..'`` even if they are present in the
+   directory.  Availability: Unix, Windows.
 
    .. versionchanged:: 2.3
       On Windows NT/2k/XP and Unix, if *path* is a Unicode object, the result will be
diff --git a/Doc/library/pdb.rst b/Doc/library/pdb.rst
index c1a0bcd..384c7d9 100644
--- a/Doc/library/pdb.rst
+++ b/Doc/library/pdb.rst
@@ -351,68 +351,3 @@
 
 q(uit)
    Quit from the debugger. The program being executed is aborted.
-
-
-.. _debugger-hooks:
-
-How It Works
-============
-
-Some changes were made to the interpreter:
-
-* ``sys.settrace(func)`` sets the global trace function
-
-* there can also a local trace function (see later)
-
-Trace functions have three arguments: *frame*, *event*, and *arg*. *frame* is
-the current stack frame.  *event* is a string: ``'call'``, ``'line'``,
-``'return'``, ``'exception'``, ``'c_call'``, ``'c_return'``, or
-``'c_exception'``. *arg* depends on the event type.
-
-The global trace function is invoked (with *event* set to ``'call'``) whenever a
-new local scope is entered; it should return a reference to the local trace
-function to be used that scope, or ``None`` if the scope shouldn't be traced.
-
-The local trace function should return a reference to itself (or to another
-function for further tracing in that scope), or ``None`` to turn off tracing in
-that scope.
-
-Instance methods are accepted (and very useful!) as trace functions.
-
-The events have the following meaning:
-
-``'call'``
-   A function is called (or some other code block entered).  The global trace
-   function is called; *arg* is ``None``; the return value specifies the local
-   trace function.
-
-``'line'``
-   The interpreter is about to execute a new line of code (sometimes multiple line
-   events on one line exist).  The local trace function is called; *arg* is
-   ``None``; the return value specifies the new local trace function.
-
-``'return'``
-   A function (or other code block) is about to return.  The local trace function
-   is called; *arg* is the value that will be returned.  The trace function's
-   return value is ignored.
-
-``'exception'``
-   An exception has occurred.  The local trace function is called; *arg* is a
-   triple ``(exception, value, traceback)``; the return value specifies the new
-   local trace function.
-
-``'c_call'``
-   A C function is about to be called.  This may be an extension function or a
-   builtin.  *arg* is the C function object.
-
-``'c_return'``
-   A C function has returned. *arg* is ``None``.
-
-``'c_exception'``
-   A C function has thrown an exception.  *arg* is ``None``.
-
-Note that as an exception is propagated down the chain of callers, an
-``'exception'`` event is generated at each level.
-
-For more information on code and frame objects, refer to :ref:`types`.
-
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 1117550..fa7b7f0 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -712,11 +712,60 @@
       single: debugger
 
    Set the system's trace function, which allows you to implement a Python
-   source code debugger in Python.  See section :ref:`debugger-hooks` in the
-   chapter on the Python debugger.  The function is thread-specific; for a
+   source code debugger in Python.  The function is thread-specific; for a
    debugger to support multiple threads, it must be registered using
    :func:`settrace` for each thread being debugged.
 
+   Trace functions should have three arguments: *frame*, *event*, and
+   *arg*. *frame* is the current stack frame.  *event* is a string: ``'call'``,
+   ``'line'``, ``'return'``, ``'exception'``, ``'c_call'``, ``'c_return'``, or
+   ``'c_exception'``. *arg* depends on the event type.
+
+   The trace function is invoked (with *event* set to ``'call'``) whenever a new
+   local scope is entered; it should return a reference to a local trace
+   function to be used that scope, or ``None`` if the scope shouldn't be traced.
+
+   The local trace function should return a reference to itself (or to another
+   function for further tracing in that scope), or ``None`` to turn off tracing
+   in that scope.
+
+   The events have the following meaning:
+
+   ``'call'`` 
+      A function is called (or some other code block entered).  The
+      global trace function is called; *arg* is ``None``; the return value
+      specifies the local trace function.
+
+   ``'line'``
+      The interpreter is about to execute a new line of code (sometimes multiple
+      line events on one line exist).  The local trace function is called; *arg*
+      is ``None``; the return value specifies the new local trace function.
+
+   ``'return'``
+      A function (or other code block) is about to return.  The local trace
+      function is called; *arg* is the value that will be returned.  The trace
+      function's return value is ignored.
+
+   ``'exception'``
+      An exception has occurred.  The local trace function is called; *arg* is a
+      tuple ``(exception, value, traceback)``; the return value specifies the
+      new local trace function.
+
+   ``'c_call'``
+      A C function is about to be called.  This may be an extension function or
+      a builtin.  *arg* is the C function object.
+
+   ``'c_return'``
+      A C function has returned. *arg* is ``None``.
+
+   ``'c_exception'``
+      A C function has thrown an exception.  *arg* is ``None``.
+
+   Note that as an exception is propagated down the chain of callers, an
+   ``'exception'`` event is generated at each level.
+
+   For more information on code and frame objects, refer to :ref:`types`.
+
    .. note::
 
       The :func:`settrace` function is intended only for implementing debuggers,
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index b1ab8fd..7304c9c 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1365,21 +1365,21 @@
       object: dictionary
       builtin: hash
 
-   Called for the key object for dictionary operations, and by the built-in
-   function :func:`hash`.  Should return an integer usable as a hash value
-   for dictionary operations.  The only required property is that objects which
-   compare equal have the same hash value; it is advised to somehow mix together
-   (e.g., using exclusive or) the hash values for the components of the object that
-   also play a part in comparison of objects.
+   Called by built-in function :func:`hash` and for operations on members of
+   hashed collections including :class:`set`, :class:`frozenset`, and
+   :class:`dict`.  :meth:`__hash__` should return an integer.  The only required
+   property is that objects which compare equal have the same hash value; it is
+   advised to somehow mix together (e.g. using exclusive or) the hash values for
+   the components of the object that also play a part in comparison of objects.
 
    If a class does not define a :meth:`__cmp__` or :meth:`__eq__` method it
    should not define a :meth:`__hash__` operation either; if it defines
    :meth:`__cmp__` or :meth:`__eq__` but not :meth:`__hash__`, its instances
-   will not be usable as dictionary keys.  If a class defines mutable objects
+   will not be usable in hashed collections.  If a class defines mutable objects
    and implements a :meth:`__cmp__` or :meth:`__eq__` method, it should not
-   implement :meth:`__hash__`, since the dictionary implementation requires that
-   a key's hash value is immutable (if the object's hash value changes, it will
-   be in the wrong hash bucket).
+   implement :meth:`__hash__`, since hashable collection implementations require
+   that a object's hash value is immutable (if the object's hash value changes,
+   it will be in the wrong hash bucket).
 
    User-defined classes have :meth:`__cmp__` and :meth:`__hash__` methods
    by default; with them, all objects compare unequal (except with themselves)
@@ -1389,13 +1389,13 @@
    change the meaning of :meth:`__cmp__` or :meth:`__eq__` such that the hash
    value returned is no longer appropriate (e.g. by switching to a value-based
    concept of equality instead of the default identity based equality) can
-   explicitly flag themselves as being unhashable by setting
-   ``__hash__ = None`` in the class definition. Doing so means that not only
-   will instances of the class raise an appropriate :exc:`TypeError` when
-   a program attempts to retrieve their hash value, but they will also be
-   correctly identified as unhashable when checking
-   ``isinstance(obj, collections.Hashable)`` (unlike classes which define
-   their own :meth:`__hash__` to explicitly raise :exc:`TypeError`).
+   explicitly flag themselves as being unhashable by setting ``__hash__ = None``
+   in the class definition. Doing so means that not only will instances of the
+   class raise an appropriate :exc:`TypeError` when a program attempts to
+   retrieve their hash value, but they will also be correctly identified as
+   unhashable when checking ``isinstance(obj, collections.Hashable)`` (unlike
+   classes which define their own :meth:`__hash__` to explicitly raise
+   :exc:`TypeError`).
 
    .. versionchanged:: 2.5
       :meth:`__hash__` may now also return a long integer object; the 32-bit
diff --git a/Lib/doctest.py b/Lib/doctest.py
index 8806d6e..8a5a22c 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -854,12 +854,12 @@
         """
         if module is None:
             return True
+        elif inspect.getmodule(object) is not None:
+            return module is inspect.getmodule(object)
         elif inspect.isfunction(object):
             return module.__dict__ is object.func_globals
         elif inspect.isclass(object):
             return module.__name__ == object.__module__
-        elif inspect.getmodule(object) is not None:
-            return module is inspect.getmodule(object)
         elif hasattr(object, '__module__'):
             return module.__name__ == object.__module__
         elif isinstance(object, property):
diff --git a/Lib/io.py b/Lib/io.py
index 8462dd5..110804e 100644
--- a/Lib/io.py
+++ b/Lib/io.py
@@ -238,8 +238,6 @@
         raise ValueError("invalid buffering size")
     if buffering == 0:
         if binary:
-            raw._name = file
-            raw._mode = mode
             return raw
         raise ValueError("can't have unbuffered text I/O")
     if updating:
@@ -251,11 +249,8 @@
     else:
         raise ValueError("unknown mode: %r" % mode)
     if binary:
-        buffer.name = file
-        buffer.mode = mode
         return buffer
     text = TextIOWrapper(buffer, encoding, errors, newline, line_buffering)
-    text.name = file
     text.mode = mode
     return text
 
@@ -622,6 +617,10 @@
     # that _fileio._FileIO inherits from io.RawIOBase (which would be hard
     # to do since _fileio.c is written in C).
 
+    def __init__(self, name, mode="r", closefd=True):
+        _fileio._FileIO.__init__(self, name, mode, closefd)
+        self._name = name
+
     def close(self):
         _fileio._FileIO.close(self)
         RawIOBase.close(self)
@@ -630,10 +629,6 @@
     def name(self):
         return self._name
 
-    @property
-    def mode(self):
-        return self._mode
-
 
 class BufferedIOBase(IOBase):
 
@@ -767,6 +762,14 @@
     def closed(self):
         return self.raw.closed
 
+    @property
+    def name(self):
+        return self.raw.name
+
+    @property
+    def mode(self):
+        return self.raw.mode
+
     ### Lower-level APIs ###
 
     def fileno(self):
@@ -1473,6 +1476,10 @@
     def closed(self):
         return self.buffer.closed
 
+    @property
+    def name(self):
+        return self.buffer.name
+
     def fileno(self):
         return self.buffer.fileno()
 
diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py
index cb9f02a..9da27d4 100644
--- a/Lib/multiprocessing/pool.py
+++ b/Lib/multiprocessing/pool.py
@@ -149,7 +149,7 @@
 
     def imap(self, func, iterable, chunksize=1):
         '''
-        Equivalent of `itertool.imap()` -- can be MUCH slower than `Pool.map()`
+        Equivalent of `itertools.imap()` -- can be MUCH slower than `Pool.map()`
         '''
         assert self._state == RUN
         if chunksize == 1:
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 6e5ffa9..45df1f3 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -725,7 +725,7 @@
         # Issue 4348.  Make sure that operations that don't mutate the array
         # copy the bytes.
         b = bytearray(b'abc')
-        #self.assertFalse(b is b.replace(b'abc', b'cde', 0))
+        self.assertFalse(b is b.replace(b'abc', b'cde', 0))
 
         t = bytearray([i for i in range(256)])
         x = bytearray(b'')
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 9ef2a81..c9bd38d 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -272,6 +272,30 @@
         self.assertRaises(ValueError, io.open, test_support.TESTFN, 'w',
                           closefd=False)
 
+    def testReadClosed(self):
+        with io.open(test_support.TESTFN, "w") as f:
+            f.write("egg\n")
+        with io.open(test_support.TESTFN, "r") as f:
+            file = io.open(f.fileno(), "r", closefd=False)
+            self.assertEqual(file.read(), "egg\n")
+            file.seek(0)
+            file.close()
+            self.assertRaises(ValueError, file.read)
+
+    def test_no_closefd_with_filename(self):
+        # can't use closefd in combination with a file name
+        self.assertRaises(ValueError,
+                          io.open, test_support.TESTFN, "r", closefd=False)
+
+    def test_closefd_attr(self):
+        with io.open(test_support.TESTFN, "wb") as f:
+            f.write(b"egg\n")
+        with io.open(test_support.TESTFN, "r") as f:
+            self.assertEqual(f.buffer.raw.closefd, True)
+            file = io.open(f.fileno(), "r", closefd=False)
+            self.assertEqual(file.buffer.raw.closefd, False)
+
+
 class MemorySeekTestMixin:
 
     def testInit(self):
@@ -1225,6 +1249,9 @@
 
 class MiscIOTest(unittest.TestCase):
 
+    def tearDown(self):
+        test_support.unlink(test_support.TESTFN)
+
     def testImport__all__(self):
         for name in io.__all__:
             obj = getattr(io, name, None)
@@ -1237,6 +1264,34 @@
                 self.assert_(issubclass(obj, io.IOBase))
 
 
+    def test_attributes(self):
+        f = io.open(test_support.TESTFN, "wb", buffering=0)
+        self.assertEquals(f.mode, "w")
+        f.close()
+
+        f = io.open(test_support.TESTFN, "U")
+        self.assertEquals(f.name,            test_support.TESTFN)
+        self.assertEquals(f.buffer.name,     test_support.TESTFN)
+        self.assertEquals(f.buffer.raw.name, test_support.TESTFN)
+        self.assertEquals(f.mode,            "U")
+        self.assertEquals(f.buffer.mode,     "r")
+        self.assertEquals(f.buffer.raw.mode, "r")
+        f.close()
+
+        f = io.open(test_support.TESTFN, "w+")
+        self.assertEquals(f.mode,            "w+")
+        self.assertEquals(f.buffer.mode,     "r+") # Does it really matter?
+        self.assertEquals(f.buffer.raw.mode, "r+")
+
+        g = io.open(f.fileno(), "wb", closefd=False)
+        self.assertEquals(g.mode,     "w")
+        self.assertEquals(g.raw.mode, "w")
+        self.assertEquals(g.name,     f.fileno())
+        self.assertEquals(g.raw.name, f.fileno())
+        f.close()
+        g.close()
+
+
 def test_main():
     test_support.run_unittest(IOTest, BytesIOTest, StringIOTest,
                               BufferedReaderTest, BufferedWriterTest,
diff --git a/Lib/test/test_xmlrpc.py b/Lib/test/test_xmlrpc.py
index bbdb93e..c9294b1 100644
--- a/Lib/test/test_xmlrpc.py
+++ b/Lib/test/test_xmlrpc.py
@@ -9,6 +9,7 @@
 import mimetools
 import httplib
 import socket
+import StringIO
 import os
 from test import test_support
 
@@ -639,9 +640,93 @@
         os.remove("xmldata.txt")
         os.remove(test_support.TESTFN)
 
+class FakeSocket:
+
+    def __init__(self):
+        self.data = StringIO.StringIO()
+
+    def send(self, buf):
+        self.data.write(buf)
+        return len(buf)
+
+    def sendall(self, buf):
+        self.data.write(buf)
+
+    def getvalue(self):
+        return self.data.getvalue()
+
+    def makefile(self, x, y):
+        raise RuntimeError
+
+class FakeTransport(xmlrpclib.Transport):
+    """A Transport instance that records instead of sending a request.
+
+    This class replaces the actual socket used by httplib with a
+    FakeSocket object that records the request.  It doesn't provide a
+    response.
+    """
+
+    def make_connection(self, host):
+        conn = xmlrpclib.Transport.make_connection(self, host)
+        conn._conn.sock = self.fake_socket = FakeSocket()
+        return conn
+
+class TransportSubclassTestCase(unittest.TestCase):
+
+    def issue_request(self, transport_class):
+        """Return an HTTP request made via transport_class."""
+        transport = transport_class()
+        proxy = xmlrpclib.ServerProxy("http://example.com/",
+                                      transport=transport)
+        try:
+            proxy.pow(6, 8)
+        except RuntimeError:
+            return transport.fake_socket.getvalue()
+        return None
+
+    def test_custom_user_agent(self):
+        class TestTransport(FakeTransport):
+
+            def send_user_agent(self, conn):
+                xmlrpclib.Transport.send_user_agent(self, conn)
+                conn.putheader("X-Test", "test_custom_user_agent")
+
+        req = self.issue_request(TestTransport)
+        self.assert_("X-Test: test_custom_user_agent\r\n" in req)
+
+    def test_send_host(self):
+        class TestTransport(FakeTransport):
+
+            def send_host(self, conn, host):
+                xmlrpclib.Transport.send_host(self, conn, host)
+                conn.putheader("X-Test", "test_send_host")
+
+        req = self.issue_request(TestTransport)
+        self.assert_("X-Test: test_send_host\r\n" in req)
+
+    def test_send_request(self):
+        class TestTransport(FakeTransport):
+
+            def send_request(self, conn, url, body):
+                xmlrpclib.Transport.send_request(self, conn, url, body)
+                conn.putheader("X-Test", "test_send_request")
+
+        req = self.issue_request(TestTransport)
+        self.assert_("X-Test: test_send_request\r\n" in req)
+
+    def test_send_content(self):
+        class TestTransport(FakeTransport):
+
+            def send_content(self, conn, body):
+                conn.putheader("X-Test", "test_send_content")
+                xmlrpclib.Transport.send_content(self, conn, body)
+
+        req = self.issue_request(TestTransport)
+        self.assert_("X-Test: test_send_content\r\n" in req)
+
 def test_main():
     xmlrpc_tests = [XMLRPCTestCase, HelperTestCase, DateTimeTestCase,
-         BinaryTestCase, FaultTestCase]
+         BinaryTestCase, FaultTestCase, TransportSubclassTestCase]
 
     # The test cases against a SimpleXMLRPCServer raise a socket error
     # 10035 (WSAEWOULDBLOCK) in the server thread handle_request call when
diff --git a/Misc/NEWS b/Misc/NEWS
index a2aacc1..af50cf7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,11 @@
 Core and Builtins
 -----------------
 
+- Issue #4233: Changed semantic of ``_fileio.FileIO``'s ``close()`` 
+  method on file objects with closefd=False. The file descriptor is still
+  kept open but the file object behaves like a closed file. The ``FileIO``
+  object also got a new readonly attribute ``closefd``.
+
 Library
 -------
 
diff --git a/Modules/_fileio.c b/Modules/_fileio.c
index 49bc29c..b9310f3 100644
--- a/Modules/_fileio.c
+++ b/Modules/_fileio.c
@@ -61,10 +61,7 @@
 fileio_close(PyFileIOObject *self)
 {
 	if (!self->closefd) {
-		if (PyErr_WarnEx(PyExc_RuntimeWarning,
-				 "Trying to close unclosable fd!", 3) < 0) {
-			return NULL;
-		}
+		self->fd = -1;
 		Py_RETURN_NONE;
 	}
 	errno = internal_close(self);
@@ -821,6 +818,12 @@
 }
 
 static PyObject *
+get_closefd(PyFileIOObject *self, void *closure)
+{
+	return PyBool_FromLong((long)(self->closefd));
+}
+
+static PyObject *
 get_mode(PyFileIOObject *self, void *closure)
 {
 	return PyString_FromString(mode_string(self));
@@ -828,6 +831,8 @@
 
 static PyGetSetDef fileio_getsetlist[] = {
 	{"closed", (getter)get_closed, NULL, "True if the file is closed"},
+	{"closefd", (getter)get_closefd, NULL, 
+		"True if the file descriptor will be closed"},
 	{"mode", (getter)get_mode, NULL, "String giving the file mode"},
 	{0},
 };