Issue #23648: Document the PEP 475 in the "Porting to Python 3.5" section and

add a version changed note in modified functions.

Doc/library/functions.rst

@@ -1065,6 +1065,11 @@ are always available.  They are listed here in alphabetical order.
 
       The ``'U'`` mode.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. function:: ord(c)
 

Doc/library/os.rst

@@ -905,6 +905,11 @@ as internal buffering of data.
    .. versionadded:: 3.3
       The *dir_fd* argument.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 The following constants are options for the *flags* parameter to the
 :func:`~os.open` function.  They can be combined using the bitwise OR operator
 ``|``.  Some of them are not available on all platforms.  For descriptions of
@@ -1082,6 +1087,11 @@ or `the MSDN <http://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Window
       :func:`popen` or :func:`fdopen`, or :data:`sys.stdin`, use its
       :meth:`~file.read` or :meth:`~file.readline` methods.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. function:: sendfile(out, in, offset, nbytes)
               sendfile(out, in, offset, nbytes, headers=None, trailers=None, flags=0)
@@ -1197,6 +1207,11 @@ or `the MSDN <http://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Window
       :func:`fdopen`, or :data:`sys.stdout` or :data:`sys.stderr`, use its
       :meth:`~file.write` method.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. function:: writev(fd, buffers)
 
@@ -3359,6 +3374,11 @@ written in Python, such as a mail server's external command delivery program.
    id is known, not necessarily a child process. The :func:`spawn\* <spawnl>`
    functions called with :const:`P_NOWAIT` return suitable process handles.
 
+   .. versionchanged:: 3.5
+      If the system call is interrupted and the signal does not raise an
+      exception, the function now retries the system call instead of raising an
+      :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
+
 
 .. function:: wait3(options)
 

Doc/whatsnew/3.5.rst

@@ -572,6 +572,14 @@ that may require changes to your code.
 Changes in the Python API
 -------------------------
 
+* :pep:`475`: the following functions are now retried when interrupted instead
+  of raising :exc:`InterruptedError` if the signal handler does not raise
+  an exception:
+
+  - :func:`os.open`, :func:`open`
+  - :func:`os.read`, :func:`os.write`
+  - :func:`time.sleep`
+
 * Before Python 3.5, a :class:`datetime.time` object was considered to be false
   if it represented midnight in UTC.  This behavior was considered obscure and
   error-prone and has been removed in Python 3.5.  See :issue:`13936` for full