diff -r 1b4fae183da3 Doc/library/shutil.rst
--- a/Doc/library/shutil.rst	Tue Aug 09 18:48:02 2011 -0500
+++ b/Doc/library/shutil.rst	Wed Aug 10 21:31:26 2011 +0700
@@ -166,8 +166,8 @@
    moved inside that directory.
 
    The destination directory must not already exist.  If the destination already
-   exists but is not a directory, it may be overwritten depending on
-   :func:`os.rename` semantics.
+   exists but is not a directory, on Unix, it may be overwritten depending on
+   :func:`os.rename` semantics. On Windows, :exc:`SameFileError` will be raised.
 
    If the destination is on the current filesystem, then :func:`os.rename` is
    used.  Otherwise, *src* is copied (using :func:`copy2`) to *dst* and then
@@ -189,6 +189,10 @@
    operation. For :func:`copytree`, the exception argument is a list of 3-tuples
    (*srcname*, *dstname*, *exception*).
 
+.. exception:: SameFileError
+
+   This exception is raised if source and destination in :func:`move`
+   are the same files.
 
 .. _shutil-example:
 
@@ -408,5 +412,3 @@
     -rw------- tarek/staff    1675 2008-06-09 13:26:54 ./id_rsa
     -rw-r--r-- tarek/staff     397 2008-06-09 13:26:54 ./id_rsa.pub
     -rw-r--r-- tarek/staff   37192 2010-02-06 18:23:10 ./known_hosts
-
-
diff -r 1b4fae183da3 Lib/shutil.py
--- a/Lib/shutil.py	Tue Aug 09 18:48:02 2011 -0500
+++ b/Lib/shutil.py	Wed Aug 10 21:31:26 2011 +0700
@@ -40,6 +40,9 @@
 class Error(EnvironmentError):
     pass
 
+class SameFileError(Error):
+    pass
+
 class SpecialFileError(EnvironmentError):
     """Raised when trying to do a kind of operation (e.g. copying) which is
     not supported on a special file (e.g. a named pipe)"""
@@ -83,7 +86,8 @@
 def copyfile(src, dst):
     """Copy data from src to dst"""
     if _samefile(src, dst):
-        raise Error("`%s` and `%s` are the same file" % (src, dst))
+        raise SameFileError("`{0}` and `{1}` are the same file".format(src,
+                                                                       dst))
 
     for fn in [src, dst]:
         try:
@@ -301,8 +305,9 @@
     is moved inside the directory. The destination path must not already
     exist.
 
-    If the destination already exists but is not a directory, it may be
-    overwritten depending on os.rename() semantics.
+    If the destination already exists but is not a directory, on Unix,
+    it may be overwritten depending on os.rename() semantics.
+    On Windows, SameFileError will be raised.
 
     If the destination is on our current filesystem, then rename() is used.
     Otherwise, src is copied to the destination and then removed.
@@ -323,7 +328,7 @@
             raise Error("Destination path '%s' already exists" % real_dst)
     try:
         os.rename(src, real_dst)
-    except OSError as exc:
+    except OSError:
         if os.path.isdir(src):
             if _destinsrc(src, dst):
                 raise Error("Cannot move a directory '%s' into itself '%s'." % (src, dst))
@@ -788,4 +793,4 @@
         """
         total, free = nt._getdiskusage(path)
         used = total - free
-        return _ntuple_diskusage(total, used, free)
+        return _ntuple_diskusage(total, used, free)
\ No newline at end of file
diff -r 1b4fae183da3 Lib/test/test_shutil.py
--- a/Lib/test/test_shutil.py	Tue Aug 09 18:48:02 2011 -0500
+++ b/Lib/test/test_shutil.py	Wed Aug 10 21:31:26 2011 +0700
@@ -16,7 +16,8 @@
                     register_archive_format, unregister_archive_format,
                     get_archive_formats, Error, unpack_archive,
                     register_unpack_format, RegistryError,
-                    unregister_unpack_format, get_unpack_formats)
+                    unregister_unpack_format, get_unpack_formats,
+                    SameFileError)
 import tarfile
 import warnings
 
@@ -780,6 +781,19 @@
         # Move a file inside an existing dir on the same filesystem.
         self._check_move_file(self.src_file, self.dst_dir, self.dst_file)
 
+    @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows")
+    def test_move_same_file(self):
+        # The source and destination are the same, should raise SameFileError
+        # on Windows (due to implementation details of os.rename()).
+        with self.assertRaises(SameFileError):
+            self._check_move_file(self.src_file, self.src_file,
+                    self.src_file)
+
+        # Check that it can be also catched with shutil.Error exception
+        with self.assertRaises(Error):
+            self._check_move_file(self.src_file, self.src_file,
+                    self.src_file)
+
     @mock_rename
     def test_move_file_other_fs(self):
         # Move a file to an existing dir on another filesystem.
@@ -978,4 +992,4 @@
     support.run_unittest(TestShutil, TestMove, TestCopyFile)
 
 if __name__ == '__main__':
-    test_main()
+    test_main()
\ No newline at end of file