Index: Doc/library/urllib.rst
===================================================================
--- Doc/library/urllib.rst	(revision 78945)
+++ Doc/library/urllib.rst	(working copy)
@@ -223,11 +223,25 @@
 
 .. function:: unquote(string)
 
-   Replace ``%xx`` escapes by their single-character equivalent.
+   Replace ``%xx`` escapes by their single-byte equivalent.
 
+   *string* may be either a :class:`str` or a :class:`unicode`.
+
+   If it is a :class:`unicode`, unescaped non-ASCII characters in *string*
+   are encoded into UTF-8 bytes. The result is a :class:`str` regardless of
+   the type of *string*.
+
+
    Example: ``unquote('/%7Econnolly/')`` yields ``'/~connolly/'``.
 
+   Example: ``unquote(u'/El%20Ni%C3%B1o/')`` yields ``'/El Ni\xc3\xb1o/'``,
+   which decodes with UTF-8 as ``u'/El Niño/'``.
 
+   .. versionchanged:: 2.7
+      :func:`unquote` now returns a :class:`str` on :class:`unicode` input,
+      where it used to return a :class:`unicode`. Unicode strings are encoded
+      with ``'utf-8'``.
+
 .. function:: unquote_plus(string)
 
    Like :func:`unquote`, but also replaces plus signs by spaces, as required for
Index: Lib/urllib.py
===================================================================
--- Lib/urllib.py	(revision 78945)
+++ Lib/urllib.py	(working copy)
@@ -1163,6 +1163,10 @@
 
 def unquote(s):
     """unquote('abc%20def') -> 'abc def'."""
+    # Note: strings are encoded as UTF-8. This is only an issue if it contains
+    # unescaped non-ASCII characters, which URIs should not.
+    if isinstance(s, unicode):
+        s = s.encode('utf-8')
     res = s.split('%')
     for i in xrange(1, len(res)):
         item = res[i]
Index: Lib/test/test_urllib.py
===================================================================
--- Lib/test/test_urllib.py	(revision 78945)
+++ Lib/test/test_urllib.py	(working copy)
@@ -463,9 +463,39 @@
         self.assertEqual(expect, result,
                          "using unquote_plus(): %s != %s" % (expect, result))
 
+    def test_unquote_nonascii_bytes(self):
+        # Test on escaped non-ASCII bytes
+        given = '%A2%D8ab%FF'
+        expect = b'\xa2\xd8ab\xff'
+        result = urllib.unquote(given)
+        self.assertEqual(expect, result, "using unquote(): %r != %r"
+                         % (expect, result))
+        # Test on unescaped non-ASCII bytes
+        # (Technically an invalid URI; expect those bytes to be preserved)
+        given = b'%A2\xd8ab%FF'
+        expect = b'\xa2\xd8ab\xff'
+        result = urllib.unquote(given)
+        self.assertEqual(expect, result, "using unquote(): %r != %r"
+                         % (expect, result))
+
     def test_unquote_with_unicode(self):
         r = urllib.unquote(u'br%C3%BCckner_sapporo_20050930.doc')
-        self.assertEqual(r, u'br\xc3\xbcckner_sapporo_20050930.doc')
+        self.assertEqual(r, 'br\xc3\xbcckner_sapporo_20050930.doc')
+        # Test on a string with unescaped non-ASCII characters
+        # (Technically an invalid URI; expect those characters to be UTF-8
+        # encoded).
+        given = u'\u6f22%C3%BC'
+        result = urllib.unquote(given)
+        expect = b'\xe6\xbc\xa2\xc3\xbc'    # UTF-8 for "\u6f22\u00fc"
+        self.assertEqual(expect, result,
+                         "using unquote(): %r != %r" % (expect, result))
+        # Test that the result of unquoting an ASCII string is the same as the
+        # result of unquoting the same string as unicode
+        given = "%C3%BC"
+        result = urllib.unquote(given)
+        expect = urllib.unquote(given.decode('ascii'))
+        self.assertEqual(expect, result, "using unquote(): %r != %r"
+                         % (expect, result))
 
 class urlencode_Tests(unittest.TestCase):
     """Tests for urlencode()"""