Index: Lib/os2emxpath.py
===================================================================
--- Lib/os2emxpath.py	(revision 77513)
+++ Lib/os2emxpath.py	(working copy)
@@ -146,7 +146,11 @@
 def abspath(path):
     """Return the absolute version of a path"""
     if not isabs(path):
-        path = join(os.getcwd(), path)
+        if isinstance(path, unicode):
+            cwd = os.getcwdu()
+        else:
+            cwd = os.getcwd()
+        path = join(cwd, path)
     return normpath(path)
 
 # realpath is a no-op on systems without islink support
Index: Lib/posixpath.py
===================================================================
--- Lib/posixpath.py	(revision 77513)
+++ Lib/posixpath.py	(working copy)
@@ -337,7 +337,11 @@
 def abspath(path):
     """Return an absolute path."""
     if not isabs(path):
-        path = join(os.getcwd(), path)
+        if isinstance(path, unicode):
+            cwd = os.getcwdu()
+        else:
+            cwd = os.getcwd()
+        path = join(cwd, path)
     return normpath(path)
 
 
Index: Lib/ntpath.py
===================================================================
--- Lib/ntpath.py	(revision 77513)
+++ Lib/ntpath.py	(working copy)
@@ -449,7 +449,11 @@
     def abspath(path):
         """Return the absolute version of a path."""
         if not isabs(path):
-            path = join(os.getcwd(), path)
+            if isinstance(path, unicode):
+                cwd = os.getcwdu()
+            else:
+                cwd = os.getcwd()
+            path = join(cwd, path)
         return normpath(path)
 
 else:  # use native Windows method on Windows
@@ -461,6 +465,8 @@
                 path = _getfullpathname(path)
             except WindowsError:
                 pass # Bad path - return unchanged.
+        elif isinstance(path, unicode):
+            path = os.getcwdu()
         else:
             path = os.getcwd()
         return normpath(path)
Index: Lib/macpath.py
===================================================================
--- Lib/macpath.py	(revision 77513)
+++ Lib/macpath.py	(working copy)
@@ -186,7 +186,11 @@
 def abspath(path):
     """Return an absolute path."""
     if not isabs(path):
-        path = join(os.getcwd(), path)
+        if isinstance(path, unicode):
+            cwd = os.getcwdu()
+        else:
+            cwd = os.getcwd()
+        path = join(cwd, path)
     return normpath(path)
 
 # realpath is a no-op on systems without islink support
Index: Lib/test/test_ntpath.py
===================================================================
--- Lib/test/test_ntpath.py	(revision 77513)
+++ Lib/test/test_ntpath.py	(working copy)
@@ -14,6 +14,13 @@
 
 
 class TestNtpath(unittest.TestCase):
+
+    def assertStr(self, s):
+        self.assertTrue(isinstance(s, str), '%r is not str' % s)
+
+    def assertUnicode(self, s):
+        self.assertTrue(isinstance(s, unicode), '%r is not unicode' % s)
+
     def test_splitext(self):
         tester('ntpath.splitext("foo.ext")', ('foo', '.ext'))
         tester('ntpath.splitext("/foo/foo.ext")', ('/foo/foo', '.ext'))
@@ -160,13 +167,25 @@
         # the rest of the tests for the ntpath module to be run to completion
         # on any platform, since most of the module is intended to be usable
         # from any platform.
+        # XXX this needs more tests
         try:
             import nt
         except ImportError:
-            pass
+            # check that the function is there even if we are not on Windows
+            ntpath.abspath
         else:
             tester('ntpath.abspath("C:\\")', "C:\\")
 
+            # Issue 3426: check that abspath retuns unicode when the arg is
+            # unicode and str when it's str, with both ASCII and non-ASCII cwds
+            for cwd in (u'cwd', u'\xe7w\xf0'):
+                with test_support.TempCWD(cwd):
+                    for path in ('', 'foo', 'f\xf2\xf2', '/foo', 'C:\\'):
+                        self.assertStr(ntpath.abspath(path))
+                    for upath in (u'', u'fuu', u'f\xf9\xf9', u'/fuu', u'U:\\'):
+                        self.assertUnicode(ntpath.abspath(upath))
+
+
     def test_relpath(self):
         currentdir = os.path.split(os.getcwd())[-1]
         tester('ntpath.relpath("a")', 'a')
Index: Lib/test/test_macpath.py
===================================================================
--- Lib/test/test_macpath.py	(revision 77513)
+++ Lib/test/test_macpath.py	(working copy)
@@ -5,9 +5,25 @@
 
 class MacPathTestCase(unittest.TestCase):
 
+    def assertStr(self, s):
+        self.assertTrue(isinstance(s, str), '%r is not str' % s)
+
+    def assertUnicode(self, s):
+        self.assertTrue(isinstance(s, unicode), '%r is not unicode' % s)
+
     def test_abspath(self):
         self.assertTrue(macpath.abspath("xx:yy") == "xx:yy")
 
+        # Issue 3426: check that abspath retuns unicode when the arg is unicode
+        # and str when it's str, with both ASCII and non-ASCII cwds
+        for cwd in (u'cwd', u'\xe7w\xf0'):
+            with test_support.TempCWD(cwd):
+                for path in ('', 'foo', 'f\xf2\xf2', '/foo', 'C:\\'):
+                    self.assertStr(macpath.abspath(path))
+                for upath in (u'', u'fuu', u'f\xf9\xf9', u'/fuu', u'U:\\'):
+                    self.assertUnicode(macpath.abspath(upath))
+
+
     def test_isabs(self):
         isabs = macpath.isabs
         self.assertTrue(isabs("xx:yy"))
Index: Lib/test/test_support.py
===================================================================
--- Lib/test/test_support.py	(revision 77513)
+++ Lib/test/test_support.py	(working copy)
@@ -612,6 +612,22 @@
         sys.path[:] = self.original_value
 
 
+class TempCWD(object):
+    def __init__(self, dirname='tempdir'):
+        self.dirname = os.path.join(TESTFN, dirname)
+        self._oldcwd = os.getcwd()
+
+    def __enter__(self):
+        if not os.path.exists(self.dirname):
+            os.makedirs(self.dirname)
+        os.chdir(self.dirname)
+        return self.dirname
+
+    def __exit__(self, exc, value, tb):
+        os.chdir(self._oldcwd)
+        rmtree(os.path.dirname(self.dirname))
+
+
 class TransientResource(object):
 
     """Raise ResourceDenied if an exception is raised while the context manager
Index: Lib/test/test_posixpath.py
===================================================================
--- Lib/test/test_posixpath.py	(revision 77513)
+++ Lib/test/test_posixpath.py	(working copy)
@@ -28,6 +28,12 @@
     def assertIs(self, a, b):
         self.assertTrue(a is b)
 
+    def assertStr(self, s):
+        self.assertTrue(isinstance(s, str), '%r is not str' % s)
+
+    def assertUnicode(self, s):
+        self.assertTrue(isinstance(s, unicode), '%r is not unicode' % s)
+
     def test_normcase(self):
         # Check that normcase() is idempotent
         p = "FoO/./BaR"
@@ -391,6 +397,15 @@
     def test_abspath(self):
         self.assertTrue("foo" in posixpath.abspath("foo"))
 
+        # Issue 3426: check that abspath retuns unicode when the arg is unicode
+        # and str when it's str, with both ASCII and non-ASCII cwds
+        for cwd in (u'cwd', u'\xe7w\xf0'):
+            with test_support.TempCWD(cwd):
+                for path in ('', 'foo', 'f\xf2\xf2', '/foo', 'C:\\'):
+                    self.assertStr(posixpath.abspath(path))
+                for upath in (u'', u'fuu', u'f\xf9\xf9', u'/fuu', u'U:\\'):
+                    self.assertUnicode(posixpath.abspath(upath))
+
         self.assertRaises(TypeError, posixpath.abspath)
 
     def test_realpath(self):