Issue #13374: The Windows bytes API has been deprecated in the os module. Use
Unicode filenames instead of bytes filenames to not depend on the ANSI code
page anymore and to support any filename.
diff --git a/Lib/test/test_genericpath.py b/Lib/test/test_genericpath.py
index 50638a1..b618d45 100644
--- a/Lib/test/test_genericpath.py
+++ b/Lib/test/test_genericpath.py
@@ -2,11 +2,12 @@
 Tests common to genericpath, macpath, ntpath and posixpath
 """
 
-import unittest
-from test import support
-import os
 import genericpath
+import os
 import sys
+import unittest
+import warnings
+from test import support
 
 
 def safe_rmdir(dirname):
@@ -258,7 +259,9 @@
 
     def test_abspath(self):
         self.assertIn("foo", self.pathmodule.abspath("foo"))
-        self.assertIn(b"foo", self.pathmodule.abspath(b"foo"))
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            self.assertIn(b"foo", self.pathmodule.abspath(b"foo"))
 
         # Abspath returns bytes when the arg is bytes
         for path in (b'', b'foo', b'f\xf2\xf2', b'/foo', b'C:\\'):
@@ -266,7 +269,9 @@
 
     def test_realpath(self):
         self.assertIn("foo", self.pathmodule.realpath("foo"))
-        self.assertIn(b"foo", self.pathmodule.realpath(b"foo"))
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            self.assertIn(b"foo", self.pathmodule.realpath(b"foo"))
 
     def test_normpath_issue5827(self):
         # Make sure normpath preserves unicode
@@ -296,8 +301,10 @@
         "Mac OS X denies the creation of a directory with an invalid utf8 name")
     def test_nonascii_abspath(self):
         # Test non-ASCII, non-UTF8 bytes in the path.
-        with support.temp_cwd(b'\xe7w\xf0'):
-            self.test_abspath()
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            with support.temp_cwd(b'\xe7w\xf0'):
+                self.test_abspath()
 
 
 def test_main():
diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
index 6464950..2c9dab9 100644
--- a/Lib/test/test_ntpath.py
+++ b/Lib/test/test_ntpath.py
@@ -1,10 +1,11 @@
 import ntpath
 import os
 import sys
+import unittest
+import warnings
 from test.support import TestFailed
 from test import support, test_genericpath
 from tempfile import TemporaryFile
-import unittest
 
 
 def tester(fn, wantResult):
@@ -21,7 +22,9 @@
     fn = fn.replace('["', '[b"')
     fn = fn.replace(", '", ", b'")
     fn = fn.replace(', "', ', b"')
-    gotResult = eval(fn)
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore", DeprecationWarning)
+        gotResult = eval(fn)
     if isinstance(wantResult, str):
         wantResult = wantResult.encode('ascii')
     elif isinstance(wantResult, tuple):
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index da143cf..ec2877e 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -213,7 +213,9 @@
             fname = self.fname.encode(sys.getfilesystemencoding())
         except UnicodeEncodeError:
             self.skipTest("cannot encode %a for the filesystem" % self.fname)
-        self.check_stat_attributes(fname)
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            self.check_stat_attributes(fname)
 
     def test_statvfs_attributes(self):
         if not hasattr(os, "statvfs"):
@@ -838,7 +840,9 @@
         with open(file1, "w") as f1:
             f1.write("test")
 
-        os.link(file1, file2)
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            os.link(file1, file2)
         with open(file1, "r") as f1, open(file2, "r") as f2:
             self.assertTrue(os.path.sameopenfile(f1.fileno(), f2.fileno()))
 
@@ -1160,8 +1164,10 @@
         self.assertNotEqual(os.lstat(link), os.stat(link))
 
         bytes_link = os.fsencode(link)
-        self.assertEqual(os.stat(bytes_link), os.stat(target))
-        self.assertNotEqual(os.lstat(bytes_link), os.stat(bytes_link))
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            self.assertEqual(os.stat(bytes_link), os.stat(target))
+            self.assertNotEqual(os.lstat(bytes_link), os.stat(bytes_link))
 
     def test_12084(self):
         level1 = os.path.abspath(support.TESTFN)
@@ -1619,6 +1625,35 @@
         self._check_xattrs(getxattr, setxattr, removexattr, listxattr)
 
 
+@unittest.skipUnless(sys.platform == "win32", "Win32 specific tests")
+class Win32DeprecatedBytesAPI(unittest.TestCase):
+    def test_deprecated(self):
+        import nt
+        filename = os.fsencode(support.TESTFN)
+        with warnings.catch_warnings():
+            warnings.simplefilter("error", DeprecationWarning)
+            for func, *args in (
+                (nt._getfullpathname, filename),
+                (nt._isdir, filename),
+                (os.access, filename, os.R_OK),
+                (os.chdir, filename),
+                (os.chmod, filename, 0o777),
+                (os.link, filename, filename),
+                (os.listdir, filename),
+                (os.lstat, filename),
+                (os.mkdir, filename),
+                (os.open, filename, os.O_RDONLY),
+                (os.rename, filename, filename),
+                (os.rmdir, filename),
+                (os.startfile, filename),
+                (os.stat, filename),
+                (os.symlink, filename, filename),
+                (os.unlink, filename),
+                (os.utime, filename),
+            ):
+                self.assertRaises(DeprecationWarning, func, *args)
+
+
 @support.reap_threads
 def test_main():
     support.run_unittest(
@@ -1643,6 +1678,7 @@
         TestSendfile,
         ProgramPriorityTests,
         ExtendedAttributeTests,
+        Win32DeprecatedBytesAPI,
     )
 
 if __name__ == "__main__":
diff --git a/Lib/test/test_pep277.py b/Lib/test/test_pep277.py
index a1a4791..4b16cbb 100644
--- a/Lib/test/test_pep277.py
+++ b/Lib/test/test_pep277.py
@@ -1,6 +1,9 @@
 # Test the Unicode versions of normal file functions
 # open, os.open, os.stat. os.listdir, os.rename, os.remove, os.mkdir, os.chdir, os.rmdir
-import sys, os, unittest
+import os
+import sys
+import unittest
+import warnings
 from unicodedata import normalize
 from test import support
 
@@ -155,7 +158,9 @@
     @unittest.skipIf(sys.platform == 'darwin', 'irrelevant test on Mac OS X')
     def test_listdir(self):
         sf0 = set(self.files)
-        f1 = os.listdir(support.TESTFN.encode(sys.getfilesystemencoding()))
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            f1 = os.listdir(support.TESTFN.encode(sys.getfilesystemencoding()))
         f2 = os.listdir(support.TESTFN)
         sf2 = set(os.path.join(support.TESTFN, f) for f in f2)
         self.assertEqual(sf0, sf2, "%a != %a" % (sf0, sf2))
diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index bb4559c..709ef04 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -1,10 +1,10 @@
-import unittest
-from test import support, test_genericpath
-
-import posixpath
 import os
+import posixpath
 import sys
+import unittest
+import warnings
 from posixpath import realpath, abspath, dirname, basename
+from test import support, test_genericpath
 
 try:
     import posix
@@ -231,7 +231,9 @@
 
     def test_ismount(self):
         self.assertIs(posixpath.ismount("/"), True)
-        self.assertIs(posixpath.ismount(b"/"), True)
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+            self.assertIs(posixpath.ismount(b"/"), True)
 
     def test_ismount_non_existent(self):
         # Non-existent mountpoint.