skip tests with a non-ascii cwd when the file system encoding is ascii

Lib/test/test_support.py

@@ -397,6 +397,13 @@ def temp_cwd(name='tempcwd', quiet=False):
     the CWD, an error is raised.  If it's True, only a warning is raised
     and the original CWD is used.
     """
+    if isinstance(name, unicode):
+        try:
+            name = name.encode(sys.getfilesystemencoding() or 'ascii')
+        except UnicodeEncodeError:
+            if not quiet:
+                raise unittest.SkipTest('unable to encode the cwd name with '
+                                        'the filesystem encoding.')
     saved_dir = os.getcwd()
     is_temporary = False
     try: