Test PEP 383 surrogateescape handling for AF_UNIX addresses.

diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -1395,6 +1395,38 @@ class TestUnixDomain(unittest.TestCase):
         self.addCleanup(support.unlink, path)
         self.assertEqual(self.sock.getsockname(), path)
 
+    def testBytearrayAddr(self):
+        # Test binding to a bytearray pathname.
+        path = os.path.abspath(support.TESTFN)
+        b = self.encoded(path)
+        self.sock.bind(bytearray(b))
+        self.addCleanup(support.unlink, path)
+        self.assertEqual(self.sock.getsockname(), path)
+
+    def testSurrogateescapeBind(self):
+        # Test binding to a valid non-ASCII pathname, with the
+        # non-ASCII bytes supplied using surrogateescape encoding.
+        path = os.path.abspath(support.TESTFN_UNICODE)
+        b = self.encoded(path)
+        self.sock.bind(b.decode("ascii", "surrogateescape"))
+        self.addCleanup(support.unlink, path)
+        self.assertEqual(self.sock.getsockname(), path)
+
+    def testUndecodableAddr(self):
+        # Test binding to a non-ASCII pathname, then reading the
+        # address back with the file system encoding set to ASCII.
+        path = os.path.abspath(support.TESTFN_UNICODE)
+        b = self.encoded(path)
+        self.sock.bind(b)
+        self.addCleanup(support.unlink, path)
+        saved_encoding = sys.getfilesystemencoding()
+        try:
+            sys.setfilesystemencoding("ascii")
+            name = self.sock.getsockname()
+        finally:
+            sys.setfilesystemencoding(saved_encoding)
+        self.assertEqual(name, b.decode("ascii", "surrogateescape"))
+
 class BufferIOTest(SocketConnectedTest):
     """
     Test the buffer versions of socket.recv() and socket.send().