#21169: fix getpass to use replace error handler on UnicodeEncodeError.

If the input stream encoding couldn't encode one or more of the
non-ascii characters in the prompt, it would fail, throwing a
UnicodeEncodeError.  Now if that happens we re-encoding using the
'replace' error handler.

Patch by Kushal Das.

Lib/getpass.py

@@ -135,6 +135,11 @@ def _raw_input(prompt="", stream=None, input=None):
         input = sys.stdin
     prompt = str(prompt)
     if prompt:
+        try:
+            stream.write(prompt)
+        except UnicodeEncodeError:
+            prompt = prompt.encode(stream.encoding, 'replace')
+            prompt = prompt.decode(stream.encoding)
             stream.write(prompt)
         stream.flush()
     # NOTE: The Python C API calls flockfile() (and unlock) during readline.

Lib/test/test_getpass.py

 import getpass
 import os
 import unittest
-from io import BytesIO, StringIO
+from io import BytesIO, StringIO, TextIOWrapper
 from unittest import mock
 from test import support
 
@@ -69,6 +69,14 @@ class GetpassRawinputTest(unittest.TestCase):
         getpass._raw_input(stream=StringIO())
         mock_input.readline.assert_called_once_with()
 
+    @mock.patch('sys.stdin')
+    def test_uses_stdin_as_different_locale(self, mock_input):
+        stream = TextIOWrapper(BytesIO(), encoding="ascii")
+        mock_input.readline.return_value = "Hasło: "
+        getpass._raw_input(prompt="Hasło: ",stream=stream)
+        mock_input.readline.assert_called_once_with()
+
+
     def test_raises_on_empty_input(self):
         input = StringIO('')
         self.assertRaises(EOFError, getpass._raw_input, input=input)

Misc/NEWS

@@ -27,6 +27,10 @@ Core and Builtins
 Library
 -------
 
+- Issue #21169: getpass now handles non-ascii characters that the
+  input stream encoding cannot encode by re-encoding using the
+  replace error handler.
+
 - Issue #21171: Fixed undocumented filter API of the rot13 codec.
   Patch by Berker Peksag.