#20206, #5803: more efficient algorithm that doesn't truncate output.

This fixes an edge case (20206) where if the input ended in a character
needing encoding but there was no newline on the string, the last byte
of the encoded character would be dropped.  The fix is to use a more
efficient algorithm, provided by Serhiy Storchaka (5803), that does not
have the bug.

1 files changed, 5 insertions, 0 deletions

diff --git a/Lib/test/test_email/test_email.py b/Lib/test/test_email/test_email.py
index 6af62788a6..c787695e12 100644
--- a/Lib/test/test_email/test_email.py
+++ b/Lib/test/test_email/test_email.py
@@ -4216,6 +4216,11 @@ class TestQuopri(unittest.TestCase):
     def test_encode_one_line_eol(self):
         self._test_encode('hello\n', 'hello\r\n', eol='\r\n')
 
+    def test_encode_one_line_eol_after_non_ascii(self):
+        # issue 20206; see changeset 0cf700464177 for why the encode/decode.
+        self._test_encode('hello\u03c5\n'.encode('utf-8').decode('latin1'),
+                          'hello=CF=85\r\n', eol='\r\n')
+
     def test_encode_one_space(self):
         self._test_encode(' ', '=20')