bpo-38332: Catch KeyError from unknown cte in encoded-word. (GH-16503)

KeyError should cause a failure in parsing the encoded word and should be caught and raised as a _InvalidEWError instead.

1 files changed, 12 insertions, 0 deletions

diff --git a/Lib/test/test_email/test__header_value_parser.py b/Lib/test/test_email/test__header_value_parser.py
index 058d902459..46d90b38e9 100644
--- a/Lib/test/test_email/test__header_value_parser.py
+++ b/Lib/test/test_email/test__header_value_parser.py
@@ -89,6 +89,10 @@ class TestParser(TestParserMixin, TestEmailBase):
         with self.assertRaises(errors.HeaderParseError):
             parser.get_encoded_word('=?abc?=')
 
+    def test_get_encoded_word_invalid_cte(self):
+        with self.assertRaises(errors.HeaderParseError):
+            parser.get_encoded_word('=?utf-8?X?somevalue?=')
+
     def test_get_encoded_word_valid_ew(self):
         self._test_get_x(parser.get_encoded_word,
                          '=?us-ascii?q?this_is_a_test?=  bird',
@@ -399,6 +403,14 @@ class TestParser(TestParserMixin, TestEmailBase):
             [],
             '')
 
+    def test_get_unstructured_invalid_ew_cte(self):
+        self._test_get_x(self._get_unst,
+            '=?utf-8?X?=somevalue?=',
+            '=?utf-8?X?=somevalue?=',
+            '=?utf-8?X?=somevalue?=',
+            [],
+            '')
+
     # get_qp_ctext
 
     def test_get_qp_ctext_only(self):