gh-68552: fix defects policy (#138579)

Extend defect handling via policy to a couple of missed defects.

---------

Co-authored-by: Martin Panter <vadmium@users.noreply.github.com>
Co-authored-by: Ivo Bellin Salarin <ivo@nilleb.com>

Lib/email/feedparser.py

@@ -504,10 +504,9 @@ def _parse_headers(self, lines):
                     self._input.unreadline(line)
                     return
                 else:
-                    # Weirdly placed unix-from line.  Note this as a defect
+                    # Weirdly placed unix-from line.
-                    # and ignore it.
                     defect = errors.MisplacedEnvelopeHeaderDefect(line)
-                    self._cur.defects.append(defect)
+                    self.policy.handle_defect(self._cur, defect)
                     continue
             # Split the line on the colon separating field name from value.
             # There will always be a colon, because if there wasn't the part of
@@ -519,7 +518,7 @@ def _parse_headers(self, lines):
             # message. Track the error but keep going.
             if i == 0:
                 defect = errors.InvalidHeaderDefect("Missing header name.")
-                self._cur.defects.append(defect)
+                self.policy.handle_defect(self._cur, defect)
                 continue
 
             assert i>0, "_parse_headers fed line with no : and no leading WS"

Lib/test/test_email/test_defect_handling.py

@@ -126,12 +126,10 @@ def test_multipart_invalid_cte(self):
             errors.InvalidMultipartContentTransferEncodingDefect)
 
     def test_multipart_no_cte_no_defect(self):
-        if self.raise_expected: return
         msg = self._str_msg(self.multipart_msg.format(''))
         self.assertEqual(len(self.get_defects(msg)), 0)
 
     def test_multipart_valid_cte_no_defect(self):
-        if self.raise_expected: return
         for cte in ('7bit', '8bit', 'BINary'):
             msg = self._str_msg(
                 self.multipart_msg.format("\nContent-Transfer-Encoding: "+cte))
@@ -300,6 +298,47 @@ def test_missing_ending_boundary(self):
         self.assertDefectsEqual(self.get_defects(msg),
                                 [errors.CloseBoundaryNotFoundDefect])
 
+    def test_line_beginning_colon(self):
+        string = (
+            "Subject: Dummy subject\r\n: faulty header line\r\n\r\nbody\r\n"
+        )
+
+        with self._raise_point(errors.InvalidHeaderDefect):
+            msg = self._str_msg(string)
+            self.assertEqual(len(self.get_defects(msg)), 1)
+            self.assertDefectsEqual(
+                self.get_defects(msg), [errors.InvalidHeaderDefect]
+            )
+
+            if msg:
+                self.assertEqual(msg.items(), [("Subject", "Dummy subject")])
+                self.assertEqual(msg.get_payload(), "body\r\n")
+
+    def test_misplaced_envelope(self):
+        string = (
+            "Subject: Dummy subject\r\nFrom wtf\r\nTo: abc\r\n\r\nbody\r\n"
+        )
+        with self._raise_point(errors.MisplacedEnvelopeHeaderDefect):
+            msg = self._str_msg(string)
+            self.assertEqual(len(self.get_defects(msg)), 1)
+            self.assertDefectsEqual(
+                self.get_defects(msg), [errors.MisplacedEnvelopeHeaderDefect]
+            )
+
+            if msg:
+                headers = [("Subject", "Dummy subject"), ("To", "abc")]
+                self.assertEqual(msg.items(), headers)
+                self.assertEqual(msg.get_payload(), "body\r\n")
+
+
+
+class TestCompat32(TestDefectsBase, TestEmailBase):
+
+    policy = policy.compat32
+
+    def get_defects(self, obj):
+        return obj.defects
+
 
 class TestDefectDetection(TestDefectsBase, TestEmailBase):
 
@@ -332,6 +371,9 @@ def _raise_point(self, defect):
         with self.assertRaises(defect):
             yield
 
+    def get_defects(self, obj):
+        return obj.defects
+
 
 if __name__ == '__main__':
     unittest.main()

Lib/test/test_email/test_email.py

@@ -2263,70 +2263,6 @@ def test_parse_missing_minor_type(self):
         eq(msg.get_content_maintype(), 'text')
         eq(msg.get_content_subtype(), 'plain')
 
-    # test_defect_handling
-    def test_same_boundary_inner_outer(self):
-        msg = self._msgobj('msg_15.txt')
-        # XXX We can probably eventually do better
-        inner = msg.get_payload(0)
-        self.assertHasAttr(inner, 'defects')
-        self.assertEqual(len(inner.defects), 1)
-        self.assertIsInstance(inner.defects[0],
-                              errors.StartBoundaryNotFoundDefect)
-
-    # test_defect_handling
-    def test_multipart_no_boundary(self):
-        msg = self._msgobj('msg_25.txt')
-        self.assertIsInstance(msg.get_payload(), str)
-        self.assertEqual(len(msg.defects), 2)
-        self.assertIsInstance(msg.defects[0],
-                              errors.NoBoundaryInMultipartDefect)
-        self.assertIsInstance(msg.defects[1],
-                              errors.MultipartInvariantViolationDefect)
-
-    multipart_msg = textwrap.dedent("""\
-        Date: Wed, 14 Nov 2007 12:56:23 GMT
-        From: foo@bar.invalid
-        To: foo@bar.invalid
-        Subject: Content-Transfer-Encoding: base64 and multipart
-        MIME-Version: 1.0
-        Content-Type: multipart/mixed;
-            boundary="===============3344438784458119861=="{}
-
-        --===============3344438784458119861==
-        Content-Type: text/plain
-
-        Test message
-
-        --===============3344438784458119861==
-        Content-Type: application/octet-stream
-        Content-Transfer-Encoding: base64
-
-        YWJj
-
-        --===============3344438784458119861==--
-        """)
-
-    # test_defect_handling
-    def test_multipart_invalid_cte(self):
-        msg = self._str_msg(
-            self.multipart_msg.format("\nContent-Transfer-Encoding: base64"))
-        self.assertEqual(len(msg.defects), 1)
-        self.assertIsInstance(msg.defects[0],
-            errors.InvalidMultipartContentTransferEncodingDefect)
-
-    # test_defect_handling
-    def test_multipart_no_cte_no_defect(self):
-        msg = self._str_msg(self.multipart_msg.format(''))
-        self.assertEqual(len(msg.defects), 0)
-
-    # test_defect_handling
-    def test_multipart_valid_cte_no_defect(self):
-        for cte in ('7bit', '8bit', 'BINary'):
-            msg = self._str_msg(
-                self.multipart_msg.format(
-                    "\nContent-Transfer-Encoding: {}".format(cte)))
-            self.assertEqual(len(msg.defects), 0)
-
     # test_headerregistry.TestContentTypeHeader invalid_1 and invalid_2.
     def test_invalid_content_type(self):
         eq = self.assertEqual
@@ -2403,30 +2339,6 @@ def test_missing_start_boundary(self):
         self.assertIsInstance(bad.defects[0],
                               errors.StartBoundaryNotFoundDefect)
 
-    # test_defect_handling
-    def test_first_line_is_continuation_header(self):
-        eq = self.assertEqual
-        m = ' Line 1\nSubject: test\n\nbody'
-        msg = email.message_from_string(m)
-        eq(msg.keys(), ['Subject'])
-        eq(msg.get_payload(), 'body')
-        eq(len(msg.defects), 1)
-        self.assertDefectsEqual(msg.defects,
-                                 [errors.FirstHeaderLineIsContinuationDefect])
-        eq(msg.defects[0].line, ' Line 1\n')
-
-    # test_defect_handling
-    def test_missing_header_body_separator(self):
-        # Our heuristic if we see a line that doesn't look like a header (no
-        # leading whitespace but no ':') is to assume that the blank line that
-        # separates the header from the body is missing, and to stop parsing
-        # headers and start parsing the body.
-        msg = self._str_msg('Subject: test\nnot a header\nTo: abc\n\nb\n')
-        self.assertEqual(msg.keys(), ['Subject'])
-        self.assertEqual(msg.get_payload(), 'not a header\nTo: abc\n\nb\n')
-        self.assertDefectsEqual(msg.defects,
-                                [errors.MissingHeaderBodySeparatorDefect])
-
     def test_string_payload_with_extra_space_after_cte(self):
         # https://github.com/python/cpython/issues/98188
         cte = "base64 "

Misc/NEWS.d/next/Library/2025-12-04-09-22-31.gh-issue-68552.I_v-xB.rst

@@ -0,0 +1 @@
+``MisplacedEnvelopeHeaderDefect`` and ``Missing header name`` defects are now correctly passed to the ``handle_defect`` method of ``policy`` in :class:`~email.parser.FeedParser`.