Update NEWS entry, test case enhance, lint code

Author: zangjiucheng

Lib/email/contentmanager.py

@@ -1,9 +1,9 @@
-import sys
 import binascii
 import email.charset
 import email.message
 import email.errors
 from email import quoprimime
+import sys
 
 class ContentManager:
 
@@ -159,8 +159,7 @@ def normal_body(lines): return b'\n'.join(lines) + b'\n'
             if policy.cte_type == '8bit':
                 return '8bit', normal_body(lines).decode('ascii', 'surrogateescape')
         sniff = embedded_body(lines[:10])
-        sniff_qp = quoprimime.body_encode(sniff.decode('latin-1'),
-                                          maxlen)
+        sniff_qp = quoprimime.body_encode(sniff.decode('latin-1'), maxlen)
         sniff_base64 = binascii.b2a_base64(sniff)
         # This is a little unfair to qp; it includes lineseps, base64 doesn't.
         if len(sniff_qp) > len(sniff_base64):

Lib/test/test_email/test_message.py

@@ -1004,33 +1004,25 @@ def test_folding_with_long_nospace_http_policy_1(self):
         parsed_msg = message_from_bytes(m.as_bytes(), policy=policy.default)
         self.assertEqual(parsed_msg['Message-ID'], m['Message-ID'])
 
-    def test_no_wrapping_with_zero_max_line_length(self):
-        pol = policy.default.clone(max_line_length=0)
-        subj = "S" * 100
-        msg = EmailMessage(policy=pol)
-        msg["From"] = "a@ex.com"
-        msg["To"] = "b@ex.com"
-        msg["Subject"] = subj
-
-        raw = msg.as_bytes()
-        self.assertNotIn(b"\r\n ", raw, "Found fold indicator; wrapping not disabled")
-
-        parsed = message_from_bytes(raw, policy=policy.default)
-        self.assertEqual(parsed["Subject"], subj)
-
-    def test_no_wrapping_with_none_max_line_length(self):
-        pol = policy.default.clone(max_line_length=None)
-        subj = "S" * 100
-        body = "B" * 100
-        msg = EmailMessage(policy=pol)
-        msg["From"] = "a@ex.com"
-        msg["To"] = "b@ex.com"
-        msg["Subject"] = subj
-        msg.set_content(body)
-
-        parsed = message_from_bytes(msg.as_bytes(), policy=policy.default)
-        self.assertEqual(parsed["Subject"], subj)
-        self.assertEqual(parsed.get_body().get_content().rstrip('\n'), body)
+    def test_no_wrapping_max_line_length(self):
+        def do_test_no_wrapping_max_line_length(n):
+            pol = policy.default.clone(max_line_length=n)
+            subj = "S" * 100
+            body = "B" * 100
+            msg = EmailMessage(policy=pol)
+            msg["From"] = "a@ex.com"
+            msg["To"] = "b@ex.com"
+            msg["Subject"] = subj
+            msg.set_content(body)
+
+            raw = msg.as_bytes()
+            self.assertNotIn(b"\r\n ", raw, "Found fold indicator; wrapping not disabled")
+
+            parsed = message_from_bytes(msg.as_bytes(), policy=policy.default)
+            self.assertEqual(parsed["Subject"], subj)
+            self.assertEqual(parsed.get_body().get_content().rstrip('\n'), body)
+        do_test_no_wrapping_max_line_length(None)
+        do_test_no_wrapping_max_line_length(0)
 
     def test_invalid_header_names(self):
         invalid_headers = [

Misc/NEWS.d/next/Library/2025-06-10-18-02-29.gh-issue-135307.fXGrcK.rst

@@ -1,2 +1,2 @@
 :mod:`email`: Ensure policy accepts unlimited line lengths by
-treating 0 or :const:`None` as :data:`sys.maxsize`.
+treating falsey values as :data:`sys.maxsize`.