5 files changed, 35 insertions, 8 deletions

diff --git a/src/mailman/docs/NEWS.rst b/src/mailman/docs/NEWS.rst
index f2c63a8f3..5408c29b4 100644
--- a/src/mailman/docs/NEWS.rst
+++ b/src/mailman/docs/NEWS.rst
@@ -86,6 +86,8 @@ Bugs
  * Nonmember subscriptions are removed when one of the addresses controlled by
    a user is subscribed as a member.  Given by Aditya Divekar.  (Closes #237)
  * Email address validation is now more compliant with RFC 5321.  (Closes #266)
+ * A mailing list's ``description`` must not contain newlines.  Given by
+   Aurélien Bompard.  (Closes: #273)
 
 Configuration
 -------------
diff --git a/src/mailman/handlers/cook_headers.py b/src/mailman/handlers/cook_headers.py
index f43e3ad5a..78109bb77 100644
--- a/src/mailman/handlers/cook_headers.py
+++ b/src/mailman/handlers/cook_headers.py
@@ -29,6 +29,7 @@ from mailman.interfaces.mailinglist import Personalization, ReplyToMunging
 from mailman.version import VERSION
 from zope.interface import implementer
 
+
 log = logging.getLogger('mailman.error')
 
 COMMASPACE = ', '
@@ -58,7 +59,7 @@ def uheader(mlist, s, header_name=None, continuation_ws='\t', maxlinelen=None):
     if '\n' in s:
         s = '{} [...]'.format(s.split('\n')[0])
         log.warning('Header {} contains a newline, truncating it.'.format(
-                    header_name, s))
+            header_name, s))
     return Header(s, charset, maxlinelen, header_name, continuation_ws)
 
 
diff --git a/src/mailman/handlers/tests/test_cook_headers.py b/src/mailman/handlers/tests/test_cook_headers.py
index f9def6ca8..8ab301f96 100644
--- a/src/mailman/handlers/tests/test_cook_headers.py
+++ b/src/mailman/handlers/tests/test_cook_headers.py
@@ -21,9 +21,11 @@ import unittest
 
 from mailman.app.lifecycle import create_list
 from mailman.handlers import cook_headers
+from mailman.interfaces.mailinglist import ReplyToMunging
 from mailman.interfaces.member import DeliveryMode
 from mailman.testing.helpers import (
-    get_queue_messages, LogFileMark, make_digest_messages, subscribe)
+    LogFileMark, get_queue_messages, make_digest_messages,
+    specialized_message_from_string as mfs, subscribe)
 from mailman.testing.layers import ConfigLayer
 
 
@@ -33,7 +35,7 @@ class TestCookHeaders(unittest.TestCase):
     layer = ConfigLayer
 
     def setUp(self):
-        self._mlist = create_list('test@example.com')
+        self._mlist = create_list('ant@example.com')
         self._mlist.send_welcome_message = False
 
     def test_process_digest(self):
@@ -56,8 +58,31 @@ class TestCookHeaders(unittest.TestCase):
         mark = LogFileMark('mailman.error')
         header = cook_headers.uheader(
             self._mlist, 'A multiline\ndescription', 'X-Header')
-        self.assertEqual(
-            header.encode(), 'A multiline [...]')
+        self.assertEqual(header.encode(), 'A multiline [...]')
         log_messages = mark.read()
         self.assertIn(
             'Header X-Header contains a newline, truncating it', log_messages)
+
+    def test_truncate_description(self):
+        # Existing multiline descriptions get truncated with ellipses.
+        self._mlist.description = 'A multiline\ndescription\nalready\nexists'
+        self._mlist.reply_goes_to_list = ReplyToMunging.point_to_list
+        msg = mfs("""\
+From: anne@example.com
+To: ant@example.com
+Subject: A subject
+X-Mailman-Version: X.Y
+
+More things to say.
+""")
+        cook_headers.process(self._mlist, msg, {})
+        self.assertMultiLineEqual(msg.as_string(), """\
+From: anne@example.com
+To: ant@example.com
+Subject: A subject
+X-Mailman-Version: X.Y
+Precedence: list
+Reply-To: "A multiline [...]" <ant@example.com>
+
+More things to say.
+""")
diff --git a/src/mailman/rest/listconf.py b/src/mailman/rest/listconf.py
index c49228c39..ad8aefcbb 100644
--- a/src/mailman/rest/listconf.py
+++ b/src/mailman/rest/listconf.py
@@ -104,8 +104,7 @@ def password_bytes_validator(value):
 def no_newlines_validator(value):
     value = str(value)
     if '\n' in value:
-        raise ValueError(
-            'This value must be on a single line: {}'.format(value))
+        raise ValueError('This value must be a single line: {}'.format(value))
     return value
 
 
diff --git a/src/mailman/rest/tests/test_listconf.py b/src/mailman/rest/tests/test_listconf.py
index 54918282f..b454337e4 100644
--- a/src/mailman/rest/tests/test_listconf.py
+++ b/src/mailman/rest/tests/test_listconf.py
@@ -439,7 +439,7 @@ class TestConfiguration(unittest.TestCase):
         self.assertTrue(self._mlist.advertised)
 
     def test_patch_bad_description_value(self):
-        # GL issue #273
+        # Do not accept multiline descriptions.  GL#273
         with self.assertRaises(HTTPError) as cm:
             call_api(
                 'http://localhost:9001/3.0/lists/ant.example.com/config'