Minor tweaks and coverage:

* Format and wrap a comment.
* Add a test for having two From: headers.
* use <alpha@example.com> as standard Message-ID
* Cover URLError case.

2 files changed, 16 insertions, 1 deletions

diff --git a/src/mailman/rules/dmarc.py b/src/mailman/rules/dmarc.py
index 90b874e32..890fe9ff2 100644
--- a/src/mailman/rules/dmarc.py
+++ b/src/mailman/rules/dmarc.py
@@ -48,7 +48,7 @@ def _get_suffixes(url):
     try:
         d = request.urlopen(url)
     except error.URLError as e:
-        elog.error('Unable to retrieve data from %s: %s', url, e)
+        elog.error('Unable to retrieve data from %s: %s', url, e.reason)
         return
     for line in d.readlines():
         line = str(line, encoding='utf-8')
diff --git a/src/mailman/rules/tests/test_dmarc.py b/src/mailman/rules/tests/test_dmarc.py
index 666375699..16cf947cc 100644
--- a/src/mailman/rules/tests/test_dmarc.py
+++ b/src/mailman/rules/tests/test_dmarc.py
@@ -21,9 +21,11 @@ organizational domain tests."""
 from dns.rdatatype import TXT
 from dns.resolver import NXDOMAIN, NoAnswer
 from mailman.rules import dmarc
+from mailman.testing.helpers import LogFileMark
 from mailman.testing.layers import ConfigLayer
 from public import public
 from unittest import TestCase, mock
+from urllib.error import URLError
 
 
 @public
@@ -108,3 +110,16 @@ class TestDMARCRules(TestCase):
     def test_exception_to_wild_card(self):
         self.assertEqual(
             dmarc._get_org_dom('ssub.sub.city.kobe.jp'), 'city.kobe.jp')
+
+    def test_no_publicsuffix_dot_org(self):
+        mark = LogFileMark('mailman.error')
+        with mock.patch('mailman.rules.dmarc.request.urlopen',
+                        side_effect=URLError('no internet')):
+            domain = dmarc._get_org_dom('ssub.sub.city.kobe.jp')
+        self.assertEqual(domain, 'kobe.jp')
+        line = mark.readline()
+        self.assertEqual(
+            line[-95:],
+            'Unable to retrieve data from '
+            'https://publicsuffix.org/list/public_suffix_list.dat: '
+            'no internet\n')