3 files changed, 37 insertions, 2 deletions
diff --git a/src/mailman/docs/NEWS.rst b/src/mailman/docs/NEWS.rst
index ac81cd386..0a4b2fb51 100644
--- a/src/mailman/docs/NEWS.rst
+++ b/src/mailman/docs/NEWS.rst
@@ -16,9 +16,11 @@ Bugs
 ----
  * Fixed Unicode errors in the digest runner and when sending messages to the
    site owner as a fallback.  Given by Aurélien Bompard.  (LP: #1130957).
- * Fix Unicode errors when a message being added to the digest has non-ascii
+ * Fixed Unicode errors when a message being added to the digest has non-ascii
    characters in its payload, but no Content-Type header defining a charset.
    Given by Aurélien Bompard.  (LP: #1170347)
+ * Fixed messages without a `text/plain` part crashing the `Approved` rule.
+   Given by Aurélien Bompard.  (LP: #1158721)
 
 Commands
 --------
diff --git a/src/mailman/rules/approved.py b/src/mailman/rules/approved.py
index 2839ffef4..3b40d5dc9 100644
--- a/src/mailman/rules/approved.py
+++ b/src/mailman/rules/approved.py
@@ -71,9 +71,10 @@ class Approved:
             # Find the first text/plain part in the message
             part = None
             stripped = False
+            payload = None
             for part in typed_subpart_iterator(msg, 'text', 'plain'):
+                payload = part.get_payload(decode=True)
                 break
-            payload = part.get_payload(decode=True)
             if payload is not None:
                 charset = part.get_content_charset('us-ascii')
                 payload = payload.decode(charset, 'replace')
diff --git a/src/mailman/rules/tests/test_approved.py b/src/mailman/rules/tests/test_approved.py
index e7f122410..9976d4eff 100644
--- a/src/mailman/rules/tests/test_approved.py
+++ b/src/mailman/rules/tests/test_approved.py
@@ -491,3 +491,35 @@ deprecated = roundup_plaintext
             self.assertFalse(result)
         self.assertEqual(self._mlist.moderator_password,
                          b'{plaintext}super secret')
+
+
+class TestApprovedNoTextPlainPart(unittest.TestCase):
+    """Test the approved handler with HTML-only messages."""
+
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._mlist = create_list('test@example.com')
+        self._rule = approved.Approved()
+
+    def test_no_text_plain_part(self):
+        # When the message body only contains HTML, the rule should not throw
+        # AttributeError: 'NoneType' object has no attribute 'get_payload'
+        # LP: #1158721
+        msg = mfs("""\
+From: anne@example.com
+To: test@example.com
+Subject: HTML only email
+Message-ID: <ant>
+MIME-Version: 1.0
+Content-Type: text/html; charset="Windows-1251"
+Content-Transfer-Encoding: 7bit
+
+<HTML>
+<BODY>
+<P>This message contains only HTML, no plain/text part</P>
+</BODY>
+</HTML>
+""")
+        result = self._rule.check(self._mlist, msg, {})
+        self.assertFalse(result)