2 files changed, 21 insertions, 5 deletions

diff --git a/src/mailman/model/member.py b/src/mailman/model/member.py
index 84f99d5ac..438796811 100644
--- a/src/mailman/model/member.py
+++ b/src/mailman/model/member.py
@@ -136,7 +136,7 @@ class Member(Model):
                 if self._address is None
                 else getUtility(IUserManager).get_user(self._address.email))
 
-    def _lookup(self, preference):
+    def _lookup(self, preference, default=None):
         pref = getattr(self.preferences, preference)
         if pref is not None:
             return pref
@@ -147,7 +147,9 @@ class Member(Model):
             pref = getattr(self.address.user.preferences, preference)
             if pref is not None:
                 return pref
-        return getattr(system_preferences, preference)
+        if default is None:
+            return getattr(system_preferences, preference)
+        return default
 
     @property
     def acknowledge_posts(self):
@@ -157,7 +159,13 @@ class Member(Model):
     @property
     def preferred_language(self):
         """See `IMember`."""
-        return self._lookup('preferred_language')
+        missing = object()
+        language = self._lookup('preferred_language', missing)
+        if language is missing:
+            language = ((self.mailing_list and
+                         self.mailing_list.preferred_language) or
+                        system_preferences.preferred_language)
+        return language
 
     @property
     def receive_list_copy(self):
diff --git a/src/mailman/model/tests/test_member.py b/src/mailman/model/tests/test_member.py
index 7ac015cd4..5bd3d1594 100644
--- a/src/mailman/model/tests/test_member.py
+++ b/src/mailman/model/tests/test_member.py
@@ -17,19 +17,21 @@
 
 """Test members."""
 
-from __future__ import absolute_import, unicode_literals
+from __future__ import absolute_import, print_function, unicode_literals
 
 __metaclass__ = type
 __all__ = [
+    'TestMember',
     ]
 
 
 import unittest
 
 from mailman.app.lifecycle import create_list
-from mailman.interfaces.member import MembershipError
+from mailman.interfaces.member import MemberRole, MembershipError
 from mailman.interfaces.user import UnverifiedAddressError
 from mailman.interfaces.usermanager import IUserManager
+from mailman.model.member import Member
 from mailman.testing.layers import ConfigLayer
 from mailman.utilities.datetime import now
 
@@ -94,3 +96,9 @@ class TestMember(unittest.TestCase):
         # The new address is not verified.
         self.assertRaises(MembershipError,
                           setattr, member, 'address', bart_address)
+
+    def test_member_ctor_value_error(self):
+        # ValueError when passing in anything but a user or address.
+        self.assertRaises(ValueError, Member, MemberRole.member,
+                          self._mlist.list_id,
+                          'aperson@example.com')