10 files changed, 198 insertions, 136 deletions

diff --git a/src/mailman/chains/headers.py b/src/mailman/chains/headers.py
index 12e86e8e6..138f34035 100644
--- a/src/mailman/chains/headers.py
+++ b/src/mailman/chains/headers.py
@@ -40,20 +40,24 @@ log = logging.getLogger('mailman.error')
 def make_link(header, pattern, chain=None):
     """Create a Link object.
 
-    The link action is always to defer, since at the end of all the header
-    checks, we'll jump to the chain defined in the configuration file, should
-    any of them have matched.
+    The link action is to defer by default, since at the end of all the
+    header checks, we'll jump to the chain defined in the configuration
+    file, should any of them have matched.  However, it is possible to
+    create a link which jumps to a specific chain.
 
     :param header: The email header name to check, e.g. X-Spam.
     :type header: string
     :param pattern: A regular expression for matching the header value.
     :type pattern: string
+    :param chain: When given, this is the chain to jump to if the
+        pattern matches the header.
+    :type chain: string
     :return: The link representing this rule check.
     :rtype: `ILink`
     """
     rule = HeaderMatchRule(header, pattern)
     if chain is None:
-        return Link(rule, LinkAction.defer)
+        return Link(rule)
     chain = config.chains[chain]
     return Link(rule, LinkAction.jump, chain)
 
@@ -135,15 +139,17 @@ class HeaderMatchChain(Chain):
             parts = line.split(':', 1)
             if len(parts) != 2:
                 log.error('Configuration error: [antispam]header_checks '
-                          'contains bogus line: {0}'.format(line))
+                          'contains bogus line: {}'.format(line))
                 continue
             yield make_link(parts[0], parts[1].lstrip())
         # Then return all the explicitly added links.
         yield from self._extended_links
-        # If any of the above rules matched, jump to the chain
-        # defined in the configuration file. This takes precedence over
-        # list-specific matches for security considerations.
-        yield Link(config.rules['any'], LinkAction.jump,
+        # If any of the above rules matched, they will have deferred their
+        # action until now, so jump to the chain defined in the configuration
+        # file.  For security considerations, this takes precedence over
+        # list-specific matches.
+        yield Link(config.rules['any'],
+                   LinkAction.jump,
                    config.chains[config.antispam.jump_chain])
         # Then return all the list-specific header matches.
         for entry in mlist.header_matches:
diff --git a/src/mailman/chains/tests/test_headers.py b/src/mailman/chains/tests/test_headers.py
index 851720f95..312f1eb54 100644
--- a/src/mailman/chains/tests/test_headers.py
+++ b/src/mailman/chains/tests/test_headers.py
@@ -25,16 +25,16 @@ __all__ = [
 import unittest
 
 from mailman.app.lifecycle import create_list
-from mailman.chains.headers import HeaderMatchRule
+from mailman.chains.headers import HeaderMatchRule, make_link
 from mailman.config import config
 from mailman.core.chains import process
 from mailman.email.message import Message
 from mailman.interfaces.chain import LinkAction, HoldEvent
 from mailman.interfaces.mailinglist import IHeaderMatchSet
-from mailman.testing.layers import ConfigLayer
 from mailman.testing.helpers import (
-    configuration, event_subscribers, get_queue_messages, LogFileMark,
+    LogFileMark, configuration, event_subscribers,
     specialized_message_from_string as mfs)
+from mailman.testing.layers import ConfigLayer
 
 
 
@@ -46,6 +46,24 @@ class TestHeaderChain(unittest.TestCase):
     def setUp(self):
         self._mlist = create_list('test@example.com')
 
+    def test_make_link(self):
+        # Test that make_link() with no given chain creates a Link with a
+        # deferred link action.
+        link = make_link('Subject', '[tT]esting')
+        self.assertEqual(link.rule.header, 'Subject')
+        self.assertEqual(link.rule.pattern, '[tT]esting')
+        self.assertEqual(link.action, LinkAction.defer)
+        self.assertIsNone(link.chain)
+
+    def test_make_link_with_chain(self):
+        # Test that make_link() with a given chain creates a Link with a jump
+        # action to the chain.
+        link = make_link('Subject', '[tT]esting', 'accept')
+        self.assertEqual(link.rule.header, 'Subject')
+        self.assertEqual(link.rule.pattern, '[tT]esting')
+        self.assertEqual(link.action, LinkAction.jump)
+        self.assertEqual(link.chain, config.chains['accept'])
+
     @configuration('antispam', header_checks="""
     Foo: a+
     Bar: bb?
@@ -129,9 +147,9 @@ class TestHeaderChain(unittest.TestCase):
         # mailing-list configuration.
         chain = config.chains['header-match']
         header_matches = IHeaderMatchSet(self._mlist)
-        header_matches.add('Foo', 'a+', None)
+        header_matches.add('Foo', 'a+')
         links = [link for link in chain.get_links(self._mlist, Message(), {})
-                  if link.rule.name != 'any']
+                 if link.rule.name != 'any']
         self.assertEqual(len(links), 1)
         self.assertEqual(links[0].action, LinkAction.defer)
         self.assertEqual(links[0].rule.header, 'foo')
@@ -146,11 +164,12 @@ class TestHeaderChain(unittest.TestCase):
         header_matches.add('Bar', 'b+', 'discard')
         header_matches.add('Baz', 'z+', 'accept')
         links = [link for link in chain.get_links(self._mlist, Message(), {})
-                  if link.rule.name != 'any']
+                 if link.rule.name != 'any']
         self.assertEqual(len(links), 3)
-        self.assertListEqual(
-            [(link.rule.header, link.rule.pattern, link.action, link.chain.name)
-              for link in links],
+        self.assertEqual([
+            (link.rule.header, link.rule.pattern, link.action, link.chain.name)
+            for link in links
+            ],
             [('foo', 'a+', LinkAction.jump, 'reject'),
              ('bar', 'b+', LinkAction.jump, 'discard'),
              ('baz', 'z+', LinkAction.jump, 'accept'),
diff --git a/src/mailman/database/alembic/versions/42756496720_header_matches.py b/src/mailman/database/alembic/versions/42756496720_header_matches.py
index 83a1275a2..5e8db9756 100644
--- a/src/mailman/database/alembic/versions/42756496720_header_matches.py
+++ b/src/mailman/database/alembic/versions/42756496720_header_matches.py
@@ -18,7 +18,8 @@ from mailman.database.helpers import is_sqlite, exists_in_db
 
 def upgrade():
     # Create the new table
-    header_match_table = op.create_table('headermatch',
+    header_match_table = op.create_table(
+        'headermatch',
         sa.Column('id', sa.Integer(), nullable=False),
         sa.Column('mailing_list_id', sa.Integer(), nullable=True),
         sa.Column('header', sa.Unicode(), nullable=False),
@@ -26,17 +27,17 @@ def upgrade():
         sa.Column('chain', sa.Unicode(), nullable=True),
         sa.ForeignKeyConstraint(['mailing_list_id'], ['mailinglist.id'], ),
         sa.PrimaryKeyConstraint('id')
-    )
-
-    # Now migrate the data. It can't be offline because we need to read the
+        )
+    # Now migrate the data.  It can't be offline because we need to read the
     # pickles.
     connection = op.get_bind()
     # Don't import the table definition from the models, it may break this
     # migration when the model is updated in the future (see the Alembic doc).
-    mlist_table = sa.sql.table('mailinglist',
+    mlist_table = sa.sql.table(
+        'mailinglist',
         sa.sql.column('id', sa.Integer),
         sa.sql.column('header_matches', sa.PickleType)
-    )
+        )
     for mlist_id, old_matches in connection.execute(mlist_table.select()):
         for old_match in old_matches:
             connection.execute(header_match_table.insert().values(
@@ -44,8 +45,7 @@ def upgrade():
                 header=old_match[0],
                 pattern=old_match[1],
                 chain=None
-            ))
-
+                ))
     # Now that data is migrated, drop the old column (except on SQLite which
     # does not support this)
     if not is_sqlite(connection):
@@ -56,23 +56,25 @@ def downgrade():
     if not exists_in_db(op.get_bind(), 'mailinglist', 'header_matches'):
         # SQLite will not have deleted the former column, since it does not
         # support column deletion.
-        op.add_column('mailinglist', sa.Column(
-            'header_matches', sa.PickleType, nullable=True))
-
-    # Now migrate the data. It can't be offline because we need to read the
+        op.add_column(
+            'mailinglist',
+            sa.Column('header_matches', sa.PickleType, nullable=True))
+    # Now migrate the data.  It can't be offline because we need to read the
     # pickles.
     connection = op.get_bind()
     # Don't import the table definition from the models, it may break this
     # migration when the model is updated in the future (see the Alembic doc).
-    mlist_table = sa.sql.table('mailinglist',
+    mlist_table = sa.sql.table(
+        'mailinglist',
         sa.sql.column('id', sa.Integer),
         sa.sql.column('header_matches', sa.PickleType)
-    )
-    header_match_table = sa.sql.table('headermatch',
+        )
+    header_match_table = sa.sql.table(
+        'headermatch',
         sa.sql.column('mailing_list_id', sa.Integer),
         sa.sql.column('header', sa.Unicode),
         sa.sql.column('pattern', sa.Unicode),
-    )
+        )
     for mlist_id, header, pattern in connection.execute(
             header_match_table.select()).fetchall():
         mlist = connection.execute(mlist_table.select().where(
@@ -84,5 +86,4 @@ def downgrade():
         connection.execute(mlist_table.update().where(
             mlist_table.c.id == mlist_id).values(
             header_matches=header_matches))
-
     op.drop_table('headermatch')
diff --git a/src/mailman/database/tests/test_migrations.py b/src/mailman/database/tests/test_migrations.py
index 6f167cd13..91f19bfb2 100644
--- a/src/mailman/database/tests/test_migrations.py
+++ b/src/mailman/database/tests/test_migrations.py
@@ -46,9 +46,9 @@ class TestMigrations(unittest.TestCase):
         md = sa.MetaData(bind=config.db.engine)
         md.reflect()
         # We have circular dependencies between user and address, thus we can't
-        # use drop_all() without getting a warning. Setting use_alter to True
+        # use drop_all() without getting a warning.  Setting use_alter to True
         # on the foreign keys helps SQLAlchemy mark those loops as known.
-        for tablename in ("user", "address"):
+        for tablename in ('user', 'address'):
             if tablename not in md.tables:
                 continue
             for fk in md.tables[tablename].foreign_keys:
@@ -70,17 +70,19 @@ class TestMigrations(unittest.TestCase):
             ('test-header-1', 'test-pattern-1'),
             ('test-header-2', 'test-pattern-2'),
             ('test-header-3', 'test-pattern-3'),
-        ]
-        mlist_table = sa.sql.table('mailinglist',
+            ]
+        mlist_table = sa.sql.table(
+            'mailinglist',
             sa.sql.column('id', sa.Integer),
             sa.sql.column('header_matches', sa.PickleType)
             )
-        header_match_table = sa.sql.table('headermatch',
+        header_match_table = sa.sql.table(
+            'headermatch',
             sa.sql.column('mailing_list_id', sa.Integer),
             sa.sql.column('header', sa.Unicode),
             sa.sql.column('pattern', sa.Unicode),
-        )
-        # Downgrading
+            )
+        # Downgrading.
         config.db.store.execute(mlist_table.insert().values(id=1))
         config.db.store.execute(header_match_table.insert().values(
             [{'mailing_list_id': 1, 'header': hm[0], 'pattern': hm[1]}
@@ -92,7 +94,7 @@ class TestMigrations(unittest.TestCase):
         self.assertEqual(results[0].header_matches, test_header_matches)
         self.assertFalse(exists_in_db(config.db.engine, 'headermatch'))
         config.db.store.commit()
-        # Upgrading
+        # Upgrading.
         alembic.command.upgrade(alembic_cfg, '42756496720')
         results = config.db.store.execute(
             header_match_table.select()).fetchall()
diff --git a/src/mailman/interfaces/mailinglist.py b/src/mailman/interfaces/mailinglist.py
index 7f3b68008..0be8c2b68 100644
--- a/src/mailman/interfaces/mailinglist.py
+++ b/src/mailman/interfaces/mailinglist.py
@@ -20,6 +20,7 @@
 __all__ = [
     'IAcceptableAlias',
     'IAcceptableAliasSet',
+    'IHeaderMatch',
     'IListArchiver',
     'IListArchiverSet',
     'IMailingList',
@@ -843,7 +844,7 @@ class IListArchiverSet(Interface):
 
 
 class IHeaderMatch(Interface):
-    """A header matching rule for mailinglist messages."""
+    """A mailing list-specific message header matching rule."""
 
     mailing_list = Attribute(
         """The mailing list for the header match.""")
@@ -868,26 +869,32 @@ class IHeaderMatchSet(Interface):
     def clear():
         """Clear the set of header matching rules."""
 
-    def add(header, pattern, chain):
-        """Add the given header matching rule to this mailinglist's set.
+    def add(header, pattern, chain=None):
+        """Add the given header matching rule to this mailing list's set.
 
-        :param header: The email header to filter on. It will be converted to
-            lowercase for easier removal.
+        :param header: The email header to filter on.  It will be converted to
+            lower case for consistency.
         :type header: string
         :param pattern: The regular expression to use.
         :type pattern: string
         :param chain: The chain to jump to, or None to use the site-wide
-            configuration. Defaults to None.
+            configuration.  Defaults to None.
         :type chain: string or None
-        :raises ValueError: there can be only one couple of header and pattern
-            for a mailinglist.
+        :raises ValueError: if the header/pattern pair already exists for this
+            mailing list.
         """
 
     def remove(header, pattern):
-        """Remove the given header matching rule from this mailinglist's set.
+        """Remove the given header matching rule from this mailing list's set.
 
         :param header: The email header part of the rule to be removed.
         :type header: string
         :param pattern: The regular expression part of the rule to be removed.
         :type pattern: string
         """
+
+    def __iter__():
+        """An iterator over all the IHeaderMatches defined in this set.
+
+        :return: iterator over `IHeaderMatch`.
+        """
diff --git a/src/mailman/model/mailinglist.py b/src/mailman/model/mailinglist.py
index 617109a7e..0a5b20dd8 100644
--- a/src/mailman/model/mailinglist.py
+++ b/src/mailman/model/mailinglist.py
@@ -37,8 +37,8 @@ from mailman.interfaces.digests import DigestFrequency
 from mailman.interfaces.domain import IDomainManager
 from mailman.interfaces.languages import ILanguageManager
 from mailman.interfaces.mailinglist import (
-    IAcceptableAlias, IAcceptableAliasSet, IListArchiver, IListArchiverSet,
-    IHeaderMatch, IHeaderMatchSet, IMailingList, Personalization,
+    IAcceptableAlias, IAcceptableAliasSet, IHeaderMatch, IHeaderMatchSet,
+    IListArchiver, IListArchiverSet, IMailingList, Personalization,
     ReplyToMunging, SubscriptionPolicy)
 from mailman.interfaces.member import (
     AlreadySubscribedError, MemberRole, MissingPreferredAddressError,
@@ -684,3 +684,8 @@ class HeaderMatchSet:
             raise ValueError('Pattern does not exist')
         else:
             self._mailing_list.header_matches.remove(existing)
+
+    @dbconnection
+    def __iter__(self, store):
+        yield from store.query(HeaderMatch).filter(
+            HeaderMatch.mailing_list == self._mailing_list)
diff --git a/src/mailman/model/tests/test_mailinglist.py b/src/mailman/model/tests/test_mailinglist.py
index c497cb474..8d35a50f6 100644
--- a/src/mailman/model/tests/test_mailinglist.py
+++ b/src/mailman/model/tests/test_mailinglist.py
@@ -173,37 +173,48 @@ class TestHeaderMatch(unittest.TestCase):
         self._mlist = create_list('ant@example.com')
 
     def test_lowercase_header(self):
-        with transaction():
-            header_matches = IHeaderMatchSet(self._mlist)
-            header_matches.add('Header', 'pattern')
-            self.assertEqual(len(self._mlist.header_matches), 1)
-            self.assertEqual(self._mlist.header_matches[0].header, 'header')
+        header_matches = IHeaderMatchSet(self._mlist)
+        header_matches.add('Header', 'pattern')
+        self.assertEqual(len(self._mlist.header_matches), 1)
+        self.assertEqual(self._mlist.header_matches[0].header, 'header')
 
     def test_chain_defaults_to_none(self):
-        with transaction():
-            header_matches = IHeaderMatchSet(self._mlist)
-            header_matches.add('header', 'pattern')
-            self.assertEqual(len(self._mlist.header_matches), 1)
-            self.assertEqual(self._mlist.header_matches[0].chain, None)
+        header_matches = IHeaderMatchSet(self._mlist)
+        header_matches.add('header', 'pattern')
+        self.assertEqual(len(self._mlist.header_matches), 1)
+        self.assertEqual(self._mlist.header_matches[0].chain, None)
 
     def test_duplicate(self):
-        with transaction():
-            header_matches = IHeaderMatchSet(self._mlist)
-            header_matches.add('Header', 'pattern')
-            self.assertRaises(ValueError,
-                header_matches.add, 'Header', 'pattern')
-            self.assertEqual(len(self._mlist.header_matches), 1)
+        header_matches = IHeaderMatchSet(self._mlist)
+        header_matches.add('Header', 'pattern')
+        self.assertRaises(
+            ValueError, header_matches.add, 'Header', 'pattern')
+        self.assertEqual(len(self._mlist.header_matches), 1)
 
     def test_remove_non_existent(self):
-        with transaction():
-            header_matches = IHeaderMatchSet(self._mlist)
-            self.assertRaises(ValueError,
-                header_matches.remove, 'header', 'pattern')
+        header_matches = IHeaderMatchSet(self._mlist)
+        self.assertRaises(
+            ValueError, header_matches.remove, 'header', 'pattern')
 
     def test_add_remove(self):
-        with transaction():
-            header_matches = IHeaderMatchSet(self._mlist)
-            header_matches.add('header', 'pattern')
-            self.assertEqual(len(self._mlist.header_matches), 1)
-            header_matches.remove('header', 'pattern')
-            self.assertEqual(len(self._mlist.header_matches), 0)
+        header_matches = IHeaderMatchSet(self._mlist)
+        header_matches.add('header', 'pattern')
+        self.assertEqual(len(self._mlist.header_matches), 1)
+        header_matches.remove('header', 'pattern')
+        self.assertEqual(len(self._mlist.header_matches), 0)
+
+    def test_iterator(self):
+        header_matches = IHeaderMatchSet(self._mlist)
+        header_matches.add('Header', 'pattern')
+        header_matches.add('Subject', 'patt.*')
+        header_matches.add('From', '.*@example.com', 'discard')
+        header_matches.add('From', '.*@example.org', 'accept')
+        matches = sorted((match.header, match.pattern, match.chain)
+                         for match in IHeaderMatchSet(self._mlist))
+        self.assertEqual(
+            matches,
+            [('from', '.*@example.com', 'discard'),
+             ('from', '.*@example.org', 'accept'),
+             ('header', 'pattern', None),
+             ('subject', 'patt.*', None),
+             ])
diff --git a/src/mailman/rules/docs/header-matching.rst b/src/mailman/rules/docs/header-matching.rst
index 05d01efb2..2eb8d9bdf 100644
--- a/src/mailman/rules/docs/header-matching.rst
+++ b/src/mailman/rules/docs/header-matching.rst
@@ -120,11 +120,11 @@ List-specific header matching
 
 Each mailing list can also be configured with a set of header matching regular
 expression rules.  These can be used to impose list-specific header filtering
-with the same semantics as the global `[antispam]` section, or to have a
+with the same semantics as the global ``[antispam]`` section, or to have a
 different action.
 
 To follow the global antispam action, the header match rule must not specify a
-`chain` to jump to. If the default antispam action is changed in the
+``chain`` to jump to.  If the default antispam action is changed in the
 configuration file and Mailman is restarted, those rules will get the new jump
 action.
 
@@ -147,8 +147,8 @@ A message with a spam score of two pluses does not match.
         x-spam-score: [+]{3,}
 
 But a message with a spam score of three pluses does match.  Because a message
-with the previous Message-Id is already in the moderation queue, we need to
-give this message a new Message-Id.
+with the previous ``Message-Id`` is already in the moderation queue, we need
+to give this message a new ``Message-Id``.
 
     >>> msgdata = {}
     >>> del msg['x-spam-score']
@@ -174,8 +174,8 @@ As does a message with a spam score of four pluses.
         x-spam-score: [+]{3,}
     No rules missed
 
-Now, the list administrator wants to match on three plus signs, but wants those
-emails to be discarded instead of held.
+Now, the list administrator wants to match on three plus signs, but wants
+those emails to be discarded instead of held.
 
     >>> header_matches.remove('x-spam-score', '[+]{3,}')
     >>> header_matches.add('x-spam-score', '[+]{3,}', 'discard')
@@ -187,10 +187,10 @@ will be discarded.
     >>> del msg['x-spam-score']
     >>> msg['X-Spam-Score'] = '+++'
     >>> del msg['message-id']
-    >>> msg['Message-Id'] = '<dee>'
+    >>> msg['Message-Id'] = '<dog>'
     >>> with event_subscribers(handler):
     ...     process(mlist, msg, msgdata, 'header-match')
-    DiscardEvent discard <dee>
+    DiscardEvent discard <dog>
     >>> hits_and_misses(msgdata)
     Rule hits:
         x-spam-score: [+]{3,}
diff --git a/src/mailman/utilities/importer.py b/src/mailman/utilities/importer.py
index 4e3eab6cf..a15eac7f9 100644
--- a/src/mailman/utilities/importer.py
+++ b/src/mailman/utilities/importer.py
@@ -39,7 +39,6 @@ from mailman.interfaces.archiver import ArchivePolicy
 from mailman.interfaces.autorespond import ResponseAction
 from mailman.interfaces.bans import IBanManager
 from mailman.interfaces.bounce import UnrecognizedBounceDisposition
-from mailman.interfaces.chain import LinkAction
 from mailman.interfaces.digests import DigestFrequency
 from mailman.interfaces.languages import ILanguageManager
 from mailman.interfaces.mailinglist import IAcceptableAliasSet, IHeaderMatchSet
@@ -132,18 +131,18 @@ def nonmember_action_mapping(value):
 
 def action_to_chain(value):
     # Converts an action number in Mailman 2.1 to the name of the corresponding
-    # chain in 3.x. The actions "approve", "subscribe" and "unsubscribe" are
-    # ignored. The defer action is converted to None, because it is not a jump
-    # to a terminal chain.
+    # chain in 3.x.  The actions 'approve', 'subscribe' and 'unsubscribe' are
+    # ignored.  The defer action is converted to None, because it is not
+    # a jump to a terminal chain.
     return {
         0: None,
-        #1: "approve",
-        2: "reject",
-        3: "discard",
-        #4: "subscribe",
-        #5: "unsubscribe",
-        6: "accept",
-        7: "hold",
+        #1: 'approve',
+        2: 'reject',
+        3: 'discard',
+        #4: 'subscribe',
+        #5: 'unsubscribe',
+        6: 'accept',
+        7: 'hold',
         }[value]
 
 
@@ -333,7 +332,7 @@ def import_config_pck(mlist, config_dict):
             # When .add() rejects this, the line probably contains a regular
             # expression.  Make that explicit for MM3.
             alias_set.add('^' + address)
-    # Handle header_filter_rules conversion to header_matches
+    # Handle header_filter_rules conversion to header_matches.
     header_match_set = IHeaderMatchSet(mlist)
     header_filter_rules = config_dict.get('header_filter_rules', [])
     for line_patterns, action, _unused in header_filter_rules:
@@ -343,26 +342,28 @@ def import_config_pck(mlist, config_dict):
             log.warning('Unsupported header_filter_rules action: %r',
                         action)
             continue
-        # now split the pattern in a header and a pattern
+        # Now split the line into a header and a pattern.
         for line_pattern in line_patterns.splitlines():
-            if not line_pattern.strip():
+            if len(line_pattern.strip()) == 0:
                 continue
             for sep in (': ', ':.', ':'):
                 header, sep, pattern = line_pattern.partition(sep)
                 if sep:
-                    break # found it.
+                    # We found it.
+                    break
             else:
-                # matches any header. Those are not supported. XXX
+                # Matches any header, which is not supported.  XXX
                 log.warning('Unsupported header_filter_rules pattern: %r',
                             line_pattern)
                 continue
-            header = header.strip().lstrip("^").lower()
+            header = header.strip().lstrip('^').lower()
             header = header.replace('\\', '')
             if not header:
-                log.warning('Can\'t parse the header in header_filter_rule: %r',
-                            line_pattern)
+                log.warning(
+                    'Cannot parse the header in header_filter_rule: %r',
+                    line_pattern)
                 continue
-            if not pattern:
+            if len(pattern) == 0:
                 # The line matched only the header, therefore the header can
                 # be anything.
                 pattern = '.*'
diff --git a/src/mailman/utilities/tests/test_import.py b/src/mailman/utilities/tests/test_import.py
index 64f8e061f..e687e8a00 100644
--- a/src/mailman/utilities/tests/test_import.py
+++ b/src/mailman/utilities/tests/test_import.py
@@ -44,7 +44,7 @@ from mailman.interfaces.bans import IBanManager
 from mailman.interfaces.bounce import UnrecognizedBounceDisposition
 from mailman.interfaces.languages import ILanguageManager
 from mailman.interfaces.mailinglist import (
-    IAcceptableAliasSet, IHeaderMatchSet, SubscriptionPolicy)
+    IAcceptableAliasSet, SubscriptionPolicy)
 from mailman.interfaces.member import DeliveryMode, DeliveryStatus
 from mailman.interfaces.nntp import NewsgroupModeration
 from mailman.interfaces.templates import ITemplateLoader
@@ -344,7 +344,8 @@ class TestBasicImport(unittest.TestCase):
             ('X-Git-Module: rhq.*git', 6, False),
             ('Approved: verysecretpassword', 6, False),
             ('^Subject: dev-\r\n^Subject: staging-', 3, False),
-            ('from: .*info@aolanchem.com\r\nfrom: .*@jw-express.com', 2, False),
+            ('from: .*info@aolanchem.com\r\nfrom: .*@jw-express.com',
+             2, False),
             ('^Received: from smtp-.*\\.fedoraproject\\.org\r\n'
              '^Received: from mx.*\\.redhat.com\r\n'
              '^Resent-date:\r\n'
@@ -356,15 +357,17 @@ class TestBasicImport(unittest.TestCase):
             ('^Received: from fedorahosted\\.org.*by fedorahosted\\.org\r\n'
              '^Received: from hosted.*\\.fedoraproject.org.*by '
              'hosted.*\\.fedoraproject\\.org\r\n'
-             '^Received: from hosted.*\\.fedoraproject.org.*by fedoraproject\\.org\r\n'
-             '^Received: from hosted.*\\.fedoraproject.org.*by fedorahosted\\.org',
+             '^Received: from hosted.*\\.fedoraproject.org.*by '
+                'fedoraproject\\.org\r\n'
+             '^Received: from hosted.*\\.fedoraproject.org.*by '
+                'fedorahosted\\.org',
              6, False),
             ]
         error_log = LogFileMark('mailman.error')
         self._import()
         self.assertListEqual(
-            [ (hm.header, hm.pattern, hm.chain)
-              for hm in self._mlist.header_matches ], [
+            [(hm.header, hm.pattern, hm.chain)
+             for hm in self._mlist.header_matches ], [
             ('x-spam-status', 'Yes.*', 'discard'),
             ('x-spam-status', 'Yes', 'reject'),
             ('x-spam-level', '\\*\\*\\*.*$', 'discard'),
@@ -386,19 +389,26 @@ class TestBasicImport(unittest.TestCase):
             ('resent-message-id', '.*', 'hold'),
             ('resent-to', '.*', 'hold'),
             ('subject', '[^mtv]', 'hold'),
-            ('received', 'from fedorahosted\\.org.*by fedorahosted\\.org', 'accept'),
-            ('received', 'from hosted.*\\.fedoraproject.org.*by hosted.*\\.fedoraproject\\.org', 'accept'),
-            ('received', 'from hosted.*\\.fedoraproject.org.*by fedoraproject\\.org', 'accept'),
-            ('received', 'from hosted.*\\.fedoraproject.org.*by fedorahosted\\.org', 'accept'),
+            ('received', 'from fedorahosted\\.org.*by fedorahosted\\.org',
+             'accept'),
+            ('received',
+             'from hosted.*\\.fedoraproject.org.*by '
+                'hosted.*\\.fedoraproject\\.org', 'accept'),
+            ('received',
+             'from hosted.*\\.fedoraproject.org.*by '
+                'fedoraproject\\.org', 'accept'),
+            ('received',
+             'from hosted.*\\.fedoraproject.org.*by '
+                'fedorahosted\\.org', 'accept'),
             ])
         loglines = error_log.read().strip()
         self.assertEqual(len(loglines), 0)
 
     def test_header_matches_header_only(self):
-        # Check that an empty pattern is skipped
+        # Check that an empty pattern is skipped.
         self._pckdict['header_filter_rules'] = [
             ('SomeHeaderName', 3, False),
-        ]
+            ]
         error_log = LogFileMark('mailman.error')
         self._import()
         self.assertListEqual(self._mlist.header_matches, [])
@@ -406,10 +416,10 @@ class TestBasicImport(unittest.TestCase):
                       error_log.readline())
 
     def test_header_matches_anything(self):
-        # Check that an empty pattern is skipped
+        # Check that a wild card header pattern is skipped.
         self._pckdict['header_filter_rules'] = [
             ('.*', 7, False),
-        ]
+            ]
         error_log = LogFileMark('mailman.error')
         self._import()
         self.assertListEqual(self._mlist.header_matches, [])
@@ -417,10 +427,10 @@ class TestBasicImport(unittest.TestCase):
                       error_log.readline())
 
     def test_header_matches_invalid_re(self):
-        # Check that an empty pattern is skipped
+        # Check that an invalid regular expression pattern is skipped.
         self._pckdict['header_filter_rules'] = [
             ('SomeHeaderName: *invalid-re', 3, False),
-        ]
+            ]
         error_log = LogFileMark('mailman.error')
         self._import()
         self.assertListEqual(self._mlist.header_matches, [])
@@ -431,20 +441,20 @@ class TestBasicImport(unittest.TestCase):
         # Check that a defer action is properly converted.
         self._pckdict['header_filter_rules'] = [
             ('^X-Spam-Status: Yes', 0, False),
-        ]
+            ]
         self._import()
         self.assertListEqual(
-            [ (hm.header, hm.pattern, hm.chain)
-              for hm in self._mlist.header_matches ],
-            [ ('x-spam-status', 'Yes', None) ]
-        )
+            [(hm.header, hm.pattern, hm.chain)
+             for hm in self._mlist.header_matches],
+            [('x-spam-status', 'Yes', None)]
+            )
 
     def test_header_matches_unsupported_action(self):
-        # Check that an unsupported actions are skipped
+        # Check that unsupported actions are skipped.
         for action_num in (1, 4, 5):
             self._pckdict['header_filter_rules'] = [
                 ('HeaderName: test-re', action_num, False),
-            ]
+                ]
             error_log = LogFileMark('mailman.error')
             self._import()
             self.assertListEqual(self._mlist.header_matches, [])
@@ -457,17 +467,17 @@ class TestBasicImport(unittest.TestCase):
                 member.unsubscribe()
 
     def test_header_matches_duplicate(self):
-        # Check that duplicate patterns don't cause tracebacks
+        # Check that duplicate patterns don't cause tracebacks.
         self._pckdict['header_filter_rules'] = [
             ('SomeHeaderName: test-pattern', 3, False),
             ('SomeHeaderName: test-pattern', 2, False),
-        ]
+            ]
         error_log = LogFileMark('mailman.error')
         self._import()
         self.assertListEqual(
-            [ (hm.header, hm.pattern, hm.chain)
-              for hm in self._mlist.header_matches ],
-            [ ('someheadername', 'test-pattern', 'discard') ]
+            [(hm.header, hm.pattern, hm.chain)
+             for hm in self._mlist.header_matches],
+            [('someheadername', 'test-pattern', 'discard')]
             )
         self.assertIn('Skipping duplicate header_filter rule',
                       error_log.readline())