SpamDetect is gone, so the chains/rules implementation experiment is deemed a

success and will now be merged into the trunk.

Move the Truth rule into the built-in rules package in a separate module, and
add a test.

Modify IChainLink so that the rule and chain attributes are not names but
indeed the actual ILink or IChain object directly.  Update the
chains.process() function accordingly.  Remove the IChain.get_rule() method.

Don't derive BuiltInChain from Chain and don't make it an IMutableChain.  It's
now just an IChain, and is implemented concretely.

Refactor the HeaderMatchChain and friends so that it can be used with both the
global HEADER_MATCHES variable and the list-specific header_matches variable,
which has exactly the same semantics.  Oh yeah, get rid of the list's
header_filter_rules attribute and replace it with header_matches so that the
semantics match, it's easy to explain, and it's all nice and clean.

3 files changed, 107 insertions, 0 deletions

diff --git a/Mailman/rules/docs/header-matching.txt b/Mailman/rules/docs/header-matching.txt
index b32feabe5..fbd0ff65f 100644
--- a/Mailman/rules/docs/header-matching.txt
+++ b/Mailman/rules/docs/header-matching.txt
@@ -61,6 +61,7 @@ untouched.
 
 But now if the header matches, then the message gets discarded.
 
+    >>> del msg['x-spam-score']
     >>> msg['X-Spam-Score'] = '****'
     >>> del msg['subject']
     >>> msg['Subject'] = 'This is spam, but barely'
@@ -75,6 +76,7 @@ But now if the header matches, then the message gets discarded.
 
 For kicks, let's show a message that's really spammy.
 
+    >>> del msg['x-spam-score']
     >>> msg['X-Spam-Score'] = '**********'
     >>> del msg['subject']
     >>> msg['Subject'] = 'This is really spammy'
@@ -87,3 +89,57 @@ For kicks, let's show a message that's really spammy.
     LOG: ... DISCARD: <four>
     <BLANKLINE>
 
+Flush out the extended header matching rules.
+
+    >>> chain.flush()
+
+
+List-specific header matching
+-----------------------------
+
+Each mailing list can also be configured with a set of header matching regular
+expression rules.  These are used to impose list-specific header filtering
+with the same semantics as the global `HEADER_MATCHES` variable.
+
+The list administrator wants to match not on four stars, but on three plus
+signs, but only for the current mailing list.
+
+    >>> mlist.header_matches = [('x-spam-score', '[+]{3,}', 'discard')]
+
+A message with a spam score of two pluses does not match.
+
+    >>> del msg['x-spam-score']
+    >>> msg['X-Spam-Score'] = '++'
+    >>> del msg['message-id']
+    >>> msg['Message-ID'] = '<five>'
+    >>> file_pos = fp.tell()
+    >>> process(mlist, msg, {}, 'header-match')
+    >>> fp.seek(file_pos)
+    >>> print 'LOG:', fp.read()
+    LOG:
+
+A message with a spam score of three pluses does match.
+
+    >>> del msg['x-spam-score']
+    >>> msg['X-Spam-Score'] = '+++'
+    >>> del msg['message-id']
+    >>> msg['Message-ID'] = '<six>'
+    >>> file_pos = fp.tell()
+    >>> process(mlist, msg, {}, 'header-match')
+    >>> fp.seek(file_pos)
+    >>> print 'LOG:', fp.read()
+    LOG: ... DISCARD: <six>
+    <BLANKLINE>
+
+As does a message with a spam score of four pluses.
+
+    >>> del msg['x-spam-score']
+    >>> msg['X-Spam-Score'] = '+++'
+    >>> del msg['message-id']
+    >>> msg['Message-ID'] = '<seven>'
+    >>> file_pos = fp.tell()
+    >>> process(mlist, msg, {}, 'header-match')
+    >>> fp.seek(file_pos)
+    >>> print 'LOG:', fp.read()
+    LOG: ... DISCARD: <seven>
+    <BLANKLINE>
diff --git a/Mailman/rules/docs/truth.txt b/Mailman/rules/docs/truth.txt
new file mode 100644
index 000000000..baa40772a
--- /dev/null
+++ b/Mailman/rules/docs/truth.txt
@@ -0,0 +1,10 @@
+Truth
+=====
+
+The 'truth' rule always matches.  This makes it useful as a terminus rule for
+unconditionally jumping to another chain.
+
+    >>> from Mailman.configuration import config
+    >>> rule = config.rules['truth']
+    >>> rule.check(False, False, False)
+    True
diff --git a/Mailman/rules/truth.py b/Mailman/rules/truth.py
new file mode 100644
index 000000000..d3cfc30f3
--- /dev/null
+++ b/Mailman/rules/truth.py
@@ -0,0 +1,41 @@
+# Copyright (C) 2008 by the Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+# USA.
+
+"""A rule which always matches."""
+
+__all__ = ['Truth']
+__metaclass__ = type
+
+
+from zope.interface import implements
+
+from Mailman.i18n import _
+from Mailman.interfaces import IRule
+
+
+
+class Truth:
+    """Look for any previous rule match."""
+    implements(IRule)
+
+    name = 'truth'
+    description = _('A rule which always matches.')
+    record = False
+
+    def check(self, mlist, msg, msgdata):
+        """See `IRule`."""
+        return True