4 files changed, 53 insertions, 3 deletions

diff --git a/src/mailman/bin/mailman.py b/src/mailman/bin/mailman.py
index 42b145e67..7ff8310a8 100644
--- a/src/mailman/bin/mailman.py
+++ b/src/mailman/bin/mailman.py
@@ -63,7 +63,7 @@ def main():
     for command_class in find_components('mailman.commands', ICLISubCommand):
         command = command_class()
         verifyObject(ICLISubCommand, command)
-        command.add(subparser)
+        command.add(parser, subparser)
     args = parser.parse_args()
     if len(args.__dict__) == 0:
         # No arguments or subcommands were given.
diff --git a/src/mailman/commands/cli_help.py b/src/mailman/commands/cli_help.py
new file mode 100644
index 000000000..4cffaaf87
--- /dev/null
+++ b/src/mailman/commands/cli_help.py
@@ -0,0 +1,48 @@
+# Copyright (C) 2009 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman 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 3 of the License, or (at your option)
+# any later version.
+#
+# GNU Mailman 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
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""The 'help' subcommand."""
+
+from __future__ import absolute_import, unicode_literals
+
+__metaclass__ = type
+__all__ = [
+    'Help',
+    ]
+
+
+from zope.interface import implements
+
+from mailman.interfaces.command import ICLISubCommand
+
+
+
+class Help:
+    """The `help` subcommand."""
+
+    implements(ICLISubCommand)
+
+    def add(self, parser, subparser):
+        """See `ICLISubCommand`."""
+        self.parser = parser
+        help_parser = subparser.add_parser(
+            'help', help=('show this help message and exit'))
+        help_parser.set_defaults(func=self.process)
+
+    def process(self, args):
+        """See `ICLISubCommand`."""
+        self.parser.print_help()
diff --git a/src/mailman/commands/cli_lists.py b/src/mailman/commands/cli_lists.py
index 6757099d9..0d61aa701 100644
--- a/src/mailman/commands/cli_lists.py
+++ b/src/mailman/commands/cli_lists.py
@@ -38,7 +38,7 @@ class Lists:
 
     implements(ICLISubCommand)
 
-    def add(self, subparser):
+    def add(self, parser, subparser):
         """See `ICLISubCommand`."""
         lists_parser = subparser.add_parser(
             'lists', help=_('List all mailing lists'))
diff --git a/src/mailman/interfaces/command.py b/src/mailman/interfaces/command.py
index 14e7f9dd6..074359707 100644
--- a/src/mailman/interfaces/command.py
+++ b/src/mailman/interfaces/command.py
@@ -73,9 +73,11 @@ class IEmailCommand(Interface):
 class ICLISubCommand(Interface):
     """A command line interface subcommand."""
 
-    def add(subparser):
+    def add(parser, subparser):
         """Add the subcommand to the subparser.
 
+        :param parser: The argument parser.
+        :type parser: `argparse.ArgumentParser`
         :param subparser: The argument subparser.
         :type subparser: `argparse.ArgumentParser`
         """