3 files changed, 39 insertions, 6 deletions

diff --git a/src/mailman/commands/cli_lists.py b/src/mailman/commands/cli_lists.py
index 830d84470..035dce898 100644
--- a/src/mailman/commands/cli_lists.py
+++ b/src/mailman/commands/cli_lists.py
@@ -153,11 +153,20 @@ class Create:
             '-q', '--quiet',
             default=False, action='store_true',
             help=_('Print less output.'))
-        command_parser.add_argument(
+        domain_options = command_parser.add_mutually_exclusive_group()
+        domain_options.add_argument(
             '-d', '--domain',
-            default=False, action='store_true',
+            default=True, action='store_true',
+            help=_("""\
+            Register the mailing list's domain if not yet registered."""),
+            dest='domain')
+        domain_options.add_argument(
+            '-D', '--no-domain',
+            default=False, action='store_false',
             help=_("""\
-            Register the mailing list's domain if not yet registered."""))
+            Do not register the mailing list's domain if not already registered."""),
+            dest='domain')
+        
         # Required positional argument.
         command_parser.add_argument(
             'listname', metavar='LISTNAME', nargs=1,
diff --git a/src/mailman/commands/docs/create.rst b/src/mailman/commands/docs/create.rst
index 1a5d2a3ab..aee6b1f05 100644
--- a/src/mailman/commands/docs/create.rst
+++ b/src/mailman/commands/docs/create.rst
@@ -33,6 +33,9 @@ domain.  Both the mailing list and domain will be created.
     >>> command.process(FakeArgs)
     Created mailing list: test@example.xx
 
+This is the default behaviour. Even if you do not specify any option, 
+Mailman will itself make the domain if it doesn't exist.
+
 Now both the domain and the mailing list exist in the database.
 ::
 
@@ -46,8 +49,8 @@ Now both the domain and the mailing list exist in the database.
     >>> getUtility(IDomainManager).get('example.xx')
     <Domain example.xx, base_url: http://example.xx>
 
-You can also create mailing lists in existing domains without the
-auto-creation flag.
+You can also create mailing lists in existing domains by using the
+``-D`` or ``--no-domain`` flag.
 ::
 
     >>> FakeArgs.domain = False
@@ -58,6 +61,10 @@ auto-creation flag.
     >>> list_manager.get('test1@example.com')
     <mailing list "test1@example.com" at ...>
 
+Although the ``--no-domain`` flag is not required when domain already 
+exists it can be used to error out when domain doesn't exist. In such
+case, Mailman will give an error message.
+
 The command can also operate quietly.
 ::
 
diff --git a/src/mailman/commands/tests/test_create.py b/src/mailman/commands/tests/test_create.py
index 67c58a13b..83a4dcb33 100644
--- a/src/mailman/commands/tests/test_create.py
+++ b/src/mailman/commands/tests/test_create.py
@@ -25,6 +25,7 @@ __all__ = [
 import sys
 import unittest
 
+from argparse import ArgumentParser
 from mailman.app.lifecycle import create_list
 from mailman.commands.cli_lists import Create
 from mailman.testing.layers import ConfigLayer
@@ -55,7 +56,8 @@ class TestCreate(unittest.TestCase):
 
     def setUp(self):
         self.command = Create()
-        self.command.parser = FakeParser()
+        self.parser = ArgumentParser()
+        self.command.add(FakeParser(), self.parser)
         self.args = FakeArgs()
 
     def test_cannot_create_duplicate_list(self):
@@ -90,3 +92,18 @@ class TestCreate(unittest.TestCase):
             pass
         self.assertEqual(self.command.parser.message,
                          'Illegal owner addresses: main=True')
+
+    def test_without_domain_option(self):
+        # Domain should be created if option not specified.
+        args = self.parser.parse_args('test@list.org'.split())
+        self.assertTrue(args.domain)
+
+    def test_with_domain_option(self):
+        # Domain should be created if option given.
+        args = self.parser.parse_args('-d test@list.org'.split())
+        self.assertTrue(args.domain)
+
+    def test_with_nodomain_option(self):
+        # Domain should not be created if --no-domain is given.
+        args = self.parser.parse_args('-D test@list.net'.split())
+        self.assertFalse(args.domain)