Add a test for a CSR with no domains

certbot/tests/cli_test.py

@@ -362,6 +362,12 @@ class CLITest(unittest.TestCase):  # pylint: disable=too-many-public-methods
             return
         assert False, "Expected supplying --csr to fail with default verb"
 
+    def test_csr_with_no_domains(self):
+        self.assertRaises(
+            errors.Error, self._call,
+            'certonly --csr {0}'.format(
+                test_util.vector_path('csr-nonames.pem')).split())
+
     def _get_argument_parser(self):
         plugins = disco.PluginsRegistry.find_all()
         return functools.partial(cli.prepare_and_parse_args, plugins)

certbot/tests/testdata/csr-nonames.pem

@@ -0,0 +1,8 @@
+-----BEGIN CERTIFICATE REQUEST-----
+MIH/MIGqAgEAMEUxCzAJBgNVBAYTAkFVMRMwEQYDVQQIDApTb21lLVN0YXRlMSEw
+HwYDVQQKDBhJbnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQwXDANBgkqhkiG9w0BAQEF
+AANLADBIAkEArHVztFHtH92ucFJD/N/HW9AsdRsUuHUBBBDlHwNlRd3fp580rv2+
+6QWE30cWgdmJS86ObRz6lUTor4R0T+3C5QIDAQABoAAwDQYJKoZIhvcNAQELBQAD
+QQBt9XLSZ9DGfWcGGaBUTCiSY7lWBegpNlCeo8pK3ydWmKpjcza+j7lF5paph2LH
+lKWVQ8+xwYMscGWK0NApHGco
+-----END CERTIFICATE REQUEST-----