Fix the check for default values of run-affecting options, and add a test

2 files changed, 11 insertions, 1 deletions

diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index 20d3589..1b54e86 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -606,7 +606,9 @@ class CoverageScript(object):
             # Can't set other run-affecting command line options with
             # multiprocessing.
             for opt_name in ['branch', 'include', 'omit', 'pylib', 'source', 'timid']:
-                if getattr(options, opt_name) != getattr(Opts, opt_name).default:
+                # As it happens, all of these options have no default, meaning
+                # they will be None if they have not been specified.
+                if getattr(options, opt_name) is not None:
                     self.help_fn(
                         "Options affecting multiprocessing must be specified "
                         "in a configuration file."
diff --git a/tests/test_cmdline.py b/tests/test_cmdline.py
index f253160..3f471b8 100644
--- a/tests/test_cmdline.py
+++ b/tests/test_cmdline.py
@@ -450,6 +450,14 @@ class CmdLineTest(BaseCmdLineTest):
             .stop()
             .save()
             """)
+        self.cmd_executes("run --concurrency=multiprocessing foo.py", """\
+            .coverage(concurrency='multiprocessing')
+            .erase()
+            .start()
+            .run_python_file('foo.py', ['foo.py'])
+            .stop()
+            .save()
+            """)
 
     def test_bad_concurrency(self):
         self.command_line("run --concurrency=nothing", ret=ERR)