Allow GStreamer to process --help-gst

mopidy/core.py

@@ -8,8 +8,10 @@ import time
 # so that GStreamer doesn't hijack e.g. ``--help``.
 # NOTE This naive fix does not support values like ``bar`` in
 # ``--gst-foo bar``. Use equals to pass values, like ``--gst-foo=bar``.
-gstreamer_args = [arg for arg in sys.argv[1:] if arg.startswith('--gst')]
-mopidy_args = [arg for arg in sys.argv[1:] if not arg.startswith('--gst')]
+def is_gst_arg(arg):
+    return arg.startswith('--gst') or arg == '--help-gst'
+gstreamer_args = [arg for arg in sys.argv[1:] if is_gst_arg(arg)]
+mopidy_args = [arg for arg in sys.argv[1:] if not is_gst_arg(arg)]
 sys.argv[1:] = gstreamer_args
 
 from pykka.registry import ActorRegistry

tests/help_test.py

@@ -17,3 +17,10 @@ class HelpTest(unittest.TestCase):
         self.assert_('--verbose' in output)
         self.assert_('--save-debug-log' in output)
         self.assert_('--list-settings' in output)
+
+    def test_help_gst_has_gstreamer_options(self):
+        mopidy_dir = os.path.dirname(mopidy.__file__)
+        args = [sys.executable, mopidy_dir, '--help-gst']
+        process = subprocess.Popen(args, stdout=subprocess.PIPE)
+        output = process.communicate()[0]
+        self.assert_('--gst-version' in output)