skip more tests in packaging if threading is not supported

Lib/packaging/tests/test_command_upload.py

@@ -7,7 +7,12 @@ from packaging.dist import Distribution
 from packaging.errors import PackagingOptionError
 
 from packaging.tests import unittest, support
-from packaging.tests.pypi_server import PyPIServer, PyPIServerTestCase
+try:
+    import threading
+    from packaging.tests.pypi_server import PyPIServerTestCase
+except ImportError:
+    threading = None
+    PyPIServerTestCase = unittest.TestCase
 
 
 PYPIRC_NOPASSWORD = """\
@@ -39,6 +44,7 @@ repository:http://another.pypi/
 """
 
 
+@unittest.skipIf(threading is None, 'needs threading')
 class UploadTestCase(support.TempdirManager, support.EnvironRestorer,
                      support.LoggingCatcher, PyPIServerTestCase):
 

Lib/packaging/tests/test_pypi_dist.py

@@ -8,7 +8,11 @@ from packaging.pypi.errors import HashDoesNotMatch, UnsupportedHashName
 
 from packaging.tests import unittest
 from packaging.tests.support import TempdirManager, requires_zlib
+try:
+    import threading
     from packaging.tests.pypi_server import use_pypi_server
+except ImportError:
+    threading = use_pypi_server = None
 
 
 def Dist(*args, **kwargs):
@@ -120,6 +124,7 @@ class TestDistInfo(TempdirManager, unittest.TestCase):
         # assert we can't compare dists with different names
         self.assertRaises(TypeError, foo1.__eq__, bar)
 
+    @unittest.skipIf(threading is None, 'needs threading')
     @use_pypi_server("downloads_with_md5")
     def test_download(self, server):
         # Download is possible, and the md5 is checked if given
@@ -158,6 +163,7 @@ class TestDistInfo(TempdirManager, unittest.TestCase):
                           hashname="invalid_hashname",
                           hashval="value")
 
+    @unittest.skipIf(threading is None, 'needs threading')
     @requires_zlib
     @use_pypi_server('downloads_with_md5')
     def test_unpack(self, server):

Lib/packaging/tests/test_pypi_xmlrpc.py

@@ -9,7 +9,12 @@ try:
     from packaging.tests.pypi_server import use_xmlrpc_server
 except ImportError:
     threading = None
-    use_xmlrpc_server = None
+    def use_xmlrpc_server():
+        def _use(func):
+            def __use(*args, **kw):
+                return func(*args, **kw)
+            return __use
+        return _use
 
 
 @unittest.skipIf(threading is None, "Needs threading")