Merge pull request #5 from vipod/3.x

fix error on App teardown, which appears when ZPublisher's get_module_info is patched with plone.app.linkintegrity; mostly when use plone.postpublicationhook addon

src/plone/testing/z2.py

@@ -554,9 +554,15 @@ def tearDownApp(self):
         # Clear out the app reference cached in get_module_info's
         # 'modules' parameter default dict. (waaaaa)
         import ZPublisher.Publish
-        d = list(ZPublisher.Publish.get_module_info.func_defaults)
-        d[0] = {}
-        ZPublisher.Publish.get_module_info.func_defaults = tuple(d)
+        if ZPublisher.Publish.get_module_info.func_defaults is not None:
+            # func_defaults is None in case get_module_info is patched.
+            # This happens if you use plone.postpublicationhook addon which
+            # deliberately applies plone.app.linkintegrity's patch even within
+            # testing environment.
+            d = list(ZPublisher.Publish.get_module_info.func_defaults)
+            d[0] = {}
+            ZPublisher.Publish.get_module_info.func_defaults = tuple(d)
+
 
     def setUpBasicProducts(self):
         """Install a minimal set of products required for Zope 2.