Fix some test isolation issues

src/plone/app/testing/layers.py

@@ -13,13 +13,15 @@
 from plone.app.testing.interfaces import TEST_USER_PASSWORD
 from plone.app.testing.interfaces import TEST_USER_ROLES
 from plone.app.testing.utils import MockMailHost
+from plone.registry.interfaces import IRegistry
 from plone.testing import Layer
 from plone.testing import zca
 from plone.testing import zodb
 from plone.testing import zope
 from plone.testing import zserver
 from Products.MailHost.interfaces import IMailHost
 from zope.component import getSiteManager
+from zope.component import getUtility
 from zope.component.hooks import setSite
 from zope.event import notify
 from zope.traversing.interfaces import BeforeTraverseEvent
@@ -382,19 +384,20 @@ class MockMailHostLayer(Layer):
     """
     defaultBases = (PLONE_FIXTURE,)
 
-    def setUp(self):
+    def testSetUp(self):
         with zope.zopeApp() as app:
             portal = app[PLONE_SITE_ID]
-            portal.email_from_address = 'noreply@example.com'
-            portal.email_from_name = 'Plone Site'
+            registry = getUtility(IRegistry, context=portal)
+            registry["plone.email_from_address"] = "noreply@example.com"
+            registry["plone.email_from_name"] = u"Plone site"
             portal._original_MailHost = portal.MailHost
             portal.MailHost = mailhost = MockMailHost('MailHost')
             portal.MailHost.smtp_host = 'localhost'
             sm = getSiteManager(context=portal)
             sm.unregisterUtility(provided=IMailHost)
             sm.registerUtility(mailhost, provided=IMailHost)
 
-    def tearDown(self):
+    def testTearDown(self):
         with zope.zopeApp() as app:
             portal = app[PLONE_SITE_ID]
             _o_mailhost = getattr(portal, '_original_MailHost', None)