fix commenting in py3

plone/app/discussion/catalog.py

@@ -13,6 +13,7 @@ from Products.CMFCore.interfaces import IContentish
 from Products.CMFPlone.utils import safe_unicode
 from Products.ZCatalog.interfaces import IZCatalog
 
+import six
 
 MAX_DESCRIPTION = 25
 
@@ -70,7 +71,12 @@ def title(object):
 
 @indexer(IComment)
 def creator(object):
-    return object.creator and safe_unicode(object.creator).encode('utf-8')
+    if not object.creator:
+        return
+    value = safe_unicode(object.creator)
+    if six.PY2:
+        return value.encode('utf8')
+    return value
 
 
 @indexer(IComment)