simplify getting the root

lib/python/Products/Five/browser/pagetemplatefile.py

@@ -18,6 +18,7 @@ $Id$
 import zope.app.pagetemplate
 
 from Acquisition import aq_base
+from Acquisition import aq_get
 from Acquisition import aq_parent
 from AccessControl import getSecurityManager
 from Products.PageTemplates.Expressions import SecureModuleImporter
@@ -39,11 +40,9 @@ class ViewPageTemplateFile(zope.app.pagetemplate.ViewPageTemplateFile):
         # get the root
         obj = context['context']
         root = None
-        while (getattr(aq_base(obj), 'getPhysicalRoot', None) is None
-               and aq_parent(obj) is not None):
-            obj = aq_parent(obj)
-        if getattr(obj, 'getPhysicalRoot', None) is not None:
-            root = obj.getPhysicalRoot()
+        meth = aq_get(obj, 'getPhysicalRoot', None)
+        if meth is not None:
+            root = meth()
 
         context.update(here=context['context'],
                        # philiKON thinks container should be the view,