Extract part of CloneAction.url into a linkto_clone_url_params function

and test it.

test/test_compound.py

@@ -371,6 +371,7 @@
             action = self.vreg['actions'].select('copy', req,
                                                  rset=entity.as_rset())
             self.assertIsInstance(action, CloneAction)
+            self.assertIn('clone_of', action.url())
 
     @staticmethod
     def _clone_setup(cnx):

views.py

@@ -25,6 +25,12 @@
 from cubes.compound.entities import copy_entity
 
 
+def linkto_clone_url_params(entity):
+    iclone = entity.cw_adapt_to('IClonable')
+    linkto = '%s:%s:%s' % (iclone.rtype, entity.eid, neg_role(iclone.role))
+    return {'__linkto': linkto}
+
+
 class CloneAction(actions.CopyAction):
     """Abstract clone action of ICloneable entities.
 
@@ -40,9 +46,7 @@
 
     def url(self):
         entity = self.cw_rset.get_entity(self.cw_row or 0, self.cw_col or 0)
-        iclone = entity.cw_adapt_to('IClonable')
-        linkto = '%s:%s:%s' % (iclone.rtype, entity.eid, neg_role(iclone.role))
-        return entity.absolute_url(vid='copy', __linkto=linkto)
+        return entity.absolute_url(vid='copy', **linkto_clone_url_params(entity))
 
 
 # In any case IClonable entities want default copy disabled since it wont handle