Check that list of predecessor is unique.

master/bt5/vifib_slapos_core/WorkflowTemplateItem/portal_workflow/instance_slap_interface_workflow/scripts/RequesterInstance_request.xml

@@ -171,6 +171,9 @@ else:\n
   raise ValueError, "state should be started, stopped or destroyed"\n
 \n
 predecessor_list = requester_instance.getPredecessorList() + [request_software_instance.getRelativeUrl()]\n
+\n
+assert predecessor_list == list(set(predecessor_list))\n
+\n
 # update graph to reflect requested operation\n
 graph[requester_instance.getUid()] = requester_instance.getPredecessorUidList() + [request_software_instance.getUid()]\n
 requester_instance.edit(predecessor_list=predecessor_list)\n

master/bt5/vifib_slapos_core/bt/revision

-19
\ No newline at end of file
+20
\ No newline at end of file