Tasks that terminate before the processing step should not throw an error

Current Situation

• A job that implements a pre-processing monitor that would prevent the task from completing throws the error:

  SCHEDULER-226 Order has not been processed because the task has been terminated before the processing step (spooler_process())
  

Desired Behavior

• The pre-processing functions spooler_task_before() and spooler_process_before() can return false without causing an error.
• SCHEDULER-226 should be a warning.

Maintainer Notes

• This feature works as designed. An error is raised by JobScheduler to allow jobs to be stopped (should the <job stop_on_error="yes"> attribute have been set) or to move an order to an error state. Suppressing an error from a pre-processing Monitor would result in repeated execution of the same job step and represents a conflicting requirement.
• For the implementation of pre-processing Monitors that are intended to skip (instead of stop) the execution of the current job based on individual conditions the order can be moved to a successor state and the error can be ignored, i.e. the error SCHEDULER-226 is visible from the log but does not affect the order state. Moving an order to a successor state can be achieved by use of the property

  spooler_task.order.state = next_state;
  

  where next_state is the state of the job node for which the order should be continued.