Add job id transformation/check to Luxi Python client

This patch adds checks to the Luxi client, making sure that job ids
are converted from strings to ints before being passed on, or that an
error is reported.
Signed-off-by: Hrvoje Ribicic <riba@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

lib/luxi.py

 #
 #
 
-# Copyright (C) 2006, 2007, 2011, 2012 Google Inc.
+# Copyright (C) 2006, 2007, 2011, 2012, 2014 Google Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -487,13 +487,25 @@ class Client(object):
       jobs_state.append([op.__getstate__() for op in ops])
     return self.CallMethod(REQ_SUBMIT_MANY_JOBS, (jobs_state, ))
 
+  @staticmethod
+  def _PrepareJobId(request_name, job_id):
+    try:
+      return int(job_id)
+    except ValueError:
+      raise RequestError("Invalid parameter passed to %s as job id: "
+                         " expected integer, got value %s" %
+                         (request_name, job_id))
+
   def CancelJob(self, job_id):
+    job_id = Client._PrepareJobId(REQ_CANCEL_JOB, job_id)
     return self.CallMethod(REQ_CANCEL_JOB, (job_id, ))
 
   def ArchiveJob(self, job_id):
+    job_id = Client._PrepareJobId(REQ_ARCHIVE_JOB, job_id)
     return self.CallMethod(REQ_ARCHIVE_JOB, (job_id, ))
 
   def ChangeJobPriority(self, job_id, priority):
+    job_id = Client._PrepareJobId(REQ_CHANGE_JOB_PRIORITY, job_id)
     return self.CallMethod(REQ_CHANGE_JOB_PRIORITY, (job_id, priority))
 
   def AutoArchiveJobs(self, age):
@@ -524,6 +536,7 @@ class Client(object):
                             min(WFJC_TIMEOUT, timeout)))
 
   def WaitForJobChange(self, job_id, fields, prev_job_info, prev_log_serial):
+    job_id = Client._PrepareJobId(REQ_WAIT_FOR_JOB_CHANGE, job_id)
     while True:
       result = self.WaitForJobChangeOnce(job_id, fields,
                                          prev_job_info, prev_log_serial)