[Findit] fix bug when display confidence score on SoM.

appengine/findit/waterfall/suspected_cl_util.py

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from google.appengine.ext import ndb
 
 from common import time_util
 from common.waterfall import failure_type
 from model import analysis_approach_type
 from model.wf_suspected_cl import WfSuspectedCL
@@ skipping 102 matching lines @@
 
     for test in tests:
       if not test in new_failures[step]:  # New test.
         return True
 
   return False
 
 
 def GetSuspectedCLConfidenceScoreAndApproach(
     confidences, cl_from_analyzed_build, cl_from_first_failed_build):
-  if not confidences or not cl_from_analyzed_build:
+  if not confidences or (
+      not cl_from_analyzed_build and not cl_from_first_failed_build):
     return None, None
 
-  if (cl_from_first_failed_build and not _HasNewFailures(
-          cl_from_analyzed_build.get('failures'),
-          cl_from_first_failed_build.get('failures'))):
+  if (cl_from_first_failed_build and (
+          not cl_from_analyzed_build or
+          not _HasNewFailures(cl_from_analyzed_build.get('failures'),
+                              cl_from_first_failed_build.get('failures')))):
       # For non-first-time failures, the try job result is not recorded.
       # If there is no new failures in current build, use first failed build to
       # make sure the confidence score is correct.
       cl_from_analyzed_build = cl_from_first_failed_build
 
   confidence = GetSuspectedCLConfidenceScore(
       confidences, cl_from_analyzed_build)
   approach = (
       analysis_approach_type.TRY_JOB if analysis_approach_type.TRY_JOB in
       cl_from_analyzed_build['approaches'] else
       analysis_approach_type.HEURISTIC)
 
   return confidence, approach