Fix call to the IssueTrackerAPI constructor

appengine/chromium_try_flakes/handlers/flake_issues.py

 # Copyright 2015 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.
 
 """Task queue endpoints for creating and updating issues on issue tracker."""
 
 import datetime
 import json
 import logging
 import urllib2
 import webapp2
 
 from google.appengine.api import app_identity
 from google.appengine.api import taskqueue
 from google.appengine.api import urlfetch
 from google.appengine.api import users
 from google.appengine.ext import ndb
 
+from apiclient.errors import HttpError
 import gae_ts_mon
 from issue_tracker import issue_tracker_api, issue
 from model.flake import (
     Flake, FlakeOccurrence, FlakeUpdate, FlakeUpdateSingleton, FlakyRun)
 from model.build_run import BuildRun
 from status import build_result, util
 from test_results.util import normalize_test_type, flatten_tests_trie
 
 
 MAX_UPDATED_ISSUES_PER_DAY = 10
@@ skipping 652 matching lines @@
     user_email = users.get_current_user().email()
     if not user_email.endswith('@chromium.org'):
       self.response.set_status(401)
       self.response.write(
           'Please login with your chromium.org account. <a href="%s">Logout'
           '</a>.' % users.create_logout_url(self.request.url))
       return
 
     try:
       issue_id = int(self.request.get('issue_id'))
-    except Exception as e:
+    except (TypeError, ValueError) as e:
       self.response.set_status(400)
       self.response.write('Failed to parse Issue ID as an integer.')
       return
 
     if issue_id < 0:
       self.response.set_status(400)
       self.response.write('Issue ID must be positive or 0.')
       return
 
     if issue_id != 0:
+      api = issue_tracker_api.IssueTrackerAPI('chromium')
       try:
-        api = issue_tracker_api.IssueTrackerAPI('chromium', True)
         api.getIssue(issue_id)
-      except Exception as e:
-        self.response.set_status(400)
+      except HttpError as e:
+        if e.resp.status != 404:
+          raise
+        self.response.set_status(404)
         self.response.write(
             'Failed to find issue %d on issue tracker: %s.' % (issue_id, e))
         return
 
     key = self.request.get('key')
     flake = ndb.Key(urlsafe=key).get()
     flake.issue_id = issue_id
     flake.put()
 
     logging.info('%s updated issue_id for flake %s to %d.', user_email,
                  flake.name, issue_id)
     self.redirect('/all_flake_occurrences?key=%s' % key)