Handle empty GitHub repositories and do not 500 if the repository cannot be read

endpoints/api/trigger.py

@@ -13,7 +13,8 @@ from endpoints.api.build import (build_status_view, trigger_view, RepositoryBuil
                                  get_trigger_config)
 from endpoints.common import start_build
 from endpoints.trigger import (BuildTrigger as BuildTriggerBase, TriggerDeactivationException,
-                               TriggerActivationException, EmptyRepositoryException)
+                               TriggerActivationException, EmptyRepositoryException,
+                               RepositoryReadException)
 from data import model
 from auth.permissions import UserAdminPermission
 
@@ -116,9 +117,14 @@ class BuildTriggerSubdirs(RepositoryParamResource):
           'status': 'success'
         }
       except EmptyRepositoryException as exc:
+        return {
+          'status': 'success',
+          'subdir': []
+        }
+      except RepositoryReadException as exc:
         return {
           'status': 'error',
-          'message': exc.msg
+          'message': exc.message
         }
     else:
       raise Unauthorized()