Comment 5 for bug 1415886

Reviewed: https://review.openstack.org/151975
Committed: https://git.openstack.org/cgit/stackforge/mistral/commit/?id=6a2481c6c6de0274d8784477b6719f4d05054ab0
Submitter: Jenkins
Branch: master

commit 6a2481c6c6de0274d8784477b6719f4d05054ab0
Author: Dmitri Zimine <email address hidden>
Date: Sun Feb 1 16:12:47 2015 -0800

    Catch workflow errors

    Avoid keeping workflow in zombie state: on unexpected errors
    fail the workflow execution and save error information. If possible,
    fail the correspondent tasks, too.

    Done:
    - [x] Introduce state_info into Execution, fill it with error info
    when workflow fails.
    - [x] Add error handlers to `on_task_result` and `run_task`
    - [x] Add error handlers and tests to `start_workflow`
    - [x] Add tests for YAQL eval exceptions
    - [x] Add error handler and tests to `resume_worklfow`

    TODO:
    - [ ] Make _fail_workflow public and let user fail workflow via API
    (on separate commit)

    Closes-bug: 1415886
    Change-Id: Ib1fd661580d3a426dbbc7401a3622a98c7840e00