Mistral IndexError on fork/join and multiple executions

[Michael Ryan]

I'm receiving an IndexError from mistral direct_workflow.py line 290. The workflow does both fork/join and multiple executions. This is on version 0.1.2.
The error I'm receiving is:
File "/opt/mistral/virtualenv/lib/python2.7/site-packages/mistral/workflow/direct_workflow.py", line 290, in _triggers_join in_t_ex = in_t_execs[-1] IndexError: list index out of range

Looking at that code I'm seeing the following comments:

# TODO(rakhmerov): Method signature is incorrect given that
# we may have multiple task executions for a task. It should
# accept inbound task execution rather than a spec.
def _triggers_join(self, join_task_spec, inbound_task_spec):

and:

# TODO(rakhmerov): Temporary hack. See the previous comment.
      in_t_ex = in_t_execs[-1]

Is this a know bug or deficiency? Search here didn't turn up anything related.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/326819

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/326819
Committed: https://git.openstack.org/cgit/openstack/mistral/commit/?id=70adb4512f0ac0be2e8162b0038f9ddba16fca92
Submitter: Jenkins
Branch: master

commit 70adb4512f0ac0be2e8162b0038f9ddba16fca92
Author: Renat Akhmerov <email address hidden>
Date: Wed Jun 8 11:42:38 2016 +0700

    Add a test that verifies an old bug with join

    * There was a bug in stable/libery that occurred in case when we
      had a "join" task that joined multiple branches sourced from
      the same task. In this case line 302 (in the current revision)
      in direct_workflow.py caused IndexError when evaluating in_t_ex[-1]
      as described in the bug. This bug was implicitly fixed since then
      but a test for it was missing. This patch adds a test to prevent
      this bug occurrence in the future.

    Change-Id: If277989cc9149b219a9c63287290daa321a3e438
    Closes-Bug: #1539173

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/mistral 3.0.0.0b2 development milestone.