If FUNCNAME[0] is undefined and 'set -u' used, devstack can fail

[Surojit Pathak]

While following ironic-devstack instructions, as per [1], on RHEL7.1, I am encountering an error at create_bridge_and_vms step[2], while running stack.sh

[1] - http://docs.openstack.org/developer/ironic/dev/dev-quickstart.html#deploying-ironic-with-devstack

[2] - 2016-02-08 23:47:44.331 | ++ /opt/stack/ironic/devstack/lib/ironic:create_bridge_and_vms:L583: sudo su stack -c /opt/stack/ironic/devstack/tools/ironic/scripts/setup-network.sh
2016-02-08 23:47:44.331 | /opt/stack/ironic/devstack/tools/ironic/scripts/setup-network.sh: line 10: FUNCNAME[0]: unbound variable

[John L. Villalovos (happycamp)]

I believe that this issue is actually caused by the PS4 variable.

It is set in devstack/stackrc as:

export PS4='+ ${BASH_SOURCE}:${FUNCNAME[0]}:L${LINENO}: '

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/278097

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/278097
Committed: https://git.openstack.org/cgit/openstack-dev/devstack/commit/?id=6f013631a27a726ae45e27b209fa769d96d5f069
Submitter: Jenkins
Branch: master

commit 6f013631a27a726ae45e27b209fa769d96d5f069
Author: John L. Villalovos <email address hidden>
Date: Tue Feb 9 13:30:58 2016 -0800

    Handle case where FUNCNAME[0] is undefined

    If FUNCNAME[0] is undefined and 'set -u' has been used it will cause the
    devstack run to fail.

    Handle undefined values in PS4.

    Closes-Bug: #1543749
    Change-Id: I06a013a5e7683e3a3461ff06361d867f61d48e6a