Acceptance tests pass, crash no longer happens.
================================================= test session starts =================================================
platform linux2 -- Python 2.7.5, pytest-3.2.1, py-1.4.34, pluggy-0.4.0 -- /usr/bin/python
cachedir: .cache
metadata: {'Python': '2.7.5', 'Platform': 'Linux-3.10.0-693.el7.x86_64-x86_64-with-redhat-7.4-Maipo', 'Packages': {'py': '1.4.34', 'pytest': '3.2.1', 'pluggy': '0.4.0'}, 'Plugins': {'html': '1.15.2', 'metadata': '1.5.0'}}
DS build: 1.3.6.1
389-ds-base: 1.3.6.1-19.el7_4
nss: 3.28.4-8.el7
nspr: 4.13.1-1.0.el7_3
openldap: 2.4.44-5.el7
svrcore: 4.1.3-2.el7

rootdir: /export/tests/suites/mapping_tree, inifile:
plugins: metadata-1.5.0, html-1.15.2
collected 1 item                                                                                                       

referral_during_tot_init.py::test_referral_during_tot PASSED

============================================== 1 passed in 32.22 seconds ==============================================

Marking as VERIFIED.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2017:2569