ssl module falls over with internationalized domain names

GitHub fields:

assignee = 'https://github.com/tiran'
closed_at = None
created_at = <Date 2018-11-13.16:06:02.413>
labels = ['expert-SSL', 'type-bug']
title = 'ssl module falls over with internationalized domain names'
updated_at = <Date 2018-11-13.16:24:39.743>
user = 'https://github.com/NCommander'

bugs.python.org fields:

activity = <Date 2018-11-13.16:24:39.743>
actor = 'christian.heimes'
assignee = 'christian.heimes'
closed = False
closed_date = None
closer = None
components = ['SSL']
creation = <Date 2018-11-13.16:06:02.413>
creator = 'mcasadevall'
dependencies = []
files = ['47932']
hgrepos = []
issue_num = 35234
keywords = []
message_count = 2.0
messages = ['329852', '329853']
nosy_count = 2.0
nosy_names = ['christian.heimes', 'mcasadevall']
pr_nums = []
priority = 'normal'
resolution = 'duplicate'
stage = 'resolved'
status = 'pending'
superseder = '28414'
type = 'behavior'
url = 'https://bugs.python.org/issue35234'
versions = ['Python 3.6']