SSL_shutdown needs SSL_read() until SSL_ERROR_ZERO_RETURN

GitHub fields:

assignee = 'https://github.com/tiran'
closed_at = None
created_at = <Date 2017-05-23.03:44:13.123>
labels = ['expert-SSL', '3.7', '3.8']
title = 'SSL_shutdown needs SSL_read() until SSL_ERROR_ZERO_RETURN'
updated_at = <Date 2018-05-23.13:55:30.894>
user = 'https://github.com/njsmith'

bugs.python.org fields:

activity = <Date 2018-05-23.13:55:30.894>
actor = 'christian.heimes'
assignee = 'christian.heimes'
closed = False
closed_date = None
closer = None
components = ['SSL']
creation = <Date 2017-05-23.03:44:13.123>
creator = 'njs'
dependencies = []
files = []
hgrepos = []
issue_num = 30437
keywords = ['patch']
message_count = 8.0
messages = ['294216', '294245', '294299', '294301', '301472', '301491', '317028', '317407']
nosy_count = 6.0
nosy_names = ['janssen', 'christian.heimes', 'alex', 'njs', 'martin.panter', 'dstufft']
pr_nums = ['6977']
priority = 'high'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue30437'
versions = ['Python 2.7', 'Python 3.6', 'Python 3.7', 'Python 3.8']