email.parser / email.policy does not correctly handle multiple RFC2047 encoded-word tokens across RFC5322 folded headers

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-12-20.17:54:07.697>
labels = ['type-bug', '3.7', 'expert-email']
title = 'email.parser / email.policy does not correctly handle multiple RFC2047 encoded-word tokens across RFC5322 folded headers'
updated_at = <Date 2019-05-31.06:45:27.528>
user = 'https://github.com/mjpieters'

bugs.python.org fields:

activity = <Date 2019-05-31.06:45:27.528>
actor = 'Jeffrey.Kintscher'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['email']
creation = <Date 2018-12-20.17:54:07.697>
creator = 'mjpieters'
dependencies = []
files = []
hgrepos = []
issue_num = 35547
keywords = []
message_count = 6.0
messages = ['332243', '332276', '332277', '332279', '332290', '332296']
nosy_count = 5.0
nosy_names = ['barry', 'mjpieters', 'r.david.murray', 'era', 'Jeffrey.Kintscher']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue35547'
versions = ['Python 3.7']