Header folder folds incorrectly causing MissingHeaderBodySeparatorDefect

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-09-23.21:22:55.097>
labels = ['type-bug', 'expert-email']
title = 'Header folder folds incorrectly causing MissingHeaderBodySeparatorDefect'
updated_at = <Date 2016-09-23.21:48:42.280>
user = 'https://bugs.python.org/vincenttc'

bugs.python.org fields:

activity = <Date 2016-09-23.21:48:42.280>
actor = 'r.david.murray'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['email']
creation = <Date 2016-09-23.21:22:55.097>
creator = 'vincenttc'
dependencies = []
files = []
hgrepos = []
issue_num = 28262
keywords = []
message_count = 2.0
messages = ['277299', '277302']
nosy_count = 3.0
nosy_names = ['barry', 'r.david.murray', 'vincenttc']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue28262'
versions = ['Python 3.4', 'Python 3.5', 'Python 3.6']