GzipFile doesn't properly handle short reads and writes on the underlying stream

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-10-13.20:29:24.336>
labels = ['type-bug', '3.7', 'docs']
title = "GzipFile doesn't properly handle short reads and writes on the underlying stream"
updated_at = <Date 2016-10-14.21:34:58.164>
user = 'https://bugs.python.org/abacabadabacaba'

bugs.python.org fields:

activity = <Date 2016-10-14.21:34:58.164>
actor = 'martin.panter'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2016-10-13.20:29:24.336>
creator = 'abacabadabacaba'
dependencies = []
files = []
hgrepos = []
issue_num = 28436
keywords = []
message_count = 4.0
messages = ['278606', '278609', '278610', '278667']
nosy_count = 4.0
nosy_names = ['abacabadabacaba', 'docs@python', 'socketpair', 'martin.panter']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'needs patch'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue28436'
versions = ['Python 3.5', 'Python 3.6', 'Python 3.7']