recv returning 0 on closed connection not documented

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-03-22.14:15:08.896>
labels = ['type-feature', 'docs']
title = 'recv returning 0 on closed connection not documented'
updated_at = <Date 2018-07-25.18:11:20.185>
user = 'https://bugs.python.org/joders'

bugs.python.org fields:

activity = <Date 2018-07-25.18:11:20.185>
actor = 'taleinat'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2018-03-22.14:15:08.896>
creator = 'joders'
dependencies = []
files = []
hgrepos = []
issue_num = 33121
keywords = []
message_count = 3.0
messages = ['314260', '314352', '322380']
nosy_count = 4.0
nosy_names = ['terry.reedy', 'taleinat', 'docs@python', 'joders']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue33121'
versions = ['Python 3.6']