gzip._GzipReader should only throw BadGzipFile errors

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-03-25.08:24:44.466>
labels = ['type-bug', '3.8', '3.9', '3.10', '3.7', 'library']
title = 'gzip._GzipReader should only throw BadGzipFile errors'
updated_at = <Date 2021-03-25.08:25:21.785>
user = 'https://github.com/rhpvorderman'

bugs.python.org fields:

activity = <Date 2021-03-25.08:25:21.785>
actor = 'rhpvorderman'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2021-03-25.08:24:44.466>
creator = 'rhpvorderman'
dependencies = []
files = []
hgrepos = []
issue_num = 43621
keywords = []
message_count = 1.0
messages = ['389494']
nosy_count = 1.0
nosy_names = ['rhpvorderman']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue43621'
versions = ['Python 3.6', 'Python 3.7', 'Python 3.8', 'Python 3.9', 'Python 3.10']