TarFile.add skips files when tarfile name matches a directory

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-10-18.20:37:06.331>
labels = ['3.8', 'library']
title = 'TarFile.add skips files when tarfile name matches a directory'
updated_at = <Date 2021-10-18.20:47:42.983>
user = 'https://github.com/jkinkead'

bugs.python.org fields:

activity = <Date 2021-10-18.20:47:42.983>
actor = 'ethan.furman'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2021-10-18.20:37:06.331>
creator = 'jkinkead'
dependencies = []
files = ['50367']
hgrepos = []
issue_num = 45517
keywords = []
message_count = 1.0
messages = ['404217']
nosy_count = 2.0
nosy_names = ['ethan.furman', 'jkinkead']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue45517'
versions = ['Python 3.8']