IDLE: exit at input() prompt is not complete

GitHub fields:

assignee = 'https://github.com/terryjreedy'
closed_at = None
created_at = <Date 2020-07-27.18:03:06.305>
labels = ['3.10', 'expert-IDLE', '3.8', '3.9', 'type-crash']
title = 'IDLE: exit at input() prompt is not complete'
updated_at = <Date 2020-07-28.23:36:30.979>
user = 'https://github.com/IrvKalb'

bugs.python.org fields:

activity = <Date 2020-07-28.23:36:30.979>
actor = 'terry.reedy'
assignee = 'terry.reedy'
closed = False
closed_date = None
closer = None
components = ['IDLE']
creation = <Date 2020-07-27.18:03:06.305>
creator = 'IrvKalb'
dependencies = []
files = []
hgrepos = []
issue_num = 41413
keywords = []
message_count = 6.0
messages = ['374407', '374412', '374456', '374532', '374534', '374539']
nosy_count = 4.0
nosy_names = ['terry.reedy', 'taleinat', 'ned.deily', 'IrvKalb']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'crash'
url = 'https://bugs.python.org/issue41413'
versions = ['Python 3.8', 'Python 3.9', 'Python 3.10']