Tkinter scroll issues on macOS

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-08-10.10:07:16.876>
labels = ['3.7', 'type-bug', 'expert-tkinter']
title = 'Tkinter scroll issues on macOS'
updated_at = <Date 2018-10-18.02:20:51.508>
user = 'https://bugs.python.org/vtudorache'

bugs.python.org fields:

activity = <Date 2018-10-18.02:20:51.508>
actor = 'wordtech'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Tkinter']
creation = <Date 2018-08-10.10:07:16.876>
creator = 'vtudorache'
dependencies = []
files = ['47742', '47743']
hgrepos = []
issue_num = 34370
keywords = []
message_count = 15.0
messages = ['323363', '323379', '323381', '323547', '323558', '326515', '326516', '326517', '326559', '326654', '326658', '326760', '327669', '327671', '327929']
nosy_count = 6.0
nosy_names = ['rhettinger', 'terry.reedy', 'wordtech', 'ned.deily', 'serhiy.storchaka', 'vtudorache']
pr_nums = []
priority = 'normal'
resolution = 'third party'
stage = 'commit review'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue34370'
versions = ['Python 3.6', 'Python 3.7']