@wohlganger, thanks for your PR! By analyzing the history of the files in this pull request, we identified @terryjreedy, @csabella and @kbkaiser to be potential reviewers.

Per Terry J. Reedy recommendation, only highlighting style is changeable.

Charles, I cannot add commits to this issue, and a few others. Please follow the instructions at https://help.github.com/articles/allowing-changes-to-a-pull-request-branch-created-from-a-fork/#enabling-repository-maintainer-permissions-on-existing-pull-requests to make sure "Allow edits from maintainers." is checked for this and other IDLE issues. Please let me know what you find. If this permission is already granted, then I have some other problem with github.

Checked "Allow edits". Thank you for pointing it out; I'll remember to check it in the future.

It is on now. 'Allow edits' is supposed to be checked by default. If that changed, let me know and I will pass the information on to whoever can change it back.

This may be complete enough, but I may decide to change the new mac bindings first, as I really do not like to leave IDLE in a can't-release regressed state after a commit.

'Code context' is visible on the option menu for Shell and Output Window but not operative. It should be gone (as before) or grayed out, but the current situation could be tolerated in a release.

I ran test suite a couple of times, but now there are two failures to look at.

FAIL: test_get_current_keyset (idlelib.idle_test.test_config.IdleConfTest)
Traceback (most recent call last):
File "/home/travis/build/python/cpython/Lib/idlelib/idle_test/test_config.py", line 526, in test_get_current_keyset
self.assertNotEqual(conf.GetCurrentKeySet(), conf.GetKeySet(conf.CurrentKeys()))

FAIL: test_click_help_source (idlelib.idle_test.test_query.HelpsourceGuiTest)
Traceback (most recent call last):
File "C:\projects\cpython\lib\idlelib\idle_test\test_query.py", line 347, in test_click_help_source
Equal(dialog.result, ('test', prefix + file))
AssertionError: Tuples differ: ('test', 'C:\projects\cpython\lib\idlelib\idle[17 chars].py') != ('test', 'file://C:\projects\cpython\lib\idleli[24 chars].py')
First differing element 1:
'C:\projects\cpython\lib\idlelib\idle_test\test_query.py'
'file://C:\projects\cpython\lib\idlelib\idle_test\test_query.py'

I ran tests before changing Mac keys. I disabled test that depended on there being Alt keys in Mac or extension bindings. The other failure was due to sys.platform not being restored in first test.

There are some regressions in the untested behavior of Config Dialog. I suspect they occurred before this patch, but I need to check before merging.

By checking out master, I verified that the problems I found yesterday pre-existed this patch. The new one I found today required a fix to the new code.

Thanks @wohlganger for the PR, and @terryjreedy for merging it 🌮🎉.. I'm working now to backport this PR to: 3.6.
🐍🍒⛏🤖 I'm not a witch! I'm not a witch!

GH-3487 is a backport of this pull request to the 3.6 branch.