Completing this enhancement will probably also solve #1663

possible duplicate of #878?

Well PR #878 was fixing #9269

As long as the issue is not fixed this can't be a duplicate.

To, this doesn't look like a duplicate, but as a followup ticket.

I guess that the py3 migration was just to make sure the current automated tests are green... but nothing more.

And we have this issue, so that now that we have a py3 base, someone who wan't to use POP3 with Twisted can continue to work and fix any other issues.

Cheers

I have made some edits to make pop3 compatible with python3. I am happy with all of them except I didn't know what to do with tap. The CLI twistd mail command uses str but everything internally is bytes. pop3 can now be used in python3 if one manually set tap options with byte options using Zectbumo:twisted:trunk. I can do a PR now or later if I can get a recommendation on a good solution as to what to do with CLI tap using strings to get it working.
this still doesn't work: twistd mail --no-smtp --maildirdbmdomain=example.com=/tmp/example.com --user=joe=password
but this tac does now:

from twisted.mail import tap
from twisted.application import service

o = tap.Options()
o.parseOptions([
'--no-smtp',
'--maildirdbmdomain', b'example.com=/tmp/example.com',
'--user', b'joe=password',
])
o.postOptions()
mailService = tap.makeService(o)
application = service.Application('pop3')
mailService.setServiceParent(application)

The CLI twistd mail command uses str but everything internally is bytes. pop3 can now be used in python3 if one manually set tap options with byte options

I am not using pop3 or imap support in Twisted.
So this is up to you.

I would say it would make sense for code in POP3 to also allow str at the high level... but I guess that when the py3 migration was done, the decision was to go with bytes since this is the most flexible option.

So for backward compatibility still allow bytes ... but also handle the case when username, password or mailboxes are passed as string.

I have also never used the Twisted Application framework (TAC) files so I don't have experience with how people are expecting to interact with Twisted via a .tac file.

I think that at this point POP3 is not actively maintained in Twisted, so if you want to suggest a change, anything is ok, as long as the tests pass and the backward compatibility policy is followed.

if thigs are broken and POP3 is not usable in py3 we don't even have to worry about backward compatibility, and just fix it as you think is best.

Thanks for help with this.