bug#41386: 28.0.50; Gnus nnimap OAuth 2.0 support

[Richard Stallman]

[[[ To any NSA and FBI agents reading my email: please consider    ]]]
[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

I got this information from someone who knows
who says it is all from published information.

Does this enable us to cope with Google's planned changes?

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GNUS could follow the same process of the the maintainers of KMail to 
get approved:

 
https://www.reddit.com/r/kde/comments/gi5bol/kmailkontact_oauth_signin_with_gmail_enabled_again/

This had nothing to do with shutting off access to free MUAs. It's a 
matter of hardening the security of GMail accounts and having all 
3rd-party clients (free and non-free alike) publish a privacy policy 
where they describe their usage of the GMail APIs, as described in this 
thread:

https://www.reddit.com/r/kde/comments/cj7t7c/kmail_doesnt_let_me_sign_in_with_gmail/evchyih/

In particular:

   Google is not concerned with the legal "significance", they just care
   about the part about what features of their API we use and how, which
   seems to be incomplete, judging from the last email I got from them
   just yesterday, which is my responsibility to update, as I'm more or
   less the Google integration maintainer in PIM, since I wrote most of
   the stuff (silly me!) :D

The implementation details for XOAUTH2 are here, along with sample code 
and links to the relevant RFCs:

   https://developers.google.com/gmail/imap/xoauth2-protocol
-- 
Dr Richard Stallman
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)