bug#60078: 30.0.50; Gnus: Can't remove groups of select methods that don't exist anymore

["Jakub Ječmínek via Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

"Eric Abrahamsen" <eric@ericabrahamsen.net> writes:
> [...]
> Where does that leave us? I think there's no safe way to say "this
> group's select method no longer exists", because in many cases the
> presence of a sexp like (nnml "<directory>") is enough to count as
> "exists".
>
> So I think "bogus" can only mean: "this group belongs to a server that
> provides a `gnus-request-list' method, but when we request the list,
> this group isn't in it".
>
> I think you're right that simply checking if a group is active shouldn't
> mean anything, as there are plenty of reasons a group might not be
> activated.
>
> WDYT?

Your analysis is brilliant, thank you. So to summarize what bogus group
 actually should be:

 1. The server of the newsgroup provides `gnus-request-list' method
 2. The server has been sucessfully opened
 3. The group is not listed in the active file
 4. We do not distinguish between native and secondary select methods
 and foreign groups.

Is it correct?

If we go back to Björn's bug report though, I still think that the
"correct" way to remove groups without corresponding select method is to
kill them (C-k) and then kill them again from the list of killed
newsgroups. This is actually what `gnus-check-bogus-newsgroups' function
does.

-- 
Kuba Ječmínek (http://kubajecminek.cz)