bug#36917: 27.0.50; debbugs-gnu: Don't hardcode switch-to-buffer

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Michael Albinus <michael.albinus@gmx.de> writes:

> Michael Heerdegen <michael_heerdegen@web.de> writes:
>
> Hi Michael,
>
>> Should I install it?  Should I also bump the version?
>
> In case you install it, pls wait with increasing the version. I have the
> hope, that bug#36903 will be fixed also soon. At least, Eric wanted to
> test his patch locally.

I tested it and it didn't work, I think because even if you blank out
`gnus-format-specs' at Gnus shutdown, that doesn't blank out the value
of eg `gnus-summary-line-format', so `gnus-format-specs' is simply
rebuilt from the customized value.

I still feel medium-strongly that the registry shouldn't be left hanging
around after Gnus exits, and that it's sheer accident that debbugs used
to work when it *was* left hanging around. On the other hand, figuring
out all the ways in which debbugs-gnu-summary-mode may or may not depend
on the user's Gnus customizations sounds a bit hopeless. Worst come to
worst, I can rework 2815174f to prevent double-loading some other way,
and remove the `gnus-registry-clear' function so the registry isn't
cleared, but I would feel a little bad about that, ha.

Eric