bug#40676: 28.0.50; gnus locks when reading email

[Robert Pluim]

>>>>> On Fri, 17 Apr 2020 08:09:28 -0700, Eric Abrahamsen 
>>>>> <eric@ericabrahamsen.net> said:

    Eric> FWIW, a " *temp*" buffer is only created in mm-util.el, in
    Eric> `mm-find-buffer-file-coding-system'. My guess is that some mime 
handler
    Eric> is calling an external process to do some sort of decoding of article
    Eric> content or attachment, and that's somehow getting attached to the temp
    Eric> buffer incorrectly.

'with-temp-buffer' also creates such buffers, so it could be any
number of things. The output of 'list-processes' will tell us.

Robert