bug#40247: 27.0.90; mailcap-mime-data erased when parsing mime parts

[Basil L. Contovounesios]

Juan José García Ripoll <juanjose.garcia.ripoll@csic.es> writes:

> Symptoms:
> - Start Emacs in a system without ~/.mailcap
> - Launch Gnus
> - Open an email / news that has some part in text/html
> - mailcap-mime-data is erased and none of the default viewers are
> available any more.

I think this is a symptom of the fix for bug#36771, and therefore
affects systems with mailcap files as well.

Since it affects me too and block Emacs 27.1, I plan to look into it in
about a week's time if no-one beats me to it.

Thanks,

-- 
Basil