Subprocess strangeness

[Alan Corey <alan01346 gmail com>]

I've been using mc for 20 years or more and only seen this in the last
couple weeks.  I use rxvt as my terminal emulator mostly.  I could
navigate to where I wanted another terminal in mc, then type rxvt &
and a new independent window would open there.  I could close the
original window and the new one stayed open.

Now whenever I close the parent one all the children close too, even
though I remember the & to make it independent.  At first I wasn't
sure it was happening.  I just did this: type mc in an rxvt, type rxvt
& in the new one, hit F10 in the original and the new one closes.  The
new one somehow depends on mc still running, lxterminal works the same
way.

This is mc 4.8.22 in Rasbian Buster, I mostly only install it from the
debs.  Some routine apt-get update and upgrade did this.