bug#25753: 25.2; Python mode shell interaction not working 100%

[Carlos Pita]

Ok, after a lot of debugging I realized that my current readline
configuration was introducing some control characters that wreak havoc
with the native completion detection mechanism. Now, my .inputrc has:

> cat .inputrc
set completion-ignore-case on
set completion-display-width 80
set completion-prefix-display-length 5
set show-all-if-ambiguous on
set skip-completed-text on
set colored-stats on
set blink-matching-paren on
set menu-complete-display-prefix on

And I like it to be so. So there are a lot of cases to deal with here.
One could force a reset by setting INPUTRC=ieiowueqoiw or whatever,
but I've spent countless hours debugging all this native completion
stuff every couple of years, it's too fragile and too complex, do you
think it's worth the effort? ipython doesn't use readline anymore, the
trend is to move to jupyter which has a clean protocol to deal with
all this, why don't keep things simple and get rid of the readline
magic for good? Just an opinion.